text: Radio telescopes may need to be extremely large in order to receive signals with high signal-to-noise ratio. Also since angular resolution is a function of the diameter of the "objective" in proportion to the wavelength of the electromagnetic radiation being observed,  radio telescopes have to be much larger in comparison to their optical counterparts. For example, a 1-meter diameter optical telescope is two million times bigger than the wavelength of light observed giving it a resolution of roughly 0.3 arc seconds, whereas a radio telescope "dish" many times that size may, depending on the wavelength observed, only be able to resolve an object the size of the full moon (30 minutes of arc).

text: Radio telescopes may need to be extremely large in order to receive signals with high

entity_name: Signal-to-noise ratio

text: signal-to-noise ratio

text: . Also since

entity_name: Angular resolution

text: angular resolution

text: is a function of the diameter of the "

entity_name: Objective (optics)

text: objective

text: " in proportion to the wavelength of the electromagnetic radiation being observed,

entity_name: Radio telescope

text: radio telescope

text: s have to be much larger in comparison to their

entity_name: Optical telescope

text: optical

text: counterparts. For example, a 1-meter diameter optical telescope is two million times bigger than the wavelength of light observed giving it a resolution of roughly 0.3

entity_name: Minute and second of arc

text: arc second

text: s, whereas a radio telescope "dish" many times that size may, depending on the wavelength observed, only be able to resolve an object the size of the full moon (30 minutes of arc).

text: The company was founded in 1988 as Synta Optics, at first producing only eyepieces. In 1992, the manufacturing was moved to Suzhou (Jiangsu) in China. Their first telescopes (4.5“ (114 mm) -Newtonians) were distributed by Celestron and Tasco. In 1993, the first refracting telescopes were produced.

text: The company was founded in 1988 as Synta Optics, at first producing only eyepieces. In 1992, the manufacturing was moved to

entity_name: Suzhou

text: Suzhou (Jiangsu)

text: in China. Their first telescopes (4.5“ (114 mm) -

entity_name: Newtonian telescope

text: Newtonians)

text: were distributed by

entity_name: Celestron

text: Celestron

text: and

entity_name: Tasco

text: Tasco

text: . In 1993, the first

entity_name: Refracting telescope

text: refracting telescope

text: s were produced.

text: CHAPS is an abbreviation for 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate. A related detergent, called CHAPSO, has the same basic chemical structure with an additional hydroxyl functional group; its full chemical name is 3-[(3-cholamidopropyl)dimethylammonio]-2-hydroxy-1-propanesulfonate. Both detergents have low light absorbance in the ultraviolet region of the electromagnetic spectrum, which is useful for laboratory workers monitoring ongoing chemical reactions or protein-protein binding with UV/Vis spectroscopy.

text: CHAPS is an abbreviation for 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate. A related detergent, called CHAPSO, has the same basic chemical structure with an additional

entity_name: Hydroxy group

text: hydroxyl

entity_name: Functional group

text: functional group

text: ; its full chemical name is 3-[(3-cholamidopropyl)dimethylammonio]-2-hydroxy-1-propanesulfonate. Both detergents have low light absorbance in the

entity_name: Ultraviolet

text: ultraviolet

text: region of the

entity_name: Electromagnetic spectrum

text: electromagnetic spectrum

text: , which is useful for laboratory workers monitoring ongoing

entity_name: Chemical reaction

text: chemical reaction

text: s or

entity_name: Protein–protein interaction

text: protein-protein binding

text: with

entity_name: Ultraviolet–visible spectroscopy

text: UV/Vis spectroscopy

text: For the unrelated British telescope manufacturer, go to Orion Optics

text: For the unrelated British telescope manufacturer, go to

entity_name: Orion Optics

text: Orion Optics

text: A high quality image requires a large number of different separations between telescopes. Projected separation between any two telescopes, as seen from the radio source, is called a baseline. For example, the Very Large Array (VLA) near Socorro, New Mexico has 27 telescopes with 351 independent baselines at once, which achieves a resolution of 0.2 arc seconds at 3 cm wavelengths. Martin Ryle's group in Cambridge obtained a Nobel Prize for interferometry and aperture synthesis. The Lloyd's mirror interferometer was also developed independently in 1946 by Joseph Pawsey's group at the University of Sydney. In the early 1950s, the Cambridge Interferometer mapped the radio sky to produce the famous 2C and 3C surveys of radio sources. An example of a large physically connected radio telescope array is the Giant Metrewave Radio Telescope, located in Pune, India. The largest array, the Low-Frequency Array (LOFAR), is currently being constructed in western Europe, consisting of about 20,000 small antennas in 48 stations distributed over an area several hundreds of kilometers in diameter, and operates between 1.25 and 30 m wavelengths. VLBI systems using post-observation processing have been constructed with antennas thousands of miles apart.  Radio interferometers have also been used to obtain detailed images of the anisotropies and the polarization of the Cosmic Microwave Background, like the CBI interferometer in 2004.

text: A high quality image requires a large number of different separations between telescopes. Projected separation between any two telescopes, as seen from the radio source, is called a baseline. For example, the

entity_name: Karl G. Jansky Very Large Array

text: Very Large Array

text: (VLA) near

entity_name: Socorro, New Mexico

text: Socorro, New Mexico

text: has 27 telescopes with 351 independent baselines at once, which achieves a resolution of 0.2

text: arc seconds

text: at 3 cm wavelengths.

entity_name: Martin Ryle

text: Martin Ryle

text: 's

entity_name: Cavendish Astrophysics Group

text: group in Cambridge

text: obtained a

entity_name: Nobel Prize

text: Nobel Prize

text: for interferometry and aperture synthesis. The

entity_name: Lloyd's mirror

text: Lloyd's mirror

text: interferometer was also developed independently in 1946 by

text: Joseph Pawsey

text: 's group at the

entity_name: University of Sydney

text: University of Sydney

text: . In the early 1950s, the

entity_name: Cambridge Interferometer

text: Cambridge Interferometer

text: mapped the radio sky to produce the famous

entity_name: Second Cambridge Catalogue of Radio Sources

text: and

entity_name: Third Cambridge Catalogue of Radio Sources

text: surveys of radio sources. An example of a large physically connected radio telescope array is the

entity_name: Giant Metrewave Radio Telescope

text: Giant Metrewave Radio Telescope

text: , located in

entity_name: Pune

text: Pune

entity_name: India

text: India

text: . The largest array, the

entity_name: LOFAR

text: Low-Frequency Array

text: (LOFAR), is currently being constructed in western Europe, consisting of about 20,000 small antennas in 48 stations distributed over an area several hundreds of kilometers in diameter, and operates between 1.25 and 30 m wavelengths. VLBI systems using post-observation processing have been constructed with antennas thousands of miles apart.  Radio interferometers have also been used to obtain detailed images of the anisotropies and the polarization of the

entity_name: Cosmic microwave background

text: Cosmic Microwave Background

text: , like the

entity_name: Cosmic Background Imager

text: CBI

text: interferometer in 2004.

text: During the next three years the telescope room was closed to the public while the work proceeded. Only the balcony was available and observations were carried out with small instruments. The telescope was completed in 1950 and described as "the first of its kind in the world." Unfortunately, it was purely for photographic work, which rather contradicted the above assurance.However, matters took a different course. The expansion of the city north and west and the development of sodium and mercury street-lighting hampered the work of stellar photography, so in February, 1951  Bruce and Professor Freundlich suggested that the pilot telescope be transferred to St. Andrews University Observatory, eleven miles (18 km) to the south, for better conditions and proximity to the workshops. The Mills would then receive in exchange the 10-inch (25 cm.) Cooke refracting telescope formerly used as a student training instrument and now surplus to requirements. At first the Town Council refused, and there was much correspondence in the local press, and indignation among local amateurs, that the University should interfere with the affairs of a public institution.  Professor W.H.M. Greaves, had succeeded Professor Sampson as Astronomer Royal for Scotland, was called upon to advise on the matter.  In view of the scientific benefits of the move, and lack of interest shown by University College, Dundee, he recommended that the transfer take place. This was done at the University's expense, and on the understanding that the two telescopes were on mutual loan.The  refractor had to be modified slightly to fit the Mills dome, and the dew-cap cannot safely be used.  However, it proved to be a much superior instrument for public viewing to the old Newtonian reflector. Originally built in 1871 it was, at one time, privately owned by Walter Goodacre, president of the British Astronomical Association (B. A. A. ), who lived in the village of Four Marks, near Winchester. The telescope was used there by many famous amateurs involved in the work of the B. A. A. and was always described by them as "the excellent 10-inch Cooke refractor".  It is particularly good for observing fine lunar and planetary detail and although not basically designed for photographic work, the lens is so good that, with modern cameras, good photographs can be taken. The Observatory has also acquired a number of smaller telescopes over the years.

text: During the next three years the telescope room was closed to the public while the work proceeded. Only the balcony was available and observations were carried out with small instruments. The telescope was completed in 1950 and described as "the first of its kind in the world." Unfortunately, it was purely for photographic work, which rather contradicted the above assurance.However, matters took a different course. The expansion of the city north and west and the development of

entity_name: Sodium

text: sodium

text: and

entity_name: Mercury (element)

text: mercury

text: street-lighting hampered the work of

entity_name: Constellation

text: stellar

entity_name: Photography

text: photography

text: , so in February, 1951  Bruce and Professor Freundlich suggested that the pilot telescope be transferred to St. Andrews University Observatory, eleven miles (18 km) to the south, for better conditions and proximity to the workshops. The Mills would then receive in exchange the 10-inch (25 cm.) Cooke refracting telescope formerly used as a student training instrument and now surplus to requirements. At first the Town Council refused, and there was much correspondence in the local press, and indignation among local amateurs, that the University should interfere with the affairs of a public institution.

entity_name: William Michael Herbert Greaves

text: Professor W.H.M. Greaves

text: , had succeeded Professor Sampson as

entity_name: Astronomer Royal for Scotland

text: Astronomer Royal for Scotland

text: , was called upon to advise on the matter.  In view of the scientific benefits of the move, and lack of interest shown by University College,

entity_name: Dundee

text: Dundee

text: , he recommended that the transfer take place. This was done at the University's expense, and on the understanding that the two telescopes were on mutual loan.The  refractor had to be modified slightly to fit the Mills dome, and the dew-cap cannot safely be used.  However, it proved to be a much superior instrument for public viewing to the old

text: Newtonian reflector

text: . Originally built in 1871 it was, at one time, privately owned by

entity_name: Walter Goodacre

text: Walter Goodacre

text: , president of the

entity_name: British Astronomical Association

text: British Astronomical Association

text: (B. A. A. ), who lived in the village of

entity_name: Four Marks

text: Four Marks

text: , near

entity_name: Winchester

text: Winchester

text: . The telescope was used there by many famous amateurs involved in the work of the B. A. A. and was always described by them as "the excellent 10-inch Cooke refractor".  It is particularly good for observing fine lunar and planetary detail and although not basically designed for photographic work, the lens is so good that, with modern cameras, good photographs can be taken. The Observatory has also acquired a number of smaller telescopes over the years.

text: Isaac Newton built his reflecting telescope as a proof for his theory that white light is composed of a spectrum of colours. He had concluded that the lens of any refracting telescope would suffer from the dispersion of light into colours (chromatic aberration). The telescope he constructed used mirrors as the objective which bypass that problem. To create the primary mirror Newton used a custom composition of metal consisting of six parts copper to two parts tin, an early composition of speculum metal. He devised means for shaping and grinding the mirror and may have been the first to use a pitch lap to polish the optical surface. He chose a spherical shape for his mirror instead of a parabola to simplify construction: he had satisfied himself that the chromatic, and not the spherical aberration, formed the chief faults of refracting telescopes. He added to his reflector what is the hallmark of the design of a "Newtonian telescope", a secondary "diagonal" mirror near the primary mirror's focus to reflect the image at 90° angle to an eyepiece mounted on the side of the telescope. This unique addition allowed the image to be viewed with minimal obstruction of the objective mirror. He also made all the tube, mount, and fittings.

text: Isaac Newton built his reflecting telescope as a proof for his theory that

entity_section: Visible radiation .28light.29

text: white light

text: is composed of a

entity_name: Spectrum

text: spectrum

text: of colours. He had concluded that the lens of any

text: refracting telescope

text: would suffer from the

entity_name: Dispersion (optics)

text: dispersion

text: of light into colours (

entity_name: Chromatic aberration

text: chromatic aberration

text: ). The telescope he constructed used mirrors as the

text: objective

text: which bypass that problem. To create the

entity_name: Primary mirror

text: primary mirror

text: Newton used a custom composition of metal consisting of six parts

entity_name: Copper

text: copper

text: to two parts

entity_name: Tin

text: tin

text: , an early composition of

entity_name: Speculum metal

text: speculum metal

text: . He devised means for shaping and grinding the mirror and may have been the first to use a

entity_name: Amateur telescope making

entity_section: Mirror making

text: pitch lap

text: to polish the optical surface. He chose a spherical shape for his mirror instead of a parabola to simplify construction: he had satisfied himself that the chromatic, and not the spherical aberration, formed the chief faults of

text: refracting telescope

text: s. He added to his reflector what is the hallmark of the design of a "Newtonian telescope", a secondary "diagonal" mirror near the primary mirror's focus to reflect the image at 90° angle to an

entity_name: Eyepiece

text: eyepiece

text: mounted on the side of the telescope. This unique addition allowed the image to be viewed with minimal obstruction of the objective mirror. He also made all the tube,

entity_name: Telescope mount

text: mount

text: , and fittings.

text: In 1980, it was used as part of the new MERLIN array with a series of smaller radio telescopes controlled from Jodrell Bank. With baselines of up to 217 km (135 mi), this gave a resolution around 0.05 arcminutes. An upgraded version of this became a national facility in 1992. It has also been used in Very Long Baseline Interferometry, with telescopes across Europe (the European VLBI Network), giving a resolution of around 0.001 arcseconds. Around half of the telescope's observing time is now spent doing interferometry with other telescopes. It is planned that the telescope will work as part of an interferometer with the Radioastron (Russian) and VLBI Space Observatory Programme (Japanese) orbital radio satellites, providing yet larger baselines and higher resolutions.

text: In 1980, it was used as part of the new

entity_name: MERLIN

text: MERLIN

text: array with a series of smaller radio telescopes controlled from Jodrell Bank. With baselines of up to 217 km (135 mi), this gave a resolution around 0.05 arcminutes. An upgraded version of this became a national facility in 1992. It has also been used in

entity_name: Very-long-baseline interferometry

text: Very Long Baseline Interferometry

text: , with telescopes across Europe (the

entity_name: European VLBI Network

text: European VLBI Network

text: ), giving a resolution of around 0.001

text: arcseconds

text: . Around half of the telescope's observing time is now spent doing interferometry with other telescopes. It is planned that the telescope will work as part of an interferometer with the Radioastron (Russian) and

entity_name: HALCA

text: VLBI Space Observatory Programme

text: (Japanese) orbital radio satellites, providing yet larger baselines and higher resolutions.

text: Optical radiation is part of the electromagnetic spectrum. It is subdivided into ultraviolet radiation (UV), the spectrum of light visible for man (VIS) and infrared radiation (IR). It ranges between wavelengths of 100 nm to 1 mm.  Electromagnetic waves in this range obey the laws of optics--they can be focused and refracted with lenses, for example.

text: Optical radiation is part of the

text: electromagnetic spectrum

text: . It is subdivided into

text: ultraviolet radiation

text: (UV), the spectrum of

entity_name: Light

text: light

text: visible for man (VIS) and

entity_name: Infrared

text: infrared radiation

text: (IR). It ranges between wavelengths of 100 nm to 1 mm.  Electromagnetic waves in this range obey the laws of optics--they can be focused and refracted with lenses, for example.

text: A space observatory is any instrument, such as a telescope, in outer space which is used for observation of distant planets, galaxies, and other outer space objects. In 1946, American theoretical astrophysicist Lyman Spitzer was the first to conceive the idea of a telescope in outer space, a decade before the Soviet Union launched the first artificial satellite, Sputnik into orbit. Spitzer's proposal called for a large telescope that would not be hindered by Earth's atmosphere. After lobbying in the 1960s and 1970s for such a system to be built, Spitzer's vision ultimately materialized into the world's first space-based optical telescope, Hubble Space Telescope, which was launched on April 20, 1990 by the Space Shuttle Discovery (STS-31).

text: A space observatory is any instrument, such as a telescope, in outer space which is used for observation of distant

entity_name: Planet

text: planets

entity_name: Galaxy

text: galaxies

text: , and other

entity_name: Outer space

text: outer space

text: objects. In 1946, American theoretical astrophysicist

entity_name: Lyman Spitzer

text: Lyman Spitzer

text: was the first to conceive the idea of a telescope in outer space, a decade before the

entity_name: Soviet Union

text: Soviet Union

text: launched the first

entity_name: Satellite

text: artificial satellite

entity_name: Sputnik 1

text: Sputnik

text: into orbit. Spitzer's proposal called for a large telescope that would not be hindered by Earth's

entity_name: Atmosphere

text: atmosphere

text: . After lobbying in the 1960s and 1970s for such a system to be built, Spitzer's vision ultimately materialized into the world's first space-based optical telescope,

entity_name: Hubble Space Telescope

text: Hubble Space Telescope

text: , which was launched on April 20, 1990 by the

entity_name: Space Shuttle Discovery

text: Space Shuttle Discovery

text: The telescope is a 0.9 meter classical Cassegrain but with a third rotatable plane mirror sending light to one of the two Nasmyth foci. The effective system is an f/10 but the primary mirror is an f/3. The telescope was built by Astro Optic and there is a sibling telescope at Albonova in Stockholm. The telescope is one of the largest optical telescope in Sweden.

text: The telescope is a 0.9 meter

entity_name: Cassegrain reflector

text: classical Cassegrain

text: but with a third rotatable

entity_name: Plane mirror

text: plane mirror

text: sending light to one of the two

entity_name: Nasmyth telescope

text: Nasmyth foci

text: . The effective system is an f/10 but the primary mirror is an f/3. The telescope was built by Astro Optic and there is a sibling telescope at Albonova in

entity_name: Stockholm

text: Stockholm

text: . The telescope is one of the largest optical telescope in

text: Sweden

text: * List of largest optical reflecting telescopes - List of large optical telescopes

entity_name: List of largest optical reflecting telescopes

text: List of largest optical reflecting telescopes

text: List of large optical telescopes

text: In the special case  ck}}, with c a constant, the waves are called non-dispersive, since all frequencies travel at the same phase speed c. For instance electromagnetic waves in vacuum are non-dispersive. In case of other forms of the dispersion relation, we have dispersive waves. The dispersion relationship depends on the medium through which the waves propagate and on the type of waves (for instance electromagnetic, sound or water waves).

text: In the special case  ck}}, with c a constant, the waves are called non-dispersive, since all frequencies travel at the same phase speed c. For instance

text: electromagnetic wave

text: s in

text: vacuum

text: are non-dispersive. In case of other forms of the dispersion relation, we have dispersive waves. The dispersion relationship depends on the medium through which the waves propagate and on the type of waves (for instance

text: electromagnetic

text: sound

text: or

text: water

text: waves).

text: According to Maxwell's theory of electromagnetism, an electromagnetic wave carries momentum, which can be transferred to a reflecting or absorbing surface hit by the wave.

text: The initial SERENDIP instrument was an 100 channel analog radio spectrometer covering 100 kHz of bandwidth. Subsequent instruments have been significantly more capable, with the number of channels doubling roughly every year. These instruments have been deployed at a large number of telescopes including the NRAO 90m telescope at Green Bank and the Arecibo 305m telescope.

text: The initial SERENDIP instrument was an 100 channel

text: analog

text: radio

text: spectrometer

text: covering 100

text: kHz

text: of

text: bandwidth

text: . Subsequent instruments have been significantly more capable, with the number of channels doubling roughly every year. These instruments have been deployed at a large number of telescopes including the NRAO 90m telescope at Green Bank and the

text: Arecibo 305m telescope

text: There are three radio telescopes designated RT-70, all in countries that were once part of the former Soviet Union, all with similar specifications: 70m dishes and an operating range of 5–300 GHz. The Yevpatoria telescope has also been used as a radar telescope in observations of space debris and asteroids.

text: There are three

text: radio telescopes

text: designated RT-70, all in countries that were once part of the former

text: Soviet Union

text: , all with similar specifications: 70m dishes and an operating range of 5–300 GHz. The Yevpatoria telescope has also been used as a

text: radar telescope

text: in observations of

text: space debris

text: and

text: asteroids

text: The telescope was located on the grounds of Observatory House, Herschel's house in Slough, between 1789 and 1840. The first observation with the telescope was on 19 February 1787, when Herschel pointed the then-incomplete telescope towards the Orion nebula, which he observed by crawling into the telescope and using a hand-held eyepiece: "The apparatus for the 40-foot telescope was by this time so far completed that I could put the mirror into the tube and direct it to a celestial object; but having no eye-glass fixed, not being acquainted with the focal length which was to be tried, I went into the tube, and laying down near the mouth of it I held the eye-glass in my hand, and soon found the place of the focus. The object I viewed was the nebula in the belt of Orion, and I found the figure of the mirror, though far from perfect, better than I had expected. It showed four small stars in the nebula and many more. The nebula was extremely bright."

text: The telescope was located on the grounds of

text: Observatory House

text: , Herschel's house in Slough, between 1789 and 1840. The

text: first observation with the telescope

text: was on 19 February 1787, when Herschel pointed the then-incomplete telescope towards the

text: Orion nebula

text: , which he observed by crawling into the telescope and using a hand-held

text: eyepiece

text: : "The apparatus for the 40-foot telescope was by this time so far completed that I could put the mirror into the tube and direct it to a celestial object; but having no eye-glass fixed, not being acquainted with the focal length which was to be tried, I went into the tube, and laying down near the mouth of it I held the eye-glass in my hand, and soon found the place of the focus. The object I viewed was the nebula in the belt of Orion, and I found the figure of the mirror, though far from perfect, better than I had expected. It showed four small stars in the nebula and many more. The nebula was extremely bright."

text: Optical telescopes have been used in astronomical research since the time of their invention in the early 17th century. Many types have be constructed over the years depending on the optical technology, such as refracting and reflecting, the nature of the light or object being imaged, and even where they are placed, such as space telescopes. Some are classified by the task they perform such as Solar telescopes.

text: Optical telescopes have been used in astronomical research since the time of their invention in the early 17th century. Many types have be constructed over the years depending on the optical technology, such as refracting and reflecting, the nature of the light or object being imaged, and even where they are placed, such as

text: space telescope

text: s. Some are classified by the task they perform such as

text: Solar telescope

text: s.

text: Lower-energy X-Rays are the highest energy electromagnetic radiation that can be formed into an image, using a Wolter telescope. There are three types of Wolter telescopes  Near infrared is typically the longest wavelength that are handled optically, such as in some large telescopes.

text: Lower-energy X-Rays are the highest energy electromagnetic radiation that can be formed into an image, using a

text: Wolter telescope

text: . There are three types of Wolter telescopes

text: Near infrared

text: is typically the longest wavelength that are handled optically, such as in some large telescopes.

text: Collectors like to look back in time when they are finding sports memorabilia. Items such as John L. Sullivan and Jack Johnson fight posters have sold well before. There is also a boxing glove signed by Sullivan, Johnson, Ruth and many Hollywood stars and American Presidents that has sold for a lot of money before. This glove is now on display at the International Boxing Hall of Fame.

text: Collectors like to look back in time when they are finding sports memorabilia. Items such as

text: John L. Sullivan

text: and

text: Jack Johnson

text: fight posters have sold well before. There is also a

text: boxing

text: glove signed by Sullivan, Johnson, Ruth and many

text: Hollywood

text: stars and American Presidents that has sold for a lot of money before. This glove is now on display at the

text: International Boxing Hall of Fame

text: After involvement in the spectrometer of INTEGRAL, Caraveo was part of the group proposing ESA's participation in the James Webb Space Telescope (then the New Generation Space Telescope) In parallel, Caraveo took part in the development of new high-energy astrophysics missions such as the AGILE mission of the Italian Space Agency and the Swift and GLAST missions of NASA, for which she holds the position of Co-Investigator.

text: After involvement in the spectrometer of INTEGRAL, Caraveo was part of the group proposing ESA's participation in the

text: James Webb Space Telescope

text: (then the New Generation Space Telescope) In parallel, Caraveo took part in the development of new high-energy astrophysics missions such as the AGILE mission of the Italian Space Agency and the Swift and GLAST missions of NASA, for which she holds the position of Co-Investigator.

text: Following Heinrich Hertz's establishment of the existence of electromagnetic radiation in the late 1880s, a variety of terms were initially used for the phenomenon, with early descriptions of the radiation itself including "Hertzian waves", "electric waves", and "ether waves", while phrases describing its use in communications included "spark telegraphy", "space telegraphy", "aerography" and, eventually and most commonly, "wireless telegraphy". However, "wireless" included a broad variety of related electronic technologies, including electrostatic induction, electromagnetic induction and aquatic and earth conduction, so there was a need for a more precise term referring exclusively to electromagnetic radiation.

text: Following

text: Heinrich Hertz

text: 's establishment of the existence of

text: electromagnetic radiation

text: in the late 1880s, a variety of terms were initially used for the phenomenon, with early descriptions of the radiation itself including "Hertzian waves", "electric waves", and "ether waves", while phrases describing its use in communications included "spark telegraphy", "space telegraphy", "aerography" and, eventually and most commonly, "wireless telegraphy". However, "wireless" included a broad variety of related electronic technologies, including

text: electrostatic induction

text: electromagnetic induction

text: and

text: aquatic and earth conduction

text: , so there was a need for a more precise term referring exclusively to electromagnetic radiation.

text: The absence of a material medium in vacuum may also constitute a transmission medium for electromagnetic waves such as light and radio waves.

text: The absence of a material medium in

text: vacuum

text: may also constitute a transmission medium for

text: electromagnetic wave

text: s such as

text: light

text: and

text: radio wave

text: s.

text: Telescoping cylinders, also known as telescopic cylinders can be either single or double-acting.  The telescoping cylinder incorporates a piston rod nested within a series of hollow stages of increasing diameter.  Upon actuation, the piston rod and each succeeding stage "telescopes" out as a segmented piston.  The main benefit of this design is the allowance for a notably longer stroke than would be achieved with a single-stage cylinder of the same collapsed (retracted) length.  One cited drawback to telescoping cylinders is the increased potential for piston flexion due to the segmented piston design.  Consequently, telescoping cylinders are primarily utilized in applications where the piston bears minimal side loading.

text: Telescoping cylinders, also known as

text: telescopic cylinder

text: s can be either single or double-acting.  The telescoping cylinder incorporates a piston rod nested within a series of hollow stages of increasing diameter.  Upon actuation, the piston rod and each succeeding stage "telescopes" out as a segmented piston.  The main benefit of this design is the allowance for a notably longer stroke than would be achieved with a single-stage cylinder of the same collapsed (retracted) length.  One cited drawback to telescoping cylinders is the increased potential for piston flexion due to the segmented piston design.  Consequently, telescoping cylinders are primarily utilized in applications where the piston bears minimal side loading.

text: The first person to use a telescope to observe the night sky and record his observations was the Italian scientist Galileo Galilei in 1609. When he turned the telescope toward some of the nebulous patches recorded by Ptolemy, he found they were not a single star, but groupings of many stars. For Praesepe, he found more than 40 stars. Where previously observers had noted only 6-7 stars in the Pleiades, he found almost 50. In his 1610 treatise Sidereus Nuncius, Galileo Galilei wrote, "the galaxy is nothing else but a mass of innumerable stars planted together in clusters." Influenced by Galileo's work, the Sicilian astronomer Giovanni Hodierna became possibly the first astronomer to use a telescope to find previously undiscovered open clusters. In 1654, he identified the objects now designated Messier 41, Messier 47, NGC 2362 and NGC 2451.

text: The first person to use a telescope to observe the night sky and record his observations was the Italian scientist

text: Galileo Galilei

text: in 1609. When he turned the telescope toward some of the nebulous patches recorded by Ptolemy, he found they were not a single star, but groupings of many stars. For Praesepe, he found more than 40 stars. Where previously observers had noted only 6-7 stars in the Pleiades, he found almost 50. In his 1610 treatise

text: Sidereus Nuncius

text: , Galileo Galilei wrote, "the galaxy is nothing else but a mass of innumerable stars planted together in clusters." Influenced by Galileo's work, the Sicilian astronomer

text: Giovanni Hodierna

text: became possibly the first astronomer to use a telescope to find previously undiscovered open clusters. In 1654, he identified the objects now designated

text: Messier 41

text: Messier 47

text: NGC 2362

text: and

text: NGC 2451

text: In 1938, the group purchased the land the institute presently occupies and initial construction was completed in the spring of 1939.  The 100-seat lecture hall was added in 1945.  In 1947, through donations by Charles Elmer and Mr. Polk, the 3-story tower/library and observatory dome were built.In 1954, Charles Elmer died; that same year, the Institute added the shed, which houses three sliding roof observatories.Over the years, Custer has acquired a large collection of telescopes of all sizes and descriptions. Most recently, this includes a 25-inch (f/5) Newtonian reflector, which is now the premier telescope in the newly-rebuilt dome.(Article not found)  In order to bring the eyepiece of this telescope to a level that does not require observers to climb a high ladder, the optics on this telescope were modified by Custer's Research Director, Jeffrey Owen Katz, Ph.D., and Research Committee Member, Justine Haupt.

text: In 1938, the group purchased the land the institute presently occupies and initial construction was completed in the spring of 1939.  The 100-seat lecture hall was added in 1945.  In 1947, through donations by Charles Elmer and Mr. Polk, the 3-story tower/library and observatory dome were built.In 1954, Charles Elmer died; that same year, the Institute added the shed, which houses three sliding roof observatories.Over the years, Custer has acquired a large collection of telescopes of all sizes and descriptions. Most recently, this includes a 25-inch (f/5) Newtonian reflector, which is now the premier telescope in the newly-rebuilt dome.(Article not found)  In order to bring the eyepiece of this telescope to a level that does not require observers to climb a high ladder, the optics on this telescope were modified by Custer's Research Director,

text: Jeffrey Owen Katz

text: , Ph.D., and Research Committee Member, Justine Haupt.

text: The Mars 4 spacecraft carried an array of instruments to study Mars. In addition to cameras, it was equipped with a radio telescope, an IR radiometer, multiple photometers, polarimeters, a magnetometer, plasma traps, an electrostatic analyzer, a gamma-ray spectrometer, and a radio probe.

text: The Mars 4 spacecraft carried an array of instruments to study Mars. In addition to cameras, it was equipped with a radio telescope, an IR

text: radiometer

text: , multiple

text: photometer

text: s,

text: polarimeter

text: s, a

text: magnetometer

text: plasma trap

text: s, an

text: electrostatic analyzer

text: , a

text: gamma-ray spectrometer

text: , and a radio probe.

text: His importance in the context of Indian art scene is much beyond a simplistic cultural exchange. On the international art scene, he represents the region as a whole, and he shares a deep connection with the country. The artist had his very first international solo in New Delhi with Nature Morte in 2004. Looking back at those times, he had once stated: “India was my launch pad. I didn’t consider myself a professional artist till that show in 2004. It changed my approach.” He has not looked back since then, and has now become a poster boy for the Indian art gallery circuit. One edition of his work "Red Carpet-1" was auctioned at Sotheby’s New York on 16 May 2008, for a record price of 623,000 USD, highest price ever paid for a work of art produced by a Pakistani.

text: In 1973, the site included  and  Cassegrain telescopes equipped with storage tubes, remote readouts and image orthicon electronic imaging tubes. The 0.6 m telescope had automated operation capability controlled by a computer. A  Cassegrain was available for photometry, and the  Chrysler Schmidt telescope was still available. By 1977, only the 0.6 m and 0.4 m telescopes were reported as operational.

text: The proposal for a larger aircraft-mounted telescope was officially presented in 1984 and called for a Boeing 747 to carry a three-meter telescope. The preliminary system concept was published in 1987 in a Red Book. It was agreed that Germany would contribute 20% of the total cost and provide the telescope. However, the reunification of Germany and budget cuts at NASA led to a five-year slide in the project. NASA then contracted the work out to the Universities Space Research Association (USRA), and in 1996, NASA and DLR (the German Space Agency or Deutsches Zentrum fur Luft- und Raumfahrt) signed a memorandum of understanding to build and operate SOFIA.

text: The proposal for a larger aircraft-mounted telescope was officially presented in 1984 and called for a

text: Boeing 747

text: to carry a three-meter telescope. The preliminary system concept was published in 1987 in a Red Book. It was agreed that Germany would contribute 20% of the total cost and provide the telescope. However, the reunification of Germany and budget cuts at NASA led to a five-year slide in the project. NASA then contracted the work out to the Universities Space Research Association (USRA), and in 1996, NASA and DLR (the German Space Agency or Deutsches Zentrum fur Luft- und Raumfahrt) signed a memorandum of understanding to build and operate SOFIA.

text: The Anglo-Australian Telescope (AAT) is a 3.9-metre equatorially mounted telescope operated by the Australian Astronomical Observatory and situated at the Siding Spring Observatory, Australia at an altitude of a little over 1,100 m. In 2009, the telescope was ranked as the fifth highest-impact of the world's optical telescopes. In 2001–2003, it was considered the most scientifically productive 4 metre-class optical telescope in the world based on scientific publications using data from the telescope.

text: The Anglo-Australian Telescope (AAT) is a 3.9-metre

text: equatorially mounted

text: telescope operated by the

text: Australian Astronomical Observatory

text: and situated at the

text: Siding Spring Observatory

text: Australia

text: at an altitude of a little over 1,100 m. In 2009, the telescope was ranked as the fifth highest-impact of the world's optical telescopes. In 2001–2003, it was considered the most scientifically productive 4 metre-class optical telescope in the world based on scientific publications using data from the telescope.

text: A refracting telescope (also called a refractor) is a type of optical telescope that uses a lens as its objective to form an image (also referred to a dioptric telescope). The refracting telescope design was originally used in spy glasses and astronomical telescopes but is also used for long focus camera lenses. Although large refracting telescopes were very popular in the second half of the 19th century, for most research purposes the refracting telescope has been superseded by the reflecting telescope which allows larger apertures. A refractor's magnification is calculated by dividing the focal length of the objective lens by that of the eyepiece.

text: A refracting telescope (also called a refractor) is a type of

text: optical telescope

text: that uses a

text: lens

text: as its

text: objective

text: to form an image (also referred to a

text: dioptric

text: telescope

text: ). The refracting telescope design was originally used in spy glasses and

text: astronomical

text: telescopes but is also used for

text: long focus

text: camera lenses. Although large refracting telescopes were very popular in the second half of the 19th century, for most research purposes the refracting telescope has been superseded by the

text: reflecting telescope

text: which allows larger apertures. A refractor's magnification is calculated by dividing the focal length of the objective lens by that of the eyepiece.

text: Far-infrared laser or terahertz laser (FIR laser, THz laser) is a laser with output wavelength in between 30-1000 µm (frequency 0.3-10 THz), in the far infrared or terahertz frequency band of the electromagnetic spectrum.

text: Far-infrared laser or terahertz laser (FIR laser, THz laser) is a

text: laser

text: with output

text: wavelength

text: in between 30-1000 µm (

text: frequency

text: 0.3-10 THz), in the

text: far infrared

text: or

text: terahertz

text: frequency band

text: of the

text: electromagnetic spectrum

text: Performing astronomy from ground-based observatories on Earth is limited by the filtering and distortion of electromagnetic radiation (scintillation or twinkling) due to the atmosphere. Some terrestrial telescopes can reduce atmospheric effects with adaptive optics. A telescope orbiting Earth outside the atmosphere is subject neither to twinkling nor to light pollution from artificial light sources on Earth. As a result, the angular resolution of space telescopes is often much smaller than a ground-based telescope with a similar aperture.

text: Performing

text: astronomy

text: from

text: ground-based observatories

text: on Earth is limited by the filtering and distortion of

text: electromagnetic radiation

text: scintillation

text: or twinkling) due to the

text: atmosphere

text: . Some terrestrial telescopes can reduce atmospheric effects with

text: adaptive optics

text: . A telescope orbiting Earth outside the atmosphere is subject neither to twinkling nor to

text: light pollution

text: from artificial light sources on Earth. As a result, the

text: angular resolution

text: of space telescopes is often much smaller than a ground-based telescope with a similar

text: aperture

text: TDP is an acronym for "Teding Diancibo Pu"(特定电磁波谱) which loosely translated means specific electromagnetic spectrum.

text: Atmosphere and Telescope Simulators are used because time in science-worthy class telescopes are generally expensive and difficult to obtain. Telescope facilities are often uncomfortable for operators working on site long periods of time. Researchers have expressed the need for a laboratory tool which could provide better and cheaper accessibility than a real telescope, and better characterization than computer simulations. A LED based illumination system in which five Galilean collimation systems have been used is reported on. It is part of a turbulence simulator for the evaluation of on ground telescopes instrumentation developed by INTA (optics) and LIDAX (opto-mechanics)  for the IAC called IACATS.

text: Atmosphere and Telescope Simulators are used because time in

text: science

text: -worthy class

text: telescope

text: s are generally expensive and difficult to obtain. Telescope facilities are often uncomfortable for operators working on site long periods of time. Researchers have expressed the need for a

text: laboratory

text: tool which could provide better and cheaper accessibility than a real telescope, and better characterization than

text: computer simulation

text: s. A

text: LED

text: based illumination system in which five Galilean

text: collimation

text: systems have been used is reported on. It is part of a

text: turbulence

text: simulator for the evaluation of on ground telescopes instrumentation developed by

entity_name: Instituto Nacional de Técnica Aeroespacial

text: INTA

text: (optics) and LIDAX (opto-mechanics)  for the IAC called IACATS.

text: Ethanimine is an organonitrogen compound classified as an imine.  It is not well known terrestrially, but has been detected in abundance towards Sagittarius B2 (Sgr B2), a dense interstellar cloud in between stars towards the galactic center of the Milky Way. The distance between the Sgr B2 cloud and center of galaxy is 100 pc (1 pc=3.26l y). Ethanimine is mainly found in hot cores of ISM clouds; in case of Sgr B2, the region would be the Sgr B2 N and Sgr B2 M. The radio telescopes such as the Green Bank Telescope and NRAO (measures radio frequency light lambda ranging from 1–300 GHz) are able to detect organic molecules such as ethanimines because its internal energy transition, more specifically the rotational transition is within the radio frequency of 14085 MHz=140.8 GHz.

text: Ethanimine is an organonitrogen

text: compound

text: classified as an

text: imine

text: .  It is not well known terrestrially, but has been detected in abundance towards

text: Sagittarius B2

text: (Sgr B2), a dense interstellar cloud in between stars towards the galactic center of the

text: Milky Way

text: . The distance between the Sgr B2 cloud and center of galaxy is 100 pc (1 pc=3.26l y). Ethanimine is mainly found in hot cores of ISM clouds; in case of Sgr B2, the region would be the Sgr B2 N and Sgr B2 M. The radio telescopes such as the

text: Green Bank Telescope

text: and

text: NRAO

text: (measures radio frequency light lambda ranging from 1–300 GHz) are able to detect organic molecules such as ethanimines because its internal energy transition, more specifically the rotational transition is within the radio frequency of 14085 MHz=140.8 GHz.

text: Electromagnetic Waves

text: Electromagnetic Waves

text: A possible supernova was first noticed during an observation in June 2015 by ASAS-SN’s twin 14-cm telescopes in Chile; the team gave it the designation ASASSN-15lh. The supernova appeared as a transient dot of light on an image and was confirmed with additional observations from other telescopes. The spectrum of ASASSN-15lh was provided by the 2.5-meter du Pont Telescope in Chile. The Southern African Large Telescope was used to determine the redshift, and hence the distance and luminosity. The Swift space telescope also contributed observations. On 24 July, the event formally received the supernova designation SN 2015L from the Central Bureau of Astronomical Telegrams.

text: A possible supernova was first noticed during an observation in June 2015 by ASAS-SN’s twin 14-cm telescopes in Chile; the team gave it the designation ASASSN-15lh. The supernova appeared as a transient dot of light on an image and was confirmed with additional observations from other telescopes. The spectrum of ASASSN-15lh was provided by the 2.5-meter

text: du Pont Telescope

text: in Chile. The

text: Southern African Large Telescope

text: was used to determine the

text: redshift

text: , and hence the distance and luminosity. The

text: Swift space telescope

text: also contributed observations. On 24 July, the event formally received the

text: supernova designation

text: SN 2015L from the

entity_name: Central Bureau for Astronomical Telegrams

text: Central Bureau of Astronomical Telegrams

text: During his early years, Marconi had an interest in science and electricity and in the early 1890s he began working on the idea of "wireless telegraphy"—i.e., the transmission of telegraph messages without connecting wires as used by the electric telegraph. This was not a new idea; numerous investigators and inventors had been exploring wireless telegraph technologies and even building systems using electric conduction, electromagnetic induction and optical (light) signalling for over 50 years, but none had proven technically and commercially successful. A relatively new development came from Heinrich Hertz, who demonstrated beginning in 1888 that one could produce and detect electromagnetic radiation—now generally known as radio waves, at the time more commonly called "Hertzian waves" or "aetheric waves".

text: During his early years, Marconi had an interest in science and

text: electricity

text: and in the early 1890s he began working on the idea of "

text: wireless telegraphy

text: "—i.e., the transmission of telegraph messages without connecting wires as used by the

text: electric telegraph

text: . This was not a new idea; numerous investigators and inventors had been exploring wireless telegraph technologies and even building systems using electric

text: conduction

text: electromagnetic induction

text: and optical (light) signalling for over 50 years, but none had proven technically and commercially successful. A relatively new development came from

text: Heinrich Hertz

text: , who demonstrated beginning in 1888 that one could produce and detect

text: electromagnetic radiation

text: —now generally known as

text: radio waves

text: , at the time more commonly called "Hertzian waves" or "aetheric waves".

text: Animals have been known to perceive the infrasonic waves going through the earth by natural disasters and can use these as an early warning. A recent example of this is the 2004 Indian Ocean earthquake and tsunami. Animals were reported to flee the area hours before the actual tsunami hit the shores of Asia. It is not known for sure that this is the cause; some have suggested that it may have been the influence of electromagnetic waves, and not of infrasonic waves, that prompted these animals to flee.

text: Animals have been known to perceive the infrasonic waves going through the earth by natural disasters and can use these as an early warning. A recent example of this is the

entity_name: 2004 Indian Ocean earthquake and tsunami

text: 2004 Indian Ocean earthquake and tsunami

text: . Animals were reported to flee the area hours before the actual tsunami hit the shores of Asia. It is not known for sure that this is the cause; some have suggested that it may have been the influence of

text: electromagnetic waves

text: , and not of infrasonic waves, that prompted these animals to flee.

text: Later that year an interim body known as the Joint Policy Committee, and including prominent scientists Edward Bowen (Aus), Olin Eggen (Aus), Richard Woolley (UK) and Jim Hosie (UK) was formed to oversee the early running of a project office which was located in Canberra. The project office finalised designs and specifications for the telescope, the mounting and the building and let contracts on a worldwide basis, exploiting the experience of those staff members who were involved in the development and construction of the Parkes radio telescope.

text: Later that year an interim body known as the Joint Policy Committee, and including prominent scientists

text: Edward Bowen

text: (Aus),

text: Olin Eggen

text: (Aus),

text: Richard Woolley

text: (UK) and Jim Hosie (UK) was formed to oversee the early running of a project office which was located in

text: Canberra

text: . The project office finalised designs and specifications for the telescope, the mounting and the building and let contracts on a worldwide basis, exploiting the experience of those staff members who were involved in the development and construction of the

text: Parkes radio telescope

text: The Large Zenith Telescope (LZT) is a 6.0 m diameter liquid mirror telescope located in the University of British Columbia's Malcolm Knapp Research Forest, about  east of Vancouver. It is one of the largest optical telescopes in the world, but still quite inexpensive. The telescope was completed in the spring of 2003.

text: The Large Zenith Telescope (LZT) is a 6.0 m diameter

text: liquid mirror telescope

text: located in the

text: University of British Columbia

text: 's

text: Malcolm Knapp Research Forest

text: , about  east of

text: Vancouver

text: . It is one of the

text: largest optical telescopes

text: in the world, but still quite inexpensive. The telescope was completed in the spring of 2003.

text: With the development of fast Internet in the last part of the 20th century along with advances in computer-controlled telescope mounts and CCD cameras 'Remote Telescope' astronomy is now a viable means for amateur astronomers not aligned with major telescope facilities to partake in research and deep sky imaging. This enables the imager to control a telescope a large distance away in a dark location. The observers can image through the telescopes using CCD cameras. Imaging can be done regardless of the location of the user or the telescopes they wish to use. The digital data collected by the telescope is then transmitted and displayed to the user by means of the Internet. An example of a digital remote telescope operation for public use via the Internet is The Bareket Observatory.

text: With the development of fast Internet in the last part of the 20th century along with advances in computer-controlled telescope mounts and CCD cameras 'Remote Telescope' astronomy is now a viable means for amateur astronomers not aligned with major telescope facilities to partake in research and deep sky imaging. This enables the imager to control a telescope a large distance away in a dark location. The observers can image through the telescopes using CCD cameras. Imaging can be done regardless of the location of the user or the telescopes they wish to use. The digital data collected by the telescope is then transmitted and displayed to the user by means of the Internet. An example of a digital remote telescope operation for public use via the Internet is

text: The Bareket Observatory

text: As the interest in transients has intensified because study of them helps astrophysicists to understand the mechanisms which produced our universe, telescopes with larger fields of view are coming into use. These, such as the Palomar Transient Factory, the Gaia (spacecraft) and the LSST, are able to spot many more such occurrences. The ability of modern instruments to observe in wavelengths invisible to the human eye (radio waves, infrared, ultraviolet, x-ray) increases the amount of information that may be obtained when a transient is studied. The proposed ULTRASAT satellite will observe a field of more than 200 square degrees continuously in the ultraviolet range. This wavelength is particularly important for detecting supernovae within minutes of their occurrence.

text: As the interest in transients has intensified because study of them helps astrophysicists to understand the mechanisms which produced our universe, telescopes with larger fields of view are coming into use. These, such as the

text: Palomar Transient Factory

text: , the

text: Gaia (spacecraft)

text: and the

text: LSST

text: , are able to spot many more such occurrences. The ability of modern instruments to observe in wavelengths invisible to the human eye (

text: radio waves

text: infrared

text: ultraviolet

text: x-ray

text: ) increases the amount of information that may be obtained when a transient is studied. The proposed

text: ULTRASAT

text: satellite will observe a field of more than 200 square degrees continuously in the ultraviolet range. This wavelength is particularly important for detecting supernovae within minutes of their occurrence.

text: This is a list of radio telescopes - over one hundred - that are or have been used for radio astronomy. The list includes both single dishes and interferometric arrays. The list is sorted by region, then by name; unnamed telescopes are in reverse size order at the end of the lists.

text: This is a list of

text: radio telescope

text: s - over one hundred - that are or have been used for

text: radio astronomy

text: . The list includes both single

text: dishes

text: and

text: interferometric

text: arrays. The list is sorted by region, then by name; unnamed telescopes are in reverse size order at the end of the lists.

text: The final was contested by England and Australia. Just before half time, England led 21-0 through tries from Andrew Harriman, Lawrence Dallaglio and Tim Rodber, all converted by Nick Beal. Michael Lynagh scored a try before haf time, but failed to convert his own try. In the second half Australia hit back strongly and first David Campese and then Semi Taupeaafe scored further tries, the latter also converted by Michael Lynagh. However, time ran out on the Australians and it was England captain "Prince" Andrew Harriman who was presented with the Melrose Cup by the Princess Royal.  Adedayo Adebayo, a member of that victorious side later recalled how surprising the victory had been to the players involved in it. He said "We were basically a scratch side. We got together for the first time as a team the week before, played one practice match and went on to win! But there were a lot of quality players in that side and looking back that's why we were able to wing it slightly - the talent came through. Looking back though we had no expectations of winning at the start. We didn't know how far we would go. It just happened."

text: The final was contested by England and Australia. Just before half time, England led 21-0 through tries from

text: Andrew Harriman

text: Lawrence Dallaglio

text: and

text: Tim Rodber

text: , all converted by

text: Nick Beal

text: Michael Lynagh

text: scored a try before haf time, but failed to convert his own try. In the second half Australia hit back strongly and first

text: David Campese

text: and then

text: Semi Taupeaafe

text: scored further tries, the latter also converted by Michael Lynagh. However, time ran out on the Australians and it was England captain "Prince" Andrew Harriman who was presented with the

text: Melrose Cup

text: by the

text: Princess Royal

text: .  Adedayo Adebayo, a member of that victorious side later recalled how surprising the victory had been to the players involved in it. He said "We were basically a scratch side. We got together for the first time as a team the week before, played one practice match and went on to win! But there were a lot of quality players in that side and looking back that's why we were able to wing it slightly - the talent came through. Looking back though we had no expectations of winning at the start. We didn't know how far we would go. It just happened."

text: Bob Nave, keyboardist for the Lemon Pipers in the late 1960s (whose big hit was the song "Green Tambourine"), was a late-night DJ for WOXR in the early 1970s. Other early to mid-1970s on-air personalities for the station included Rick Sellers, Ray Smith and Ed Pharr. Nave's program featured a brief comedy program known as "The Purple Nurd," produced by four high school students from Fairfield, Ohio who billed themselves as HPW Squared Productions.  The Purple Nurd program later grew into "The Electromagnetic Spectrum," which featured spoofs of local commercials and television shows.

text: Bob Nave

text: , keyboardist for

text: the Lemon Pipers

text: in the late 1960s (whose big hit was the song "

text: Green Tambourine

text: "), was a late-night DJ for WOXR in the early 1970s. Other early to mid-1970s on-air personalities for the station included Rick Sellers, Ray Smith and Ed Pharr. Nave's program featured a brief comedy program known as "The Purple Nurd," produced by four high school students from

text: Fairfield, Ohio

text: who billed themselves as HPW Squared Productions.  The Purple Nurd program later grew into "The Electromagnetic Spectrum," which featured spoofs of local commercials and television shows.

text: The twin 10-meter telescopes at W. M. Keck Observatory in Hawaii and the 8.2-meter Subaru Telescope sited next to them support an array of specialized instruments on Nasmyth platforms, with a similar design being used for the future Thirty Meter Telescope. The 2.4-meter Automated Planet Finder telescope at Lick Observatory supports the use of two Nasmyth foci. The Sierra Nevada Observatory (OSN) in Spain has two Nasmyth telescopes, including a 1.5-meter diameter aperture one. The SOFIA airborne telescope also uses this design.

text: The twin 10-meter telescopes at

text: W. M. Keck Observatory

text: in Hawaii and the 8.2-meter

text: Subaru Telescope

text: sited next to them support an array of specialized instruments on Nasmyth platforms, with a similar design being used for the future

text: Thirty Meter Telescope

text: . The 2.4-meter

text: Automated Planet Finder

text: telescope at

text: Lick Observatory

text: supports the use of two Nasmyth

text: foci

text: . The

text: Sierra Nevada Observatory

text: (OSN) in Spain has two Nasmyth telescopes, including a 1.5-meter diameter aperture one. The

entity_name: Stratospheric Observatory for Infrared Astronomy

text: SOFIA

text: airborne telescope also uses this design.

text: By the early 1960s, Mount Stromlo had developed into one of the leading facilities for observational astronomy in the southern hemisphere. However, Bok appreciated the limitations of the site of Mount Stromlo due to weather and increasing light pollution, and he initiated a site-testing program which stretched across the country. In 1962, Siding Spring Mountain was chosen for the creation of a world-class telescope facility. As Siding Spring grew, Bok threw his support behind a new project: what would become Australia's largest optical telescope, the  Anglo-Australian Telescope.

text: By the early 1960s, Mount Stromlo had developed into one of the leading facilities for observational astronomy in the southern hemisphere. However, Bok appreciated the limitations of the site of Mount Stromlo due to weather and increasing light pollution, and he initiated a site-testing program which stretched across the country. In 1962, Siding Spring Mountain was chosen for the creation of a world-class telescope facility. As Siding Spring grew, Bok threw his support behind a new project: what would become Australia's largest optical telescope, the

text: Anglo-Australian Telescope

text: List of large optical reflecting telescopes. For telescopes larger than 3 meters in aperture see List of largest optical reflecting telescopes. This list combines large or expensive reflecting telescopes from any era, as what constitutes famous reflector has changed over time. In 1900 a 1-meter reflector would be among the largest in the world, but by 2000, would be relatively common for professional observatories.

text: List of large optical reflecting telescopes. For telescopes larger than 3 meters in aperture see

text: . This list combines large or expensive reflecting telescopes from any era, as what constitutes famous reflector has changed over time. In 1900 a 1-meter reflector would be among the largest in the world, but by 2000, would be relatively common for professional observatories.

text: Electromagnetic radiation consists of emissions of electromagnetic waves, the properties of which depend on the wavelength.

text: Electromagnetic radiation

text: consists of emissions of

text: electromagnetic wave

text: s, the properties of which depend on the

text: wavelength

text: Leuschner Observatory is home to a single  radio telescope. The telescope was one of the prototypes for the Allen Telescope Array that were tested at Leuschner, and has since been used in the undergraduate radio astronomy lab. The telescope operates between 1320–1740 MHz and uses an 8192 element spectrometer with spectral resolution of about 1.5 kHz and a 12 MHz bandwidth. The operating range allows for it to be used to observe the 21-cm hydrogen line as well as hydroxyl lines from astrophysical masers.

text: Leuschner Observatory is home to a single

text: radio telescope

text: . The telescope was one of the prototypes for the Allen Telescope Array that were tested at Leuschner, and has since been used in the undergraduate radio astronomy lab. The telescope operates between 1320–1740

text: MHz

text: and uses an 8192 element

text: spectrometer

text: with

text: spectral resolution

text: of about 1.5 kHz and a 12 MHz

text: bandwidth

text: . The operating range allows for it to be used to observe the 21-cm

text: hydrogen line

text: as well as

text: hydroxyl

text: lines from

text: astrophysical maser

text: s.

text: The design is named after Dobson because he is credited for being the first person to have combined all these construction techniques in a single telescope design. He was reluctant to take credit, however, pointing out that he built it that way because it was all he needed. In his own words, he jokes that he was "too retarded" to build a more sophisticated telescope with an equatorial telescope mount. With its simplicity of construction and use, the Dobsonian has become a very popular design today, particularly for large amateur telescopes.

text: The design is named after Dobson because he is credited for being the first person to have combined all these construction techniques in a single telescope design. He was reluctant to take credit, however, pointing out that he built it that way because it was all he needed. In his own words, he jokes that he was "too retarded" to build a more sophisticated telescope with an

text: equatorial telescope mount

text: . With its simplicity of construction and use, the Dobsonian has become a very popular design today, particularly for large amateur telescopes.

text: The Spitzer Space Telescope (SST), formerly the Space Infrared Telescope Facility (SIRTF), is an infrared space telescope launched in 2003. It is the fourth and final of the NASA Great Observatories program.

text: The Spitzer Space Telescope (SST), formerly the Space Infrared Telescope Facility (SIRTF), is an

text: infrared

text: space telescope

text: launched in 2003. It is the fourth and final of the

text: NASA

text: Great Observatories program

text: For the special case of an electromagnetic wave in vacuum, where v = c, k is given by

text: For the special case of an

text: electromagnetic wave

text: in vacuum, where v = c, k is given by

text: Optical Mechanics, Inc. or OMI is a high-end American telescope and optics instrument manufacturer. OMI was founded in 2002 and produces observatory telescopes, Lidar telescopes, optical tube assemblies, telescope mirrors and reflective coatings for mirrors. OMI mirrors are used by other telescope makers such as Obsession Telescopes. Also taking on custom projects, they produced the 48-inch Dob, a  aperture, 4, Dobsonian telescope  called "Barbarella" and featured in Astronomy Technology Today magazine (June 2008 Issue). OMI is located in the US state of Iowa.

text: Optical Mechanics, Inc. or OMI is a high-end American

text: telescope

text: and optics instrument manufacturer. OMI was founded in 2002 and produces observatory telescopes,

text: Lidar

text: telescopes, optical tube assemblies, telescope mirrors and reflective coatings for mirrors. OMI mirrors are used by other telescope makers such as

text: Obsession Telescopes

text: . Also taking on custom projects, they produced the 48-inch Dob, a

text: aperture

text: , 4,

text: Dobsonian

text: telescope  called "Barbarella" and featured in

text: Astronomy Technology Today

text: magazine (June 2008 Issue). OMI is located in the US state of

text: Iowa

text: The transit method also makes it possible to study the atmosphere of the transiting planet. When the planet transits the star, light from the star passes through the upper atmosphere of the planet. By studying the high-resolution stellar spectrum carefully, one can detect elements present in the planet's atmosphere.  A planetary atmosphere (and planet for that matter) could also be detected by measuring the polarisation of the starlight as it passed through or is reflected off the planet's atmosphere.

text: The beginning of the 20th century saw construction of the first of the "modern" large research reflectors, designed for precision photographic imaging and located at remote high altitude clear sky locations such as the 60-inch Hale telescope of 1908, and the  Hooker telescope in 1917, both located at Mount Wilson Observatory. These and other telescopes of this size had to have provisions to allow for the removal of their main mirrors for re-silvering every few months. John Donavan Strong, a young physicist at the California Institute of Technology, developed a technique for coating a mirror with a much longer lasting aluminum coating using thermal vacuum evaporation. In 1932, he became the first person to "aluminize" a mirror; three years later the  and  telescopes became the first large astronomical telescopes to have their mirrors aluminized. 1948 saw the completion of the  Hale reflector at Mount Palomar which was the largest telescope in the world up until the completion of the massive  BTA-6 in Russia twenty-seven years later. The Hale reflector introduced several technical innovations used in future telescopes, including hydrostatic bearings for very low friction, the Serrurier truss for equal deflections of the two mirrors as the tube sags under gravity, and the use of Pyrex low-expansion glass for the mirrors. The arrival of substantially larger telescopes had to await the introduction of methods other than the rigidity of glass to maintain the proper shape of the mirror.

text: The beginning of the 20th century saw construction of the first of the "modern" large research reflectors, designed for precision photographic imaging and located at remote high altitude clear sky locations such as the

text: 60-inch Hale telescope

text: of 1908, and the

text: Hooker telescope

text: in 1917, both located at

text: Mount Wilson Observatory

text: . These and other telescopes of this size had to have provisions to allow for the removal of their main mirrors for re-silvering every few months. John Donavan Strong, a young physicist at the

text: California Institute of Technology

text: , developed a technique for coating a mirror with a much longer lasting aluminum coating using thermal

text: vacuum evaporation

text: . In 1932, he became the first person to "aluminize" a mirror; three years later the  and  telescopes became the first large astronomical telescopes to have their mirrors aluminized. 1948 saw the completion of the

text: Hale reflector

text: at

text: Mount Palomar

text: which was the largest telescope in the world up until the completion of the massive

text: in Russia twenty-seven years later. The Hale reflector introduced several technical innovations used in future telescopes, including

text: hydrostatic bearings

text: for very low friction, the

text: Serrurier truss

text: for equal deflections of the two mirrors as the tube sags under gravity, and the use of

text: Pyrex

text: low-expansion glass for the mirrors. The arrival of substantially larger telescopes had to await the introduction of methods other than the rigidity of glass to maintain the proper shape of the mirror.

text: Between 1972 and 1973, the telescope was used for "a detailed survey of the radio sources in a limited area of the sky … up to the sensitivity limit of the instrument". Among the objects catalogued was the first gravitational lens, which was confirmed optically in 1979 after its position was found to coincide with a pair of faint blue stars by using the Mark I as an interferometer with the Mark II. The telescope was also involved in the detection of the first Einstein ring in 1998, in conjunction with observations made with the Hubble Space Telescope.

text: Between 1972 and 1973, the telescope was used for "a detailed survey of the radio sources in a limited area of the sky … up to the sensitivity limit of the instrument". Among the objects catalogued was the first

text: gravitational lens

text: , which was confirmed optically in 1979 after its position was found to coincide with a pair of faint blue stars by using the Mark I as an interferometer with the

text: Mark II

text: . The telescope was also involved in the detection of the first

text: Einstein ring

text: in 1998, in conjunction with observations made with the

text: Hubble Space Telescope

text: The Newtonian telescope is a type of reflecting telescope invented by the British scientist Sir Isaac Newton (1642–1727), using a concave primary mirror and a flat diagonal secondary mirror. Newton’s first reflecting telescope was completed in 1668 and is the earliest known functional reflecting telescope. The Newtonian telescope's simple design makes it very popular with amateur telescope makers.

text: The Newtonian telescope is a type of

text: reflecting telescope

text: invented by the British scientist

text: Sir Isaac Newton

text: (1642–1727), using a

text: concave

text: primary mirror

text: and a flat diagonal secondary mirror. Newton’s

text: first reflecting telescope

text: was completed in 1668 and is the earliest known functional reflecting telescope. The Newtonian telescope's simple design makes it very popular with

text: amateur telescope maker

text: s.

text: The California Extremely Large Telescope (CELT) was a proposal for an extremely large telescope design first proposed in the 1990s by a consortium of Californian Universities. The design was for a segmented 30 m diameter astronomical telescope. The CELT had a positive reception and continued to be developed, and was renamed The Thirty Meter Telescope around 2003-4. The CELT was one of the earlier and more successful proposals for extremely large telescopes.

text: The California Extremely Large Telescope (CELT) was a proposal for an

text: extremely large telescope

text: design first proposed in the 1990s by a consortium of Californian Universities. The design was for a segmented 30 m diameter astronomical telescope. The CELT had a positive reception and continued to be developed, and was renamed

text: The Thirty Meter Telescope

text: around 2003-4. The CELT was one of the earlier and more successful proposals for extremely large telescopes.

text: Largest does not always equate to being the best telescopes, and overall light gathering power of the optical system can be a poor measure of a telescope's performance. Space-based telescopes, such as the Hubble Space Telescope, take advantage of being above the Earth's atmosphere to reach higher resolution and greater light gathering through longer exposure time. Location in the northern or southern hemisphere of the Earth can also limit what part of the sky can be observed.

text: Largest does not always equate to being the best telescopes, and overall light gathering power of the optical system can be a poor measure of a telescope's performance.

text: Space-based telescopes

text: , such as the

text: Hubble Space Telescope

text: , take advantage of being above the Earth's

text: atmosphere

text: to reach higher resolution and greater light gathering through longer exposure time. Location in the northern or southern hemisphere of the Earth can also limit what part of the sky can be observed.

text: The telescope is more a discovery of optical craftsmen than an invention of a scientist. The lens and the properties of refracting and reflecting light had been known since antiquity and theory on how they worked were developed by ancient Greek philosophers, preserved and expanded on in the medieval Islamic world, and had reached a significantly advanced state by the time of the telescope's invention in early modern Europe. But the most significant step cited in the invention of the telescope was the development of lens manufacture for spectacles, first in Venice and Florence in the thirteenth century, and later in the spectacle making centers in both the Netherlands and Germany. It is in the Netherlands in 1608 where the first recorded optical telescopes (refracting telescopes) appeared. The invention is credited to the spectacle makers Hans Lippershey and Zacharias Janssen in Middelburg, and the instrument-maker and optician Jacob Metius of Alkmaar.

text: The telescope is more a discovery of optical craftsmen than an invention of a scientist. The

text: lens

text: and the properties of refracting and reflecting light had been known since

text: antiquity

text: and theory on how they worked were developed by ancient

text: Greek

text: philosophers, preserved and expanded on in the

text: medieval Islamic world

text: , and had reached a significantly advanced state by the time of the telescope's invention in

text: early modern Europe

text: . But the most significant step cited in the invention of the telescope was the development of lens manufacture for

text: spectacles

text: , first in Venice and Florence in the thirteenth century, and later in the spectacle making centers in both the

text: Netherlands

text: and Germany. It is in the Netherlands in 1608 where the first recorded optical telescopes (

text: refracting telescope

text: s) appeared. The invention is credited to the spectacle makers

text: Hans Lippershey

text: and

text: Zacharias Janssen

text: in

text: Middelburg

text: , and the instrument-maker and optician

text: Jacob Metius

text: of

text: Alkmaar

text: A wave consists of successive troughs and crests, and the distance between two adjacent crests or troughs is called the wavelength. Waves of the electromagnetic spectrum vary in size, from very long radio waves the size of buildings to very short gamma rays smaller than atom nuclei. Frequency is inversely proportional to wavelength, according to the equation:

text: A wave consists of successive troughs and crests, and the distance between two adjacent crests or troughs is called the

text: wavelength

text: . Waves of the electromagnetic spectrum vary in size, from very long radio waves the size of buildings to very short gamma rays smaller than atom nuclei. Frequency is inversely proportional to wavelength, according to the equation:

text: The album cover of Motivation Radio features Hillage standing on a shoreline holding a Statocaster guitar, with a large radio telescope in the background further along the bay. The radio telescope in question is the radio telescope at Parkes Observatory in New South Wales, Australia, superimposed on top of a shoreline picture. Hillage's father bought him the Stratocaster on the cover because Steve went to a public school - the City of London School - and "did quite well" on his O levels and won a scholarship, meaning that his father did not have to pay fees any more and bought him the guitar. Hillage recalled that "We found it through Exchange & Mart or Melody Maker - one or the other, I don't know." American art director Bob Cato is credited on the album sleeve for "design and photography."

text: The album cover of Motivation Radio features Hillage standing on a shoreline holding a

text: Statocaster

text: guitar, with a large radio telescope in the background further along the bay. The radio telescope in question is the

text: radio telescope

text: at

text: Parkes Observatory

text: in

text: New South Wales

text: Australia

text: , superimposed on top of a shoreline picture. Hillage's father bought him the Stratocaster on the cover because Steve went to a public school - the

text: City of London School

text: - and "did quite well" on his

text: O levels

text: and won a

text: scholarship

text: , meaning that his father did not have to pay fees any more and bought him the guitar. Hillage recalled that "We found it through

text: Exchange & Mart

text: or

text: Melody Maker

text: - one or the other, I don't know." American art director Bob Cato is credited on the album sleeve for "design and photography."

text: Since the Earth is constantly rotating, telescopes and equipment are rotated in the opposite direction to follow the apparent motion of the stars overhead (called diurnal motion).  This is accomplished by using either equatorial or computer-controlled altazimuth telescope mounts to keep celestial objects centered while the earth rotates. All telescope mount systems suffer from induced tracking error due to imperfect motor drives and mechanical sag of the telescope. Tracking errors are corrected by keeping a selected aiming point, usually a bright guide star, centered during the entire exposure. Sometimes (as in the case of comets) the object to be imaged is moving, so the telescope has to be kept constantly centered on that object. This guiding is done through a second co-mounted telescope called a "guide scope" or via some type of "off-axis guider", a device with a prism or optical beam splitter that allows the observer to view the same image in the telescope that is taking the picture. Guiding was formerly done manually throughout the exposure with an observer standing at (or riding inside) the telescope making corrections to keep a cross hair on the guide star. Since the advent of computer-controlled systems this is accomplished by an automated systems in professional and even amateur equipment.

text: Since the Earth is constantly rotating, telescopes and equipment are rotated in the opposite direction to follow the apparent motion of the stars overhead (called

text: diurnal motion

text: ).  This is accomplished by using either

text: equatorial

text: or computer-controlled

text: altazimuth

text: telescope mounts to keep celestial objects centered while the earth rotates. All

text: telescope mount

text: systems suffer from induced tracking error due to imperfect motor drives and mechanical sag of the telescope. Tracking errors are corrected by keeping a selected aiming point, usually a bright

text: guide star

text: , centered during the entire exposure. Sometimes (as in the case of

text: comet

text: s) the object to be imaged is moving, so the telescope has to be kept constantly centered on that object. This guiding is done through a second co-mounted telescope called a "guide scope" or via some type of "off-axis guider", a device with a prism or optical

text: beam splitter

text: that allows the observer to view the same image in the telescope that is taking the picture. Guiding was formerly done manually throughout the exposure with an observer standing at (or riding inside) the telescope making corrections to keep a

text: cross hair

text: on the guide star. Since the advent of computer-controlled systems this is accomplished by an automated systems in professional and even amateur equipment.

text: The main aim for the telescope when constructed was to use it in conjunction with the Lovell Telescope as a fully steerable interferometer to determine the sizes of radio sources. It was not known what size the radio sources would be, and so the optimal telescope separation was not known (the separation is inversely proportional to the resolution of the interferometer). As a result, the telescope was built such that it could be completely disassembled and reassembled on a new site within 6 months.

text: The main aim for the telescope when constructed was to use it in conjunction with the

text: Lovell Telescope

text: as a fully steerable interferometer to determine the sizes of radio sources. It was not known what size the radio sources would be, and so the optimal telescope separation was not known (the separation is inversely proportional to the resolution of the interferometer). As a result, the telescope was built such that it could be completely disassembled and reassembled on a new site within 6 months.

text: Once the Space Telescope project had been given the go-ahead, work on the program was divided among many institutions. Marshall Space Flight Center (MSFC) was given responsibility for the design, development, and construction of the telescope, while Goddard Space Flight Center was given overall control of the scientific instruments and ground-control center for the mission. MSFC commissioned the optics company Perkin-Elmer to design and build the Optical Telescope Assembly (OTA) and Fine Guidance Sensors for the space telescope. Lockheed was commissioned to construct and integrate the spacecraft in which the telescope would be housed.

text: Once the Space Telescope project had been given the go-ahead, work on the program was divided among many institutions.

text: Marshall Space Flight Center

text: (MSFC) was given responsibility for the design, development, and construction of the telescope, while

text: Goddard Space Flight Center

text: was given overall control of the scientific instruments and ground-control center for the mission. MSFC commissioned the optics company

text: Perkin-Elmer

text: to design and build the Optical Telescope Assembly (OTA) and Fine Guidance Sensors for the space telescope.

text: Lockheed

text: was commissioned to construct and integrate the spacecraft in which the telescope would be housed.

text: Between 1861 and 1865, James Clerk Maxwell developed and published Maxwell's equations, which explained and united all of classical electricity and magnetism. The first set of these equations was published in a paper entitled On Physical Lines of Force in 1861. These equations were valid although incomplete. Maxwell completed his set of equations in his later 1865 paper A Dynamical Theory of the Electromagnetic Field and demonstrated the fact that light is an electromagnetic wave. Heinrich Hertz experimentally confirmed this fact in 1887.

text: Between 1861 and 1865,

text: James Clerk Maxwell

text: developed and published

text: Maxwell's equations

text: , which explained and united all of

text: classical

text: electricity and magnetism. The first set of these equations was published in a paper entitled

text: On Physical Lines of Force

text: in 1861. These equations were valid although incomplete. Maxwell completed his set of equations in his later 1865 paper

entity_name: A Dynamical Theory of the Electromagnetic Field

text: A Dynamical Theory of the Electromagnetic Field

text: and demonstrated the fact that light is an

text: electromagnetic wave

text: Heinrich Hertz

text: experimentally confirmed this fact in 1887.

text: All climate models take account of incoming energy as short wave electromagnetic radiation, chiefly visible and short-wave (near) infrared, as well as outgoing energy as long wave (far) infrared electromagnetic radiation from the earth. Any imbalance results in a change in temperature.

text: All climate models take account of incoming energy as short wave

text: electromagnetic radiation

text: , chiefly

text: visible

text: and short-wave (near)

text: infrared

text: , as well as outgoing energy as long wave (far) infrared electromagnetic radiation from the earth. Any imbalance results in a

text: change in temperature

text: Team scientists used 137 different microorganism species, including extremophiles that were isolated from Earth's most extreme environments, and cataloged how each life form uniquely reflects sunlight in the visible and near-infrared to the short-wavelength infrared (0.35–2.5 µm) portions of the electromagnetic spectrum. This database of individual reflection 'fingerprints' (spectrum) might be used by astronomers as biosignatures to find large colonies of microscopic life on distant exoplanets. A combination of organisms would produce a mixed spectrum, also cataloged,  of light bouncing off the planet. The goal of the catalog is to provide astronomers with a baseline comparison to help scientists interpret the data that will come back from telescopes like WFIRST and E-ELT.

text: Team scientists used 137 different microorganism species, including

text: extremophile

text: s that were isolated from Earth's most extreme environments, and cataloged how each life form uniquely reflects sunlight in the visible and near-infrared to the short-wavelength infrared (0.35–2.5 µm) portions of the

text: electromagnetic spectrum

text: . This database of individual reflection 'fingerprints' (spectrum) might be used by astronomers as

text: biosignature

text: s to find large colonies of microscopic life on distant exoplanets. A combination of organisms would produce a mixed spectrum, also cataloged,  of light bouncing off the planet. The goal of the catalog is to provide astronomers with a baseline comparison to help scientists interpret the data that will come back from telescopes like

text: WFIRST

text: and

text: E-ELT

text: In 2008, the TMT corporation selected two semi-finalists for further study, Mauna Kea and Cerro Amazones. In July 2009, Mauna Kea was selected. Once TMT selected Mauna Kea, the project began a regulatory and community process for approval. Mauna Kea is ranked as one of the best sites on Earth for telescope viewing and is home to 13 other telescopes built at the summit of the mountain, within the Mauna Kea Observatories grounds. Telescopes generate money for the big island, with millions of dollars in jobs and subsidies gained by the state. The TMT would be one of the most expensive telescopes ever created.

text: In 2008, the TMT corporation selected two semi-finalists for further study, Mauna Kea and Cerro Amazones. In July 2009, Mauna Kea was selected. Once TMT selected Mauna Kea, the project began a regulatory and community process for approval. Mauna Kea is ranked as one of the best sites on Earth for telescope viewing and is home to 13 other telescopes built at the summit of the mountain, within the

text: Mauna Kea Observatories

text: grounds. Telescopes generate money for the big island, with millions of dollars in jobs and subsidies gained by the state. The TMT would be one of the most expensive telescopes ever created.

text: The SAFARI imaging spectrometer is the European ‘nerve center’ of Japanese infrared telescope SPICA (Space Infra-Red Telescope for Cosmology and Astrophysics telescope) and is being developed under the leadership of SRON Netherlands Institute for Space Research. SAFARI is an infrared camera with about 6,000 pixels that can make real ‘photos’ of the sky in three adjacent wavelength areas. Using a Fourier transform spectroscopy (FTS) detailed spectral information is obtained, allowing astronomers to determine the chemical composition of the observed celestial sources. TNO is developing the mechanism of this FTS.

text: The SAFARI imaging spectrometer is the European ‘nerve center’ of Japanese infrared telescope

text: SPICA (Space Infra-Red Telescope for Cosmology and Astrophysics telescope)

text: and is being developed under the leadership of

entity_name: Netherlands Institute for Space Research

text: SRON Netherlands Institute for Space Research

text: . SAFARI is an

text: infrared camera

text: with about 6,000 pixels that can make real ‘photos’ of the sky in three adjacent wavelength areas. Using a

text: Fourier transform spectroscopy

text: (FTS) detailed spectral information is obtained, allowing astronomers to determine the chemical composition of the observed celestial sources.

entity_name: Netherlands Organisation for Applied Scientific Research

text: TNO

text: is developing the mechanism of this FTS.

text: The potential effects of electromagnetic fields on human health vary widely depending on the frequency and intensity of the fields. For more information on the health effects due to specific parts of the electromagnetic spectrum, see the following articles:

text: The potential effects of electromagnetic fields on human health vary widely depending on the frequency and intensity of the fields. For more information on the health effects due to specific parts of the

text: electromagnetic spectrum

text: , see the following articles:

text: WEBT observations are often carried out in conjunction with observations at higher frequencies, from ultraviolet to gamma rays, performed by both space and ground-based telescopes. In this way, information on blazar emission over almost the whole electromagnetic spectrum can be obtained.

text: WEBT observations are often carried out in conjunction with observations at higher

text: frequencies

text: , from ultraviolet to gamma rays, performed by both space and ground-based telescopes. In this way, information on blazar emission over almost the whole

text: electromagnetic spectrum

text: can be obtained.

text: The Balmer series is characterized by the electron transitioning from n ≥ 3 to n = 2, where n refers to the radial quantum number or principal quantum number of the electron. The transitions are named sequentially by Greek letter: n = 3 to n = 2 is called H-α, 4 to 2 is H-β, 5 to 2 is H-γ, and 6 to 2 is H-δ. As the first spectral lines associated with this series are located in the visible part of the electromagnetic spectrum, these lines are historically referred to as "H-alpha", "H-beta", "H-gamma" and so on, where H is the element hydrogen.

text: The Balmer series is characterized by the

text: electron

text: transitioning from n ≥ 3 to n = 2, where n refers to the

text: radial quantum number

text: or

text: principal quantum number

text: of the electron. The transitions are named sequentially by Greek letter: n = 3 to n = 2 is called H-α, 4 to 2 is H-β, 5 to 2 is H-γ, and 6 to 2 is H-δ. As the first spectral lines associated with this series are located in the visible part of the

text: electromagnetic spectrum

text: , these lines are historically referred to as "H-alpha", "H-beta", "H-gamma" and so on, where H is the element hydrogen.

text: With its 70-meter antenna diameter, it is among the largest single dish radio telescopes in the world. It has an advantage in comparison with other large radio telescopes in the fact that the complex includes powerful transmitters that allow active space experiments. Powerful electromagnetic beams can be accurately targeted and the signals received can be analyzed. For this reason, the Yevpatoria RT-70 radio telescope is one of only two in the world that are able to transmit messages to extraterrestrial civilizations. Radio telescopes are highly sensitive detectors of signals from outer space.

text: With its 70-meter antenna diameter, it is among the largest single dish radio telescopes in the world. It has an advantage in comparison with other large radio telescopes in the fact that the complex includes powerful transmitters that allow active space experiments. Powerful electromagnetic beams can be accurately targeted and the signals received can be analyzed. For this reason, the Yevpatoria RT-70 radio telescope is one of only two in the world that are able to transmit

text: messages to extraterrestrial civilizations

text: . Radio telescopes are highly sensitive detectors of signals from outer space.

text: Each of the three spectrometers was tuned to measure the absorption in a specific range of colors. Each of these ranges includes dozens of dark absorption lines produced by either carbon dioxide or molecular oxygen. The amount of light absorbed in each spectral line increases with the number of molecules along the optical path. OCO's spectrometers measure the fraction of the light absorbed in each of these lines with very high precision. This information was then to be analyzed to determine the number of molecules along the path between the top of the atmosphere and the surface.

text: Some images from Wikisky, such as Digitized Sky Survey (DSS2) and Sloan Digital Sky Survey (SDSS) images are "non-commercial use".  The DSS datarights are held by multiple institutions.  SDSS data is also non-commercial use.  Images from the Hubble Space Telescope (HST), Spitzer Space Telescope (infrared) or GALEX space telescope (ultraviolet) are "PD-NASA-USgov".

text: Some images from Wikisky, such as

text: Digitized Sky Survey

text: (DSS2) and

text: Sloan Digital Sky Survey

text: (SDSS) images are "non-commercial use".  The DSS datarights are held by multiple institutions.  SDSS data is also non-commercial use.  Images from the

text: Hubble Space Telescope

text: (HST),

text: Spitzer Space Telescope

text: infrared

text: ) or

text: GALEX

text: space telescope (

text: ultraviolet

text: ) are "

text: PD

text: NASA

text: USgov

text: The radio spectrum is the part of the electromagnetic spectrum from 3 Hz to 3000 GHz (3 THz).  Electromagnetic waves in this frequency range, called radio waves, are extremely widely used in modern technology, particularly in telecommunication.   To prevent interference between different users, the generation and transmission of radio waves is strictly regulated by national laws, coordinated by an international body, the International Telecommunication Union (ITU).

text: The radio spectrum is the part of the

text: electromagnetic spectrum

text: from 3

text: Hz

text: to 3000

text: GHz

text: THz

text: ).  Electromagnetic waves in this frequency range, called

text: radio wave

text: s, are extremely widely used in modern technology, particularly in

text: telecommunication

text: .   To prevent interference between different users, the generation and

text: transmission

text: of radio waves is strictly regulated by national laws, coordinated by an international body, the

text: International Telecommunication Union

text: (ITU).

text: The era of radio telescopes (along with radio astronomy) was born with Karl Guthe Jansky's serendipitous discovery of an astronomical radio source in 1931. Many types of telescopes were developed in the 20th century for a wide range of wavelengths from radio to gamma-rays.  The development of space observatories after 1960 allowed accessto several bands impossible to observe from the ground, including X-rays and longer wavelength infrared bands.

text: The era of

text: radio telescope

text: s (along with

text: radio astronomy

text: ) was born with

text: Karl Guthe Jansky

text: 's

text: serendipitous

text: discovery of an astronomical radio source in 1931. Many types of telescopes were developed in the 20th century for a wide range of wavelengths from radio to

text: gamma-rays

text: .  The development of

text: space observatories

text: after 1960 allowed accessto several bands impossible to observe from the ground, including

text: X-rays

text: and longer wavelength

text: infrared

text: bands.

text: Again there are technical issues relating to spin, but in several important cases, including electrically charged particles and particles interacting via nuclear forces, the solution to the problem is to impute physical reality to the gauge function θ(x). We say that if the function θ oscillates, it represents a new type of quantum-mechanical wave, and this new wave has its own momentum p = h/λ, which turns out to patch up the discrepancies that otherwise would have broken conservation of momentum. In the context of electromagnetism, the particles A and B would be charged particles such as electrons, and the quantum mechanical wave represented by θ would be the electromagnetic field. (Here we ignore the technical issues raised by the fact that electrons actually have spin 1/2, not spin zero. This oversimplification is the reason that the gauge field θ comes out to be a scalar, whereas the electromagnetic field is actually represented by a vector consisting of V and A.) The result is that we have an explanation for the presence of electromagnetic interactions: if we try to construct a gauge-symmetric theory of identical, non-interacting particles, the result is not self-consistent, and can only be repaired by adding electric and magnetic fields that cause the particles to interact.

text: In "out of bounds" areas, many maps have hollow objects that the player can move through freely. These objects usually are in the distance and are for decoration. The floor or terrain can also be hollow. The floor can appear the same as a normal floor, but moving over it will cause the player to fall as if it does not exist. Depending on the game, after falling a certain distance the player will freeze, die, respawn on the map again or just keep falling. Two good examples are the Nintendo 64 games The Legend of Zelda: Ocarina of Time and The Legend of Zelda: Majora's Mask. In the former, there is a section of "wall" at the entrance to the water temple that will allow players to fall through the ground. Eventually players respawn rather than the game crashing. In the latter, there is a 3-day cycle (after which the moon will fall) that can be surpassed by going to the observatory and looking out the telescope on the last minutes of the final day. If you look out the telescope while the timer is counting down and exit the telescope when the timer hits 0, (if you're lucky) the timer will be gone and you can continue the game without it. The glitch is removed when you play the Song of Time.

text: In "out of bounds" areas, many maps have hollow objects that the player can move through freely. These objects usually are in the distance and are for decoration. The floor or terrain can also be hollow. The floor can appear the same as a normal floor, but moving over it will cause the player to fall as if it does not exist. Depending on the game, after falling a certain distance the player will freeze, die, respawn on the map again or just keep falling. Two good examples are the

text: Nintendo 64

text: games

text: The Legend of Zelda: Ocarina of Time

text: and

text: The Legend of Zelda: Majora's Mask

text: . In the former, there is a section of "wall" at the entrance to the water temple that will allow players to fall through the ground. Eventually players respawn rather than the game crashing. In the latter, there is a 3-day cycle (after which the moon will fall) that can be surpassed by going to the observatory and looking out the telescope on the last minutes of the final day. If you look out the telescope while the timer is counting down and exit the telescope when the timer hits 0, (if you're lucky) the timer will be gone and you can continue the game without it. The glitch is removed when you play the Song of Time.

text: The Fibre-fed Échelle Spectrograph (FIES) on the Canary Islands' Nordic Optical Telescope was operated in October 2009, using Doppler spectroscopy to gather information that would accompany the gathered photometric observations. The High Resolution Échelle Spectrometer (HIRES) at the W.M. Keck Observatory was also utilized. Use of the WIYN Observatory for speckle imaging found that the host star of KOI-98 was actually a close-knit binary star, which complicated the analysis. A November 2009 operation of the ARIES instrument on the MMT Observatory and the July 2010 use of the PHARO near-infrared camera on the Palomar Observatory's  200 inch Hale telescope used adaptive optics to confirm WIYN's findings. Although suspected as a planet early on, KOI-98 was not included when Kepler-4b, Kepler-5b, Kepler-6b, Kepler-7b, and Kepler-8b were published, as further investigation was still required.

text: The Fibre-fed Échelle Spectrograph (FIES) on the Canary Islands'

text: Nordic Optical Telescope

text: was operated in October 2009, using

text: Doppler spectroscopy

text: to gather information that would accompany the gathered photometric observations. The High Resolution Échelle Spectrometer (HIRES) at the

text: W.M. Keck Observatory

text: was also utilized. Use of the

text: WIYN Observatory

text: for

text: speckle imaging

text: found that the host star of KOI-98 was actually a close-knit

text: binary star

text: , which complicated the analysis. A November 2009 operation of the ARIES instrument on the

text: MMT Observatory

text: and the July 2010 use of the PHARO near-infrared camera on the

text: Palomar Observatory

text: 's  200 inch

text: Hale telescope

text: used

text: adaptive optics

text: to confirm WIYN's findings. Although suspected as a planet early on, KOI-98 was not included when

text: , and

text: were published, as further investigation was still required.

text: The problems with seating the second RSU set the spacewalkers back in the timeline by approximately two hours, but after Altman asked Massimino and Good how they felt, they replied they were doing well and felt fine to continue. Flight controllers on the ground evaluated the consumables for the two spacesuits, and decided that if Massimino recharged his suit's oxygen in the airlock, the pair could safely continue with the battery installation. After moving to the battery unit site, Good and Massimino removed one of the original battery modules from Bay 2 of the telescope, and replaced it with a new unit. The batteries provide power to the telescope when it passes into the Earth's shadow and its solar arrays are not exposed to the sun. The spacewalk officially ended at 20:45 UTC, for a time of seven hours, fifty-six minutes. It was the twentieth spacewalk to service Hubble, bringing the total time in EVA servicing the telescope to one hundred forty-four hours and twenty-six minutes.

text: The problems with seating the second RSU set the spacewalkers back in the timeline by approximately two hours, but after Altman asked Massimino and Good how they felt, they replied they were doing well and felt fine to continue. Flight controllers on the ground evaluated the consumables for the two

text: spacesuits

text: , and decided that if Massimino recharged his suit's oxygen in the airlock, the pair could safely continue with the battery installation. After moving to the battery unit site, Good and Massimino removed one of the original battery modules from Bay 2 of the telescope, and replaced it with a new unit. The batteries provide power to the telescope when it passes into the Earth's shadow and its solar arrays are not exposed to the sun. The spacewalk officially ended at 20:45 UTC, for a time of seven hours, fifty-six minutes. It was the twentieth spacewalk to service Hubble, bringing the total time in EVA servicing the telescope to one hundred forty-four hours and twenty-six minutes.

text: The native resolution of an interferometer depends not on the size of the individual telescopes (as with a traditional single telescope), but on their separation. Pairs of telescopes with large separations provide sensitivity to small-scale structure, while short spacings are sensitive to large-scale structure on the sky. The 8 SZA telescopes are small enough to be placed very close together, which provides maximum sensitivity to the (large-scale) SZ signal from clusters.  When the SZA is combined with the other telescopes in the CARMA array, which have longer separations and are sensitive to finer angular scales, it can form a complete picture of galaxy clusters at very high resolution.

text: A telescopic tower crane has a telescopic mast and often a superstructure (jib) on top so that it functions as a tower crane.  Some telescopic tower cranes also have a telescopic jib.

text: The BTA-6 (Большой Телескоп Альтазимутальный, or Large Altazimuth Telescope), with first light in 1975, was for several years the world's largest single primary mirror optical reflecting telescope. The BTA-6's primary mirror has a diameter of 6 metres (236 inches) and is housed in a 48 m (157.5 ft) diameter dome at an altitude of 2,070 m (6,791 ft).  It held the record from its completion until 1993, when it was surpassed by the Keck 1 telescope, Hawaii. Telescopes of comparable or larger size have subsequently employed flexible or segmented mirrors, and the BTA-6 remained the world's largest rigid-mirror telescope until the advent of spin-casting technology (which produced, for example, the single 8.4-meter primary mirror of the Large Binocular Telescope in the late 1990s). Its altazimuth mounting dictates the need for a field derotation mechanism to maintain the orientation of the field of view.

text: The

text: (Большой Телескоп Альтазимутальный, or Large Altazimuth Telescope), with

text: first light

text: in 1975, was for several years the world's largest single primary mirror optical

text: reflecting telescope

text: . The BTA-6's

text: primary mirror

text: has a diameter of 6 metres (236 inches) and is housed in a 48 m (157.5 ft) diameter dome at an altitude of 2,070 m (6,791 ft).  It held the record from its completion until 1993, when it was surpassed by the

text: Keck 1

text: telescope,

text: Hawaii

text: . Telescopes of comparable or larger size have subsequently employed flexible or segmented mirrors, and the BTA-6 remained the world's largest rigid-mirror telescope until the advent of spin-casting technology (which produced, for example, the single 8.4-meter primary mirror of the

text: Large Binocular Telescope

text: in the late 1990s). Its

text: altazimuth

text: mounting dictates the need for a field derotation mechanism to maintain the orientation of the

text: field of view

text: In 2014, Sullivan was honored in the Time 100 list. According to John Glenn, "Kathy is not just an ivory-tower scientist. She was part of NASA's first class of female astronauts, selected in 1978, and went on to fly three shuttle missions. She is the first American woman to walk in space and served aboard the mission that deployed the Hubble Space Telescope. That role in helping humanity look outward has not prevented her from looking homeward. The planet is suffering increasingly severe upheavals, at least partly a result of climate change — droughts, floods, typhoons, tornadoes. I believe my good friend Kathy is the right person for the right job at the right time."

text: In 2014, Sullivan was honored in the

text: Time 100

text: list. According to

text: John Glenn

text: , "Kathy is not just an ivory-tower scientist. She was part of NASA's first class of female astronauts, selected in 1978, and went on to fly three shuttle missions. She is the first American woman to walk in space and served aboard the mission that deployed the

text: Hubble Space Telescope

text: . That role in helping humanity look outward has not prevented her from looking homeward. The planet is suffering increasingly severe upheavals, at least partly a result of climate change —

text: droughts

text: floods

text: typhoons

text: tornadoes

text: . I believe my good friend Kathy is the right person for the right job at the right time."

text: The deployment and retrieval of a satellite designed to study Earth's middle atmosphere along with a test of potential International Space Station hardware highlighted NASA's sixth Shuttle mission of 1997. The prime payload for the flight, the Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere-Shuttle Pallet Satellite-2 (CRISTA-SPAS-2) made its second flight on the Space Shuttle (previous flight STS-66 in 1994) and was the fourth mission in a cooperative venture between the German Space Agency (DARA) and NASA.

text: The deployment and retrieval of a satellite designed to study Earth's middle atmosphere along with a test of potential International Space Station hardware highlighted NASA's sixth Shuttle mission of 1997. The prime payload for the flight, the Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere-Shuttle Pallet Satellite-2 (

text: ) made its second flight on the Space Shuttle (previous flight

text: in 1994) and was the fourth mission in a cooperative venture between the German Space Agency (DARA) and NASA.

text: Clough states "But looking back, sure, I wish I had taken more time. We have a lot of friends who felt left out. We needed to spend more time letting our friends know where this was going. I regret that."

text: Military operations are executed in an information environment increasingly complicated by the electromagnetic (EM) spectrum. The electromagnetic spectrum portion of the information environment is referred to as the electromagnetic environment (EME). The recognized need for military forces to have unimpeded access to and use of the electromagnetic environment creates vulnerabilities and opportunities for electronic warfare (EW) in support of military operations.

text: Military operations are executed in an information environment increasingly complicated by the electromagnetic (EM) spectrum. The

text: electromagnetic spectrum

text: portion of the information environment is referred to as the electromagnetic environment (EME). The recognized need for military forces to have unimpeded access to and use of the electromagnetic environment creates vulnerabilities and opportunities for electronic warfare (EW) in support of military operations.

text: Observatory's first radio telescope was a parabolic antenna of  diameter, which was donated by the Marmara Research Center (MAM) of Scientific and Technological Research Council of Turkey (TÜBİTAK). The radio telescope, then called MRT-2, was initially purchased from the Institute of Radio Astronomy in Kharkiv, Ukraine with the financial help of UNIDO in 1996. Built to operate in the radio frequency range of 85-115 GHz, it was intended for the acquisition of carbon monoxide data in the Milky Way. In 1997, the telescope became inoperable, and the Ukrainian technicians were unavailable for its reparature. After some unsuccessful attempts to fix the radio telescope at site, it was handed over in 2000 to Erciyes University, where its rehabilation was carried out between 2001-2002.

text: Observatory's first

text: radio telescope

text: was a

text: parabolic antenna

text: of  diameter, which was donated by the

text: Marmara Research Center

text: (MAM) of

entity_name: Scientific and Technological Research Council of Turkey

text: Scientific and Technological Research Council of Turkey

text: (TÜBİTAK). The radio telescope, then called MRT-2, was initially purchased from the Institute of Radio Astronomy in

text: Kharkiv

text: Ukraine

text: with the financial help of

entity_name: United Nations Industrial Development Organization

text: UNIDO

text: in 1996. Built to operate in the

text: radio frequency

text: range of 85-115

text: GHz

text: , it was intended for the acquisition of

text: carbon monoxide

text: data in the

text: Milky Way

text: . In 1997, the telescope became inoperable, and the Ukrainian technicians were unavailable for its reparature. After some unsuccessful attempts to fix the radio telescope at site, it was handed over in 2000 to Erciyes University, where its rehabilation was carried out between 2001-2002.

text: Ingalls's primary interests were in the areas of astronomy and telescope construction. After reading an article by Russell W. Porter on telescope making, he arranged a visit by Porter to New York in June 1925, out of which came an article later that year in Scientific American. The article was so well received that Ingalls began a series of columns on amateur telescope making, some written in collaboration with Porter. Ingalls and Porter became close friends and the two men remained at the center of the American amateur telescope making community for the next thirty years. A number of articles from the columns, together with illustrations by Porter, were published in book form as Amateur Telescope Making, the first volume of which appeared in 1926, followed by volumes 2 and 3 in 1937 and 1953.  These books helped to create lasting public interest in observational astronomy. The books have come to be called "the bible of telescope making".

text: Ingalls's primary interests were in the areas of astronomy and

text: telescope

text: construction. After reading an article by

text: Russell W. Porter

text: on telescope making, he arranged a visit by Porter to New York in June 1925, out of which came an article later that year in Scientific American. The article was so well received that Ingalls began a series of columns on amateur telescope making, some written in collaboration with Porter. Ingalls and Porter became close friends and the two men remained at the center of the American amateur telescope making community for the next thirty years. A number of articles from the columns, together with illustrations by Porter, were published in book form as Amateur Telescope Making, the first volume of which appeared in 1926, followed by volumes 2 and 3 in 1937 and 1953.  These books helped to create lasting public interest in observational astronomy. The books have come to be called "the bible of telescope making".

text: Eight years later the CAA got the chance to make observations from the Gerlitze. In 1997 the observatory was modernized and the old telescope was replaced by an Ritchey-Chrétien telescope. Today this telescope is also used for astrophotography.

text: Eight years later the CAA got the chance to make observations from the Gerlitze. In 1997 the observatory was modernized and the old telescope was replaced by an

text: Ritchey-Chrétien telescope

text: . Today this telescope is also used for

text: astrophotography

text: A changing electromagnetic field propagates away from its origin in the form of a wave. These waves travel in vacuum at the speed of light and exist in a wide spectrum of wavelengths. Examples of the dynamic fields of electromagnetic radiation (in order of increasing frequency): radio waves, microwaves, light (infrared, visible light  and ultraviolet), x-rays and gamma rays. In the field of particle physics this electromagnetic radiation is the manifestation of the electromagnetic interaction between charged particles.

text: A changing electromagnetic field propagates away from its origin in the form of a

text: wave

text: . These waves travel in vacuum at the

text: speed of light

text: and exist in a wide

text: spectrum

text: of

text: wavelength

text: s. Examples of the dynamic fields of

text: electromagnetic radiation

text: (in order of increasing frequency):

text: radio

text: waves,

text: microwave

text: s,

text: light

text: infrared

text: visible light

text: and

text: ultraviolet

text: x-ray

text: s and

text: gamma rays

text: . In the field of

text: particle physics

text: this electromagnetic radiation is the manifestation of the

text: electromagnetic interaction

text: between charged particles.

text: A modern-day example of this type of telescope is the 8 inch (~0.2m) Flagstaff Astrometric Scanning Transit Telescope (FASTT) at the USNO Flagstaff Station Observatory. Modern meridian circles are usually automated. The observer is replaced with a CCD camera. As the sky drifts across the field of view, the image built up in the CCD is clocked across (and out of) the chip at the same rate. This allows some improvements:

text: A modern-day example of this type of telescope is the 8 inch (~0.2m) Flagstaff Astrometric Scanning Transit Telescope (FASTT) at the

entity_name: United States Naval Observatory Flagstaff Station

text: USNO Flagstaff Station Observatory

text: . Modern meridian circles are usually automated. The observer is replaced with a

text: CCD

text: camera. As the sky drifts across the field of view, the image built up in the CCD is clocked across (and out of) the chip at the same rate. This allows some improvements:

text: However, if someone decides to look at the same situation outside of the frame— which rarely happens because people are always convinced that common sense does not require justification— that person will have a completely different understanding of what is in the frame, and feel that common sense no longer makes sense. Continuing the corset example, in our present time it is common sense that corsets are unhealthy and will do more harm than good to a female body. This is why the majority of people these days don’t wear corsets. And when we look back to the old frame from the 19th century, we think that fashion sense of that time is strange. This is the outcome of shifted frames.

text: After a short stint in a wood-cutting crew bringing in fuel for the coming winter, Ken is called to assist in the work at the college.  Along with his friends and the other scientists, he helps with experiments aimed at identifying the cause of the cold-welding phenomenon.  A spectroscopic look through a telescope, compared to spectrograms of the affected metals confirms that the comet is the source of the trouble.  At the same time Ken and his friends make contact with several ham radio operators around the country, intending to share information.

text: After a short stint in a wood-cutting crew bringing in fuel for the coming winter, Ken is called to assist in the work at the college.  Along with his friends and the other scientists, he helps with experiments aimed at identifying the cause of the cold-welding phenomenon.  A spectroscopic look through a telescope, compared to

text: spectrogram

text: s of the affected metals confirms that the comet is the source of the trouble.  At the same time Ken and his friends make contact with several ham radio operators around the country, intending to share information.

text: In 2007, the 20 cm full-disk telescope was replaced by the  Full Disk H-alpha (FDHA) Patrol Telescope, located in an additional small building called the Ash Dome.  It is co-mounted with another small telescope dedicated to observing earthshine.

text: In 2007, the 20 cm full-disk telescope was replaced by the  Full Disk H-alpha (FDHA) Patrol Telescope, located in an additional small building called the Ash Dome.  It is co-mounted with another small telescope dedicated to observing

text: earthshine

text: Astronomers observe objects in the infrared portion of the electromagnetic spectrum using optical components, including mirrors, lenses and solid state digital detectors. For this reason it is classified as part of optical astronomy. To form an image, the components of an infrared telescope need to be carefully shielded from heat sources, and the detectors are chilled using liquid helium.

text: Astronomers observe objects in the infrared portion of the electromagnetic spectrum using optical components, including mirrors, lenses and solid state digital detectors. For this reason it is classified as part of

text: optical astronomy

text: . To form an image, the components of an infrared telescope need to be carefully shielded from heat sources, and the detectors are chilled using liquid

text: helium

text: In 1963 Gascoigne published an article in the journal Nature titled "Towards a Southern Commonwealth Observatory".Gascoigne was then given a significant opportunity that became the focus of the remainder of his paid academic career: to help establish one of the world's largest optical telescopes, at Siding Spring. In the early 1960s, the Australian and British governments proposed a partnership to build a joint optical telescope facility, and Gascoigne was among the experts involved. Former Mount Stromlo director and now head of the Greenwich observatory, Richard Woolley, was prominent in supporting the project from the British end. In 1967, the two governments formally agreed to collaborate on the construction of a large telescope, to be known as the Anglo-Australian Telescope (AAT). Given the existing infrastructure of the ANU's Siding Spring Observatory, the site was readily agreed as the location for the AAT. Gascoigne was one of the four members of the Technical Committee established to guide the telescope's development. He provided leadership on the design and optics of the new telescope, and was made the chief commissioning astronomer in 1974.

text: In 1963 Gascoigne published an article in the journal Nature titled "Towards a Southern Commonwealth Observatory".Gascoigne was then given a significant opportunity that became the focus of the remainder of his paid academic career: to help establish one of the world's largest optical telescopes, at Siding Spring. In the early 1960s, the Australian and British governments proposed a partnership to build a joint optical telescope facility, and Gascoigne was among the experts involved. Former Mount Stromlo director and now head of the Greenwich observatory, Richard Woolley, was prominent in supporting the project from the British end. In 1967, the two governments formally agreed to collaborate on the construction of a large telescope, to be known as the

text: Anglo-Australian Telescope

text: (AAT). Given the existing infrastructure of the ANU's Siding Spring Observatory, the site was readily agreed as the location for the AAT. Gascoigne was one of the four members of the Technical Committee established to guide the telescope's development. He provided leadership on the design and optics of the new telescope, and was made the chief commissioning astronomer in 1974.

text: The RAPTOR system (Rapid Telescopes for Optical Response) is a specialized suite of telescopes designed to detect and track transient objects, including gamma-ray bursts and near-earth objects. RAPTOR was built by a Los Alamos team headed by astrophysicist Tom Vestrand. The system consists of six robotic observatories—RAPTOR-A, -S, -P, -K, and -T are located at Fenton Hill and RAPTOR-B is located at the Los Alamos Neutron Science Center,  away. The telescopes are all networked and controlled by a centralized computer system. The older RAPTOR telescopes, RAPTORs A,B,S and P each consist of a wide-field telescope and a narrow-field telescope. They are mounted on platforms that can swivel to any point in the sky in less than 3 seconds, making them the fastest moving telescopes ever built. Each wide-field telescope has a nominal field of view of 38 by 38 degrees, which equates to being able to cover the sky in eleven patches. Each telescope is actually two telescopes giving stereoscopic vision. There is a zoom mechanism built into each telescope as well. While in monitoring mode, RAPTOR takes two consecutive 30-second exposures through its two wide-field telescopes and analyzes the resulting digital images. If it sees an interesting event, RAPTOR zooms in for a closer look with the two narrow-field telescopes.

text: The RAPTOR system (Rapid Telescopes for Optical Response) is a specialized suite of telescopes designed to detect and track transient objects, including

text: gamma-ray burst

text: s and

text: near-earth object

text: s. RAPTOR was built by a Los Alamos team headed by astrophysicist Tom Vestrand. The system consists of six robotic observatories—RAPTOR-A, -S, -P, -K, and -T are located at Fenton Hill and RAPTOR-B is located at the

text: Los Alamos Neutron Science Center

text: ,  away. The telescopes are all networked and controlled by a centralized computer system. The older RAPTOR telescopes, RAPTORs A,B,S and P each consist of a wide-field telescope and a narrow-field telescope. They are mounted on platforms that can swivel to any point in the sky in less than 3 seconds, making them the fastest moving telescopes ever built. Each wide-field telescope has a nominal field of view of 38 by 38 degrees, which equates to being able to cover the sky in eleven patches. Each telescope is actually two telescopes giving stereoscopic vision. There is a zoom mechanism built into each telescope as well. While in monitoring mode, RAPTOR takes two consecutive 30-second exposures through its two wide-field telescopes and analyzes the resulting digital images. If it sees an interesting event, RAPTOR zooms in for a closer look with the two narrow-field telescopes.

text: Radio and submillimeter telescopes use much larger dishes or antennae, which do not have to be made as precisely as the mirrors used in optical telescopes. The Arecibo Observatory uses a 305 m dish, which is the world largest single-dish radio telescope fixed to the ground. The Green Bank Telescope has the world's largest steerable single radio dish with 100 m in diameter. There are largest radio arrays, composed of multiple dishes which have better image resolution but less sensitivity.

text: Radio and submillimeter telescopes use much larger dishes or antennae, which do not have to be made as precisely as the mirrors used in optical telescopes. The

text: Arecibo Observatory

text: uses a 305 m dish, which is the world largest single-dish radio telescope fixed to the ground. The

text: Green Bank Telescope

text: has the world's largest steerable single radio dish with 100 m in diameter. There are largest radio arrays, composed of multiple dishes which have better

text: image resolution

text: but less

text: sensitivity

text: The main instrument at each TCCON site is a Bruker IFS 125HR (HR for high resolution, ~0.02 cm) or occasionally 120HR Fourier transform spectrometer. Sunlight is directed into the spectrometer by solar tracking mirrors and other optics. The spectrometers measure the absorption of direct sunlight by atmospheric trace gases primarily in the near infrared region. This remote sensing technique produces a precise and accurate measurement of the total column abundance of the trace gas. The main limitation to this technique is that measurements can not be recorded when it is not sunny (i.e. there are no measurements available at nighttime or when there is heavy cloud cover).

text: The main instrument at each TCCON site is a

text: Bruker

text: IFS 125HR (HR for high resolution, ~0.02 cm) or occasionally 120HR

text: Fourier transform spectrometer

text: . Sunlight is directed into the spectrometer by solar tracking mirrors and other optics. The spectrometers measure the absorption of direct sunlight by atmospheric

text: trace gases

text: primarily in the near

text: infrared

text: region. This

text: remote sensing

text: technique produces a precise and accurate measurement of the

text: total column

text: abundance of the

text: trace gas

text: . The main limitation to this technique is that measurements can not be recorded when it is not sunny (i.e. there are no measurements available at nighttime or when there is heavy cloud cover).

text: In electromagnetics, an evanescent field, or  evanescent wave, is an oscillating electric and/or magnetic field which does not propagate as an electromagnetic wave but whose energy is spatially concentrated in the vicinity of the source (oscillating charges and currents). Even when there in fact is an electromagnetic wave produced (e.g., by a transmitting antenna) one can still identify as an evanescent field the component of the electric or magnetic field that cannot be attributed to the propagating wave observed at a distance of many wavelengths (such as the far field of a transmitting antenna).

text: In electromagnetics, an evanescent field, or  evanescent wave, is an oscillating electric and/or magnetic field which does not propagate as an

text: electromagnetic wave

text: but whose energy is spatially concentrated in the vicinity of the source (oscillating charges and currents). Even when there in fact is an electromagnetic wave produced (e.g., by a transmitting

text: antenna

text: ) one can still identify as an evanescent field the component of the electric or magnetic field that cannot be attributed to the propagating wave observed at a distance of many wavelengths (such as the

text: far field

text: of a transmitting antenna).

text: A 14/60 4-door 4-light saloon was road tested by The Times. Head clearance was described as moderate but it was felt there was good width and leg room for two persons in the back seat and the doorways gave "reasonable entrance". Interior fittings included three electric lights, 2-way visors, a sliding roof, three handy ashtrays, an instrument board with large dial clock and speedometer, a telescopic spring steering wheel, wholly automatic chassis lubrication, a jacking system and a windscreen which could be wound out to give a direct view.

text: Even though the nebula has a relatively bright integrated magnitude of 7, it is spread over so large an area that the surface brightness is quite low, so the nebula is notorious among astronomers as being difficult to see. However, an observer can see the nebula clearly in a telescope using an OIII filter (a filter isolating the wavelength of light from doubly ionized oxygen), as almost all light from this nebula is emitted at this wavelength. An  telescope equipped with an OIII filter shows the delicate lacework apparent in photographs, and with an OIII filter almost any telescope could conceivably see this nebula.  Some argue that it can be seen without any optical aid except an OIII filter held up to the eye.

text: Even though the nebula has a relatively bright integrated magnitude of 7, it is spread over so large an area that the surface brightness is quite low, so the nebula is notorious among astronomers as being difficult to see. However, an observer can see the nebula clearly in a telescope using an OIII filter (a filter isolating the

text: wavelength

text: of light from doubly

text: ionized

text: oxygen

text: ), as almost all light from this nebula is emitted at this wavelength. An  telescope equipped with an OIII filter shows the delicate lacework apparent in photographs, and with an OIII filter almost any telescope could conceivably see this nebula.  Some argue that it can be seen without any optical aid except an OIII filter held up to the eye.

text: Infrared energy is just one part of the electromagnetic spectrum, which encompasses radiation from gamma rays, x-rays, ultra violet, a thin region of visible light, infrared, terahertz waves, microwaves, and radio waves. These are all related and differentiated in the length of their wave (wavelength). All objects emit a certain amount of black body radiation as a function of their temperatures.

text: Infrared energy is just one part of the

text: electromagnetic spectrum

text: , which encompasses radiation from

text: gamma rays

text: x-rays

text: ultra violet

text: , a thin region of

text: visible light

text: infrared

text: terahertz waves

text: microwaves

text: , and

text: radio waves

text: . These are all related and differentiated in the length of their wave (wavelength). All objects emit a certain amount of

text: black body

text: radiation as a function of their

text: temperature

text: s.

text: The Dwingeloo Radio Observatory is a single-dish radio telescope near the village of Dwingeloo () in the northeastern Netherlands. Construction started in 1954, and the telescope was completed in 1956. The radio telescope has a diameter of 25 m and at the time of completion it was the largest radio telescope in the world.

text: The Dwingeloo Radio Observatory is a single-dish

text: radio telescope

text: near the village of

text: Dwingeloo

text: () in the northeastern

text: Netherlands

text: . Construction started in 1954, and the telescope was completed in 1956. The radio telescope has a diameter of 25 m and at the time of completion it was the largest radio telescope in the world.

text: Chronological list of optical telescopes by historical significance, which reflects the overall technological progression and not only the primary mirror's diameter (as shown in table above).

text: Chronological list of optical telescopes by historical significance, which reflects the overall technological progression and not only the primary mirror's diameter (as shown in

entity_name: List of largest optical telescopes historically

text: table above

text: The 2.2-metre telescope has been in operation at La Silla since early 1984, and is on indefinite loan to ESO from the Max Planck Society ( or MPG). Telescope time is shared between MPG and ESO observing programmes, while the operation and maintenance of the telescope are ESO's responsibility. However, due to a new agreement between the Max Planck Institute for Astronomy (MPIA) and ESO, the instrument is operated by MPG until the end of September 2016. The telescope hosts three instruments: the 67-million pixel Wide Field Imager with a field of view as large as the full Moon, which has taken many amazing images of celestial objects; GROND, the Gamma-Ray Burst Optical/Near-Infrared Detector, which chases the afterglows of the most powerful explosions in the Universe, known as gamma-ray bursts; and the high-resolution spectrograph, FEROS, used to make detailed studies of stars. MPG's 2.2-metre telescope in La Silla also has a twin brother located at the Calar Alto Observatory in southern Spain.

text: The 2.2-metre telescope has been in operation at La Silla since early 1984, and is on indefinite loan to ESO from the

text: Max Planck Society

text: ( or MPG). Telescope time is shared between MPG and ESO observing programmes, while the operation and maintenance of the telescope are ESO's responsibility. However, due to a new agreement between the

text: Max Planck Institute for Astronomy

text: (MPIA) and ESO, the instrument is operated by MPG until the end of September 2016. The telescope hosts three instruments: the 67-million pixel Wide Field Imager with a field of view as large as the full Moon, which has taken many amazing images of celestial objects; GROND, the Gamma-Ray Burst Optical/Near-Infrared Detector, which chases the afterglows of the most powerful explosions in the Universe, known as gamma-ray bursts; and the high-resolution spectrograph, FEROS, used to make detailed studies of stars. MPG's 2.2-metre telescope in La Silla also has a twin brother located at the

text: Calar Alto Observatory

text: in southern Spain.

text: Direct detection of gravitational waves has long been sought. Their discovery would launch a new branch of astronomy to complement electromagnetic telescopes and neutrino observatories. Joseph Weber pioneered the effort to detect gravitational waves in the 1960s through his work on resonant mass bar detectors. Bar detectors continue to be used at six sites worldwide. By the 1970s, scientists including Rainer Weiss realized the applicability of laser interferometry to gravitational wave measurements. Robert Forward operated an interferometric detector at Hughes in the early 1970s.

text: Direct detection of gravitational waves has long been sought. Their discovery would launch a new branch of astronomy to complement

text: electromagnetic

text: telescopes and

text: neutrino

text: observatories.

text: Joseph Weber

text: pioneered the effort to detect gravitational waves in the 1960s through his work on

text: resonant mass bar detectors

text: . Bar detectors continue to be used at six sites worldwide. By the 1970s, scientists including

text: Rainer Weiss

text: realized the applicability of laser

text: interferometry

text: to gravitational wave measurements.

text: Robert Forward

text: operated an interferometric detector at Hughes in the early 1970s.

text: During the 1840s, he had the Leviathan of Parsonstown built, a 72-inch  (6 feet/1.83 m) telescope at Birr Castle, Parsonstown, County Offaly.  The  telescope replaced a  telescope that he had built previously.He had to invent many of the techniques he used for constructing the Leviathan, both because its size was without precedent and because earlier telescope builders had guarded their secrets or had simply failed to publish their methods. Details of the metal, casting, grinding and polishing of the 3-ton 'speculum' were presented in 1844 at the Belfast Natural History Society. Rosse's telescope was considered a marvellous technical and architectural achievement, and images of it were circulated widely within the British commonwealth. Building of the Leviathan began in 1842 and it was first used in 1845; regular use waited another two years, due to the Great Irish Famine. It was the world's largest telescope, in terms of aperture size, until the early 20th century. Using this telescope Rosse saw and catalogued a large number of nebulae (including a number that would later be recognised as galaxies).

text: During the 1840s, he had the

text: Leviathan of Parsonstown

text: built, a 72-inch  (6 feet/1.83 m) telescope at

text: Birr Castle

text: Parsonstown

text: , County Offaly.  The  telescope replaced a  telescope that he had built previously.He had to invent many of the techniques he used for constructing the Leviathan, both because its size was without precedent and because earlier telescope builders had guarded their secrets or had simply failed to publish their methods. Details of the metal, casting, grinding and polishing of the 3-ton 'speculum' were presented in 1844 at the

text: Belfast Natural History Society

text: . Rosse's telescope was considered a marvellous technical and architectural achievement, and images of it were circulated widely within the British commonwealth. Building of the Leviathan began in 1842 and it was first used in 1845; regular use waited another two years, due to the

text: Great Irish Famine

text: . It was the world's largest telescope, in terms of aperture size, until the early 20th century. Using this telescope Rosse saw and catalogued a large number of nebulae (including a number that would later be recognised as galaxies).

text: At the location of the correlator the data are played back. The timing of the playback is adjusted according to the atomic clock signals on the (tapes/disk drives/fibre optic signal), and the estimated times of arrival of the radio signal at each of the telescopes. A range of playback timings over a range of nanoseconds are usually tested until the correct timing is found.

text: Mr. Woodruff has over 45 years experience designing optical systems for United States space program missions. He has made significant contributions to projects ranging from Skylab, Nimbus, Apollo-Soyuz, Galileo, SIRTF/Spitzer, microgravity science, the Hubble Space Telescope (HST), and Next Generation Space Telescope (NGST), Terrestrial Planet Finder (TPF), Beyond Einstein, Exo-planet detection, Kepler, as well as others. He has wide and varied experience in the definition of optical space-borne telescopes and instruments. His technical specialties are optical physic, optics design, and optical system engineering. He has served in various technical roles in optical design, system engineering, system test, and system calibration in the development of more than 20 flight hardware instruments, so one or more of his designs have been operational in space continuously for nearly 40 years. Among his accomplishments, two activities standout: 1) He helped fix the Hubble Space Telescope spherical aberration flaw and 2) He conceived and generated the optical concept and design for the Kepler mission. He is the author or co-author of well over 25 published or presented papers. He is also an Associate of Center for Astrophysics and Space Astronomy (CASA) of the University of Colorado in Boulder, CO. Recently he retired from Lockheed Martin as a Technical Fellow in the position of Chief Scientist for Optical Systems.

text: Another difficulty is that a liquid metal mirror can only be used in zenith telescopes, i.e., that look straight up, so it is not suitable for investigations where the telescope must remain pointing at the same location of inertial space (a possible exception to this rule may exist for a mercury mirror space telescope, where the effect of Earth's gravity is replaced by artificial gravity, perhaps by rotating the telescope on a very long tether, or propelling it gently forward with rockets). Only a telescope located at the North Pole or South Pole would offer a relatively static view of the sky, although the freezing point of mercury and the remoteness of the location would need to be considered. A very large telescope already exists at the South Pole, but the North Pole is located in the Arctic Ocean.

text: Another difficulty is that a liquid metal mirror can only be used in

text: zenith telescope

text: s, i.e., that look straight

text: up

text: , so it is not suitable for investigations where the telescope must remain pointing at the same location of

text: inertial space

text: (a possible exception to this rule may exist for a

text: mercury mirror space telescope

text: , where the effect of Earth's gravity is replaced by

text: artificial gravity

text: , perhaps by rotating the telescope on a very long tether, or propelling it gently forward with rockets). Only a telescope located at the

text: North Pole

text: or

text: South Pole

text: would offer a relatively static view of the sky, although the freezing point of mercury and the

text: remoteness

text: of the location would need to be considered. A

text: very large telescope

text: already exists at the South Pole, but the North Pole is located in the Arctic Ocean.

text: Closer to the visible range of the electromagnetic spectrum is the ultraviolet. The draft ISO standard on determining solar irradiances (ISO-DIS-21348) describes the ultraviolet as ranging from ~10 nm to ~400 nm. That portion closest to X-rays is often referred to as the "extreme ultraviolet" (EUV or XUV). When an EUV photon is absorbed, photoelectrons and secondary electrons are generated by ionization, much like what happens when X-rays or electron beams are absorbed by matter.

text: Closer to the visible range of the electromagnetic spectrum is the

text: ultraviolet

text: . The draft ISO standard on determining solar

text: irradiance

text: s (ISO-DIS-21348) describes the ultraviolet as ranging from ~10 nm to ~400 nm. That portion closest to X-rays is often referred to as the "extreme ultraviolet" (

text: EUV

text: or XUV). When an EUV photon is absorbed,

text: photoelectrons

text: and

text: secondary electrons

text: are generated by

text: ionization

text: , much like what happens when X-rays or electron beams are absorbed by matter.

text: A Ritchey–Chrétien telescope (RCT or simply RC) is a specialized variant of the Cassegrain telescope that has a hyperbolic primary mirror and a hyperbolic secondary mirror designed to eliminate off-axis optical errors (coma). The RCT has a wider field of view free of optical errors compared to a more traditional reflecting telescope configuration. Since the mid 20th century, a majority of large professional research telescopes have been Ritchey–Chrétien configurations; some well-known examples are the Hubble Space Telescope, the Keck telescopes and the ESO Very Large Telescope.

text: A Ritchey–Chrétien telescope (RCT or simply RC) is a specialized variant of the

text: Cassegrain telescope

text: that has a

text: hyperbolic

text: primary mirror

text: and a hyperbolic

text: secondary mirror

text: designed to eliminate off-axis optical errors (

text: coma

text: ). The RCT has a wider field of view free of optical errors compared to a more traditional

text: reflecting telescope

text: configuration. Since the mid 20th century, a majority of large professional research telescopes have been Ritchey–Chrétien configurations; some well-known examples are the

text: Hubble Space Telescope

text: , the

text: Keck telescopes

text: and the ESO

text: Very Large Telescope

text: A green rim is present in every sunset, but it is too thin to be seen with a naked eye.The best time to observe the green rim is about 10 minutes before sunset time. However the solar disc is too bright at that time to use magnification such as binoculars or telescopes to look directly at the Sun. Of course a telescope or binoculars image can be projected on a sheet of paper for viewing. When the Sun gets closer to the horizon, the green rim gets fainter because  of atmospheric reddening.Although a green rim is present in every sunset, and a green flash is rare because it requires a mirage to be present, it is actually more common for people to have seen a green flash than the green rim.

text: A green rim is present in every sunset, but it is too thin to be seen with a naked

text: eye

text: .The best time to observe the green rim is about 10 minutes before sunset time. However the solar disc is too bright at that time to use

text: magnification

text: such as

text: binoculars

text: or

text: telescope

text: s to look directly at the Sun. Of course a telescope or binoculars image can be projected on a sheet of paper for viewing. When the Sun gets closer to the horizon, the green rim gets fainter because  of atmospheric reddening.Although a green rim is present in every sunset, and a green flash is rare because it requires a mirage to be present, it is actually more common for people to have seen a green flash than the green rim.

text: ASU is also involved with NASA in the field of space exploration. In order to meet the needs of NASA programs, ASU built the LEED Gold Certified, 298,000-square-foot Interdisciplinary Science and Technology Building IV (ISTB 4) at a cost of $110 million in 2012. The building includes space for the School of Earth and Space Exploration (SESE) and includes labs and other facilities for the Ira A. Fulton Schools of Engineering. One of the main projects at ISTB 4 includes the OSIRIS-REx Thermal Emission Spectrometer (OTES). Although ASU built the spectrometers aboard the Martian rovers Spirit and Opportunity, OTES will be the first major scientific instrument completely designed and built at ASU for a NASA space mission. Phil Christensen, the principal investigator for the Mars Global Surveyor Thermal Emission Spectrometer (TES), is a Regents' Professor at ASU. He also serves as the principal investigator for the Mars Odyssey THEMIS instruments, as well as co-investigator for the Mars Exploration Rovers. ASU scientists are responsible for the Mini-TES instruments aboard the Mars Exploration Rovers. The Center for Meteorite Studies, which is home to rare Martian meteorites and exotic fragments from space, and the Mars Space Flight Facility are both located on ASU's Tempe campus.

text: ASU is also involved with

text: NASA

text: in the field of

text: space exploration

text: . In order to meet the needs of NASA programs, ASU built the

entity_name: Leadership in Energy and Environmental Design

text: LEED

text: Gold Certified, 298,000-square-foot Interdisciplinary Science and Technology Building IV (ISTB 4) at a cost of $110 million in 2012. The building includes space for the School of Earth and Space Exploration (SESE) and includes labs and other facilities for the

text: Ira A. Fulton Schools of Engineering

text: . One of the main projects at ISTB 4 includes the

text: OSIRIS-REx

text: Thermal Emission Spectrometer

text: (OTES). Although ASU built the

text: spectrometers

text: aboard the

text: Martian rovers

text: Spirit

text: and

text: Opportunity

text: , OTES will be the first major scientific instrument completely designed and built at ASU for a NASA

text: space mission

text: Phil Christensen

text: , the

text: principal investigator

text: for the

text: Mars Global Surveyor

text: Thermal Emission Spectrometer

text: (TES), is a

text: Regents' Professor

text: at ASU. He also serves as the principal investigator for the

text: Mars Odyssey

text: THEMIS

text: instruments, as well as co-investigator for the

text: Mars Exploration Rover

text: s. ASU scientists are responsible for the

text: Mini-TES

text: instruments aboard the Mars Exploration Rovers. The

text: Center for Meteorite Studies

text: , which is home to rare

text: Martian

text: meteorite

text: s and exotic fragments from space, and the

text: Mars Space Flight Facility

text: are both located on ASU's Tempe campus.

text: The Space Telescope Science Data Analysis System (STSDAS) is an IRAF-based suite of astronomical software for reducing and analyzing astronomical data.  It contains general purpose tools and packages for processing data from the Hubble Space Telescope. STSDAS is produced by Space Telescope Science Institute (STScI).  The STSDAS software is in the public domain and the source code is available.

text: The Space Telescope Science Data Analysis System (STSDAS) is an

text: IRAF

text: -based suite of astronomical software for reducing and analyzing astronomical data.  It contains general purpose tools and packages for processing data from the

text: Hubble Space Telescope

text: . STSDAS is produced by

text: Space Telescope Science Institute

text: (STScI).  The STSDAS software is in the public domain and the source code is available.

text: GOTO telescopes have become more popular since the 1980s as technology has improved and prices have been reduced.  With these computer-driven telescopes, the user typically enters the name of the item of interest and the mechanics of the telescope point the telescope towards that item automatically.  They have several notable advantages for amateur astronomers intent on research.  For example, GOTO telescopes tend to be faster for locating items of interest than star hopping, allowing more time for studying of the object.  GOTO also allows manufacturers to add equatorial tracking to mechanically simpler alt-azimuth telescope mounts, allowing them to produce an overall less expensive product. GOTO telescopes usually have to be calibrated using alignment stars in order to provide accurate tracking and positioning. However, several telescope manufacturers have recently developed telescope systems that are calibrated with the use of built-in GPS, decreasing the time it takes to set up a telescope at the start of an observing session.

text: GOTO telescopes have become more popular since the 1980s as technology has improved and prices have been reduced.  With these computer-driven telescopes, the user typically enters the name of the item of interest and the mechanics of the telescope point the telescope towards that item automatically.  They have several notable advantages for amateur astronomers intent on

text: research

text: .  For example, GOTO telescopes tend to be faster for locating items of interest than star hopping, allowing more time for studying of the object.  GOTO also allows manufacturers to add equatorial tracking to mechanically simpler alt-azimuth telescope mounts, allowing them to produce an overall less expensive product. GOTO telescopes usually have to be calibrated using alignment stars in order to provide accurate tracking and positioning. However, several telescope manufacturers have recently developed telescope systems that are calibrated with the use of built-in GPS, decreasing the time it takes to set up a telescope at the start of an observing session.

text: Each Keck Observatory telescope sits on an altazimuth mount. Most current 8–10 m class telescopes use altazimuth designs due to the reduced structural requirements compared to older equatorial designs. This mounting style provides the greatest strength and stiffness for the least amount of steel, which, for Keck Observatory, totals about 270 tons per telescope. The total weight of each telescope is more than 300 tons. Two of the proposed designs for the next generation 30 and 40 m telescopes use the same basic technology pioneered at Keck Observatory, a hexagonal mirror array coupled with an altazimuth mounting.

text: Each Keck Observatory telescope sits on an

text: altazimuth

text: mount. Most current 8–10 m class telescopes use altazimuth designs due to the reduced structural requirements compared to older

text: equatorial designs

text: . This mounting style provides the greatest strength and stiffness for the least amount of steel, which, for Keck Observatory, totals about 270 tons per telescope. The total weight of each telescope is more than 300 tons. Two of the

text: proposed designs

text: for the next generation 30 and 40 m telescopes use the same basic technology pioneered at Keck Observatory, a hexagonal mirror array coupled with an altazimuth mounting.

text: The telescope was designed from the start to be operated in real time, rather than by remote control. This required that it would be launched into a geosynchronous orbit – that is, one with a period equal to one sidereal day of 23h 56m. A satellite in such an orbit remains visible from a given point on the Earth's surface for many hours at a time, and can thus transmit to a single ground station for a long period of time. Most space observatories in Earth orbit, such as the Hubble Space Telescope, are in a low orbit in which they spend most of their time operating autonomously because only a small fraction of the Earth's surface can see them at a given time. Hubble, for example, orbits the Earth at an altitude of approximately 600 km, while a geosynchronous orbit has an average altitude of 36,000 km.

text: The telescope was designed from the start to be operated in real time, rather than by remote control. This required that it would be launched into a

text: geosynchronous orbit

text: – that is, one with a period equal to one

text: sidereal day

text: of 23h 56m. A satellite in such an orbit remains visible from a given point on the Earth's surface for many hours at a time, and can thus transmit to a single ground station for a long period of time. Most space observatories in Earth orbit, such as the

text: Hubble Space Telescope

text: , are in a low orbit in which they spend most of their time operating autonomously because only a small fraction of the Earth's surface can see them at a given time. Hubble, for example, orbits the Earth at an altitude of approximately 600 km, while a geosynchronous orbit has an average altitude of 36,000 km.

text: Newton's second telescope was made in 1671; it had a mirror of 2 inches diameter and a focal length of between 6.25" and 6.3".  He made two mirrors and chose the best one for the telescope.  He did not keep this telescope long, but presented it to the Royal Society for examination.  An account of this telescope just after its presentation in December 1671 described it as being about 7 inches long and about 2.25 inches in diameter.  The image was viewed through a hole in the side of the tube "about the size of a great pins head".  The tube was one piece and the mirror was moved up from the bottom in order to focus it. It was mounted on a ball and socket mount. This second telescope stayed with the society and by 1731 it had disintegrated to the point of only the two metal mirrors remaining.  It then subsequently disappeared.  It is certain that this is not the telescope that the Royal Society now hold in their possession as this mirror contained silver and the third telescope mirror contains no silver but has the addition of arsenic. This was something which Newton proposed as an improvement on his second telescope mirror as he found that the metal was too soft due to the silver.

text: Hubble is the only telescope designed to be serviced in space by astronauts.  After launch by  in 1990, four subsequent Space Shuttle missions repaired, upgraded, and replaced systems on the telescope, including all five of the main instruments.  A fifth mission was canceled on safety grounds following the Columbia disaster (2003). However, after spirited public discussion, NASA administrator Mike Griffin approved one final servicing mission, completed in 2009. The telescope is operating , and could last until 2030–2040. Its scientific successor, the James Webb Space Telescope (JWST), is scheduled for launch in 2018.

text: Hubble is the only telescope designed to be serviced in space by astronauts.  After launch by  in 1990, four subsequent Space Shuttle missions repaired, upgraded, and replaced systems on the telescope, including all five of the main instruments.  A fifth mission was canceled on safety grounds following the

text: Columbia disaster

text: (2003). However, after spirited public discussion, NASA administrator

text: Mike Griffin

text: approved

text: one final servicing mission

text: , completed in 2009. The telescope is operating , and could last until 2030–2040. Its scientific successor, the

text: James Webb Space Telescope

text: (JWST), is scheduled for launch in 2018.

text: The region of the spectrum where a particular observed electromagnetic radiation falls, is reference frame-dependent (due to the Doppler shift for light), so EM radiation that one observer would say is in one region of the spectrum could appear to an observer moving at a substantial fraction of the speed of light with respect to the first to be in another part of the spectrum. For example, consider the cosmic microwave background. It was produced, when matter and radiation decoupled, by the de-excitation of hydrogen atoms to the ground state. These photons were from Lyman series transitions, putting them in the ultraviolet (UV) part of the electromagnetic spectrum. Now this radiation has undergone enough cosmological red shift to put it into the microwave region of the spectrum for observers moving slowly (compared to the speed of light) with respect to the cosmos.

text: The region of the spectrum where a particular observed electromagnetic radiation falls, is

text: reference frame

text: -dependent (due to the

text: Doppler shift

text: for light), so EM radiation that one observer would say is in one region of the spectrum could appear to an observer moving at a substantial fraction of the speed of light with respect to the first to be in another part of the spectrum. For example, consider the

text: cosmic microwave background

text: . It was produced, when matter and radiation decoupled, by the de-excitation of hydrogen atoms to the ground state. These photons were from

text: Lyman series

text: transitions, putting them in the ultraviolet (UV) part of the electromagnetic spectrum. Now this radiation has undergone enough cosmological

text: red shift

text: to put it into the microwave region of the spectrum for observers moving slowly (compared to the speed of light) with respect to the cosmos.

text: Evans took up supernova hunting around 1955, but his first adequate instrument was a 10-inch (25 cm) Newtonian telescope he had assembled only about 1968. He made his first official supernova discovery in 1981 and found nine more before using larger telescopes. While living in Coonabarabran, New South Wales he used his own 16 inch (40 cm) telescope. From early 1995 to mid-1997 he also had limited access to the Siding Spring  Telescope at Siding Spring Observatory (he was allocated about 110 nights, half of which were suitable for observing), resulting in about 10,000 galaxy observations, another three visual supernovae discoveries, and an additional four supernovae spotted on photographs made at the observatory.

text: Evans took up supernova hunting around 1955, but his first adequate instrument was a 10-inch (25 cm)

text: Newtonian telescope

text: he had assembled only about 1968. He made his first official supernova discovery in 1981 and found nine more before using larger telescopes. While living in

text: Coonabarabran, New South Wales

text: he used his own 16 inch (40 cm) telescope. From early 1995 to mid-1997 he also had limited access to the

text: Siding Spring  Telescope

text: at

text: Siding Spring Observatory

text: (he was allocated about 110 nights, half of which were suitable for observing), resulting in about 10,000 galaxy observations, another three visual supernovae discoveries, and an additional four supernovae spotted on photographs made at the observatory.

text: The Catalina Real-Time Transient Survey is a collaboration using three telescopes looking for optical transients.  The same telescopes are used as in the Catalina Sky Survey. They are Mt. Lemmon Survey, Catalina Sky Survey, and Siding Spring Survey.  When transients are detected they are alerted on a short time scale so that others can observe the event as well using  VOEventNet and SkyAlert.  It has detected supernovae, cataclysmic variables, blazars, active galactic nuclei and flares.

text: The Catalina Real-Time Transient Survey is a collaboration using three telescopes looking for

text: optical transient

text: s.  The same telescopes are used as in the

text: Catalina Sky Survey

text: . They are

text: Mt. Lemmon Survey

text: Catalina Sky Survey

text: , and

text: Siding Spring Survey

text: .  When transients are detected they are alerted on a short time scale so that others can observe the event as well using  VOEventNet and

text: SkyAlert

text: .  It has detected

text: supernova

text: e,

text: cataclysmic variable

text: s,

text: blazar

text: s,

text: active galactic nuclei

text: and

text: flares

text: The song is a nostalgic song recalling a former love that the narrator had in the summertime. John Osborne said, "It’s about looking back on a time in your life, regardless of how a previous relationship went. Whatever went wrong seemed to drift away and you only remember the glow of it, and the beauty of it and the importance of it."

text: COAST, the Cambridge Optical Aperture Synthesis Telescope, is a multi-element optical astronomical interferometer with baselines of up to 100 metres, which uses aperture synthesis to observe stars with angular resolution as high as one thousandth of one arcsecond (producing images with much higher resolution than can be obtained using individual telescopes such as the Hubble Space Telescope). The principal limitation is that COAST can only image bright stars. COAST was the first long-baseline interferometer to obtain high-resolution images of the surfaces of stars other than our sun (although the surfaces of other stars had previously been imaged at lower resolution using Aperture Masking Interferometry on the William Herschel Telescope).

text: COAST, the Cambridge Optical Aperture Synthesis Telescope, is a multi-element optical

text: astronomical interferometer

text: with baselines of up to 100 metres, which uses

text: aperture synthesis

text: to observe stars with

text: angular resolution

text: as high as one thousandth of one

text: arcsecond

text: (producing images with much higher resolution than can be obtained using individual telescopes such as the

text: Hubble Space Telescope

text: ). The principal limitation is that COAST can only image bright

text: star

text: s. COAST was the first long-baseline interferometer to obtain high-resolution images of the surfaces of stars other than our sun (although the surfaces of other stars had previously been imaged at lower resolution using

text: Aperture Masking Interferometry

text: on the

text: William Herschel Telescope

text: Since 1990 – artistic director of the creative association Contact (Gorky Film Studio). One of the founders and artistic director of the studio Starlight  (Russia, Sweden, the United Kingdom, Denmark). President of the  Starlight-fest  – International Children's Film Festival in Artek (1992–1996). One of the founders of the Festival of Visual Arts at the Russian Children's Center  Eaglet  (1997–2006).

text: The Nasmyth telescope, also called Nasmyth–Cassegrain or Cassegrain–Nasmyth, is a reflecting telescope developed by James Nasmyth. It is a modified form of a Cassegrain telescope, with light reflected sideways before reaching the primary mirror again.

text: The Nasmyth telescope, also called Nasmyth–Cassegrain or Cassegrain–Nasmyth, is a

text: reflecting telescope

text: developed by

text: James Nasmyth

text: . It is a modified form of a

text: Cassegrain telescope

text: , with light reflected sideways before reaching the primary mirror again.

text: We can compare this with "real" answers from exposure time calculators. For an 8 m unit Very Large Telescope telescope, according to the FORS exposure time calculator you need 40 hours of observing time to reach V = 28, while the 2.4 m Hubble only takes 4 hours according to the ACS exposure time calculator. A hypothetical 8 m Hubble telescope would take about 30 minutes.

text: We can compare this with "real" answers from exposure time calculators. For an 8 m unit

text: Very Large Telescope

text: telescope, according to the FORS exposure time calculator you need 40 hours of observing time to reach V = 28, while the 2.4 m Hubble only takes 4 hours according to the ACS exposure time calculator. A hypothetical 8 m Hubble telescope would take about 30 minutes.

text: The OTFC processing system was developed at the Canadian Astronomy Data Centre (CADC) and the Space Telescope European Coordinating Facility  (ST-ECF) and is implemented at both sites and at Space Telescope Science Institute (STScI). The OTFC system currently provides data calibration for the Wide Field and Planetary Camera 2 (WFPC2) and Space Telescope Imaging Spectrograph (STIS). In the future, the Advanced Camera for Surveys (ACS) and possibly the Near Infrared Camera and Multi-Object Spectrometer (NICMOS) will be supported.

text: The OTFC processing system was developed at the Canadian Astronomy Data Centre (CADC) and the

entity_name: Space Telescope European Coordinating Facility

text: Space Telescope European Coordinating Facility

text: (ST-ECF) and is implemented at both sites and at

text: Space Telescope Science Institute

text: (STScI). The OTFC system currently provides data calibration for the

text: Wide Field and Planetary Camera 2

text: (WFPC2) and

text: Space Telescope Imaging Spectrograph

text: (STIS). In the future, the

text: Advanced Camera for Surveys

text: (ACS) and possibly the

entity_name: Near Infrared Camera and Multi-Object Spectrometer

text: Near Infrared Camera and Multi-Object Spectrometer

text: (NICMOS) will be supported.

text: At , the DCT is the fifth largest optical telescope in the continental United States, following  the Hobby-Eberly Telescope  segmented telescope,  the Large Binocular Telescope twin  telescopes, the MMT  telescope, and the Hale  telescope.

text: At , the DCT is the fifth largest optical

text: telescope

text: in the

text: continental United States

text: , following  the

text: Hobby-Eberly Telescope

text: segmented telescope,  the

text: Large Binocular Telescope

text: twin  telescopes, the

text: MMT

text: telescope, and the

text: Hale

text: telescope.

text: Spektr-R's tracking was to be handled by the RT-22 radio telescope in Pushchino, Russia. Flight control would be operated by ground stations in Medvezhi Ozera, near Moscow, and Ussuriysk in Russia’s Far East. Other Spektr-R joint observations would be handled by ground telescopes in Arecibo, Badary, Effelsberg, Green Bank, Medicina, Noto, Svetloe, and Zelenchukskaya.

text: Spektr-R's tracking was to be handled by the RT-22

text: radio telescope

text: in

text: Pushchino

text: , Russia. Flight control would be operated by ground stations in Medvezhi Ozera, near

text: Moscow

text: , and Ussuriysk in Russia’s Far East. Other Spektr-R joint observations would be handled by ground telescopes in Arecibo, Badary, Effelsberg, Green Bank, Medicina, Noto, Svetloe, and Zelenchukskaya.

text: Xuntian is a planned Chinese space telescope currently in the designing stages. It is to feature a 2-meter diameter primary mirror and is expected to have a field of view 300 times larger than the Hubble Space Telescope. The launch of the telescope is planned for around 2022 and its orbit is planned to be near the upcoming Chinese large modular space station.

text: Xuntian is a planned Chinese

text: space telescope

text: currently in the designing stages. It is to feature a 2-meter diameter

text: primary mirror

text: and is expected to have a field of view 300 times larger than the

text: Hubble Space Telescope

text: . The launch of the telescope is planned for around 2022 and its orbit is planned to be near the upcoming

text: Chinese large modular space station

text: of the electromagnetic four-potential.  This shows a formal similarity between gravitational waves and electromagnetic waves, with the Lanczos tensor well-suited for studying gravitational waves.

text: of the electromagnetic four-potential.  This shows a formal similarity between

text: gravitational wave

text: s and

text: electromagnetic wave

text: s, with the Lanczos tensor well-suited for studying gravitational waves.

text: In MASINT, the active signal source can be anywhere in the electromagnetic spectrum, from radio waves to X-rays, limited only by the propagation of the signal from the source. X-ray sources, for example, must be in very close proximity to the target, while lasers can illuminate a target from a high satellite orbit. While this discussion has emphasized the electromagnetic spectrum, there are also both active (e.g., sonar) and passive (e.g., hydrophone and microbarograph) acoustic sensors.

text: In MASINT, the active signal source can be anywhere in the electromagnetic spectrum, from radio waves to X-rays, limited only by the propagation of the signal from the source. X-ray sources, for example, must be in very close proximity to the target, while lasers can illuminate a target from a high satellite orbit. While this discussion has emphasized the electromagnetic spectrum, there are also both active (e.g., sonar) and passive (e.g.,

text: hydrophone

text: and

text: microbarograph

text: ) acoustic sensors.

text: The ABS telescope images the sky at a frequency of 145 GHz (2 mm wavelength), in the microwave region of the electromagnetic spectrum, where the CMB emission is at its maximum. It is sensitive to both the intensity and polarization of the CMB. The CMB is expected to be weakly polarized, and the ABS instrument is designed to measure this very faint signal. The camera consists of 240 polarization-sensitive pixels, with two transition-edge-sensor (TES) bolometers per pixel. This TES array is cooled to a temperature of 0.3 Kelvin to reduce thermal noise in the detectors. The optics consist of two 60-cm mirrors that are kept at a temperature of 4 K.

text: The ABS telescope images the sky at a frequency of 145 GHz (2 mm wavelength), in the

text: microwave

text: region of the

text: electromagnetic spectrum

text: , where the CMB emission is at its maximum. It is sensitive to both the intensity and polarization of the CMB. The CMB is expected to be weakly polarized, and the ABS instrument is designed to measure this very faint signal. The camera consists of 240 polarization-sensitive pixels, with two

text: transition-edge-sensor

text: (TES) bolometers per pixel. This TES array is cooled to a temperature of 0.3

text: Kelvin

text: to reduce thermal noise in the detectors. The optics consist of two 60-cm mirrors that are kept at a temperature of 4 K.

text: On January 6, 2011, the 10m Keck-I telescope equipped with the Low Resolution Imaging Spectrometer (LRIS) conducted spectroscopic measurements of the host galaxy of GRB 101225A. A 900s spectrum was obtained; it consisted of blue and red channels, covering the wavelength ranges ~320–550 nm and ~500–820 nm, respectively. Isotropic energy was estimated at (7.8 ± 1.6) erg from the Burst Alert Telescope (BAT) data.

text: On January 6, 2011, the 10m

text: Keck-I telescope

text: equipped with the

text: Low Resolution Imaging Spectrometer

text: (LRIS) conducted

text: spectroscopic

text: measurements of the host galaxy of GRB 101225A. A 900s spectrum was obtained; it consisted of blue and red channels, covering the wavelength ranges ~320–550 nm and ~500–820 nm, respectively. Isotropic energy was estimated at (7.8 ± 1.6) erg from the

text: Burst Alert Telescope

text: (BAT) data.

text: There are many amateur astronomical techniques and activities associated with deep-sky objects. Some of these objects are bright enough to find and see in binoculars and small telescopes. But the faintest objects need the light-gathering power of telescopes with large objectives, and since they are invisible to the naked eye, can be hard to find. This has led to increased popularity in GoTo telescopes that can find DSOs automatically, and large reflecting telescopes, such as Dobsonian style telescopes, with wide fields of view well suited for such observing. Observing faint objects needs dark skies, so these relatively portable types of telescopes also lend themselves to the majority of amateurs who need to travel outside light polluted urban locations. To cut down light pollution and enhance contrast observers employ "nebular filters" designed to admit certain wavelength and block others.

text: There are many amateur astronomical techniques and activities associated with deep-sky objects. Some of these objects are bright enough to find and see in binoculars and small telescopes. But the faintest objects need the

text: light-gathering power

text: of telescopes with large

text: objectives

text: , and since they are invisible to the naked eye, can be hard to find. This has led to increased popularity in

text: GoTo telescopes

text: that can find DSOs automatically, and large

text: reflecting telescope

text: s, such as

text: Dobsonian

text: style telescopes, with wide fields of view well suited for such observing. Observing faint objects needs dark skies, so these relatively portable types of telescopes also lend themselves to the majority of amateurs who need to travel outside

text: light polluted

text: urban locations. To cut down light pollution and enhance contrast observers employ "

text: nebular filters

text: " designed to admit certain wavelength and block others.

text: The scientific instruments consisted of an ion chamber and Geiger-Müller tube to measure total radiation flux, a proportional radiation counter telescope to measure high energy radiation, a scintillation counter to monitor low-energy radiation, a scintillation spectrometer to study the Earth's (and possible lunar) radiation belts, a VLF receiver for natural radio waves, a transponder to study electron density, and part of the flux-gate and search coil magnetometers mounted on the instrument platform. A plasma probe was mounted on the sphere to measure energy and momentum distribution of protons above a few kilovolts to study the radiation effect of solar flares. The micrometeorite detector and sun scanner were mounted on the sphere as well. The only difference between Pioneer P-31 and the earlier Pioneer P-30 was the addition of a solid state detector sensitive to low energy protons on the satellite and an STL-designed rubidium frequency standard experiment placed on a pod attached to the booster. The total mass of the science package including electronics and power supply was roughly 60 kg. Total cost of the mission was estimated at 9 - 10 million dollars.

text: The scientific instruments consisted of an

text: ion chamber

text: and

text: Geiger-Müller tube

text: to measure total

text: radiation flux

text: , a proportional radiation counter telescope to measure high energy radiation, a scintillation counter to monitor low-energy radiation, a

text: scintillation spectrometer

text: to study the Earth's (and possible lunar)

text: radiation belt

text: s, a VLF receiver for natural

text: radio wave

text: s, a transponder to study electron density, and part of the flux-gate and search coil magnetometers mounted on the instrument platform. A plasma probe was mounted on the sphere to measure energy and momentum distribution of protons above a few kilovolts to study the radiation effect of solar flares. The micrometeorite detector and sun scanner were mounted on the sphere as well. The only difference between Pioneer P-31 and the earlier Pioneer P-30 was the addition of a solid state detector sensitive to low energy protons on the satellite and an STL-designed rubidium frequency standard experiment placed on a pod attached to the booster. The total mass of the science package including electronics and power supply was roughly 60 kg. Total cost of the mission was estimated at 9 - 10 million dollars.

text: Regular orbital boosts are also needed by the Hubble Space Telescope, though on a longer time scale, due to its much higher altitude. However, orbital decay is also a limiting factor to the length of time the Hubble can go without a maintenance rendezvous, the most recent performed successfully by STS-125, with space shuttle Atlantis launching May 11, 2009, though newer telescopes are in much higher orbits or in some cases in solar orbit, so orbital boosting may not be needed.

text: Regular orbital boosts are also needed by the Hubble Space Telescope, though on a longer time scale, due to its much higher altitude. However, orbital decay is also a limiting factor to the length of time the Hubble can go without a maintenance rendezvous, the most recent performed successfully by

text: , with space shuttle Atlantis launching May 11, 2009, though newer telescopes are in much higher orbits or in some cases in solar orbit, so orbital boosting may not be needed.

text: The study of this proposed mission ended in 2007 with no further activities planned.<ref name='Darwin factsheet'></ref> To produce an image, the telescopes would have had to operate in formation with distances between the telescopes controlled to within a few micrometres, and the distance between the telescopes and receiver controlled to within about one nanometre. Several more detailed studies would have been needed to determine whether technology capable of such precision is actually feasible.

text: Seares also studied interstellar absorption and reddening of starlight.

text: Seares also studied interstellar

text: absorption

text: and reddening of starlight.

text: Already as a student was Rubens fascinated by electromagnetic radiation as theoretically described by Maxwell and experimentally demonstrated by Hertz. Through the influence of Kundt he had become interested in understanding the optical properties of different materials. In his doctoral work he showed that reflection of light increases with increasing wavelengths into the infrared region. As a related result he could present an experimental verification of Maxwell's theory for electromagnetic waves in different media. This effort also turned into a demonstration of the validity of these equations for infrared radiation. Rubens succeeded in this for wavelengths up to 10 μm.

text: Already as a student was Rubens fascinated by

text: electromagnetic radiation

text: as theoretically described by

text: Maxwell

text: and experimentally demonstrated by

text: Hertz

text: . Through the influence of

text: Kundt

text: he had become interested in understanding the optical properties of different materials. In his doctoral work he showed that reflection of light increases with increasing wavelengths into the

text: infrared

text: region. As a related result he could present an experimental verification of Maxwell's theory for

text: electromagnetic wave

text: s in different media. This effort also turned into a demonstration of the validity of these

text: equations

text: for

text: infrared radiation

text: . Rubens succeeded in this for wavelengths up to 10

text: μm

text: In 1946, a technique called astronomical interferometry was developed. Astronomical radio interferometers usually consist either of arrays of parabolic dishes or two-dimensional arrays of omni-directional antennas. All of the telescopes in the array are widely separated and are usually connected together using coaxial cable, waveguide, optical fiber, or other type of transmission line. Interferometry increases the total signal collected, but its primary purpose is to vastly increase the resolution through a process called Aperture synthesis. This technique works by superposing (interfering) the signal waves from the different telescopes on the principle that waves that coincide with the same phase will add to each other while two waves that have opposite phases will cancel each other out. This creates a combined telescope that is equivalent in resolution (though not in sensitivity) to a single antenna whose diameter is equal to the spacing of the antennas furthest apart in the array.

text: In 1946, a technique called

text: astronomical interferometry

text: was developed. Astronomical radio interferometers usually consist either of arrays of parabolic dishes or two-dimensional arrays of omni-directional antennas. All of the telescopes in the array are widely separated and are usually connected together using

text: coaxial cable

text: waveguide

text: optical fiber

text: , or other type of

text: transmission line

text: . Interferometry increases the total signal collected, but its primary purpose is to vastly increase the resolution through a process called

text: Aperture synthesis

text: . This technique works by superposing (interfering) the signal waves from the different telescopes on the principle that waves that coincide with the same phase will add to each other while two waves that have opposite phases will cancel each other out. This creates a combined telescope that is equivalent in resolution (though not in sensitivity) to a single antenna whose diameter is equal to the spacing of the antennas furthest apart in the array.

text: Cutbacks in funding hit Canada's premier astronomical research organization the Herzberg Institute of Astrophysics hard. Money could not be found to resurface the Algonquin Park Radio Telescope and it along with the solar telescope near Ottawa were closed in 1986. However that same year, the HIA did establish the Canadian Astronomy Data Centre (CADC) which created special software for the archiving of astronomical date. In 1987, the HAI took a 25 percent stake in the 15-m James Clerk Maxwell Telescope (submillimetre radio) and in the nineties a 15 percent stake in the optical 8 metre Gemini Telescope, which became operational in 1999. Headquarters for the HIA moved from Ottawa to Victoria in 1995. In the 21st century, the Institute designed instruments for its international telescope programme, including the Gemini multi-object spectrograph, the JCMT auto-correlation spectrometer and imaging system and the CFHT adaptive optics bonnette. Of note is the initiation of the CFHT Legacy Survey in 2003. Using the telescope's wide field Megacam the survey consists of three studies, "Very Wide", "Wide", and "Deep", and investigates a number of phenomena including the nature of dark matter and dark energy. The University of Calgary is participating in the development of the software to be used for data acquisition and image production at the Atacama Large Millimeter Array Telescope under construction in the Atacama Desert in Chile. First light is expected in 2011.

text: Cutbacks in funding hit Canada's premier astronomical research organization the Herzberg Institute of Astrophysics hard. Money could not be found to resurface the Algonquin Park Radio Telescope and it along with the solar telescope near Ottawa were closed in 1986. However that same year, the HIA did establish the Canadian Astronomy Data Centre (CADC) which created special software for the archiving of astronomical date. In 1987, the HAI took a 25 percent stake in the 15-m James Clerk Maxwell Telescope (submillimetre radio) and in the nineties a 15 percent stake in the optical 8 metre Gemini Telescope, which became operational in 1999. Headquarters for the HIA moved from Ottawa to Victoria in 1995. In the 21st century, the Institute designed instruments for its international telescope programme, including the Gemini multi-object spectrograph, the JCMT auto-correlation spectrometer and imaging system and the CFHT adaptive optics bonnette. Of note is the initiation of the CFHT Legacy Survey in 2003. Using the telescope's wide field Megacam the survey consists of three studies, "Very Wide", "Wide", and "Deep", and investigates a number of phenomena including the nature of

text: dark matter

text: and

text: dark energy

text: . The University of Calgary is participating in the development of the software to be used for data acquisition and image production at the

text: Atacama Large Millimeter Array

text: Telescope under construction in the Atacama Desert in Chile. First light is expected in 2011.

text: There are organized activities associated with DSOs such as the Messier marathon which occurs at a specific time each year and involve observers trying to spot all 110 Messier objects in one night. Since the Messier catalog objects were discovered with relatively small 18th century telescopes it is a popular list with observers, being well within the grasp of most modern amateur telescopes. A much more demanding test known as the Herschel 400 is designed to tax larger telescopes and experienced amateur astronomers.

text: There are organized activities associated with DSOs such as the

text: Messier marathon

text: which occurs at a specific time each year and involve observers trying to spot all 110 Messier objects in one night. Since the Messier catalog objects were discovered with relatively small 18th century telescopes it is a popular list with observers, being well within the grasp of most modern amateur telescopes. A much more demanding test known as the

text: Herschel 400

text: is designed to tax larger

text: telescopes

text: and experienced amateur astronomers.

text: Photoacoustic spectroscopy is the measurement of the effect of absorbed electromagnetic energy (particularly of light) on matter by means of acoustic detection. The discovery of the photoacoustic effect dates to 1880 when Alexander Graham Bell showed that thin discs emitted sound when exposed to a beam of sunlight that was rapidly interrupted with a rotating slotted disk. The absorbed energy from the light causes local heating and through thermal expansion a pressure wave or sound. Later Bell showed that materials exposed to the non-visible portions of the solar spectrum (i.e., the infrared and the ultraviolet) can also produce sounds.

text: Photoacoustic spectroscopy is the measurement of the effect of absorbed

text: electromagnetic energy

text: (particularly of

text: light

text: ) on

text: matter

text: by means of

text: acoustic

text: detection. The discovery of the

text: photoacoustic effect

text: dates to 1880 when

text: Alexander Graham Bell

text: showed that thin discs emitted

text: sound

text: when exposed to a

text: beam

text: of

text: sunlight

text: that was rapidly interrupted with a rotating slotted disk. The

text: absorbed

text: energy

text: from the light causes local

text: heat

text: ing and through

text: thermal expansion

text: a

text: pressure

text: wave or sound. Later Bell showed that materials exposed to the non-visible portions of the solar

text: spectrum

text: (i.e., the

text: infrared

text: and the

text: ultraviolet

text: ) can also produce sounds.

text: The South Pole Telescope (SPT) is a 10 meter (394 in) diameter telescope located at the Amundsen–Scott South Pole Station, Antarctica. The telescope is designed for observations in the microwave, millimeter-wave, and submillimeter-wave regions of the electromagnetic spectrum, with the particular design goal of measuring the faint, diffuse emission from the cosmic microwave background (CMB). The first major survey with the SPT–designed to find distant, massive, clusters of galaxies through their interaction with the CMB, with the goal of constraining the dark energy equation of state–was completed in October 2011.  In early 2012, a new camera was installed on the SPT with even greater sensitivity and the capability to measure the polarization of incoming light.  This camera is designed to measure the so-called "B-mode" or "curl" component of the polarized CMB, leading to constraints on the mass of the neutrino and the energy scale of inflation.

text: The South Pole Telescope (SPT) is a 10

text: meter

text: in

text: ) diameter telescope located at the

text: Amundsen–Scott South Pole Station

text: , Antarctica. The telescope is designed for observations in the

text: microwave

text: millimeter-wave

text: , and

text: submillimeter-wave

text: regions of the electromagnetic spectrum, with the particular design goal of measuring the faint, diffuse emission from the

text: cosmic microwave background

text: (CMB). The first major survey with the SPT–designed to find distant, massive,

text: clusters of galaxies

text: through their interaction with the CMB, with the goal of constraining the

text: dark energy

text: equation of state–was completed in October 2011.  In early 2012, a new camera was installed on the SPT with even greater sensitivity and the capability to measure the polarization of incoming light.  This camera is designed to measure the so-called "

text: B-mode

text: " or "

text: curl

text: " component of the polarized CMB, leading to constraints on the mass of the

text: neutrino

text: and the energy scale of

text: inflation

text: The Hubble Space Telescope was launched in April 1990, but gave flawed images. It had been designed at MSFC, but used a primary mirror that had spherical aberration due to incorrect grinding and polishing by the contractor. The defect was found when the telescope was in orbit. The design was such that repairs were possible, and three maintenance missions were flown in Shuttles during the 1990s. Another servicing mission (STS-109) was flown on March 1, 2002. Each mission resulted in considerable improvements, with the images receiving worldwide attention from astronomers as well as the public.

text: The

text: Hubble Space Telescope

text: was launched in April 1990, but gave flawed images. It had been designed at MSFC, but used a primary mirror that had

text: spherical aberration

text: due to incorrect grinding and polishing by the contractor. The defect was found when the telescope was in orbit. The design was such that repairs were possible, and three maintenance missions were flown in Shuttles during the 1990s. Another servicing mission (STS-109) was flown on March 1, 2002. Each mission resulted in considerable improvements, with the images receiving worldwide attention from astronomers as well as the public.

text: David Bohm had suggested that were we to view the cosmos without the lenses that outfit our telescopes, the universe would appear to us as a hologram. Pribram extended this insight by noting that were we deprived of the lenses of our eyes and the lens-like processes of our other sensory receptors, we would be immersed in holographic experiences.

text: David Bohm

text: had suggested that were we to view the cosmos without the lenses that outfit our telescopes, the universe would appear to us as a hologram. Pribram extended this insight by noting that were we deprived of the lenses of our eyes and the lens-like processes of our other sensory receptors, we would be immersed in holographic experiences.

text: None of the three telescopes was constructed, although several design studies were carried out and some scale models were made. This was partly due to the changing political climate over the time (the period was from a Labour Party government under Harold Wilson to a Conservative Party one under Margaret Thatcher), and partly to the financial constraints of astronomical research in the UK at the time. Also, at a vital time, it became necessary to upgrade the Lovell Telescope to the Mark IA, which subsequently overran in terms of cost.

text: None of the three telescopes was constructed, although several design studies were carried out and some scale models were made. This was partly due to the changing political climate over the time (the period was from a

text: Labour Party

text: government under

text: Harold Wilson

text: to a

text: Conservative Party

text: one under

text: Margaret Thatcher

text: ), and partly to the financial constraints of astronomical research in the UK at the time. Also, at a vital time, it became necessary to upgrade the

text: Lovell Telescope

text: to the Mark IA, which subsequently overran in terms of cost.

text: The range of frequencies in the electromagnetic spectrum that makes up the radio spectrum is very large. This means that the types of antennas that are used as radio telescopes vary widely in design, size, and configuration. At wavelengths of 30 meters to 3 meters (10 MHz - 100 MHz), they are generally either directional antenna arrays similar to "TV antennas" or large stationary reflectors with moveable focal points. Since the wavelengths being observed with these types of antennas are so long, the "reflector" surfaces can be constructed from coarse wire mesh such as chicken wire. At shorter wavelengths parabolic "dish" antennas predominate. The angular resolution of a dish antenna is determined by the ratio of the diameter of the dish to the wavelength of the radio waves being observed. This dictates the dish size a radio telescope needs for a useful resolution. Radio telescopes that operate at wavelengths of 3 meters to 30 cm (100 MHz to 1 GHz) are usually well over 100 meters in diameter. Telescopes working at wavelengths shorter than 30 cm (above 1 GHz) range in size from 3 to 90 meters in diameter.

text: The range of frequencies in the

text: electromagnetic spectrum

text: that makes up the

text: radio spectrum

text: is very large. This means that the types of antennas that are used as radio telescopes vary widely in design, size, and configuration. At wavelengths of 30 meters to 3 meters (10 MHz - 100 MHz), they are generally either

text: directional antenna

text: arrays similar to "TV antennas" or large stationary reflectors with moveable focal points. Since the wavelengths being observed with these types of antennas are so long, the "reflector" surfaces can be constructed from coarse wire

text: mesh

text: such as

text: chicken wire

text: . At shorter wavelengths

text: parabolic "dish" antennas

text: predominate. The

text: angular resolution

text: of a dish antenna is determined by the ratio of the diameter of the dish to the

text: wavelength

text: of the radio waves being observed. This dictates the dish size a radio telescope needs for a useful resolution. Radio telescopes that operate at wavelengths of 3 meters to 30 cm (100 MHz to 1 GHz) are usually well over 100 meters in diameter. Telescopes working at wavelengths shorter than 30 cm (above 1 GHz) range in size from 3 to 90 meters in diameter.

text: In electromagnetism and applications, an inhomogeneous electromagnetic wave equation, or nonhomogeneous electromagnetic wave equation, is one of a set of wave equations describing the propagation of electromagnetic waves generated by nonzero source charges and currents. The source terms in the wave equations makes the partial differential equations inhomogeneous, if the source terms are zero the equations reduce to the homogeneous electromagnetic wave equations. The equations follow from Maxwell's equations.

text: In

text: electromagnetism

text: and applications, an inhomogeneous

text: electromagnetic wave equation

text: , or nonhomogeneous electromagnetic wave equation, is one of a set of

text: wave equation

text: s describing the propagation of

text: electromagnetic wave

text: s generated by nonzero source

text: charge

text: s and

text: currents

text: . The source terms in the wave equations makes the

text: partial differential equations

text: inhomogeneous, if the source terms are zero the equations reduce to the homogeneous

text: electromagnetic wave equation

text: s. The equations follow from

text: Maxwell's equations

text: As the atmosphere is transparent for radio waves, radio telescopes in space are of most use for Very Long Baseline Interferometry; doing simultaneous observations of a source with both a satellite and a ground-based telescope and by correlating their signals to simulate a radio telescope the size of the separation between the two telescopes. Observations can be of supernova remnants, masers, gravitational lenses, starburst galaxies, and many other things.

text: As the atmosphere is transparent for radio waves, radio telescopes in space are of most use for

text: Very Long Baseline Interferometry

text: ; doing simultaneous observations of a source with both a satellite and a ground-based telescope and by correlating their signals to simulate a radio telescope the size of the separation between the two telescopes. Observations can be of

text: supernova remnant

text: s,

text: masers

text: gravitational lens

text: es,

text: starburst galaxies

text: , and many other things.

text: In 2000, astronomers began considering the potential of telescopes larger than 20 meters in diameter. Two technologies were considered; segmented mirrors like that of the Keck Observatory and the use of a group of 8-meter mirrors mounted to form a single unit. The US National Academy of Sciences made a suggestion that a 30-meter telescope should be the focus of US astronomy interests and recommended it to be built within the decade. The University of California, along with Caltech began development of a 30-meter telescope that same year. The California Extremely Large Telescope (CELT) began development along with the Giant Magellan Telescope, the Giant Segmented Mirror Telescope (GSMT) and the Very Large Optical Telescope (VLOT). These studies would eventually become the Thirty Meter Telescope. The TMT would have nine times the collecting area of the older Keck telescope using slightly smaller mirror segments in a vastly larger group. Another telescope of a large diameter in the works is the European Extremely Large Telescope (E-ELT) being built in northern Chile.

text: In 2000, astronomers began considering the potential of telescopes larger than 20 meters in diameter. Two technologies were considered; segmented mirrors like that of the

text: Keck Observatory

text: and the use of a group of 8-meter mirrors mounted to form a single unit. The US National Academy of Sciences made a suggestion that a 30-meter telescope should be the focus of US astronomy interests and recommended it to be built within the decade. The University of California, along with Caltech began development of a 30-meter telescope that same year. The California Extremely Large Telescope (CELT) began development along with the

text: Giant Magellan Telescope

text: , the Giant Segmented Mirror Telescope (GSMT) and the Very Large Optical Telescope (VLOT). These studies would eventually become the Thirty Meter Telescope. The TMT would have nine times the collecting area of the older Keck telescope using slightly smaller mirror segments in a vastly larger group. Another telescope of a large diameter in the works is the

text: European Extremely Large Telescope (E-ELT)

text: being built in northern Chile.

text: The completion of all the major objectives, as well as some that were not considered vital, upgraded the telescope to its most technologically advanced state since its launch nineteen years ago, and made it more powerful than ever. The upgrades will also help Hubble to see deeper into the universe, and farther into the past, closer to the time of the Big Bang. Hubble's importance to science is not just seen in the dramatic images it provides, but also in the volume of work it has generated – an average of fourteen scientific articles are published each week based on data gathered from the telescope. Officially, the upgrades should extend Hubble's life through 2014, but Hubble Space Telescope Senior Scientist David Leckrone noted prior to the mission that if all of the mission's objectives were successful, the telescope could easily last longer than that. The next large telescope scheduled to be launched is the James Webb Space Telescope in 2018, which is infrared-only, so to have Hubble, which has ultraviolet, visible, and near-infrared capabilities, still operational after 2018 would be of great benefit to the scientific community.

text: The completion of all the major objectives, as well as some that were not considered vital, upgraded the telescope to its most technologically advanced state since its launch nineteen years ago, and made it more powerful than ever. The upgrades will also help Hubble to see deeper into the universe, and farther into the past, closer to the time of the

text: Big Bang

text: . Hubble's importance to science is not just seen in the dramatic images it provides, but also in the volume of work it has generated – an average of fourteen scientific articles are published each week based on data gathered from the telescope. Officially, the upgrades should extend Hubble's life through 2014, but Hubble Space Telescope Senior Scientist David Leckrone noted prior to the mission that if all of the mission's objectives were successful, the telescope could easily last longer than that. The next large telescope scheduled to be launched is the

text: James Webb Space Telescope

text: in 2018, which is infrared-only, so to have Hubble, which has ultraviolet, visible, and near-infrared capabilities, still operational after 2018 would be of great benefit to the scientific community.

text: Zeiss is currently in the process of designing the optical components for the James Webb Space Telescope set to replace the Hubble Space Telescope sometime in 2018.

text: Zeiss is currently in the process of designing the optical components for the

text: James Webb Space Telescope

text: set to replace the

text: Hubble Space Telescope

text: sometime in 2018.

text: In the earliest uses of lenses, chromatic aberration was reduced by increasing the focal length of the lens where possible.  For example, this  could result in extremely long telescopes such as the very long aerial telescopes of the 17th century. Isaac Newton's theories about white light being composed of a spectrum of colors led him to the conclusion that uneven refraction of light caused chromatic aberration (leading him to build the first reflecting telescope, his Newtonian telescope, in 1668).

text: In the earliest uses of lenses, chromatic aberration was reduced by increasing the focal length of the lens where possible.  For example, this  could result in extremely long

text: telescopes

text: such as the very long

text: aerial telescope

text: s of the 17th century.

text: Isaac Newton

text: 's theories about

text: white light

text: being composed of a

text: spectrum

text: of colors led him to the conclusion that uneven refraction of light caused chromatic aberration (leading him to build the first

text: reflecting telescope

text: , his

text: Newtonian telescope

text: , in 1668).

text: Electromagnetic waves are typically described by any of the following three physical properties: the frequency f, wavelength λ, or photon energy E. Frequencies observed in astronomy range from  (1 GeV gamma rays) down to the local plasma frequency of the ionized interstellar medium (~1 kHz). Wavelength is inversely proportional to the wave frequency, so gamma rays have very short wavelengths that are fractions of the size of atoms, where as wavelengths on the opposite end of the spectrum can be as long as the universe. Photon energy is directly proportional to the wave frequency, so gamma ray photons have the highest energy (around a billion electron volts), while radio wave photons have very low energy (around a femtoelectronvolt). These relations are illustrated by the following equations:

text: Electromagnetic waves are typically described by any of the following three physical properties: the

text: frequency

text: f,

text: wavelength

text: λ

text: , or

text: photon

text: energy

text: E. Frequencies observed in astronomy range from  (1

text: GeV

text: gamma rays) down to the local

text: plasma frequency

text: of the ionized interstellar medium (~1 kHz). Wavelength is inversely proportional to the wave frequency, so gamma rays have very short wavelengths that are fractions of the size of

text: atom

text: s, where as wavelengths on the opposite end of the spectrum can be as long as the

text: universe

text: Photon energy

text: is directly proportional to the wave frequency, so gamma ray photons have the highest energy (around a billion

text: electron volt

text: s), while radio wave photons have very low energy (around a

text: femto

text: electronvolt). These relations are illustrated by the following equations:

text: Electromagnetic waves occur in the ionosphere and magnetosphere as well as the Earth's outer core. Dawn chorus is believed to be caused by high-energy electrons that get caught in the Van Allen radiation belt. Whistlers are produced by lightning strikes. Hiss may be generated by both. Electromagnetic waves may also be generated by earthquakes (see seismo-electromagnetics).

text: Electromagnetic waves

text: occur in the

text: ionosphere

text: and

text: magnetosphere

text: as well as the Earth's

text: outer core

text: Dawn chorus

text: is believed to be caused by high-energy electrons that get caught in the

text: Van Allen radiation belt

text: Whistlers

text: are produced by

text: lightning

text: strikes.

text: Hiss

text: may be generated by both. Electromagnetic waves may also be generated by earthquakes (see

text: seismo-electromagnetics

text: The instrumentation group at Mount Stromlo Observatory has built two instruments for the Gemini Telescope.  This includes the near infrared integral field spectrometer, NIFS, deployed on Gemini-North,  and the adaptive optics imager for Gemini-South, GSAOI. NIFS, when nearly completed, was destroyed in the bushfires of 18 January 2003, and rebuilt.

text: In 2011 a dedicated search for suitable KBOs using ground telescopes was started by mission scientists. Large ground telescopes with wide-field cameras, notably the twin 6.5-meter Magellan Telescopes in Chile, the 8.2-meter Subaru Observatory in Hawaii, and the Canada–France–Hawaii Telescope were used to search for potential targets. Through the citizen-science project, the public helped to scan telescopic images for possible suitable mission candidates by participating in the Ice Hunters project. The ground-based search resulted in the discovery of about 143 KBOs of potential interest, but none of these were close enough to the flight path of New Horizons. Only the Hubble Space Telescope was deemed likely to find a suitable target in time for a successful KBO mission. On June 16, 2014, time on Hubble was granted. Hubble has a much greater ability to find suitable KBOs than ground telescopes. The probability that a target for New Horizons would be found was estimated beforehand at about 95%.

text: In 2011 a dedicated search for suitable KBOs using ground telescopes was started by mission scientists. Large ground telescopes with wide-field cameras, notably the twin 6.5-meter

text: Magellan Telescopes

text: in Chile, the 8.2-meter

text: Subaru Observatory

text: in Hawaii, and the

text: Canada–France–Hawaii Telescope

text: were used to search for potential targets. Through the

text: citizen-science

text: project, the public helped to scan telescopic images for possible suitable mission candidates by participating in the

text: Ice Hunters

text: project. The ground-based search resulted in the discovery of about 143 KBOs of potential interest, but none of these were close enough to the flight path of New Horizons. Only the

text: Hubble Space Telescope

text: was deemed likely to find a suitable target in time for a successful KBO mission. On June 16, 2014, time on Hubble was granted. Hubble has a much greater ability to find suitable KBOs than ground telescopes. The probability that a target for New Horizons would be found was estimated beforehand at about 95%.

text: The UKST is a Schmidt camera, with a design based on the Oschin Schmidt Telescope. It is a survey telescope with a 6° by 6° field of view, originally imaged onto a 35 cm square glass photographic plate, and was the primary source of optical survey data in the southern sky from the 1970s to after 2000. The original sky survey plates were digitally scanned by the Space Telescope Science Institute to create the Guide Star Catalog for the Hubble Space Telescope, and the Digitized Sky Survey.

text: The UKST is a Schmidt camera, with a design based on the Oschin Schmidt Telescope. It is a survey telescope with a 6

text: by 6°

text: field of view

text: , originally imaged onto a 35 cm square glass photographic plate, and was the primary source of optical survey data in the southern sky from the 1970s to after 2000. The original sky survey plates were digitally scanned by the

text: Space Telescope Science Institute

text: to create the Guide Star Catalog for the

text: Hubble Space Telescope

text: , and the

text: Digitized Sky Survey

text: The company's primary focus of investigation includes the development of terahertz light into a usefulspectroscopic and imaging technique. The ‘terahertz gap’ – where until recently bright sources of light and sensitive means of detection were difficult to access – encompasses frequencies invisible to the naked eye in the electromagnetic spectrum, lying between microwave and infrared in the range from 0.3 to 3THz. TeraView's existing instruments generate, detect and manipulate THz light and have been tested in a number of application areas.

text: The company's primary focus of investigation includes the development of terahertz light into a useful

text: spectroscopic

text: and imaging technique. The ‘

text: terahertz gap

text: ’ – where until recently bright sources of light and sensitive means of detection were difficult to access – encompasses frequencies invisible to the naked eye in the

text: electromagnetic spectrum

text: , lying between

text: microwave

text: and

text: infrared

text: in the range from 0.3 to 3THz. TeraView's existing instruments generate, detect and manipulate THz light and have been tested in a number of application areas.

text: The telescope eyepieces for the telescope provided a range between 60 and 350 times magnification. The telescope was adapted to use more modern eyepieces. In its day the Airdrie Observatory telescope would have been considered to be a research grade telescope.

text: In his Ultra high frequency (UHF) experiments, Hertz transmitted and received radio waves over short distances and showed that the properties of radio waves were consistent with Maxwell’s electromagnetic theory. He demonstrated that radio radiation had all the properties of waves (now called electromagnetic radiation), and discovered that the electromagnetic equations could be reformulated into a partial differential equation called the wave equation.

text: In his

text: Ultra high frequency

text: (UHF) experiments, Hertz transmitted and received radio waves over short distances and showed that the properties of radio waves were consistent with Maxwell’s electromagnetic theory. He demonstrated that radio radiation had all the properties of waves (now called

text: electromagnetic radiation

text: ), and discovered that the electromagnetic equations could be reformulated into a

text: partial differential equation

text: called the

text: wave equation

text: WFIRST is based on an existing 2.4m wide field-of-view telescope and will carry two scientific instruments. The Wide-Field Instrument is a 288-megapixel multi-band near-infrared camera, providing a sharpness of images comparable to that achieved by the Hubble Space Telescope over 100 times the area. The Coronagraphic Instrument is a high contrast small field of view camera and spectrometer covering visible and near-infrared wavelengths  using novel starlight-suppression technology.

text: WFIRST is based on an existing 2.4m wide field-of-view telescope and will carry two scientific instruments. The Wide-Field Instrument is a 288-megapixel multi-band near-infrared camera, providing a sharpness of images comparable to that achieved by the

text: Hubble Space Telescope

text: over 100 times the area. The Coronagraphic Instrument is a high contrast small field of view camera and spectrometer covering visible and near-infrared wavelengths  using novel starlight-suppression technology.

text: Type I diamond has nitrogen (N) atoms as the main impurity, at a concentration of up to 1%. If the N atoms are in pairs or larger aggregates, they do not affect the diamond's color; these are Type Ia. About 98% of gem diamonds are type Ia: these diamonds belong to the Cape series, named after the diamond-rich region formerly known as Cape Province in South Africa, whose deposits are largely Type Ia. If the nitrogen atoms are dispersed throughout the crystal in isolated sites (not paired or grouped), they give the stone an intense yellow or occasionally brown tint (type Ib); the rare canary diamonds belong to this type, which represents only ~0.1% of known natural diamonds. Synthetic diamond containing nitrogen is usually of type Ib. Type Ia and Ib diamonds absorb in both the infrared and ultraviolet region of the electromagnetic spectrum, from 320 nm. They also have a characteristic fluorescence and visible absorption spectrum (see Optical properties).

text: Type I diamond has

text: nitrogen

text: (N) atoms as the main impurity, at a concentration of up to 1%. If the N atoms are in pairs or larger aggregates, they do not affect the diamond's color; these are Type Ia. About 98% of gem diamonds are type Ia: these diamonds belong to the Cape series, named after the diamond-rich region formerly known as

text: Cape Province

text: in

text: South Africa

text: , whose deposits are largely Type Ia. If the nitrogen atoms are dispersed throughout the crystal in isolated sites (not paired or grouped), they give the stone an intense yellow or occasionally brown tint (type Ib); the rare canary diamonds belong to this type, which represents only ~0.1% of known natural diamonds. Synthetic diamond containing nitrogen is usually of type Ib. Type Ia and Ib diamonds absorb in both the

text: infrared

text: and

text: ultraviolet

text: region of the

text: electromagnetic spectrum

text: , from 320

text: nm

text: . They also have a characteristic fluorescence and visible absorption spectrum (see

text: Optical properties

text: In 1891, Patrick Alexander ordered the telescope from the well-known Victorian telescope makers Thomas and Howard Grubb of Dublin with all the usual fittings associated with a professional instrument of the time. It is not entirely clear where the telescope was first installed, accounts vary. It is probable that the telescope was first erected at one of Patrick Alexander's several private workshops in Bath: either 'DeMontalat Wood' or 'The Mount'. The telescope was a substantial instrument, which together with its mounting, must have weighed several tons. The telescope was fully equipped for astronomical observations and Patrick became a fellow member of the Royal Astronomical Society up until 1921. Although he enjoyed showing his telescope to friends and distinguished visitors, any interest he had in astronomy was overshadowed by his other aviation related passions — especially ballooning; the telescope was probably a scientific toy. Barry Bellinger suggests that the telescope was used to track pilot balloons released into the air, before releasing any main balloons; however, a telescope of this size and type seems ill-suited to such a task.

text: In 1891, Patrick Alexander ordered the telescope from the well-known Victorian telescope makers

text: Thomas

text: and

text: Howard Grubb

text: of Dublin with all the usual fittings associated with a professional instrument of the time. It is not entirely clear where the telescope was first installed, accounts vary. It is probable that the telescope was first erected at one of Patrick Alexander's several private workshops in Bath: either 'DeMontalat Wood' or 'The Mount'. The telescope was a substantial instrument, which together with its mounting, must have weighed several tons. The telescope was fully equipped for astronomical observations and Patrick became a fellow member of the

text: Royal Astronomical Society

text: up until 1921. Although he enjoyed showing his telescope to friends and distinguished visitors, any interest he had in astronomy was overshadowed by his other aviation related passions — especially ballooning; the telescope was probably a scientific toy. Barry Bellinger suggests that the telescope was used to track pilot balloons released into the air, before releasing any main balloons; however, a telescope of this size and type seems ill-suited to such a task.

text: Hercules has no first or second magnitude stars. However, it does have several stars above magnitude 4. Alpha Herculis, traditionally called Rasalgethi, is a triple star system, partly resolvable in small amateur telescopes, 359 light-years from Earth. The primary is an irregular variable star; it is a bright giant with a minimum magnitude of 4 and a maximum magnitude of 3. It has a diameter of roughly 400 solar diameters. The secondary, a spectroscopic binary that orbits the primary every 3600 years, is a blue-green hued star of magnitude 5.6. Its common name means "the kneeler's head". Beta Herculis, also called Kornephoros, is the brightest star in Hercules. It is a yellow giant of magnitude 2.8, 148 light-years from Earth. Its traditional name means "club-bearer". deltoide 5512 is a double star divisible in small amateur telescopes. The primary is a blue-white star of magnitude 3.1, and is 78 light-years from Earth. The optical companion is of magnitude 8.2. Gamma Herculis is also a double star divisible in small amateur telescopes. The primary is a white giant of magnitude 3.8, 195 light-years from Earth. The optical companion, widely separated, is 10th magnitude. Zeta Herculis is a binary star that is becoming divisible in medium-aperture amateur telescopes, as the components widen to their peak in 2025. The system, 35 light-years from Earth, has a period of 34.5 years. The primary is a yellow-tinged star of magnitude 2.9 and the secondary is an orange star of magnitude 5.7.

text: Hercules has no

text: first or second magnitude

text: stars. However, it does have several stars above magnitude 4.

text: Alpha Herculis

text: , traditionally called Rasalgethi, is a

text: triple star

text: system, partly resolvable in small amateur telescopes, 359 light-years from Earth. The primary is an irregular

text: variable star

text: ; it is a

text: bright giant

text: with a minimum magnitude of 4 and a maximum magnitude of 3. It has a diameter of roughly 400

text: solar diameter

text: s. The secondary, a

text: spectroscopic binary

text: that orbits the primary every 3600 years, is a blue-green hued star of magnitude 5.6. Its common name means "the kneeler's head".

text: Beta Herculis

text: , also called Kornephoros, is the brightest star in Hercules. It is a

text: yellow giant

text: of magnitude 2.8, 148 light-years from Earth. Its traditional name means "club-bearer". deltoide 5512 is a double star divisible in small amateur telescopes. The primary is a blue-white star of magnitude 3.1, and is 78 light-years from Earth. The optical companion is of magnitude 8.2.

text: Gamma Herculis

text: is also a double star divisible in small amateur telescopes. The primary is a

text: white giant

text: of magnitude 3.8, 195 light-years from Earth. The optical companion, widely separated, is 10th magnitude.

text: Zeta Herculis

text: is a binary star that is becoming divisible in medium-aperture amateur telescopes, as the components widen to their peak in 2025. The system, 35 light-years from Earth, has a period of 34.5 years. The primary is a yellow-tinged star of magnitude 2.9 and the secondary is an orange star of magnitude 5.7.

text: Unusually for a radio telescope, the primary reflector is an off-axis segment of a paraboloid. This is the same design used in familiar home satellite television (e.g., DirecTV) dishes. The asymmetric reflector allows the telescope's focal point and feed horn to be located at the side of the dish, so that it and its retractable support boom do not obstruct the incoming radio waves, as occurs in conventional radio telescope designs with the feed located on the telescope's beam axis.

text: Unusually for a radio telescope, the primary reflector is an off-axis segment of a paraboloid. This is the same design used in familiar home

text: satellite television

text: (e.g., DirecTV) dishes. The asymmetric reflector allows the telescope's

text: focal point

text: and

text: feed horn

text: to be located at the side of the dish, so that it and its retractable support boom do not obstruct the incoming radio waves, as occurs in conventional radio telescope designs with the feed located on the telescope's beam axis.

text: Time on the telescopes is sold either by a subscription or pay as you go. The cost of using one of the telescopes in its global network varies depending on the model. Compared to its contemporaries, LightBuckets allows new images of the sky to be observed, as opposed to Microsoft WorldWide Telescope or Google Sky, which use stored images. It is more similar to Slooh, which also allows live-views from telescopes located in places such as Chile and Spain.

text: Time on the telescopes is sold either by a subscription or pay as you go. The cost of using one of the telescopes in its global network varies depending on the model. Compared to its contemporaries, LightBuckets allows new images of the sky to be observed, as opposed to Microsoft

text: WorldWide Telescope

text: or

text: Google Sky

text: , which use stored images. It is more similar to

text: Slooh

text: , which also allows live-views from telescopes located in places such as Chile and Spain.

text: Pip begins spying on her new neighbors with her telescope, and taking pictures of the Marshall's around town. She tries with her telescope to look inside the shed to discover the cause of the strange noises but fails. She also sees Sally's teenage brother "Wayne Marshall" dance stripping in his room by himself with a biker helmet on his head that he never takes off while playing rock music from his stereo. The next day Pip walks by the Marshalls' house and begins throwing tennis balls over the fence. After throwing several balls over the fence "Granny Marshall", who seems to be floating on air, gives Pip the ball back. Pip walks around to the front of the house then walks through the gate into the Marshall's back yard. Pip sees the huge tomatoes growing in bushes alongside the fence and takes one just as Sally comes outside. Before Sally talks to Pip she gives her dad a full glass of lemonade that he drinks in a matter of seconds. When Sally takes the glass back she says "Hi" to Pip, and they have a short conversation. Sally asks Pip if she would like to hang out but Pip says she can't, but maybe another time. Pip then leaves with the tomato in hand. Meanwhile Ben is at the playground because Pip is mad that he kissed her. He then gives Rhonnie the pictures she took in exchange for Pip's walkman in hopes that she will forgive him.

text: In 2002, a planned space telescope, originally called the Next Generation Space Telescope (NGST), was renamed the James Webb Space Telescope as a tribute to Webb.

text: In 2002, a planned

text: space telescope

text: , originally called the Next Generation Space Telescope (NGST), was renamed the

text: James Webb Space Telescope

text: as a tribute to Webb.

text: Triumph only possesses superhuman powers when he has a connection to the electromagnetic spectrum; without that source he has no powers.

text: Radio waves were first identified in German physicist Heinrich Hertz's 1887 series of experiments to prove James Clerk Maxwell's electromagnetic theory.  Hertz used spark-excited dipole antennas to generate the waves and micrometer spark gaps attached to dipole and loop antennas to detect them.  These primitive devices are more accurately described as radio wave sensors, not "receivers", as they could only detect radio waves within about 100 feet of the transmitter, and were not used to attempt communication but were instead used as part of an experiment to verify a theoretical proof.

text: Radio waves were first identified in German physicist

text: Heinrich Hertz

text: 's 1887 series of experiments to prove James Clerk Maxwell's

text: electromagnetic theory

text: .  Hertz used spark-excited dipole antennas to generate the waves and micrometer

text: spark gap

text: s attached to

text: dipole

text: and

text: loop antenna

text: s to detect them.  These primitive devices are more accurately described as radio wave sensors, not "receivers", as they could only detect radio waves within about 100 feet of the transmitter, and were not used to attempt communication but were instead used as part of an experiment to verify a theoretical proof.

text: Live projections from the telescopes to the lecture room enable a big audience to do observations. They assist visually impaired people by enhancing details, that are hard to see in a telescope. For people with mobility constraints, they simplify or enable access to the observation.

text: The Suffa RT-70 radio telescope is an RT-70 radio telescope under construction at the Suffa Radio Observatory on the Suffa plateau, Uzbekistan.  Construction began in the late 80's, but was put on hold when the USSR fell.  As of 2008, construction had resumed, with an updated emphasis on millimeter-wave band observations at 100–300 GHz. Construction was scheduled to be completed in 2012, but information on the current status of the observatory is spotty as of 2013.

text: The Suffa RT-70 radio telescope is an

text: radio telescope

text: under construction at the

text: Suffa Radio Observatory

text: on the

text: Suffa plateau

text: Uzbekistan

text: .  Construction began in the late 80's, but was put on hold when the USSR fell.  As of 2008, construction had resumed, with an updated emphasis on millimeter-wave band observations at 100–300 GHz. Construction was scheduled to be completed in 2012, but information on the current status of the observatory is spotty as of 2013.

text: In 2009, NASA's Kepler spacecraft was completing the last of tests on its photometer, the instrument it uses to detect transit events, in which a planet crosses in front of and dims its host star for a brief and roughly regular period of time. In this last test, Kepler observed  stars in the Kepler Input Catalog, including Kepler-7; the preliminary light curves were sent to the Kepler science team for analysis, who chose obvious planetary companions from the bunch for follow-up at observatories. Kepler-7 was not one of these original candidates. After a resting period of 1.3 days, Kepler began a nonstop 33.5-day period in which it observed  targets uninterrupted until June 15, 2009, when the collected data was downloaded and tested for false positives. Kepler-7's candidate was not found to be one of these false positives, such as an eclipsing binary star that may generate a light curve that mimics that of transiting planetary companions. Kepler-7 was then observed using Doppler spectroscopy using the Fibre-fed Echelle Spectrograph at the Canary Islands' Nordic Optical Telescope for ten nights in October 2009, taken with respect to the star HD 182488 to compensate for possible telescope error. Speckle imaging of the star was taken at WIYN Observatory in Arizona to check for close companions; when none were found, the High Resolution Echelle Spectrometer instrument at the W.M. Keck Observatory on Hawaii, the Harlan J. Smith Telescope at the McDonald Observatory in Texas, the PRISM camera at the Lowell Observatory, and the Faulkes Telescope North at the Haleakala Observatory on Maui were also used to analyze Doppler spectroscopy of the planetary candidate. The radial velocity observations confirmed that a planetary body was responsible for the dips observed in Kepler-7's light curve, thus confirming it as a planet.

text: In 2009,

text: NASA

text: 's

text: Kepler

text: spacecraft was completing the last of tests on its

text: photometer

text: , the instrument it uses to detect

text: transit

text: events, in which a planet crosses in front of and dims its host star for a brief and roughly regular period of time. In this last test, Kepler observed  stars in the

text: Kepler Input Catalog

text: , including Kepler-7; the preliminary light curves were sent to the Kepler science team for analysis, who chose obvious planetary companions from the bunch for follow-up at observatories. Kepler-7 was not one of these original candidates. After a resting period of 1.3 days, Kepler began a nonstop 33.5-day period in which it observed  targets uninterrupted until June 15, 2009, when the collected data was downloaded and tested for

text: false positive

text: s. Kepler-7's candidate was not found to be one of these false positives, such as an

text: eclipsing binary

text: star that may generate a light curve that mimics that of transiting planetary companions. Kepler-7 was then observed using

text: Doppler spectroscopy

text: using the

text: Fibre-fed Echelle Spectrograph

text: at the Canary Islands'

text: Nordic Optical Telescope

text: for ten nights in October 2009, taken with respect to the star HD 182488 to compensate for possible telescope error.

text: Speckle imaging

text: of the star was taken at

text: WIYN Observatory

text: in Arizona to check for close companions; when none were found, the

text: High Resolution Echelle Spectrometer

text: instrument at the

text: W.M. Keck Observatory

text: on Hawaii, the

text: Harlan J. Smith Telescope

text: at the

text: McDonald Observatory

text: in Texas, the PRISM camera at the

text: Lowell Observatory

text: , and the

text: Faulkes Telescope North

text: at the

text: Haleakala Observatory

text: on Maui were also used to analyze Doppler spectroscopy of the planetary candidate. The radial velocity observations confirmed that a planetary body was responsible for the dips observed in Kepler-7's light curve, thus confirming it as a planet.

text: The above stationary dishes are not fully "steerable"; they can only be aimed at points in an area of the sky near the zenith, and cannot receive from sources near the horizon. The largest fully steerable dish radio telescope is the 100 meter Green Bank Telescope in West Virginia, United States, constructed in 2000. The largest fully steerable radio telescope in Europe is the Effelsberg 100-m Radio Telescope near Bonn, Germany, operated by the Max Planck Institute for Radio Astronomy, which also was the world's largest fully steerable telescope for 30 years until the Green Bank antenna was constructed. The third-largest fully steerable radio telescope is the 76-meter Lovell Telescope at Jodrell Bank Observatory in Cheshire, England, completed in 1957. The fourth-largest fully steerable radio telescopes are six 70-meter dishes: three Russian RT-70, and three in the NASA Deep Space Network. , the planned Qitai Radio Telescope will be the world's largest fully steerable single-dish radio telescope with a diameter of .

text: The above stationary dishes are not fully "steerable"; they can only be aimed at points in an area of the sky near the

text: zenith

text: , and cannot receive from sources near the horizon. The largest fully steerable dish radio telescope is the 100 meter

text: Green Bank Telescope

text: in

text: West Virginia

text: , United States, constructed in 2000. The largest fully steerable radio telescope in Europe is the

text: Effelsberg 100-m Radio Telescope

text: near

text: Bonn

text: , Germany, operated by the

entity_name: Max Planck Institute for Radio Astronomy

text: Max Planck Institute for Radio Astronomy

text: , which also was the world's largest fully steerable telescope for 30 years until the Green Bank antenna was constructed. The third-largest fully steerable radio telescope is the 76-meter

text: Lovell Telescope

text: at

text: Jodrell Bank Observatory

text: in

text: Cheshire

text: , England, completed in 1957. The fourth-largest fully steerable radio telescopes are six 70-meter dishes: three Russian

text: , and three in the

text: NASA Deep Space Network

text: . , the planned

text: Qitai Radio Telescope

text: will be the world's largest fully steerable single-dish radio telescope with a diameter of .

text: The second launch attempt had no such problems and lifted off into overcast skies at January 29, 1964, 11:25 EST. The rocket sent back 1,183 measurements to the ground during the flight while at the same time it was tracked by six telescopes. For the first 1000 meters the rocket was filmed by 13 cameras that looked for any pitch, yaw, and roll movements.

text: The second launch attempt had no such problems and lifted off into overcast skies at January 29, 1964, 11:25

text: EST

text: . The

text: rocket

text: sent back 1,183 measurements to the ground during the flight while at the same time it was tracked by six telescopes. For the first 1000 meters the rocket was filmed by 13 cameras that looked for any

text: pitch, yaw, and roll

text: movements.

text: NOAO operates world class research telescopes in both the northern and southern hemispheres. These telescopes are located at Kitt Peak and Cerro Tololo in the US and Chile, respectively. Complemented with similar astronomical instruments, the two sites allow US astronomers to make observations over the entire sky. Instrumentation includes optical to near infrared wavelength (0.4 to 5 micrometres) cameras and spectrometers.

text: NOAO operates world class research telescopes in both the northern and southern hemispheres. These telescopes are located at Kitt Peak and Cerro Tololo in the US and Chile, respectively. Complemented with similar astronomical instruments, the two sites allow US astronomers to make observations over the entire sky. Instrumentation includes optical to near infrared wavelength (0.4 to 5 micrometres) cameras and

text: spectrometers

text: As is the case for visible light telescopes, space is the ideal place for infrared telescopes. In space, images from infrared telescopes can achieve higher resolution, as they do not suffer from blurring caused by the Earth's atmosphere, and are also free from absorption caused by the Earth's atmosphere. Current infrared telescopes in space include the Herschel Space Observatory, the Spitzer Space Telescope, and the Wide-field Infrared Survey Explorer. Since putting telescopes in orbit is expensive, there are also airborne observatories, such as the Stratospheric Observatory for Infrared Astronomy and the Kuiper Airborne Observatory. These observatories place telescopes above most, but not all, of the atmosphere, which means there is absorption of infrared light from space by water vapor in the atmosphere.

text: As is the case for visible light telescopes, space is the ideal place for infrared telescopes. In space, images from infrared telescopes can achieve higher resolution, as they do not suffer from

text: blurring

text: caused by the Earth's atmosphere, and are also free from absorption caused by the Earth's atmosphere. Current infrared telescopes in space include the Herschel Space Observatory, the Spitzer Space Telescope, and the

text: Wide-field Infrared Survey Explorer

text: . Since putting telescopes in orbit is expensive, there are also airborne observatories, such as the

text: Stratospheric Observatory for Infrared Astronomy

text: and the

text: Kuiper Airborne Observatory

text: . These observatories place telescopes above most, but not all, of the atmosphere, which means there is absorption of infrared light from space by water vapor in the atmosphere.

text: The Goddard High Resolution Spectrograph (GHRS or HRS) was a spectrograph installed on the Hubble Space Telescope. It was replaced by the Near Infrared Camera and Multi-Object Spectrometer (NICMOS) in 1997.

text: The Goddard High Resolution Spectrograph (GHRS or HRS) was a

text: spectrograph

text: installed on the

text: Hubble Space Telescope

text: . It was replaced by the

text: (NICMOS) in 1997.

text: at which the intensity or power of the field decays to 1/e of its surface value. In many contexts one is concentrating on the field quantities themselves: the electric and magnetic fields in the case of electromagnetic waves. Since the power of a wave in a particular medium is proportional to the square of a field quantity, one may speak of a penetration depth at which the magnitude of the electric (or magnetic) field has decayed to 1/e of its surface value, and at which point the power of the wave has thereby decreased to

text: When initial assessments were being made for the feasibility of restoring the observatory, both the telescope and observatory were in a poor condition as a result of years of neglect and an arson attempt by some local children. The telescope is made predominantly from brass and thus suffered minimal corrosion and damage. Most importantly the lens of the telescope survived unscathed allowing for restoration. This was carried out at first by several dedicated parents and governors of the school, amongst them Syd Little. Soon after the basic restoration ideas were raised for a larger project allowing the teaching of astronomy on a larger scale. After getting clearance from the original owners of the telescope to go ahead with the project, Rossall was given funds from the Lawrence House Trust, an educational charity, to go forward with their plans. The centre had an official opening on 26 September 2006 with Old Rossallian and former Astronomer Royal Sir Francis Graham Smith in attendance. The centre's motto is 'Astronomy For All' meaning that it offers courses to Rossall Students but also at a small cost to the general public. Courses also range from beginner to advanced to ensure that anybody who wishes to study Astronomy can do so.

text: When initial assessments were being made for the feasibility of restoring the observatory, both the telescope and observatory were in a poor condition as a result of years of neglect and an arson attempt by some local children. The telescope is made predominantly from

text: brass

text: and thus suffered minimal corrosion and damage. Most importantly the lens of the telescope survived unscathed allowing for restoration. This was carried out at first by several dedicated parents and governors of the school, amongst them

text: Syd Little

text: . Soon after the basic restoration ideas were raised for a larger project allowing the teaching of astronomy on a larger scale. After getting clearance from the original owners of the telescope to go ahead with the project, Rossall was given funds from the Lawrence House Trust, an educational charity, to go forward with their plans. The centre had an official opening on 26 September 2006 with Old Rossallian and former Astronomer Royal

text: Sir Francis Graham Smith

text: in attendance. The centre's motto is 'Astronomy For All' meaning that it offers courses to Rossall Students but also at a small cost to the general public. Courses also range from beginner to advanced to ensure that anybody who wishes to study

text: Astronomy

text: can do so.

text: Huygens eyepieces consist of two plano-convex lenses with the plane sides towards the eye separated by an air gap. The lenses are called the eye lens and the field lens. The focal plane is located between the two lenses. It was invented by Christiaan Huygens in the late 1660s and was the first compound (multi-lens) eyepiece. Huygens discovered that two air spaced lenses can be used to make an eyepiece with zero transverse chromatic aberration. These eyepieces work well with the very long focal length telescopes (in Huygens day they were used with single element long focal length non-achromatic refracting telescopes, including very long focal length aerial telescopes). This optical design is now considered obsolete since with today's shorter focal length telescopes the eyepiece suffers from short eye relief, high image distortion, chromatic aberration, and a very narrow apparent field of view. Since these eyepieces are cheap to make they can often be found on inexpensive telescopes and microscopes. Because Huygens eyepieces do not contain cement to hold the lens elements, telescope users sometimes use these eyepieces in the role of "solar projection", i.e. projecting an image of the Sun onto a screen. Other cemented eyepieces can be damaged by the intense, concentrated light of the Sun.

text: Huygens eyepiece

text: s consist of two

text: plano-convex lens

text: es with the plane sides towards the eye separated by an air gap. The lenses are called the eye lens and the field lens. The focal plane is located between the two lenses. It was invented by

text: Christiaan Huygens

text: in the late 1660s and was the first compound (multi-lens)

text: eyepiece

text: . Huygens discovered that two air spaced lenses can be used to make an eyepiece with zero transverse chromatic aberration. These eyepieces work well with the very long focal length telescopes (in Huygens day they were used with single element long focal length

text: non-achromatic

text: refracting telescope

text: s, including very long focal length

text: aerial telescope

text: s). This optical design is now considered obsolete since with today's shorter focal length telescopes the eyepiece suffers from short eye relief, high image distortion, chromatic aberration, and a very narrow apparent field of view. Since these eyepieces are cheap to make they can often be found on inexpensive telescopes and microscopes. Because Huygens eyepieces do not contain cement to hold the lens elements, telescope users sometimes use these eyepieces in the role of "solar projection", i.e. projecting an image of the

text: Sun

text: onto a screen. Other cemented eyepieces can be damaged by the intense, concentrated light of the Sun.

text: Most modern professional telescopes use a guide star. An autoguider is pointed to a sufficiently luminous star that lies near the object being observed and, if the pointing begins to drift, the error can be detected and the movement corrected. This is most accurate when the corrections are applied by a computer, but amateur telescopes often have manual correction (requiring the observer to continuously follow the star by eye for the exposure period, which may be a significant length of time).

text: Most modern professional telescopes use a guide star. An

text: autoguider

text: is pointed to a sufficiently luminous star that lies near the object being observed and, if the pointing begins to drift, the error can be detected and the movement corrected. This is most accurate when the corrections are applied by a computer, but amateur telescopes often have manual correction (requiring the observer to continuously follow the star by eye for the exposure period, which may be a significant length of time).

text: Submillimetre astronomy or submillimeter astronomy (see spelling differences) is the branch of observational astronomy that is conducted at submillimetre wavelengths (i.e., terahertz radiation) of the electromagnetic spectrum. Astronomers place the submillimetre waveband between the far-infrared and microwave wavebands, typically taken to be between a few hundred micrometres and a millimetre. It is still common in submillimetre astronomy to quote wavelengths in 'microns', the old name for micrometre.

text: Submillimetre astronomy or submillimeter astronomy (see

entity_name: American and British English spelling differences

text: spelling differences

text: ) is the branch of

text: observational astronomy

text: that is conducted at submillimetre wavelengths (i.e.,

text: terahertz radiation

text: ) of the

text: electromagnetic spectrum

text: . Astronomers place the submillimetre waveband between the

text: far-infrared

text: and

text: microwave

text: wavebands, typically taken to be between a few hundred

text: micrometre

text: s and a

text: millimetre

text: . It is still common in submillimetre astronomy to quote wavelengths in 'microns', the old name for micrometre.

text: According to NASA, the Roentgensatellit (ROSAT) was a joint German, U.S. and British X-ray astrophysics project. ROSAT carried a German-built imaging X-ray Telescope (XRT) with three focal plane instruments: two German Position Sensitive Proportional Counters (PSPC) and the US-supplied High Resolution Imager (HRI). The X-ray mirror assembly was a grazing incidence four-fold nested Wolter I telescope with an 84-cm diameter aperture and 240-cm focal length. The angular resolution was less than 5 arcsecond at half energy width (the "angle within which half of the electromagnetic radiation" is focused). The XRT assembly was sensitive to X-rays between 0.1 and 2 keV (one thousand Electronvolt).

text: According to NASA, the Roentgensatellit (ROSAT) was a joint German, U.S. and British X-ray astrophysics project. ROSAT carried a German-built imaging X-ray Telescope (XRT) with three focal plane instruments: two German Position Sensitive

text: Proportional Counter

text: s (PSPC) and the US-supplied High Resolution Imager (HRI). The X-ray mirror assembly was a

text: grazing incidence

text: four-fold nested

text: Wolter I telescope

text: with an 84-cm diameter aperture and 240-cm focal length. The angular resolution was less than 5

text: arcsecond

text: at half energy width (the "angle within which half of the electromagnetic radiation" is focused). The XRT assembly was sensitive to X-rays between 0.1 and 2 keV (one thousand

text: Electronvolt

text: An ion trap mass spectrometer may incorporate a Penning trap (Fourier transform ion cyclotron resonance), Paul trap or the Kingdon trap. The Orbitrap, introduced in 2005, is based on the Kingdon trap. Other types of mass spectrometers may also use a linear quadrupole ion trap as a selective mass filter.

text: An ion trap

text: mass spectrometer

text: may incorporate a Penning trap (

entity_name: Fourier transform ion cyclotron resonance

text: Fourier transform ion cyclotron resonance

text: Paul trap

text: or the

text: Kingdon trap

text: . The

text: Orbitrap

text: , introduced in 2005, is based on the Kingdon trap. Other types of mass spectrometers may also use a linear quadrupole ion trap as a selective mass filter.

text: The NIMS instrument was sensitive to 0.7-to-5.2-micrometre wavelength IR light, overlapping the wavelength range of the SSI. The telescope associated with NIMS was all reflective (using only mirrors and no lenses) with an aperture of 229 mm. The spectrometer of NIMS used a grating to disperse the light collected by the telescope. The dispersed spectrum of light was focused on detectors of indium antimonide and silicon. The NIMS weighed 18 kilograms and used 12 watts of power on average.

text: The NIMS instrument was sensitive to 0.7-to-5.2-

text: micrometre

text: wavelength

text: IR

text: light, overlapping the wavelength range of the SSI. The telescope associated with NIMS was all reflective (using only mirrors and no lenses) with an aperture of 229 mm. The

text: spectrometer

text: of NIMS used a grating to disperse the light collected by the telescope. The dispersed spectrum of light was focused on detectors of

text: indium

text: antimonide

text: and

text: silicon

text: . The NIMS weighed 18 kilograms and used 12 watts of power on average.

text: We use a telescoping argument to simplify the computation of the sum:

text: We use a

text: telescoping

text: argument to simplify the computation of the sum:

text: The Large Binocular Telescope (LBT) is an optical telescope for astronomy located on  Mount Graham, in the Pinaleno Mountains of southeastern Arizona, United States.  It is a part of the Mount Graham International Observatory. The LBT is currently one of the world's most advanced optical telescopes; using two 8.4 m (27 ft) wide mirrors, with centres 14.4m apart, it has the same light-gathering ability as an 11.8 m (39 ft) wide single circular telescope and detail of a 22.8 m (75 ft) wide one. Its mirrors individually are the joint second-largest optical telescope in continental North America, behind the Hobby–Eberly Telescope in West Texas; it is also the largest monolithic, or , in an optical telescope. Strehl ratios of 60–90% in the infrared H band and 95% in the infrared M band have been achieved by the LBT.

text: The Large Binocular Telescope (LBT) is an optical telescope for astronomy located on

text: Mount Graham

text: , in the

text: Pinaleno Mountains

text: of southeastern

text: Arizona

text: , United States.  It is a part of the

text: Mount Graham International Observatory

text: . The LBT is currently one of the world's most advanced optical telescopes; using two 8.4 m (27 ft) wide mirrors, with centres 14.4m apart, it has the same light-gathering ability as an 11.8 m (39 ft) wide single circular telescope and detail of a 22.8 m (75 ft) wide one. Its mirrors individually are the joint second-

text: largest optical telescope

text: in continental North America, behind the

text: Hobby–Eberly Telescope

text: in

text: West Texas

text: ; it is also the largest monolithic, or , in an optical telescope.

text: Strehl ratios

text: of 60–90% in the

text: infrared

text: H band

text: and 95% in the

text: infrared

text: M band

text: have been achieved by the LBT.

text: Tony McCoy, whose horse came home third, said: "I was a bit disappointed because after last year I thought he was the perfect National horse. He's such a good jumper and so intelligent, but looking back he was happier on the soft ground last year than he was this time round."

text: Low was named to serve as facility scientist for NASA's Space Infrared Telescope Facility, later renamed the Spitzer Space Telescope. The effort had been delayed by cost overruns, until Low had an inspiration at a 1993 retreat for the project's scientists; the passive cooling technique could be used - rather than place the entire telescope in a bath of liquid helium to cool the unit to temperatures near absolute zero, the unit could be exposed to the vacuum of space to radiate most of its heat while the detectors themselves were the only components cooled using liquid helium, a design change that allowed the Spitzer project to go ahead towards its launch in 2003.  Timothy Hawarden has been recognized by NASA for the development of the passive cooling technique, which has also been included in other space probes, such as the James Webb Space Telescope, a partial successor to the Hubble Space Telescope, that will search for the oldest objects in the universe.

text: Low was named to serve as facility scientist for NASA's Space Infrared Telescope Facility, later renamed the

text: Spitzer Space Telescope

text: . The effort had been delayed by cost overruns, until Low had an inspiration at a 1993 retreat for the project's scientists; the passive cooling technique could be used - rather than place the entire telescope in a bath of

text: liquid helium

text: to cool the unit to temperatures near

text: absolute zero

text: , the unit could be exposed to the vacuum of space to radiate most of its heat while the detectors themselves were the only components cooled using liquid helium, a design change that allowed the Spitzer project to go ahead towards its launch in 2003.  Timothy Hawarden has been recognized by NASA for the development of the passive cooling technique, which has also been included in other space probes, such as the

text: James Webb Space Telescope

text: , a partial successor to the

text: Hubble Space Telescope

text: , that will search for the oldest objects in the universe.

text: Participation does not require a telescope, as most amateur astronomers let visitors look through their telescopes. Daytime events include guest speakers, such as telescope makers, NASA representatives, and optics manufacturers. Also, OSP has a guided tour through the "telescope fields" which discusses many of the different telescope designs and custom builds. OSP also offers activities for children and offers an observing challenge ranging in difficulty from beginner to advanced.

text: Throughout his career, Henning has been involved in large cooperative research projects, such as instrument-building for the ESA space telescope Herschel, for the James Webb Space Telescope and for the telescopes of the European Southern Observatory; construction of the Large Binocular Telescope in Arizona; the Spitzer Legacy Project "Formation of Planetary Systems", several Herschel legacy projects, the Pan-STARRS survey and the HAT-South transit network. Henning is a member of several astronomical steering and advisory committees, including the ESO Council, the German National COSPAR committee, the CAHA board, the boards of directors of the LBT and of PS1, and the scientific advisory council of the Thüringer Landessternwarte Tautenburg. He is also chair of the ERC Advanced Grants committee "Universe Science" and a member of the Dutch Academy Professorship Review Committee.

text: Throughout his career, Henning has been involved in large cooperative research projects, such as instrument-building for the

text: ESA

text: space telescope

text: Herschel

text: , for the

text: James Webb Space Telescope

text: and for the telescopes of the

text: European Southern Observatory

text: ; construction of the

text: Large Binocular Telescope

text: in

text: Arizona

text: ; the

text: Spitzer

text: Legacy Project "Formation of Planetary Systems", several Herschel legacy projects, the

text: Pan-STARRS

text: survey and the HAT-South transit network. Henning is a member of several astronomical steering and advisory committees, including the

text: ESO

text: Council, the German National

text: COSPAR

text: committee, the

text: CAHA

text: board, the boards of directors of the

text: LBT

text: and of

text: , and the scientific advisory council of the

text: Thüringer Landessternwarte Tautenburg

text: . He is also chair of the

text: ERC

text: Advanced Grants committee "Universe Science" and a member of the

entity_name: Royal Netherlands Academy of Arts and Sciences

text: Dutch Academy

text: Professorship Review Committee.

text: Slooh is a robotic telescope service that can be viewed live through a web browser with Flash plug-in. It was not the first robotic telescope, but it was the first that offered "live" viewing through a telescope via the web. Other online telescopes traditionally email a picture to the recipient. The site has a patent on their live image processing method. Slooh is an online astronomy platform with live-views and telescope rental for a fee. Observations come from a global network of telescopes located in places including Spain and Chile.

text: Slooh is a

text: robotic telescope

text: service that can be viewed live through a

text: web browser

text: with

text: Flash

text: plug-in

text: . It was not the first robotic telescope, but it was the first that offered "live" viewing through a telescope via the

text: web

text: . Other online telescopes traditionally email a picture to the recipient. The site has a patent on their live image processing method. Slooh is an online astronomy platform with live-views and telescope rental for a fee. Observations come from a global network of telescopes located in places including

text: Spain

text: and

text: Chile

text: The 3.6m Devesthal Optical Telescope is a clear aperture Ritchey-Chretien style telescope built by Aryabhatta Research Institute of Observational Sciences(ARIES) and is located at the Devasthal Observatory site near Nainital, India. ARIES operates another 1.3m telescope at the same location. The telescope was activated remotely on March 31, 2016 by Indian Prime Minister Narendra Modi and Belgian Prime Minister Charles Michel from Brussels. The telescope optics has been built in collaboration with the Belgian firm Advanced Mechanical & Optical System (AMOS).

text: The 3.6m Devesthal Optical Telescope is a clear aperture

text: Ritchey-Chretien

text: style telescope built by

entity_name: Aryabhatta Research Institute of Observational Sciences

text: Aryabhatta Research Institute of Observational Sciences

text: (ARIES) and is located at the Devasthal Observatory site near Nainital, India. ARIES operates another 1.3m telescope at the same location. The telescope was activated remotely on March 31, 2016 by Indian Prime Minister

text: Narendra Modi

text: and Belgian Prime Minister

text: Charles Michel

text: from Brussels. The telescope optics has been built in collaboration with the Belgian firm Advanced Mechanical & Optical System (AMOS).

text: RCI Starlight acrylic shells are "welded" at the seam, not tabbed. According to RCI-Starlight international, claims vibration characteristics of their shells were tested and are superior to glued and tabbed shells. Like the vistalite, they are factory-equipped with a 45 degree bearing edge. Many of the designs are made to replicate original vistalite colors and patterns.

text: Gasholders were constructed of a variety of materials, brick, stone, concrete, steel, or wrought iron. The holder or floating vessel is the storage reservoir for the gas, and it serves the purpose of equalizing the distribution of the gas under pressure, and ensures a continuity of supply, while gas remains in the holder. They are cylindrical like an inverted beaker and work up and down in the tank. In order to maintain a true vertical position, the vessel has rollers which work on guide-rails attached to the tank sides and to the columns surrounding the holder. Gasholders may be either single or telescopic in two or more lifts. When it is made in the telescopic form, its capacity could be increased to as much as four times the capacity of the single-lift holder for equal dimensions of tank. The telescopic versions were found to be useful as they conserved ground space and capital.

text: Gasholders

text: were constructed of a variety of materials, brick, stone, concrete, steel, or wrought iron. The holder or floating vessel is the storage reservoir for the gas, and it serves the purpose of equalizing the distribution of the gas under pressure, and ensures a continuity of supply, while gas remains in the holder. They are cylindrical like an inverted beaker and work up and down in the tank. In order to maintain a true vertical position, the vessel has rollers which work on guide-rails attached to the tank sides and to the columns surrounding the holder. Gasholders may be either single or telescopic in two or more lifts. When it is made in the telescopic form, its capacity could be increased to as much as four times the capacity of the single-lift holder for equal dimensions of tank. The telescopic versions were found to be useful as they conserved ground space and capital.

text: The 1.8 meter Alice P. Lennon Telescope and its Thomas J. Bannan Astrophysics Facility, known together as the Vatican Advanced Technology Telescope (VATT), is a Gregorian telescope observing in the optical and infrared  situated on Mount Graham in southeast Arizona, United States. It achieved "first light", the first starlight to pass through the telescope onto a detector, in 1993.

text: The 1.8 meter Alice P. Lennon Telescope and its Thomas J. Bannan Astrophysics Facility, known together as the Vatican Advanced Technology Telescope (VATT), is a

text: Gregorian telescope

text: observing in the

text: optical

text: and

text: infrared

text: situated on

text: Mount Graham

text: in southeast

text: Arizona

text: United States

text: . It achieved "first light", the first starlight to pass through the telescope onto a detector, in 1993.

text: Once on Button Moon, which hangs in "blanket sky", they have an adventure, and look through Mr. Spoon's telescope at someone else such as the Hare and the Tortoise, before heading back to their home on 'Junk Planet'. Episodes also include Mr. Spoon's wife Mrs. Spoon, their daughter, Tina Tea-Spoon and her friend Eggbert. The series ended in 1988 after 91 episodes.

text: Electron-capture dissociation (ECD) was developed in 1998 to fragment large proteins for mass spectrometric analysis. Because ECD requires a large amount of near-thermal electrons (<0.2eV), originally it was used exclusively with Fourier transform ion cyclotron resonance mass spectrometry (FTICR), the most expensive form of MS instrumentation. Less costly options such as quadrupole time-of-flight (Q-TOF), quadrupole ion trap (QIT) and linear quadrupole ion trap (QLT) instruments used the more energy-intensive collision-induced dissociation method (CID), resulting in random fragmentation of peptides and proteins. In 2004 Syka et al. announced the creation of ETD, a dissociation method similar to ECD, but using a low-cost, widely available commercial spectrometer. The first ETD experiments were run on a QLT mass spectrometer with an electrospray ionization (ESI) source.

text: Electron-capture dissociation (ECD) was developed in 1998 to fragment large proteins for mass spectrometric analysis. Because ECD requires a large amount of near-thermal electrons (<0.2eV), originally it was used exclusively with

text: Fourier transform ion cyclotron resonance mass spectrometry

text: (FTICR), the most expensive form of MS instrumentation. Less costly options such as

text: quadrupole time-of-flight

text: (Q-TOF),

text: quadrupole ion trap

text: (QIT) and

text: linear quadrupole ion trap

text: (QLT) instruments used the more energy-intensive

text: collision-induced dissociation

text: method (CID), resulting in random fragmentation of peptides and proteins. In 2004 Syka et al. announced the creation of ETD, a dissociation method similar to ECD, but using a low-cost, widely available commercial spectrometer. The first ETD experiments were run on a QLT mass spectrometer with an

text: electrospray ionization

text: (ESI) source.

text: The pointing of the telescope is fine tuned at the beginning of each season by using a coaligned optical telescope to observe a large number of stars covering a wide range of azimuths and elevations. A least-squares fit to the pointing errors is used to define 5 pointing parameters (offsets of the azimuth and elevation encoders, effective longitude and latitude, and the small nonperpendicularity of the azimuth and elevation axes). Because the relatively large beam of the telescope makes continuum observations of planets inconvenient, pointing is checked weekly by radio continuum observations of the limb of the sun. Although during the observing season (fall, winter, and spring) the sun transits below the elevation of most CO observations, it is the only practical astronomical source for pointing checks. At elevations used for observations, the root mean square pointing errors of the telescope were less than about 1', about 1/9 beamwidth.

text: A camera may work with the light of the visible spectrum or with other portions of the electromagnetic spectrum. A still camera is an optical device which creates a single image of an object or scene and records it on an electronic sensor or photographic film. All cameras use the same basic design: light enters an enclosed box through a converging lens/convex lens and an image is recorded on a light-sensitive medium(mainly a transition metal-halide). A shutter mechanism controls the length of time that light can enter the camera. Most photographic cameras have functions that allow a person to view the scene to be recorded, allow for a desired part of the scene to be in focus, and to control the exposure so that it is not too bright or too dim. A display, often a liquid crystal display (LCD), permits the user to view scene to be recorded and settings such as ISO speed, exposure, and shutter speed.

text: A camera may work with the

text: light

text: of the

text: visible spectrum

text: or with other portions of the

text: electromagnetic spectrum

text: . A

text: still camera

text: is an optical device which creates a single

text: image

text: of an object or scene and records it on an

text: electronic sensor

text: or

text: photographic film

text: . All cameras use the same basic design: light enters an enclosed box through a

text: converging lens

text: convex

text: lens and an image is recorded on a light-sensitive medium(mainly a

text: transition metal

text: halide

text: ). A

text: shutter

text: mechanism controls the length of time that light can enter the camera. Most photographic cameras have functions that allow a person to view the scene to be recorded, allow for a desired part of the scene to be in

text: focus

text: , and to control the

text: exposure

text: so that it is not too bright or too dim. A display, often a

text: liquid crystal display

text: (LCD), permits the user to view scene to be recorded and settings such as ISO speed, exposure, and shutter speed.

text: Many types of telescope fold or divert the optical path with secondary or tertiary mirrors. These may be integral part of the optical design (Newtonian telescope, Cassegrain reflector or similar types), or may simply be used to place the eyepiece or detector at a more convenient position. Telescope designs may also use specially designed additional lenses or mirrors to improve image quality over a larger field of view.

text: Many types of telescope fold or divert the optical path with secondary or tertiary mirrors. These may be integral part of the optical design (

text: Newtonian telescope

text: Cassegrain reflector

text: or similar types), or may simply be used to place the eyepiece or detector at a more convenient position. Telescope designs may also use specially designed additional lenses or mirrors to improve image quality over a larger field of view.

text: The experiment consists of three major parts: the beam telescope, the target area and the two-staged spectrometer.

text: Ever since Galileo took a Dutch invention and adapted it to astronomical use, astronomical telescope making has been an evolving discipline. Many astronomers after the time of Galileo built their own telescopes out of necessity, but the advent of amateurs in the field building telescopes for their own enjoyment and education seems to have come into prominence in the 20th century.

text: Ever since

text: Galileo

text: took a Dutch invention and adapted it to astronomical use, astronomical telescope making has been an evolving discipline. Many astronomers after the time of Galileo built their own telescopes out of necessity, but the advent of amateurs in the field building telescopes for their own enjoyment and education seems to have come into prominence in the 20th century.

text: With a keen interest in astronomy for a facility well-suited to study the sky, Mr. & Mrs. Frank Altschul contributed the funds to construct an observatory on the property, which was completed in 1960. Materials were donated by local corporations, and the telescope was built by volunteers and the Fairfield County Astronomical Society. The largest telescope in the East available for public viewing was dedicated on June 13, 1965.

text: In 1666 Isaac Newton, based on his theories of refraction and color, perceived that the faults of the refracting telescope were due more to a lens's varying refraction of light of different colors than to a lens's imperfect shape. He concluded that light could not be refracted through a lens without causing chromatic aberrations, although he incorrectly concluded from some rough experiments that all refracting substances would diverge the prismatic colors in a constant proportion to their mean refraction. From these experiments Newton concluded that no improvement could be made in the refracting telescope. Newton's experiments with mirrors showed that they did not suffer from the chromatic errors of lenses, for all colors of light the angle of incidence reflected in a mirror was equal to the angle of reflection, so as a proof to his theories Newton set out to build a reflecting telescope. Newton completed his first telescope in 1668 and it is the earliest known functional reflecting telescope.  After much experiment, he chose an alloy (speculum metal) of tin and copper as the most suitable material for his objective  mirror. He later devised means for grinding and polishing them, but chose a spherical shape for his mirror instead of a parabola to simplify construction. He added to his reflector what is the hallmark of the design of a "Newtonian telescope", a secondary "diagonal" mirror near the primary mirror's focus to reflect the image at 90° angle to an eyepiece mounted on the side of the telescope. This unique addition allowed the image to be viewed with minimal obstruction of the objective mirror. He also made all the tube, mount, and fittings. Newton's first compact reflecting telescope had a mirror diameter of 1.3 inches and a focal ratio of f/5. With it he found that he could see the four Galilean moons of Jupiter and the crescent phase of the planet Venus. Encouraged by this success, he made a second telescope with a magnifying power of 38x which he presented to the Royal Society of London in December 1672. This type of telescope is still called a Newtonian telescope.

text: In 1666

text: Isaac Newton

text: , based on his theories of refraction and color, perceived that the faults of the refracting telescope were due more to a lens's varying refraction of light of different colors than to a lens's imperfect shape. He concluded that light could not be refracted through a lens without causing chromatic aberrations, although he incorrectly concluded from some rough experiments that all refracting substances would diverge the prismatic colors in a constant proportion to their mean refraction. From these experiments Newton concluded that no improvement could be made in the refracting telescope. Newton's experiments with mirrors showed that they did not suffer from the chromatic errors of lenses, for all colors of light the

text: angle of incidence

text: reflected in a mirror was equal to the

text: angle of reflection

text: , so as a proof to his theories Newton set out to build a reflecting telescope. Newton completed his

text: first telescope

text: in 1668 and it is the earliest known functional reflecting telescope.  After much experiment, he chose an

text: alloy

text: speculum metal

text: ) of

text: tin

text: and

text: copper

text: as the most suitable material for his

text: objective

text: mirror. He later devised means for grinding and polishing them, but chose a spherical shape for his mirror instead of a parabola to simplify construction. He added to his reflector what is the hallmark of the design of a "Newtonian telescope", a secondary "diagonal" mirror near the primary mirror's focus to reflect the image at 90° angle to an

text: eyepiece

text: mount

text: , and fittings. Newton's first compact reflecting telescope had a mirror diameter of 1.3 inches and a

text: focal ratio

text: of f/5. With it he found that he could see the four

text: Galilean moons

text: of

text: Jupiter

text: and the

text: crescent phase of the planet Venus

text: . Encouraged by this success, he made a second telescope with a magnifying power of 38x which he presented to the

text: Royal Society of London

text: in December 1672. This type of telescope is still called a

text: Newtonian telescope

text: Drizzle was developed as a collaboration between the Space Telescope Science Instituteand the Space Telescope European Coordinating Facility.

text: Drizzle was developed as a collaboration between the

text: Space Telescope Science Institute

text: and the

text: For much of the history of observational astronomy, almost all observation was performed in the visual spectrum with optical telescopes. While the Earth's atmosphere is relatively transparent in this portion of the electromagnetic spectrum, most telescope work is still dependent on seeing conditions and air transparency, and is generally restricted to the night time. The seeing conditions depend on the turbulence and thermal variations in the air. Locations that are frequently cloudy or suffer from atmospheric turbulence limit the resolution of observations. Likewise the presence of the full Moon can brighten up the sky with scattered light, hindering observation of faint objects.

text: For much of the history of observational astronomy, almost all observation was performed in the visual spectrum with

text: optical telescope

text: s. While the Earth's atmosphere is relatively transparent in this portion of the

text: electromagnetic spectrum

text: , most telescope work is still dependent on

text: seeing

text: conditions and air transparency, and is generally restricted to the night time. The seeing conditions depend on the turbulence and thermal variations in the air. Locations that are frequently cloudy or suffer from atmospheric turbulence limit the resolution of observations. Likewise the presence of the full

text: Moon

text: can brighten up the sky with scattered light, hindering observation of faint objects.

text: Furthermore, electromagnetic energy is light energy, but only a small part of it is visible light. This energy travels in waves. Shorter wavelengths, such as visible light and infrared, carry more energy per photon than longer waves, such as microwaves and radio waves. For the sciences, the light spectrum is known as the electromagnetic spectrum.

text: Furthermore, electromagnetic energy is light energy, but only a small part of it is

text: visible light

text: . This energy travels in waves. Shorter wavelengths, such as visible light and

text: infrared

text: , carry more energy per

text: photon

text: than longer waves, such as

text: microwave

text: s and

text: radio waves

text: . For the

text: science

text: s, the light spectrum is known as the

text: electromagnetic spectrum

text: The American astronomer and lens designer James Gilbert Baker first proposed a Cassegrain design for Bernhard Schmidt's Schmidt camera in 1940. The optical shop at Mount Wilson Observatory manufactured the first one during World War II as part of their research into optical designs for the military. As in the Schmidt camera this design uses a spherical primary mirror and a Schmidt corrector plate to correct for spherical aberration. In this Cassegrain configuration the convex secondary mirror acts as a field flattener and relays the image through the perforated primary mirror to a final focal plane located behind the primary. Some designs include additional optical elements (such as field flatteners) near the focal plane. The first large telescope to use the design was the James Gregory Telescope of 1962 at the University of St Andrews.

text: The American astronomer and lens designer

text: James Gilbert Baker

text: first proposed a

text: Cassegrain

text: design for

text: Bernhard Schmidt

text: 's

text: Schmidt camera

text: in 1940. The optical shop at

text: Mount Wilson Observatory

text: manufactured the first one during World War II as part of their research into optical designs for the military. As in the

text: Schmidt camera

text: this design uses a

text: spherical

text: primary mirror

text: and a

text: Schmidt corrector plate

text: to correct for

text: spherical aberration

text: . In this

text: Cassegrain

text: configuration the

text: convex

text: secondary mirror

text: acts as a

text: field flattener

text: and relays the image through the perforated

text: primary mirror

text: to a final

text: focal plane

text: located behind the primary. Some designs include additional optical elements (such as field flatteners) near the focal plane. The first large telescope to use the design was the

text: James Gregory Telescope

text: of 1962 at the

text: University of St Andrews

text: Several infrared space telescopes have continued and greatly expanded the study of the infrared Universe, such as the Infrared Space Observatory launched in 1995, the Spitzer Space Telescope launched in 2003, and the Akari Space Telescope launched in 2006.

text: Several infrared space telescopes have continued and greatly expanded the study of the infrared Universe, such as the

text: Infrared Space Observatory

text: launched in 1995, the

text: Spitzer Space Telescope

text: launched in 2003, and the

text: Akari

text: Space Telescope launched in 2006.

text: In the 1980s the aperture synthesis interferometric imaging technique was extended to visible light and infrared astronomy by the Cavendish Astrophysics Group, providing the first very high resolution images of nearby stars.  In 1995 this technique was demonstrated on an array of separate optical telescopes for the first time, allowing a further improvement in resolution, and allowing even higher resolution imaging of stellar surfaces. Software packages such as BSMEM or MIRA are used to convert the measured visibility amplitudes and closure phases into astronomical images. The same techniques have now been applied at a number of other astronomical telescope arrays, including the Navy Prototype Optical Interferometer, the Infrared Spatial Interferometer and the IOTA array. A number of other interferometers have made closure phase measurements and are expected to produce their first images soon, including the VLTI, the CHARA array and Le Coroller and Dejonghe's Hypertelescope prototype. If completed, the MRO Interferometer with up to ten movable telescopes will produce among the first higher fidelity images from a long baseline interferometer. The Navy Optical Interferometer took the first step in this direction in 1996, achieving 3-way synthesis of an image of Mizar; then a first-ever six-way synthesis of Eta Virginis in 2002; and most recently "closure phase" as a step to the first synthesized images produced by geostationary satellites.

text: In the 1980s the aperture synthesis interferometric imaging technique was extended to visible light and infrared astronomy by the

text: Cavendish Astrophysics Group

text: , providing the first very high resolution images of nearby stars.  In 1995 this technique was demonstrated on

entity_name: Cambridge Optical Aperture Synthesis Telescope

text: an array of separate optical telescopes

text: for the first time, allowing a further improvement in resolution, and allowing even higher resolution imaging of stellar surfaces. Software packages such as BSMEM or MIRA are used to convert the measured visibility amplitudes and

text: closure phase

text: s into astronomical images. The same techniques have now been applied at a number of other astronomical telescope arrays, including the

text: Navy Prototype Optical Interferometer

text: , the

text: Infrared Spatial Interferometer

text: and the

text: IOTA

text: array. A number of other interferometers have made

text: closure phase

text: measurements and are expected to produce their first images soon, including the

text: VLT

text: I, the

text: CHARA array

text: and Le Coroller and Dejonghe's

text: Hypertelescope

text: prototype. If completed, the

text: MRO Interferometer

text: with up to ten movable telescopes will produce among the first higher fidelity images from a long baseline interferometer. The Navy Optical Interferometer took the first step in this direction in 1996, achieving 3-way synthesis of an image of

text: Mizar

text: ; then a first-ever six-way synthesis of

text: Eta Virginis

text: in 2002; and most recently "

text: closure phase

text: " as a step to the first synthesized images produced by

text: geostationary satellites

text: NCRA has set up a unique facility for radio astronomical research using the metrewavelengths range of the radio spectrum, known as the Giant Metrewave Radio Telescope (GMRT), it is located at a site about 80 km north of Pune. GMRT consists of 30 fully steerable gigantic parabolic dishes of 45m diameter each spread over distances of up to 25 km. GMRT is one of the most challenging experimental programmes in basic sciences undertaken by Indian scientists and engineers. GMRT is a unique instrument which opens up the sky at the Metrewave range of the Electromagnetic spectrum and using the technique of Aperture synthesis allows to make high sensitive maps of the sky. The instrument is at par with other radio telescopes in the world like the VLA in terms of resolution. It compliments VLA at the metre-wavelengths.

text: NCRA has set up a unique facility for radio astronomical research using the metrewavelengths range of the

text: radio spectrum

text: , known as the Giant Metrewave Radio Telescope (GMRT), it is located at a site about 80 km north of Pune. GMRT consists of 30 fully steerable gigantic parabolic dishes of 45m diameter each spread over distances of up to 25 km. GMRT is one of the most challenging experimental programmes in basic sciences undertaken by Indian scientists and engineers. GMRT is a unique instrument which opens up the

text: sky

text: at the Metrewave range of the

text: Electromagnetic spectrum

text: and using the technique of

text: Aperture synthesis

text: allows to make high sensitive maps of the sky. The instrument is at par with other radio telescopes in the world like the

text: VLA

text: in terms of resolution. It compliments VLA at the metre-wavelengths.

text: CFBDSIR 1458+10 B was discovered in 2011 by Liu et al. with laser guide star (LGS) adaptive optics (AO) system of the 10 m Keck II Telescope on Mauna Kea, Hawaii, using infra-red camera NIRC2 (the observations were made on 2010 May 22 and 2010 July 8 (UT)). In 2011 Liu et al. published a paper in The Astrophysical Journal where they presented discovery of CFBDSIR 1458+10 system component B (the only discovery presented in the article). Also they presented a near-infrared (J-band) trigonometric parallax of the system, measured using WIRCam on the Canada-France-Hawaii Telescope (CFHT), Mauna Kea, in seven epochs during the 2009—2010; and spectroscopy with the X-Shooter spectrograph at the European Southern Observatory's Very Large Telescope (VLT) Unit Telescope 2 (UT2) in Chile (the observations have been performed from May 5 to July 9, 2010), that allowed to calculate the temperature (and other physical parameters) of the two brown dwarfs.

text: CFBDSIR 1458+10 B was discovered in 2011 by Liu et al. with

text: laser guide star (LGS)

text: adaptive optics (AO)

text: system of the 10 m

text: Keck II Telescope

text: on

text: Mauna Kea

text: Hawaii

text: , using

text: infra-red

text: camera NIRC2 (the observations were made on 2010 May 22 and 2010 July 8 (

text: UT

text: )). In 2011 Liu et al. published a paper in

text: The Astrophysical Journal

text: where they presented discovery of CFBDSIR 1458+10 system component B (the only discovery presented in the article). Also they presented a near-infrared (J-band)

text: trigonometric parallax

text: of the system, measured using WIRCam on the

text: Canada-France-Hawaii Telescope (CFHT)

text: Mauna Kea

text: , in seven epochs during the 2009—2010; and

text: spectroscopy

text: with the X-Shooter

text: spectrograph

text: at the

text: European Southern Observatory

text: 's

text: Very Large Telescope (VLT)

text: Unit Telescope 2 (UT2) in

text: Chile

text: (the observations have been performed from May 5 to July 9, 2010), that allowed to calculate the temperature (and other physical parameters) of the two brown dwarfs.

text: The UK ATC was formed in 1998 in Edinburgh from the technology departments of the Royal Observatory, Edinburgh (ROE), and the Royal Greenwich Observatory, Cambridge (RGO). Its initial "customers" were the then new Gemini Observatory, the former ROE observatories in Hawaii (the James Clerk Maxwell Telescope (JCMT) and the United Kingdom Infrared Telescope (UKIRT)), and a former RGO observatory, the Isaac Newton Group on La Palma, Canary Islands. More recently, collaboration with the European Southern Observatory (ESO) and for the James Webb Space Telescope (JWST) have gained importance. Major projects and collaborations include:

text: The UK ATC was formed in 1998 in Edinburgh from the technology departments of the

text: Royal Observatory

text: , Edinburgh (ROE), and the

text: Royal Greenwich Observatory

text: , Cambridge (RGO). Its initial "customers" were the then new

text: Gemini Observatory

text: , the former ROE observatories in Hawaii (the

text: James Clerk Maxwell Telescope

text: (JCMT) and the

text: United Kingdom Infrared Telescope

text: (UKIRT)), and a former RGO observatory, the

text: Isaac Newton Group

text: on

text: La Palma

text: Canary Islands

text: . More recently, collaboration with the

text: European Southern Observatory

text: (ESO) and for the

text: James Webb Space Telescope

text: (JWST) have gained importance. Major projects and collaborations include:

text: The project aims to discover signs of extraterrestrial civilizations by searching stars and galaxies for radio signals and laser transmissions. The search for radio signals is carried out on the Green Bank Telescope in the Northern Hemisphere and the Parkes Telescope in the Southern Hemisphere. The Green Bank Telescope is the world's largest steerable radio telescope, and the Parkes Telescope is second largest telescope in the Southern Hemisphere.

text: The project aims to discover signs of

text: extraterrestrial civilizations

text: by searching stars and galaxies for

text: radio signals

text: and

text: laser

text: transmissions. The search for radio signals is carried out on the

text: Green Bank Telescope

text: in the

text: Northern Hemisphere

text: and the

text: Parkes Telescope

text: in the

text: Southern Hemisphere

text: . The Green Bank Telescope is the world's largest steerable radio telescope, and the Parkes Telescope is second largest telescope in the Southern Hemisphere.

text: The last program for which she set up the committee and with which she was highly involved was the Hubble Telescope. Roman was very involved with the early planning and specifically the setting up of the program's structure. Because of her contribution she is often called the “Mother of Hubble." NASA’s current chief astronomer, who worked with Roman at the agency, calls her “the mother of the Hubble Space Telescope.” “Which is often forgotten by our younger generation of astronomers who make their careers by using Hubble Space Telescope," says Ed Weiler. "Regretfully, history has forgotten a lot in today’s Internet age, but it was Nancy in the old days before the Internet and before Google and e-mail and all that stuff, who really helped to sell the Hubble Space Telescope, organize the astronomers, who eventually convinced Congress to fund it.”

text: The last program for which she set up the committee and with which she was highly involved was the

text: Hubble Telescope

text: . Roman was very involved with the early planning and specifically the setting up of the program's structure. Because of her contribution she is often called the “Mother of Hubble." NASA’s current chief astronomer, who worked with Roman at the agency, calls her “the mother of the Hubble Space Telescope.” “Which is often forgotten by our younger generation of astronomers who make their careers by using Hubble Space Telescope," says Ed Weiler. "Regretfully, history has forgotten a lot in today’s Internet age, but it was Nancy in the old days before the Internet and before Google and e-mail and all that stuff, who really helped to sell the Hubble Space Telescope, organize the astronomers, who eventually convinced Congress to fund it.”

text: In 1971, Sir Martin Ryle described why, in the late 1950s, radio astronomers at MRAO decided on the construction of the new One Mile telescope: "Our object was twofold. First we wanted to extend the range of our observations far back in time to the earliest days of the Universe, and this required a large increase in both sensitivity and resolution. With greater resolution we hoped that we might be able to draw radio maps of individual radio sources with sufficient detail to give some indication of the physical processes which brought them into being."

text: In 1971, Sir

text: Martin Ryle

text: described why, in the late 1950s, radio astronomers at MRAO decided on the construction of the new One Mile telescope: "Our object was twofold. First we wanted to extend the range of our observations far back in time to the earliest days of the Universe, and this required a large increase in both sensitivity and resolution. With greater resolution we hoped that we might be able to draw radio maps of individual radio sources with sufficient detail to give some indication of the physical processes which brought them into being."

text: During the 1970s, the telescope was used in conjunction with the Mark III to develop phase stable long baseline interferometers, leading to the development of MERLIN. The telescope was used as an interferometer with the Lovell Telescope to provide more accurate positions for radio sources found from a survey done in 1972 and 1973; the position of one radio source was found to coincide with a pair of faint blue stars, and after optical observations were made it was found to be the first gravitational lens. The majority of the current observational time of the Mark II is spent either on MERLIN or VLBI observations.

text: During the 1970s, the telescope was used in conjunction with the

text: Mark III

text: to develop phase stable long baseline interferometers, leading to the development of

text: MERLIN

text: . The telescope was used as an interferometer with the

text: Lovell Telescope

text: to provide more accurate positions for radio sources found from a survey done in 1972 and 1973; the position of one radio source was found to coincide with a pair of faint blue stars, and after optical observations were made it was found to be the first

text: gravitational lens

text: . The majority of the current observational time of the Mark II is spent either on

text: MERLIN

text: or

text: VLBI

text: observations.

text: Observatories are the places equipped with highly advanced Optical or Solar telescope and other electronic equipments. It is located in the best place for observation of the Cosmos, still is not in the reach of many hobbyist and enthusiasts. These places are meant mainly for research work and scientific observations. In India " Vainu bappu Observatory - Kavalur Observatory" in Kavalur has the largest Optical telescope planted, which is also counted as second largest optical telescope of Asia. Still to many fellow mates, visit to such observatories are not feasible. To help out such people and work as a group, "Astronomy clubs" are the best places. Astronomy clubs provide various opportunities to local individuals in enhancing their interests in astronomy through telescope observations, group discussions, Senior / professional training and many such activities.

text: Observatories are the places equipped with highly advanced Optical or

text: Solar telescope

text: and other electronic equipments. It is located in the best place for observation of the

text: Cosmos

text: , still is not in the reach of many hobbyist and enthusiasts. These places are meant mainly for research work and scientific observations. In India " Vainu bappu Observatory -

text: Kavalur Observatory

text: " in Kavalur has the largest

text: Optical telescope

text: planted, which is also counted as second largest optical telescope of Asia. Still to many fellow mates, visit to such observatories are not feasible. To help out such people and work as a group, "Astronomy clubs" are the best places. Astronomy clubs provide various opportunities to local individuals in enhancing their interests in astronomy through telescope observations, group discussions, Senior / professional training and many such activities.

text: The seven optical telescopes at Bayfordbury campus allow students to observe detailed images of objects in space. They can be equipped with a variety of research-grade CCD cameras, high resolution spectrographs or high frame-rate video cameras. Moreover, the five newest telescopes are also able to be operated remotely, and students and staff can request observations via the internet and have images taken automatically when the weather allows. The 4.5-metre radio telescope and 3-dish 115-metre baseline interferometer allow a completely different view of the universe. These are connected to 21 cm line receivers, to detect the neutral hydrogen in the galaxy and extragalactic radio sources.

text: The seven

text: optical telescopes

text: at Bayfordbury campus allow students to observe detailed images of objects in space. They can be equipped with a variety of research-grade CCD cameras, high resolution spectrographs or high frame-rate

text: video cameras

text: . Moreover, the five newest telescopes are also able to be operated remotely, and students and staff can request observations via the internet and have images taken automatically when the weather allows. The 4.5-metre

text: radio telescope

text: and 3-dish 115-metre baseline

text: interferometer

text: allow a completely different view of the universe. These are connected to 21 cm line receivers, to detect the

text: neutral hydrogen

text: in the galaxy and extragalactic radio sources.

text: Space telescopes such as the Hubble Space Telescope has signified a new era of detailed observations of faint objects from afar in all of the electromagnetic spectrum. This includes faint objects in the Solar system, such as Neptune. Adaptive optics technology has also allowed for detailed observations of faint objects from ground-based telescopes and this technology has been used since 1997 to obtain scientific information on Neptune and its atmosphere. These image recordings now exceed the capability of HST by far and in some instances even the Voyager images, such as Uranus. Ground-based observations are however always limited in their registration of electromagnetic waves of certain wavelengths, due to the inevitable atmospheric absorption, in particular of high energy waves.

text: Space telescopes such as the Hubble Space Telescope has signified a new era of detailed observations of faint objects from afar in all of the

text: electromagnetic spectrum

text: . This includes faint objects in the Solar system, such as Neptune.

text: Adaptive optics

text: technology has also allowed for detailed observations of faint objects from ground-based telescopes and this technology has been used since 1997 to obtain scientific information on Neptune and its atmosphere. These image recordings now exceed the capability of HST by far and in some instances even the Voyager images, such as Uranus. Ground-based observations are however always limited in their registration of electromagnetic waves of certain wavelengths, due to the inevitable

text: atmospheric absorption

text: , in particular of high energy waves.

text: Radio waves are a type of electromagnetic radiation with wavelengths in the electromagnetic spectrum longer than infrared light.  Radio waves have frequencies as high as 300 GHz to as low as 3 kHz, though some definitions describe waves above 1 or 3 GHz as microwaves, or include waves of any lower frequency. At 300 GHz, the corresponding wavelength is , and at 3 kHz is . Like all other electromagnetic waves, they travel at the speed  of light. Naturally occurring radio waves are generated by lightning, or by astronomical objects.

text: Radio waves are a type of

text: electromagnetic radiation

text: with

text: wavelength

text: s in the

text: electromagnetic spectrum

text: longer than

text: infrared

text: light.  Radio waves have

text: frequencies

text: as high as 300

text: GHz

text: to as low as 3

text: kHz

text: , though some definitions describe waves above 1 or 3 GHz as

text: microwaves

text: , or include waves of any lower frequency. At 300 GHz, the corresponding wavelength is , and at 3 kHz is . Like all other electromagnetic waves, they travel at the

text: speed  of light

text: . Naturally occurring radio waves are generated by

text: lightning

text: , or by

text: astronomical objects

text: Before the advent of telescopic photography, eight moons of Saturn were discovered by direct observation using optical telescopes. Saturn's largest moon, Titan, was discovered in 1655 by Christiaan Huygens using a  objective lens on a refracting telescope of his own design. Tethys, Dione, Rhea and Iapetus (the "Sidera Lodoicea") were discovered between 1671 and 1684 by Giovanni Domenico Cassini. Mimas and Enceladus were discovered in 1789 by William Herschel. Hyperion was discovered in 1848 by W.C. Bond, G.P. Bond and William Lassell.

text: Before the advent of

text: telescopic photography

text: , eight moons of Saturn were discovered by direct observation using

text: optical telescope

text: s. Saturn's largest moon,

text: Titan

text: , was discovered in 1655 by

text: Christiaan Huygens

text: using a

text: objective lens

text: on a

text: refracting telescope

text: of his own design.

text: Tethys

text: Dione

text: Rhea

text: and

text: Iapetus

text: (the "

text: Sidera Lodoicea

text: ") were discovered between 1671 and 1684 by

text: Giovanni Domenico Cassini

text: Mimas

text: and

text: Enceladus

text: were discovered in 1789 by

text: William Herschel

text: Hyperion

text: was discovered in 1848 by

text: W.C. Bond

text: G.P. Bond

text: and

text: William Lassell

text: When the telescope was proposed, a series of objectives for the telescope's observations were set out. These included:

text: The telescope is owned and operated by LCOGT. This telescope and its sister telescope Faulkes Telescope North are used by research and education groups across the globe. The Faulkes Telescope Project is one such group which provides observing time (awarded by LCOGT) for educational projects for UK schools.  Funds were initially sourced by charitable donations from philanthropist Dr. Martin C. Faulkes.

text: The telescope is owned and operated by

text: LCOGT

text: . This telescope and its sister telescope

text: Faulkes Telescope North

text: are used by research and education groups across the globe. The

text: Faulkes Telescope Project

text: is one such group which provides observing time (awarded by LCOGT) for educational projects for UK schools.  Funds were initially sourced by charitable donations from philanthropist

text: Dr. Martin C. Faulkes

text: However, in the domains of professional and semi-professional photography, as well as in the domain of special cameras, interchangeable optics are often used. In these cases, a system specialist has to adapt the optics and the chip to the application (see System integration). Besides normal lenses, such interchangeable lenses may be microscopes, endoscopes, telescopes, etc. With the exception of the standard C-mount and CS-mount, the mounts of interchangeable optics are company-specific.

text: However, in the domains of

text: professional

text: and semi-professional

text: photography

text: , as well as in the domain of

text: special

text: cameras, interchangeable optics are often used. In these cases, a system specialist has to adapt the optics and the chip to the application (see

text: System integration

text: ). Besides normal

text: lenses

text: , such interchangeable lenses may be

text: microscope

text: s,

text: endoscope

text: s,

text: telescope

text: s, etc. With the exception of the standard C-mount and CS-mount, the mounts of interchangeable optics are company-specific.

text: A small structure on the south side of the summit of Schultz Peak and referred to by some as a shepherd's cabin was actually built by Lowell Observatory in 1927 to house a telescope.  The site was selected by Dr. V. M. Slipher, Director of Lowell Observatory, for a pair of Bristlecone Pine trees oriented in a north-south line so that they could be cut and pressed into service as supports for the Polar Axle of the telescope.  The Polar Axle and telescopes were constructed by the Stanley Sykes of Lowell Observatory, and the cabin housing the telescope was constructed by Ramon Vilma (spelling?), a local stonemason <Personal Communication with Dr. H. L. Giclas>.  The structure had a corrugated metal roof that could be rolled off to expose the telescope for observations.  The Polar Axle was taken by truck on the then-new Weatherford Road to Schultz Saddle, then by mule to the Schultz Peak summit, and the two telescopes used there were hauled up in the same way.  The telescopes were a  reflector and a  reflector.  The observing site also had a small dormitory partially cut into the hillside east of the telescope, but only an indistinct depression remains.  From 1927 until 1932 this was the highest astronomical observing site on Planet Earth.  This distinction passed to the Swiss in 1932 when they commissioned a slightly higher observing site on the Jungfrau.  The original purpose of the site was to make spectroscopic observations of planets, stars, and nebulae to exploit the increased atmospheric transmission - especially in ultraviolet and infrared wavelengths - at high altitude.  A similar telescope and roll-off structure was constructed at the Mars Hill campus of Lowell Observatory so that spectroscopic observations made at the two sites could be compared.  The telescope at Mars Hill is still in service and now mounts a  reflector.  Today it is used by Dr. G. W. Lockwood to collect long-term data on variability of Solar Radiation and it has a fascinating history in its own right <http://www2.lowell.edu/users/wes/index.htm>.  The telescopes and Polar Axle from the Schultz Peak site still exist, and one of the bearing assemblies from the original roll-off roof has been retrieved from Schultz Peak as a possible future museum exhibit.

text: Since the atmosphere is opaque for most of the electromagnetic spectrum, only a few bands can be observed from the Earth's surface. These bands are visible – near-infrared and a portion of the radio-wave part of the spectrum. For this reason there are no X-ray or far-infrared ground-based telescopes as these have to be observed from orbit. Even if a wavelength is observable from the ground, it might still be advantageous to place a telescope on a satellite due to astronomical seeing.

text: Since the atmosphere is opaque for most of the electromagnetic spectrum, only a few bands can be observed from the Earth's surface. These bands are visible – near-infrared and a portion of the radio-wave part of the spectrum. For this reason there are no X-ray or far-infrared ground-based telescopes as these have to be observed from orbit. Even if a wavelength is observable from the ground, it might still be advantageous to place a telescope on a satellite due to

text: astronomical seeing

text: The Wisconsin Experiment Package had eleven different telescopes for ultraviolet observations. For example, there was a photoelectric photometer fed by a 16 inch telescope with a six-position filter wheel. WEP observed over 1200 targets in ultraviolet light before the mission ended in early 1973.

text: The planet was claimed to be detected by astronomers in the Lick–Carnegie Exoplanet Survey, led by principal investigator Steven S. Vogt, professor of astronomy and astrophysics at the University of California, Santa Cruz, and co-investigator R. Paul Butler of the Carnegie Institution of Washington. The discovery was made using radial velocity measurements, combining 122 observations obtained over 11 years from the High Resolution Echelle Spectrometer (HIRES) instrument of the Keck 1 telescope with 119 measurements obtained over 4.3 years from the High Accuracy Radial Velocity Planet Searcher (HARPS) instrument of the European Southern Observatory's 3.6 m telescope at La Silla Observatory.

text: The planet was claimed to be detected by astronomers in the

text: Lick–Carnegie Exoplanet Survey

text: , led by principal investigator

text: Steven S. Vogt

text: , professor of astronomy and astrophysics at the

text: University of California, Santa Cruz

text: , and co-investigator

text: R. Paul Butler

text: of the

text: Carnegie Institution of Washington

text: . The discovery was made using

text: radial velocity measurements

text: , combining 122 observations obtained over 11 years from the

text: High Resolution Echelle Spectrometer

text: (HIRES) instrument of the

text: Keck 1 telescope

text: with 119 measurements obtained over 4.3 years from the

entity_name: High Accuracy Radial Velocity Planet Searcher

text: High Accuracy Radial Velocity Planet Searcher

text: (HARPS) instrument of the

text: European Southern Observatory

text: 's

text: 3.6 m telescope

text: at

text: La Silla Observatory

text: For electromagnetic waves in vacuum, the angular frequency is proportional to the wavenumber:

text: For

text: electromagnetic wave

text: s in vacuum, the angular frequency is proportional to the wavenumber:

text: The Hubble Space Telescope (HST) has been used to perform systematic studies of Mars and has taken the highest resolution images of Mars ever captured from Earth. This telescope can produce useful images of the planet when it is at an angular distance of at least 50° from the Sun. The HST can take images of a hemisphere, which yields views of entire weather systems. Earth-based telescopes equipped with charge-coupled devices can produce useful images of Mars, allowing for regular monitoring of the planet's weather during oppositions.

text: The

text: Hubble Space Telescope

text: (HST) has been used to perform systematic studies of Mars and has taken the highest resolution images of Mars ever captured from Earth. This telescope can produce useful images of the planet when it is at an

text: angular distance

text: of at least 50° from the Sun. The HST can take images of a

text: hemisphere

text: , which yields views of entire weather systems. Earth-based telescopes equipped with

text: charge-coupled device

text: s can produce useful images of Mars, allowing for regular monitoring of the planet's weather during oppositions.

text: Before the invention of telescopes, events such as these that were visible to the naked eye, from within or near the Milky Way Galaxy, were very rare, and sometimes hundreds of years apart. However, such events were recorded in antiquity, such as the supernova in 1054 observed by Chinese, Japanese and Arab astronomers, and the event in 1572 known as "Tychos's Supernova" after Tycho Brahe, who studied it until it faded after two years. Even though telescopes made it possible to see more distant events, their small fields of view – typically less than 1 square degree – meant that the chances of looking in the right place at the right time were low.

text: Before the invention of telescopes, events such as these that were visible to the naked eye, from within or near the

text: Milky Way Galaxy

text: , were very rare, and sometimes hundreds of years apart. However, such events were recorded in antiquity, such as the

text: supernova in 1054

text: observed by Chinese, Japanese and Arab astronomers, and the event in 1572 known as "

text: Tychos's Supernova

text: " after

text: Tycho Brahe

text: , who studied it until it faded after two years. Even though telescopes made it possible to see more distant events, their small fields of view – typically less than 1

text: square degree

text: – meant that the chances of looking in the right place at the right time were low.

text: In April 1640, Neile was elected Member of Parliament for Ripon in the Short Parliament. During the interregnum he was living at White Waltham, Berkshire where he studied astronomy and built telescopes. Sir Christopher Wren was using Neile's telescope at White Waltham in 1655 and in 1658 Neile gave a 35-foot telescope to Gresham College. He was one of the twelve founder members of the Royal Society and in 1661 the Society "desired him to continue his employment of the artificer for making glasses for perspectives".

text: In April 1640, Neile was elected

text: Member of Parliament

text: for

text: Ripon

text: in the

text: Short Parliament

text: . During the interregnum he was living at

text: White Waltham

text: , Berkshire where he studied astronomy and built telescopes.

text: Sir Christopher Wren

text: was using Neile's telescope at White Waltham in 1655 and in 1658 Neile gave a 35-foot telescope to Gresham College. He was one of the twelve founder members of the

text: Royal Society

text: and in 1661 the Society "desired him to continue his employment of the artificer for making glasses for perspectives".

text: The network currently consists of  two fully operational 2-meter telescopes, Faulkes Telescope North and Faulkes Telescope South., three 1-meter telescopes at each of CTIO observatory in Chile and SAAO observatory in South Africa, two 1-meter telescopes  at Siding Spring Observatory in Australia (site of FTS) and one 1-meter telescope in Texas (McDonald Observatory), and seven 0.4 meter telescopes sited in Haleakala (site of FTN), CTIO, Tenerife in the Canary Islands (TO) and Siding Spring.  A 0.8-meter telescope at Sedgwick Reserve is also operational.

text: The network currently consists of  two fully operational 2-meter telescopes,

text: Faulkes Telescope North

text: and

text: Faulkes Telescope South

text: ., three 1-meter telescopes at each of

text: CTIO

text: observatory in Chile and

text: SAAO

text: observatory in South Africa, two 1-meter telescopes  at

text: Siding Spring Observatory

text: in Australia (site of FTS) and one 1-meter telescope in Texas (

text: McDonald Observatory

text: ), and seven 0.4 meter telescopes sited in Haleakala (site of FTN), CTIO, Tenerife in the Canary Islands (

text: TO

text: ) and Siding Spring.  A 0.8-meter telescope at

text: Sedgwick Reserve

text: is also operational.

text: The technique was developed in the 1960s, but was largely replaced in the 1970s and 1980s by spectroscopic redshifts, using spectroscopy to observe the frequency (or wavelength) of characteristic spectral lines, and measure the shift of these lines from their laboratory positions.  The photometric redshift technique has come back into mainstream use since 2000, as a result of large sky surveys conducted in the late 1990s and 2000s which have detected a large number of faint high-redshift objects, and telescope time limitations mean that only a small fraction of these can be observed by spectroscopy.

text: The technique was developed in the 1960s, but was largely replaced in the 1970s and 1980s by

text: spectroscopic redshift

text: s, using

text: spectroscopy

text: to observe the

text: frequency

text: (or

text: wavelength

text: ) of characteristic

text: spectral line

text: s, and measure the shift of these lines from their laboratory positions.  The photometric redshift technique has come back into mainstream use since 2000, as a result of large sky surveys conducted in the late 1990s and 2000s which have detected a large number of faint high-redshift objects, and telescope time limitations mean that only a small fraction of these can be observed by spectroscopy.

text: Space Surveillance Telescope is a telescope for detecting and tracking orbital debris. It has a 3.5 meter (138″) aperture mirror and came online in 2011.

text: Space Surveillance Telescope is a telescope for detecting and tracking

text: orbital debris

text: . It has a 3.5 meter (138″) aperture mirror and came online in 2011.

text: Many of the existing telescopes on satellites are compounded of multiple copies or variations of a detector-telescope system, whose capabilities add or complement each other and additional fixed or removable elements (filters, spectrometers) that add functionalities to the instrument.

text: Hewitt was born in Washington, D.C. on September 4, 1958 to parents Warren E. Hewitt, a retired international lawyer from the State Department, and Gertrud (Graedel) Hewitt.  She attended Bryn Mawr College where she graduated magna cum laude with a degree in economics in 1980.  Hewitt took an astronomy class her sophomore year, which sparked her interest in science.  She attended the Massachusetts Institute of Technology for graduate school.  During her graduate studies, she began studying gravitational lensing using the Very Large Array radio telescope.  She preferred using a radio telescope, as gravitational lenses emit a large amounts of radio waves, making them easier to discern with a radio telescope than with an optical telescope.  Hewitt obtained a Ph.D. in physics in 1986.  Some sources erroneously state that she received her Ph. D. in 1988.

text: Hewitt was born in Washington, D.C. on September 4, 1958 to parents Warren E. Hewitt, a retired international lawyer from the State Department, and Gertrud (Graedel) Hewitt.  She attended

text: Bryn Mawr College

text: where she graduated magna cum laude with a degree in economics in 1980.  Hewitt took an astronomy class her sophomore year, which sparked her interest in science.  She attended the

text: Massachusetts Institute of Technology

text: for graduate school.  During her graduate studies, she began studying gravitational lensing using the

text: Very Large Array

text: radio telescope.  She preferred using a radio telescope, as gravitational lenses emit a large amounts of radio waves, making them easier to discern with a radio telescope than with an optical telescope.  Hewitt obtained a Ph.D. in physics in 1986.  Some sources erroneously state that she received her Ph. D. in 1988.

text: In 1969, the Westerbork Synthesis Radio Telescope was installed near the site of the former camp. The radio telescope consists of an array of 14 antennas with a diameter of 25 metres each and is operated by ASTRON.

text: In 1969, the

text: Westerbork Synthesis Radio Telescope

text: was installed near the site of the former camp. The radio telescope consists of an array of 14 antennas with a diameter of 25 metres each and is operated by

text: ASTRON

text: The music video was directed by Chris Applebaum. The main premise of the video was centered around the conclusion of the movie A Walk to Remember. It showed Moore in Heaven and Shane West looking through a telescope at her. The movie featured the couple stargazing and Moore's character Jamie Sullivan believed that when she would look through a telescope at the stars she can see into Heaven. Landon Carter (West's character) looks through the telescope and can see a now passed Jamie in Heaven. As the video comes to a climax, there is an explosion and stars shoot from behind Moore. The video also shows West looking at random video clips of him and Moore. The home video was the summer that Moore and West's characters spent together before she died. The video was not a huge success on MTV like her prior video "Crush". The music video is included on A Walk to Remember DVD as an extra content. It was also included as a multi-media track on the 2003 special expanded edition of the film's soundtrack. However, the song is not yet included in her Vevo channel.

text: The music video was directed by

text: Chris Applebaum

text: . The main premise of the video was centered around the conclusion of the movie

text: A Walk to Remember

text: . It showed Moore in

text: Heaven

text: and

text: Shane West

text: looking through a telescope at her. The movie featured the couple stargazing and Moore's character Jamie Sullivan believed that when she would look through a telescope at the stars she can see into Heaven. Landon Carter (West's character) looks through the telescope and can see a now passed Jamie in Heaven. As the video comes to a climax, there is an explosion and stars shoot from behind Moore. The video also shows West looking at random video clips of him and Moore. The home video was the summer that Moore and West's characters spent together before she died. The video was not a huge success on MTV like her prior video "

text: Crush

text: ". The music video is included on A Walk to Remember DVD as an extra content. It was also included as a multi-media track on the 2003 special expanded edition of the film's

text: soundtrack

text: . However, the song is not yet included in her

text: Vevo

text: channel.

text: In 2004, Texas A&M joined a consortium of universities and countries to build the Giant Magellan Telescope in Chile; the largest optical telescope ever constructed, the facility has seven mirrors, each with a diameter of . This gives the telescope the equivalent of a  primary mirror and is ten times more powerful than the Hubble Space Telescope. Ground-breaking for the construction of the telescope began in November 2015.

text: In 2004, Texas A&M joined a consortium of universities and countries to build the

text: Giant Magellan Telescope

text: in

text: Chile

text: ; the largest optical telescope ever constructed, the facility has seven mirrors, each with a diameter of . This gives the telescope the equivalent of a  primary mirror and is ten times more powerful than the

text: Hubble Space Telescope

text: . Ground-breaking for the construction of the telescope began in November 2015.

text: Instruments used by SETI Institute scientists include the ground-based Allen Telescope Array, several ground-based optical telescopes such as the Shane telescope at Lick Observatory, the W.M. Keck telescopes & IRTF in Hawaii, the Very Large Telescopes in Chile. SETI researchers also use space telescope facilities, mostly  the Hubble Space Telescope, the Spitzer Space Telescope and the Herschel Space Telescope. SETI scientists are also involved in space missions, the New Horizons mission toward Pluto, the Cassini mission, currently in orbit around Saturn, and the Mars Rovers Opportunity and Curiosity.

text: Instruments used by SETI Institute scientists include the ground-based

text: Allen Telescope Array

text: , several ground-based optical telescopes such as the

text: Shane telescope

text: at

text: Lick Observatory

text: , the W.M.

text: Keck telescopes

text: IRTF

text: in Hawaii, the

text: Very Large Telescope

text: s in Chile. SETI researchers also use space telescope facilities, mostly  the

text: Hubble Space Telescope

text: , the

text: Spitzer Space Telescope

text: and the

text: Herschel Space Telescope

text: . SETI scientists are also involved in space missions, the

text: New Horizons

text: mission toward Pluto, the

text: Cassini

text: mission, currently in orbit around Saturn, and the Mars Rovers

text: Opportunity

text: and

text: Curiosity

text: Measurements of near-Earth orbital debris are accomplished by conducting ground-based and space-based observations of the orbital debris environment. Data is acquired using ground-based radars and optical telescopes , space-based telescopes, and analysis of spacecraft surfaces returned from space. Some important data sources have been the U.S. Space Surveillance Network, the Haystack X-Band Radar, and returned surfaces from the Solar Max, Long Duration Exposure Facility (LDEF), and the Space Shuttle spacecraft. The data provide validation of the environment models and identify the presence of new sources.

text: Measurements of near-Earth orbital debris are accomplished by conducting ground-based and space-based observations of the orbital debris environment. Data is acquired using ground-based radars and optical telescopes , space-based telescopes, and analysis of spacecraft surfaces returned from space. Some important data sources have been the

entity_name: United States Space Surveillance Network

text: U.S. Space Surveillance Network

text: , the

text: Haystack X-Band Radar

text: , and returned surfaces from the Solar Max,

text: Long Duration Exposure Facility

text: (LDEF), and the Space Shuttle spacecraft. The data provide validation of the environment models and identify the presence of new sources.

text: Thaddeus and his colleagues designed a radio telescope custom-built for the task of mapping the entire Milky Way in CO. The 1.2 meter Millimeter-Wave Telescope was designed with a relatively small dish and consequently a relatively large beamwidth of about 1/8 degree, which can be likened to a wide-angle lens. With this new instrument, it suddenly became possible to map large stretches of sky in relatively small amounts of time. The telescope is nicknamed "The Mini" because of its unusually small size. Together, "The Mini" and its twin in Chile have obtained what is by far the most extensive, uniform, and widely used Galactic survey of interstellar carbon monoxide (CO).

text: Thaddeus and his colleagues designed a radio telescope custom-built for the task of mapping the entire

text: Milky Way

text: in CO. The 1.2 meter Millimeter-Wave Telescope was designed with a relatively small dish and consequently a relatively large beamwidth of about 1/8 degree, which can be likened to a wide-angle lens. With this new instrument, it suddenly became possible to map large stretches of sky in relatively small amounts of time. The telescope is nicknamed "The Mini" because of its unusually small size. Together, "The Mini" and its twin in Chile have obtained what is by far the most extensive, uniform, and widely used Galactic survey of interstellar carbon monoxide (CO).

text: NASA officials decided to move up part of the servicing mission that had been scheduled for June 2000 after three of the telescope's six gyroscopes failed. Three gyroscopes must be working to meet the telescope's very precise pointing requirements, and the telescope's flight rules dictated that NASA consider a "call-up" mission before a fourth gyroscope failed. Four new gyros were installed during the first servicing mission (STS-61) in December 1993 and all six gyros were working during the second servicing mission (STS-82) in February 1997. Since then, a gyro failed in 1997, another in 1998 and a third in 1999. The Hubble team believed they understood the cause of the failures, although they could not be certain until the gyros were returned from space. Having fewer than three working gyroscopes would have precluded science observations, although the telescope would have remained safely in orbit until a servicing crew arrived.

text: NASA officials decided to move up part of the servicing mission that had been scheduled for June 2000 after three of the telescope's six

text: gyroscope

text: s failed. Three gyroscopes must be working to meet the telescope's very precise pointing requirements, and the telescope's flight rules dictated that NASA consider a "call-up" mission before a fourth gyroscope failed. Four new gyros were installed during the first servicing mission (

text: ) in December 1993 and all six gyros were working during the second servicing mission (

text: ) in February 1997. Since then, a gyro failed in 1997, another in 1998 and a third in 1999. The Hubble team believed they understood the cause of the failures, although they could not be certain until the gyros were returned from space. Having fewer than three working gyroscopes would have precluded science observations, although the telescope would have remained safely in orbit until a servicing crew arrived.

text: The Space Solar Telescope (SST) is a planned Chinese optical space solar telescope.

text: The Space Solar Telescope (SST) is a planned Chinese

text: optical

text: space

text: solar telescope

text: Noise-equivalent temperature (NET) is a measure of the sensitivity of a detector of thermal radiation in the infrared, terahertz or microwave portions of the electromagnetic spectrum.   It is the amount of incident signal temperature that would be needed to match the internal noise of the detector such that the signal-to-noise ratio is equal to one.  Often the spectrum of the NET is reported as a temperature per root bandwidth.  A detector that measures power is often interested in the analogous noise-equivalent power (NEP).  If a relation between intensity and temperature is well defined over the pass band, as in the case of a blackbody, then the NET simply scales with the NEP.

text: Noise-equivalent temperature (NET) is a measure of the sensitivity of a detector of thermal radiation in the

text: infrared

text: terahertz

text: or

text: microwave

text: portions of the

text: electromagnetic spectrum

text: .   It is the amount of incident signal

text: temperature

text: that would be needed to match the internal noise of the detector such that the

text: signal-to-noise ratio

text: is equal to one.  Often the spectrum of the NET is reported as a temperature per root bandwidth.  A detector that measures power is often interested in the analogous

text: noise-equivalent power

text: (NEP).  If a relation between intensity and temperature is well defined over the

text: pass band

text: , as in the case of a

text: blackbody

text: , then the NET simply scales with the NEP.

text: In the early 1970s, O'Leary and other gay liberation activists did not actively include all transsexuals and transvestites in proposed gay rights legislation, largely due to the belief that this would make basic legislation too difficult to pass at the time. O'Leary later regretted her stance against the drag queens attending in 1973: "Looking back, I find this so embarrassing because my views have changed so much since then. I would never pick on a transvestite now." "It was horrible. How could I work to exclude transvestites and at the same time criticize the feminists who were doing their best back in those days to exclude lesbians?"

text: In the early 1970s, O'Leary and other

text: gay liberation

text: activists did not actively include all

text: transsexual

text: s and

text: transvestite

text: s in proposed gay rights legislation, largely due to the belief that this would make basic legislation too difficult to pass at the time. O'Leary later regretted her stance against the drag queens attending in 1973: "Looking back, I find this so embarrassing because my views have changed so much since then. I would never pick on a transvestite now." "It was horrible. How could I work to exclude transvestites and at the same time criticize the feminists who were doing their best back in those days to exclude lesbians?"

text: Between 1886 and 1889 Hertz would conduct a series of experiments that would prove the effects he was observing were results of Maxwell's predicted electromagnetic waves. Starting in November 1887 with his paper "On Electromagnetic Effects Produced by Electrical Disturbances in Insulators", Hertz would send a series of papers to Helmholtz at the Berlin Academy, including papers in 1888 that showed transverse free space electromagnetic waves traveling at a finite speed over a distance. In the apparatus Hertz used, the electric and magnetic fields would radiate away from the wires as transverse waves. Hertz had positioned the oscillator about 12 meters from a zinc reflecting plate to produce standing waves. Each wave was about 4 meters long. Using the ring detector, he recorded how the wave's magnitude and component direction varied. Hertz measured Maxwell's waves and demonstrated that the velocity of these waves was equal to the velocity of light. The electric field intensity, polarity and reflection of the waves were also measured by Hertz. These experiments established that light and these waves were both a form of electromagnetic radiation obeying the Maxwell equations. Hertz also described the "Hertzian cone", a type of wave-front propagation through various media.

text: Between 1886 and 1889 Hertz would conduct a series of experiments that would prove the effects he was observing were results of Maxwell's predicted electromagnetic waves. Starting in November 1887 with his paper "On Electromagnetic Effects Produced by Electrical Disturbances in Insulators", Hertz would send a series of papers to Helmholtz at the Berlin Academy, including papers in 1888 that showed transverse

text: free space

text: electromagnetic wave

text: s traveling at a finite speed over a distance. In the apparatus Hertz used, the electric and magnetic fields would radiate away from the wires as

text: transverse waves

text: . Hertz had positioned the

text: oscillator

text: about 12 meters from a

text: zinc

text: reflecting plate to produce

text: standing wave

text: s. Each wave was about 4 meters long. Using the ring detector, he recorded how the wave's

text: magnitude

text: and component direction varied. Hertz measured Maxwell's waves and demonstrated that the

text: velocity

text: of these waves was equal to the velocity of light. The

text: electric field intensity

text: polarity

text: and

text: reflection

text: of the waves were also measured by Hertz. These experiments established that light and these waves were both a form of electromagnetic radiation obeying the Maxwell equations. Hertz also described the "

text: Hertzian cone

text: ", a type of wave-front propagation through various

text: media

text: The Hubble Space Telescope (HST) is a space telescope that was launched into low Earth orbit in 1990, and remains in operation. Although not the first space telescope, Hubble is one of the largest and most versatile, and is well known as both a vital research tool and a public relations boon for astronomy. The HST is named after the astronomer Edwin Hubble, and is one of NASA's Great Observatories, along with the Compton Gamma Ray Observatory, the Chandra X-ray Observatory, and the Spitzer Space Telescope.

text: The Hubble Space Telescope (HST) is a

text: space telescope

text: that was launched into

text: low Earth orbit

text: in 1990, and remains in operation. Although not the

text: first space telescope

text: , Hubble is one of the largest and most versatile, and is well known as both a vital research tool and a public relations boon for

text: astronomy

text: . The HST is named after the

text: astronomer

text: Edwin Hubble

text: , and is one of NASA's

text: Great Observatories

text: , along with the

text: Compton Gamma Ray Observatory

text: , the

text: Chandra X-ray Observatory

text: , and the

text: Spitzer Space Telescope

text: Born in Melbourne, Australia, Cowan completed his studies in Sydney. His first published works were Nine Poems (Mauritius, 1964) and A Rambling Man (Sydney, 1966). In the 1960s he travelled and worked in Mauritius, Vancouver, New York, Paris and London. For some years he lived in Marrakech, and in Libya, studying the Berber and Tuareg peoples. Returning to Australia in 1973, he decided to view his homeland as a foreign country. He made journeys throughout the continent, sometimes on horseback, exploring early European culture and its imprint on the land.  This led to a succession of books, The Mountain Men, The River People, and Starlight's Trail.

text: Born in

text: Melbourne

text: , Australia, Cowan completed his studies in Sydney. His first published works were Nine Poems (Mauritius, 1964) and A Rambling Man (Sydney, 1966). In the 1960s he travelled and worked in

text: Mauritius

text: , Vancouver, New York, Paris and London. For some years he lived in

text: Marrakech

text: , and in

text: Libya

text: , studying the Berber and Tuareg peoples. Returning to Australia in 1973, he decided to view his homeland as a foreign country. He made journeys throughout the continent, sometimes on horseback, exploring early

text: European culture

text: and its imprint on the land.  This led to a succession of books, The Mountain Men, The River People, and Starlight's Trail.

text: The Lovell Telescope  is a radio telescope at Jodrell Bank Observatory, near Goostrey, Cheshire in the north-west of England. When construction was finished in 1957, the telescope was the largest steerable dish radio telescope in the world at 76.2 m (250 ft) in diameter;it is now the third largest, after the Green Bank telescope in West Virginia, United States, and the Effelsberg telescope in Germany.It was originally known as the "250 ft telescope" or the Radio Telescope at Jodrell Bank, before becoming the Mark I telescope around 1961 when future telescopes (the Mark II, III, and IV) were being discussed. It was renamed to the Lovell Telescope in 1987 after Sir Bernard Lovell, and became a Grade I listed building in 1988. The telescope forms part of the MERLIN and European VLBI Network arrays of radio telescopes.

text: The Lovell Telescope  is a

text: radio telescope

text: at

text: Jodrell Bank Observatory

text: , near

text: Goostrey

text: Cheshire

text: in the north-west of England. When construction was finished in 1957, the telescope was the largest steerable dish radio telescope in the world at 76.2 m (250 ft) in diameter;it is now the third largest, after the

text: Green Bank

text: telescope in

text: West Virginia

text: , United States, and the

text: Effelsberg

text: telescope in Germany.It was originally known as the "250 ft telescope" or the Radio Telescope at Jodrell Bank, before becoming the Mark I telescope around 1961 when future telescopes (the

text: Mark II

text: III

text: , and IV) were being discussed. It was renamed to the Lovell Telescope in 1987 after Sir

text: Bernard Lovell

text: , and became a Grade I

text: listed building

text: in 1988. The telescope forms part of the

text: MERLIN

text: and

text: European VLBI Network

text: arrays of radio telescopes.

text: Radio – transmission of signals by modulation of electromagnetic waves with frequencies below those of visible light. Electromagnetic radiation travels by means of oscillating electromagnetic fields that pass through the air and the vacuum of space. Information is carried by systematically changing (modulating) some property of the radiated waves, such as amplitude, frequency, phase, or pulse width. When radio waves pass an electrical conductor, the oscillating fields induce an alternating current in the conductor. This can be detected and transformed into sound or other signals that carry information.

text: Radio

text: – transmission of signals by modulation of

text: electromagnetic waves

text: with

text: frequencies

text: below those of

text: visible light

text: . Electromagnetic radiation

text: travels

text: by means of oscillating

text: electromagnetic field

text: s that pass through the air and the

text: vacuum

text: of space. Information is carried by systematically changing (

text: modulating

text: ) some property of the radiated waves, such as

text: amplitude

text: frequency

text: phase

text: , or pulse width. When radio waves pass an electrical conductor, the oscillating fields induce an alternating current in the conductor. This can be

text: detected

text: and transformed into sound or other signals that carry information.

text: A duplex communication system is a system composed of two connected parties or devices which can communicate with one another in both directions. The term duplex is used when describing communication between two parties or devices. Duplex systems are employed in nearly all communications networks, either to allow for a communication "two-way street" between two connected parties or to provide a "reverse path" for the monitoring and remote adjustment of equipment in the field.An Antenna is basically a small length of a qwert conductor that is used to radiate or receive electromagnetic waves.It acts as a conversion device.At the transmitting end it converts high frequency current into electromagnetic waves.At the receiving end it transforms electromagnetic waves into electrical signals that is fed into the input of the receiver. several types of antenna are used in communication.

text: A

text: duplex communication system

text: is a system composed of two connected parties or devices which can communicate with one another in both directions. The term duplex is used when describing communication between two parties or devices. Duplex systems are employed in nearly all communications networks, either to allow for a communication "two-way street" between two connected parties or to provide a "reverse path" for the monitoring and remote adjustment of equipment in the field.An

text: Antenna

text: is basically a small length of a qwert conductor that is used to radiate or receive electromagnetic waves.It acts as a conversion device.At the transmitting end it converts high frequency current into electromagnetic waves.At the receiving end it transforms electromagnetic waves into electrical signals that is fed into the input of the receiver. several types of antenna are used in communication.

text: The sensitivity of Earth-based infrared telescopes is significantly limited by water vapor in the atmosphere, which absorbs a portion of the infrared radiation arriving from space outside of selected atmospheric windows. This limitation can be partially alleviated by placing the telescope observatory at a high altitude, or by carrying the telescope aloft with a balloon or an aircraft. Space telescopes do not suffer from this handicap, and so outer space is considered the ideal location for infrared astronomy.

text: The sensitivity of Earth-based infrared telescopes is significantly limited by water vapor in the atmosphere, which absorbs a portion of the infrared radiation arriving from space outside of selected

text: atmospheric window

text: s. This limitation can be partially alleviated by placing the telescope observatory at a high altitude, or by carrying the telescope aloft with a balloon or an aircraft. Space telescopes do not suffer from this handicap, and so outer space is considered the ideal location for infrared astronomy.

text: Raymond N. Wilson is an English physicist and telescope optics designer, best known for pioneering the use of active optics in large telescopes.

text: Raymond N. Wilson is an English physicist and telescope optics designer, best known for pioneering the use of

text: active optics

text: in large telescopes.

text: There have been three main phases in the observation and exploration of Saturn. The first era was ancient observations (such as with the naked eye), before the invention of the modern telescopes. Starting in the 17th century progressively more advanced telescopic observations from Earth have been made. The other type is visitation by spacecraft, either by orbiting or flyby. In the 21st century observations continue from the Earth (or Earth-orbiting observatories) and from the Cassini orbiter at Saturn.

text: There have been three main phases in the observation and exploration of Saturn. The first era was ancient observations (such as with the

text: naked eye

text: ), before the invention of the modern telescopes. Starting in the 17th century progressively more advanced telescopic observations from Earth have been made. The other type is visitation by spacecraft, either by orbiting or flyby. In the 21st century observations continue from the Earth (or Earth-orbiting observatories) and from the Cassini orbiter at Saturn.

text: The phase velocity of an electromagnetic wave, when traveling through a medium, can routinely exceed c, the vacuum velocity of light. For example, this occurs in most glasses at X-ray frequencies. However, the phase velocity of a wave corresponds to the propagation speed of a theoretical single-frequency (purely monochromatic) component of the wave at that frequency. Such a wave component must be infinite in extent and of constant amplitude (otherwise it is not truly monochromatic), and so cannot convey any information.Thus a phase velocity above c does not imply the propagation of signals with a velocity above c.

text: The

text: phase velocity

text: of an

text: electromagnetic wave

text: , when traveling through a medium, can routinely exceed c, the vacuum velocity of light. For example, this occurs in most glasses at

text: X-ray

text: frequencies. However, the phase velocity of a wave corresponds to the propagation speed of a theoretical single-frequency (purely

text: monochromatic

text: ) component of the wave at that frequency. Such a wave component must be infinite in extent and of constant amplitude (otherwise it is not truly monochromatic), and so cannot convey any information.Thus a phase velocity above c does not imply the propagation of

text: signals

text: with a velocity above c.

text: Two additional telescopes were added in Phase 2 of the project, along with their radio links to Jodrell Bank. While it was originally proposed that one of the telescopes would be sited at Jodrell Bank and the other at Darnhall, the pair were finally sited at Pickmere (also known as Tabley) and Darnhall. The two telescopes were the same as that at Knockin. Construction on both telescopes started on 9 April 1979, and was completed by 31 October 1979. The Pickmere telescope was connected into MTRLI for the first time on 20 July 1980, followed by the Darnhall telescope on 16 December 1980. The second phase was formally completed on the 31 December 1981, and had cost £3,142,210.

text: ASCA carried four large-area X-ray telescopes. At the focus of two of the telescopes is a gas imaging spectrometer (GIS), while a solid-state imaging spectrometer (SIS) is at the focus of the other two. The GIS is a gas-imaging scintillation proportional counter and is based on the GSPC that flew on the second Japanese X-ray astronomy mission TENMA. The two identical charge-coupled device (CCD) cameras were provided for the two SISs by a hardware team from MIT, Osaka University and ISAS.

text: ASCA carried four large-area

text: X-ray telescope

text: s. At the focus of two of the telescopes is a

text: gas imaging spectrometer

text: (GIS), while a

text: solid-state imaging spectrometer

text: (SIS) is at the focus of the other two. The GIS is a gas-imaging scintillation proportional counter and is based on the GSPC that flew on the second Japanese X-ray astronomy mission TENMA. The two identical

text: charge-coupled device

text: (CCD) cameras were provided for the two SISs by a hardware team from MIT, Osaka University and ISAS.

text: The ARIESXXI radio telescope is an alt-azimuthal design with a rotating head above an azimuthal bearing or turning head.  It has full 360-degree movement in azimuth and horizon to horizon coverage in elevation (180 degrees total or slightly less?). As previously mentioned the telescope is Nasmyth-Cassegrain model that consists of a parabolic primary reflector and a hyperbolic secondary reflector that brings the dual system to a focus some 11 metres below, within the structure of the telescope housing, via a beam-guide. The optical configuration of the tertiary Nasmyth system is such that the focus is always maintained in the same place as the flat Nasmyth mirrors track the movement of the principle axis of the dual reflector to ensure a constant illumination of the receivers. This allows the receiver antennas to remain fixed in position and greatly simplifies the opto-mechanical design of the receiver suite.

text: The ARIESXXI

text: radio telescope

text: is an alt-azimuthal design with a rotating head above an azimuthal bearing or turning head.  It has full 360-degree movement in

text: azimuth

text: and horizon to horizon coverage in elevation (180 degrees total or slightly less?). As previously mentioned the telescope is Nasmyth-Cassegrain model that consists of a parabolic primary reflector and a hyperbolic secondary reflector that brings the dual system to a focus some 11 metres below, within the structure of the telescope housing, via a beam-guide. The optical configuration of the tertiary Nasmyth system is such that the focus is always maintained in the same place as the flat Nasmyth mirrors track the movement of the principle axis of the dual reflector to ensure a constant illumination of the receivers. This allows the receiver antennas to remain fixed in position and greatly simplifies the opto-mechanical design of the receiver suite.

text: Natural sources produce EM radiation across the spectrum. EM radiation with a wavelength between approximately 400 nm and 700 nm is directly detected by the human eye and perceived as visible light. Other wavelengths, especially nearby infrared (longer than 700 nm) and ultraviolet (shorter than 400 nm) are also sometimes referred to as light.

text: Natural sources produce EM radiation across the spectrum. EM radiation with a

text: wavelength

text: between approximately 400

text: nm

text: and 700 nm is directly detected by the

text: human eye

text: and perceived as visible

text: light

text: . Other wavelengths, especially nearby infrared (longer than 700 nm) and ultraviolet (shorter than 400 nm) are also sometimes referred to as light.

text: Several years later, when Rundgren was asked how, looking back, he would characterize his time with The New Cars, he replied "Bittersweet. You know, we all put a lot of effort into it, but we got practically nothing out of it but aggravation".

text: In the following years, the telescope was used to track a variety of space probes. Between 11 March and 12 June 1960, it tracked the Pioneer 5 probe. The telescope was also used to send commands to the probe, including the one to separate the probe from its carrier rocket and the ones to turn on the more powerful transmitter when the probe was eight million miles away. It also received data from the probe, being the only telescope in the world capable of doing so at the time. In February 1966, Jodrell Bank was asked by the Soviet Union to track the USSR unmanned moon lander Luna 9 and recorded on its facsimile transmission of photographs from the moon's surface. The photos were sent to the British press and published before the Soviets themselves had made the photos public.

text: In the following years, the telescope was used to track a variety of space probes. Between 11 March and 12 June 1960, it tracked the

text: Pioneer 5

text: probe. The telescope was also used to send commands to the probe, including the one to separate the probe from its carrier rocket and the ones to turn on the more powerful transmitter when the probe was eight million miles away. It also received data from the probe, being the only telescope in the world capable of doing so at the time. In February 1966, Jodrell Bank was asked by the Soviet Union to track the

text: USSR

text: unmanned moon lander

text: Luna 9

text: and recorded on its

text: facsimile

text: transmission of photographs from the moon's surface. The photos were sent to the British press and published before the Soviets themselves had made the photos public.

text: Theorized by Lyman Spitzer in 1946, the first operational space telescopes were the American Orbiting Astronomical Observatory OAO-2 launched in 1968 and the Soviet Orion 1 ultraviolet telescope aboard space station Salyut 1 in 1971.

text: Theorized by

text: Lyman Spitzer

text: in 1946, the first operational space telescopes were the American

text: Orbiting Astronomical Observatory

text: OAO-2 launched in 1968 and the Soviet

text: Orion 1 ultraviolet telescope

text: aboard space station

text: Salyut 1

text: in 1971.

text: SOR's optical equipment includes a 3.5 meter telescope which is "one of the largest telescopes in the world equipped with adaptive optics designed for satellite tracking" according to the Air Force, a 1.5 meter telescope, and a 1-meter beam director.

text: SOR's optical equipment includes a 3.5 meter

text: telescope

text: which is "one of the largest telescopes in the world equipped with adaptive optics designed for satellite tracking" according to the Air Force, a 1.5 meter telescope, and a 1-meter beam director.

text: The Robert C. Byrd Green Bank Telescope (GBT) is the world's largest fully steerable radio telescope. The Green Bank site was part of the National Radio Astronomy Observatory (NRAO) until September 30, 2016. Since October 1, 2016, the telescope has been operated by the newly created Green Bank Observatory. The telescope honors the name of the late Senator Robert C. Byrd who represented West Virginia and who pushed the funding of the telescope through Congress.

text: The Robert C. Byrd Green Bank Telescope (GBT) is the world's largest fully steerable

text: radio telescope

text: . The

text: Green Bank

text: site was part of the

text: National Radio Astronomy Observatory

text: (NRAO) until September 30, 2016. Since October 1, 2016, the telescope has been operated by the newly created

text: Green Bank Observatory

text: . The telescope honors the name of the late

text: Senator Robert C. Byrd

text: who represented West Virginia and who pushed the funding of the telescope through Congress.

text: For many years, the Moon has been recognized as an excellent site for telescopes. It is relatively nearby; astronomical seeing is not a concern; certain craters near the poles are permanently dark and cold, and thus especially useful for infrared telescopes; and radio telescopes on the far side would be shielded from the radio chatter of Earth. The lunar soil, although it poses a problem for any moving parts of telescopes, can be mixed with carbon nanotubes and epoxies and employed in the construction of mirrors up to 50 meters in diameter. A lunar zenith telescope can be made cheaply with ionic liquid.

text: For many years, the Moon has been recognized as an excellent site for telescopes. It is relatively nearby;

text: astronomical seeing

text: is not a concern; certain craters near the poles are permanently dark and cold, and thus especially useful for

text: infrared telescope

text: s; and

text: radio telescope

text: s on the far side would be shielded from the radio chatter of Earth. The

text: lunar soil

text: , although it poses a problem for any moving parts of

text: telescope

text: s, can be mixed with

text: carbon nanotube

text: s and

text: epoxies

text: and employed in the construction of mirrors up to 50 meters in diameter. A lunar

text: zenith telescope

text: can be made cheaply with

text: ionic liquid

text: The sizes of both moons are calculated with the assumption that they have the same infrared albedo as Haumea, which is reasonable as their spectra show them to have the same surface composition. Haumea's albedo has been measured by the Spitzer Space Telescope: from ground-based telescopes, the moons are too small and close to Haumea to be seen independently. Based on this common albedo, the inner moon, Namaka, which is a tenth the mass of Hiʻiaka, would be about 170 km in diameter.

text: The sizes of both moons are calculated with the assumption that they have the same infrared

text: albedo

text: as Haumea, which is reasonable as their spectra show them to have the same surface composition. Haumea's albedo has been measured by the

text: Spitzer Space Telescope

text: : from ground-based telescopes, the moons are too small and close to Haumea to be seen independently. Based on this common albedo, the inner moon, Namaka, which is a tenth the mass of Hiʻiaka, would be about 170 km in diameter.

text: The detectors will be located on two instrument platforms—the Moveable Instrument Platform (MIP) and the Fixed Instrument Platform (FIP). The Moveable Instrument Platform is needed because an X-ray telescopes cannot be folded as it can be done with visible-spectrum telescopes. Therefore, IXO will use the MIP that holds the following detectors—a wide field imaging & hard X-ray imaging detector, a high-spectral-resolution imaging spectrometer, a high timing resolution spectrometer, and a polarimeter—and rotates them into the focus in turn.

text: The detectors will be located on two instrument platforms—the Moveable Instrument Platform (MIP) and the Fixed Instrument Platform (FIP). The Moveable Instrument Platform is needed because an

text: X-ray telescopes

text: cannot be folded as it can be done with visible-spectrum telescopes. Therefore, IXO will use the MIP that holds the following detectors—a wide field imaging & hard X-ray imaging detector, a high-spectral-resolution imaging spectrometer, a high timing resolution spectrometer, and a polarimeter—and rotates them into the focus in turn.

text: The Submillimeter Array (SMA) consists of eight  diameter radio telescopes arranged as an interferometer for submillimeter wavelength observations. It is the first purpose-built submillimeter interferometer, constructed after successful interferometry experiments using the pre-existing  James Clerk Maxwell Telescope and  Caltech Submillimeter Observatory as an interferometer. All three of these observatories are located at Mauna Kea Observatory on Mauna Kea, Hawaii, and can be operated together as a ten element interferometer in the 230 and 345 GHz bands (eSMA, for extended Submillimeter Array). The baseline lengths presently in use range from , and up to  for eSMA operations. The radio frequencies accessible to this telescope range from 180 to 700 GHz which includes rotational transitions of dozens of molecular species as well as continuum emission from interstellar dust grains. Although the array is capable of operating both day and night, most of the observations take place at nighttime when the atmospheric phase stability is best.

text: The Submillimeter Array (SMA) consists of eight  diameter

text: radio telescope

text: s arranged as an

text: interferometer

text: for

text: submillimeter

text: wavelength observations. It is the first purpose-built submillimeter interferometer, constructed after successful interferometry experiments using the pre-existing

text: James Clerk Maxwell Telescope

text: and

text: Caltech Submillimeter Observatory

text: as an interferometer. All three of these observatories are located at

text: Mauna Kea Observatory

text: on

text: Mauna Kea

text: Hawaii

text: , and can be operated together as a ten element interferometer in the 230 and 345

text: GHz

text: bands (eSMA, for extended Submillimeter Array). The baseline lengths presently in use range from , and up to  for eSMA operations. The radio frequencies accessible to this telescope range from 180 to 700 GHz which includes rotational transitions of dozens of molecular species as well as continuum emission from interstellar dust grains. Although the array is capable of operating both day and night, most of the observations take place at nighttime when the atmospheric phase stability is best.

text: Today, the telescope is used for public outreach. It is the second largest telescope in the world devoted to the general public. Custom made 10 cm eyepieces are fitted to its focus using the bent cassegrain configuration to provide views of the moon, planetary, and deep-sky objects. Groups of up to 25 individuals are able to book the telescope for an evening of observing, with a Telescope Operator and a Session Director taking care of the safe operation of the telescope. As of the 2015 observing season, the cost for a half-night of observing is $900 and full night of observing is $1700.

text: The Hopkins Ultraviolet Telescope (HUT) was a space telescope designed to make spectroscopic observations in the far-ultraviolet region of the electromagnetic spectrum. It was flown into orbit on the Space Shuttle and operated from the Shuttle's payload bay on two occasions: in December 1990, as part of Shuttle mission STS-35, and in March 1995, as part of mission STS-67.

text: The Hopkins Ultraviolet Telescope (HUT) was a space telescope designed to make

text: spectroscopic

text: observations in the

text: far-ultraviolet

text: region of the

text: electromagnetic spectrum

text: . It was flown into orbit on the

text: Space Shuttle

text: and operated from the Shuttle's payload bay on two occasions: in December 1990, as part of Shuttle mission

text: , and in March 1995, as part of mission

text: Some psychologists suggest telescoping errors are due to the heuristics used to answer dating and frequency questions. When asked questions about frequency, people often answer using phrases like "all the time" and "everyday" and therefore don't account for exceptions. Depending on the events in question, this could lead to an over or under estimation of the occurrence of an event, and be perceived as telescoping. This over reporting is a result of telescoping because telescoping causes participants include events beyond the period. Therefore, heuristics may be responsible for some of the telescoping errors.

text: The main result of loop quantum gravity is the derivation of a granular structure of space at the Planck length.  This is derived from following considerations: In the case of electromagnetism, the quantum operator representing the energy of each frequency of the field has a discrete spectrum. Thus the energy of each frequency is quantized, and the quanta are the photons. In the case of gravity, the operators representing the area and the volume of each surface or space region likewise have discrete spectrum. Thus area and volume of any portion of space are also quantized, where the quanta are elementary quanta of space.  It follows, then, that spacetime has an elementary quantum granular structure at the Planck scale, which cuts off the ultraviolet infinities of quantum field theory.

text: Comets can be gone but not considered lost, even though they may not be expected back for hundreds or even thousands of years. With more powerful telescopes it has become possible to observe comets for longer periods of time after perihelion. For example, Comet Hale–Bopp was observable with the naked eye about 18 months after its approach in 1997. It is expected to remain observable with large telescopes until perhaps 2020, by which time it will be nearing 30th magnitude.

text: Comets can be gone but not considered lost, even though they may not be expected back for hundreds or even thousands of years. With more powerful telescopes it has become possible to observe comets for longer periods of time after perihelion. For example,

text: Comet Hale–Bopp

text: was observable with the naked eye about 18 months after its approach in 1997. It is expected to remain observable with large telescopes until perhaps 2020, by which time it will be nearing 30th

text: magnitude

text: For example, the SOAR 4 meter telescope has a small field of view (~f/16) which is useful for stellar studies. The LSST 8.4 m telescope, which will cover the entire sky every three days has a very large field of view. Its short 10.3 m focal length (f/1.2) is made possible by an error correction system which includes secondary and tertiary mirrors, a three element refractive system and active mounting and optics.

text: For example, the

entity_name: Southern Astrophysical Research Telescope

text: SOAR

text: 4 meter telescope has a small field of view (~f/16) which is useful for stellar studies. The

text: LSST

text: 8.4 m telescope, which will cover the entire sky every three days has a very large field of view. Its short 10.3 m focal length (f/1.2) is made possible by an error correction system which includes secondary and tertiary mirrors, a three element refractive system and active mounting and optics.

text: STS-37, the eighth flight of the Space Shuttle Atlantis, was a six-day mission with the primary objective of launching the Compton Gamma Ray Observatory (GRO), the second of the Great Observatories program which included the visible-spectrum Hubble Space Telescope, the Chandra X-ray Observatory and the infrared Spitzer Space Telescope. The mission also featured two spacewalks, the first since 1985.

text: STS-37, the eighth flight of the

text: Space Shuttle

text: Atlantis

text: , was a six-day mission with the primary objective of launching the

text: Compton Gamma Ray Observatory

text: (GRO), the second of the

text: Great Observatories program

text: which included the visible-spectrum

text: Hubble Space Telescope

text: , the

text: Chandra X-ray Observatory

text: and the infrared

text: Spitzer Space Telescope

text: . The mission also featured two spacewalks, the first since 1985.

text: GoTo mounts are pre-aligned before use. When they are powered on, they may ask for the user's latitude, longitude, time, and date (they can get this data from a GPS receiver connected to the telescope, or even built into the telescope mount itself and the telescope mount controller can have a real time clock).

text: GoTo mounts are pre-aligned before use. When they are powered on, they may ask for the user's latitude, longitude, time, and date (they can get this data from a

text: GPS

text: receiver connected to the telescope, or even built into the telescope mount itself and the telescope mount controller can have a real time clock).

text: 1865: James Clerk Maxwell publishes his landmark paper A Dynamical Theory of the Electromagnetic Field, in which Maxwell's equations demonstrated that electric and magnetic forces are two complementary aspects ofelectromagnetism. He shows that the associated complementary electric and magnetic fields of electromagnetism travel through space, in the form of waves, at a constant velocity of 3.0 × 10 m/s. He also proposes that light is a form of electromagnetic radiation and that waves of oscillating electric and magnetic fields travel through empty space at a speed that could be predicted from simple electrical experiments. Using available data, he obtains a velocity of 310,740,000 m/s and states "This velocity is so nearly that of light, that it seems we have strong reason to conclude that light itself (including radiant heat, and other radiations if any) is an electromagnetic disturbance in the form of waves propagated through the electromagnetic field according to electromagnetic laws."

text: James Clerk Maxwell

text: publishes his landmark paper

text: , in which

text: Maxwell's equations

text: demonstrated that electric and

text: magnetic

text: forces are two complementary aspects of

text: electromagnetism

text: . He shows that the associated complementary electric and magnetic fields of electromagnetism travel through space, in the form of waves, at a constant velocity of 3.0 × 10 m/s. He also proposes that light is a form of electromagnetic radiation and that waves of oscillating electric and magnetic fields travel through empty space at a speed that could be predicted from simple electrical experiments. Using available data, he obtains a velocity of 310,740,000 m/s and states "This velocity is so nearly that of light, that it seems we have strong reason to conclude that light itself (including radiant heat, and other

text: radiation

text: s if any) is an electromagnetic disturbance in the form of waves propagated through the electromagnetic field according to electromagnetic laws."

text: In 1887, the German physicist Heinrich Hertz in a series of experiments proved the actual existence electromagnetic waves, showing that transverse free space electromagnetic waves can travel over some distance as predicted by Maxwell and Faraday. Hertz published his work in a book titled: Electric waves: being researches on the propagation of electric action with finite velocity through space. The discovery of electromagnetic waves in space led to the development in the closing years of the 19th century of radio.

text: In 1887, the German physicist

text: Heinrich Hertz

text: in a series of experiments proved the actual existence

text: electromagnetic wave

text: s, showing that transverse

text: free space

text: electromagnetic waves can travel over some distance as predicted by Maxwell and Faraday. Hertz published his work in a book titled: Electric waves: being researches on the propagation of electric action with finite velocity through space. The discovery of electromagnetic waves in space led to the development in the closing years of the 19th century of radio.

text: The space telescopes were to observe in the infrared part of the electromagnetic spectrum. As well as studying extrasolar planets, the telescopes would probably have been useful for general purpose imaging, producing very high resolution (i.e. milliarcsecond) infrared images, allowing detailed study of a variety of astrophysical processes.

text: The space telescopes were to observe in the

text: infrared

text: part of the

text: electromagnetic spectrum

text: . As well as studying

text: extrasolar planet

text: s, the telescopes would probably have been useful for general purpose imaging, producing very high resolution (i.e.

text: milliarcsecond

text: ) infrared images, allowing detailed study of a variety of astrophysical processes.

text: GN-108036 is a distant galaxy discovered and confirmed by the Subaru Telescope and the Keck Observatory located in Hawaii; its study was also completed by the Hubble Space Telescope and the Spitzer Space Telescope.

text: GN-108036 is a distant

text: galaxy

text: discovered and confirmed by the

text: Subaru Telescope

text: and the

text: Keck Observatory

text: located in

text: Hawaii

text: ; its study was also completed by the Hubble Space Telescope and the Spitzer Space Telescope.

text: Phasor approach refers to a method which is used for vectorial representation of  sinusoidal waves like alternative currents and voltages or electromagnetic waves. The amplitude and the phase of the waveform is transformed into a vector where the phase is translated to the angle between the phasor vector and X axis and the amplitude is translated to vector length or magnitude.In this concept the representation and the analysis becomes very simple and the addition of two wave forms is realized by their vectorial summation.

text: Phasor

text: approach refers to a method which is used for vectorial representation of  sinusoidal waves like alternative currents and voltages or electromagnetic waves. The amplitude and the phase of the waveform is transformed into a vector where the phase is translated to the angle between the phasor vector and X axis and the amplitude is translated to vector length or magnitude.In this concept the representation and the analysis becomes very simple and the addition of two wave forms is realized by their vectorial summation.

text: All climate models take account of incoming energy from the sun as short wave electromagnetic radiation, chiefly visible and short-wave (near) infrared, as well as outgoing long wave (far) infrared electromagnetic. Any imbalance results in a change in temperature.

text: All climate models take account of incoming

text: energy

text: from the sun as short wave

text: electromagnetic radiation

text: , chiefly

text: visible

text: and short-wave (near)

text: infrared

text: , as well as outgoing long wave (far)

text: infrared

text: electromagnetic. Any imbalance results in a

text: change in temperature

text: Meniscus correctors are used as full aperture correctors, most commonly in a Maksutov telescope sub type called the Gregory or “spot” Maksutov–Cassegrain telescope. They are also used in the Bouwers meniscus telescope. There are Maksutov variations that use the same principle but place the meniscus lens as a sub-aperture corrector near the focus of the objective. There are other sub-aperture meniscus corrector catadioptric telescopes such as the Argunov–Cassegrain telescope and the Klevtsov–Cassegrain telescope.

text: Meniscus correctors are used as full aperture correctors, most commonly in a

text: Maksutov telescope

text: sub type called the Gregory or “spot”

text: Maksutov–Cassegrain telescope

text: . They are also used in the

text: Bouwers meniscus telescope

text: . There are Maksutov variations that use the same principle but place the meniscus lens as a sub-aperture corrector near the focus of the objective. There are other sub-aperture meniscus corrector catadioptric telescopes such as the

text: Argunov–Cassegrain telescope

text: and the

text: Klevtsov–Cassegrain telescope

text: Telescopic Handlers are like forklift trucks that have a telescoping extendable boom like a crane. Early telescopic handlers only lifted in one direction and did not rotate, however, several of the manufacturers have designed telescopic handlers that rotate 360 degrees through a turntable and these machines look almost identical to the Rough Terrain Crane. These new 360 degree telescopic handler/crane models have outriggers or stabiliser legs that must be lowered before lifting, however their design has been simplified so that they can be more quickly deployed. These machines are often used to handle pallets of bricks and install frame trusses on many new building sites and they have eroded much of the work for small telescopic truck cranes. Many of the worlds Armed forces have purchased telescopic handlers and some of these are the much more expensive fully rotating types. Their off road capability and their on site versatility to unload pallets using forks, or lift like a crane makes them a valuable piece of machinery.

text: Classical waves transfer energy without transporting matter through the medium (material). For example, waves in a pond do not carry the water molecules from place to place; rather the wave's energy travels through the water, leaving the water molecules in place. Additionally, charged particles, such as electrons and protons create electromagnetic fields when they move, and these fields transport the type of energy known as electromagnetic radiation, or light. A changing magnetic field will induce a changing electric field and vice versa—the two are linked. These changing fields form electromagnetic waves. Electromagnetic waves differ from mechanical waves in that they do not require a medium to propagate. This means that electromagnetic waves can travel not only through air and solid materials, but also through the vacuum of space.

text: Classical wave

text: s transfer

text: energy

text: without transporting

text: matter

text: through the medium (material). For example, waves in a pond do not carry the water molecules from place to place; rather the wave's energy travels through the water, leaving the water molecules in place. Additionally, charged particles, such as

text: electron

text: s and

text: proton

text: s create electromagnetic fields when they move, and these fields transport the type of energy known as electromagnetic radiation, or light. A changing magnetic field will induce a changing electric field and vice versa—the two are linked. These changing fields form electromagnetic waves. Electromagnetic waves differ from mechanical waves in that they do not require a medium to propagate. This means that electromagnetic waves can travel not only through air and solid materials, but also through the vacuum of space.

text: The Pushchino Radio Astronomy Observatory has four notable radio telescopes (RT 22), each with mirrors at 22 meters. Constructed in 1959 these are fully steerable, and are designed to operate in millimeter and centimeter range of wavelength. Added to the equipage is the DKR 1000, a  wide-band  radio telescope instrument, on-line in 1964, operating  in the meter wavelength range. The DKR 1000 has arms that are 40 by 1000 meters. In 1973, another telescope was added to this set. The nomenclature is Large Phased Array with the designation BSA/LPI, operating in the meter wavelength range. The DKR 1000 and BSA/LPI, are currently the largest radio telescopes in the world, which operate in the meter range.

text: The Pushchino Radio Astronomy Observatory has four notable radio telescopes (RT 22), each with

text: mirror

text: s at 22 meters. Constructed in 1959 these are fully steerable, and are designed to operate in

text: millimeter and centimeter

text: range of

text: wavelength

text: . Added to the equipage is the DKR 1000, a  wide-band  radio telescope instrument, on-line in 1964, operating  in the meter wavelength range. The DKR 1000 has arms that are 40 by 1000 meters. In 1973, another telescope was added to this set. The nomenclature is Large Phased Array with the designation BSA/LPI, operating in the meter wavelength range. The DKR 1000 and BSA/LPI, are currently the largest radio telescopes in the world, which operate in the meter range.

text: The high sensitivity of superconducting niobium nitride bolometers make them an ideal detector for electromagnetic radiation in the THz frequency band. These detectors were tested at the Heinrich Hertz Submillimeter Telescope, the South Pole Telescope, the Receiver Lab Telescope, and at APEX, and are now used in the HIFI instrument on board the Herschel Space Observatory.

text: The high sensitivity of superconducting niobium nitride

text: bolometers

text: make them an ideal detector for

text: electromagnetic radiation

text: in the THz frequency band. These detectors were tested at the

text: Heinrich Hertz Submillimeter Telescope

text: , the

text: South Pole Telescope

text: , the

text: Receiver Lab Telescope

text: , and at

text: APEX

text: , and are now used in the HIFI instrument on board the

text: Herschel Space Observatory

text: The angular resolution of the naked eye is about 1′; however, some people have sharper vision than that. There is anecdotal evidence that people had seen the Galilean moons of Jupiter before telescopes were invented. Of similar magnitude, Uranus and Vesta had most probably been seen but could not be recognized as planets because they appear so faint even at maximum brightness that their motion could not be detected. Uranus, when discovered in 1781, was the first planet discovered using technology (a telescope) rather than being spotted by the naked eye.

text: The angular resolution of the naked eye is about 1′; however, some people have sharper vision than that. There is anecdotal evidence that people had

text: seen

text: the Galilean

text: moons of Jupiter

text: before telescopes were invented. Of similar magnitude,

text: Uranus

text: and

text: Vesta

text: had most probably been seen but could not be recognized as planets because they appear so faint even at maximum brightness that their motion could not be detected. Uranus, when discovered in 1781, was the first planet discovered using

text: technology

text: (a

text: telescope

text: ) rather than being spotted by the naked eye.

text: Electromagnetic spectrum refers to the full range of all frequencies of electromagnetic radiation and also to the characteristic distribution of electromagnetic radiation emitted or absorbed by that particular object. Devices used to measure an electromagnetic spectrum are called spectrograph or spectrometer. The visible spectrum is the part of the electromagnetic spectrum that can be seen by the human eye. The wavelength of visible light ranges from 390 to 700 nm. The absorption spectrum of a chemical element or chemical compound is the spectrum of frequencies or wavelengths of incident radiation. The emission spectrum refers to the spectrum of radiation emitted due to an atom or molecule making a transition from a higher to a lower energy state.

text: Electromagnetic spectrum refers to the full range of all frequencies of

text: electromagnetic radiation

text: and also to the characteristic distribution of electromagnetic radiation emitted or absorbed by that particular object. Devices used to measure an electromagnetic spectrum are called

text: spectrograph

text: or

text: spectrometer

text: . The

text: visible spectrum

text: is the part of the electromagnetic spectrum that can be seen by the

text: human eye

text: . The wavelength of visible light ranges from

text: 390 to 700 nm

text: . The

text: absorption spectrum

text: of a

text: chemical element

text: or

text: chemical compound

text: is the spectrum of frequencies or wavelengths of incident radiation. The

text: emission spectrum

text: refers to the spectrum of radiation emitted due to an atom or molecule making a

text: transition

text: from a higher to a lower energy state.

text: The tune to the chorus is used throughout the show, for instance, when Rusty first hears of the Starlight Express; during the 'Starlight Sequence'; and when Rusty triumphs over his challengers (see main article). It is probably meant to show a point where there is a strong development in Rusty's character.

text: The tune to the chorus is used throughout the show, for instance, when Rusty first hears of the Starlight Express; during the '

text: Starlight Sequence

text: '; and when Rusty triumphs over his challengers

text: (see main article)

text: . It is probably meant to show a point where there is a strong development in Rusty's character.

text: Upon completion (fall 2006) the Large Binocular Telescope (LBT) will peer deeper into space than ever before, and with ten times the clarity of the Hubble Space Telescope.  With unparalleled observational capability, astronomers will be able to view planets in distant solar systems, and detect and measure objects dating back to the beginning of time (14 billion years ago). The LBT is already partially operational.

text: Upon completion (fall 2006) the

text: Large Binocular Telescope

text: (LBT) will peer deeper into space than ever before, and with ten times the clarity of the

text: Hubble Space Telescope

text: .  With unparalleled observational capability, astronomers will be able to view planets in distant solar systems, and detect and measure objects dating back to the beginning of time (14 billion years ago). The LBT is already partially operational.

text: The Company was originally founded in Dublin by Thomas Grubb as the Grubb Telescope Company in 1833. Thomas Grubb was joined in 1864 by his son Howard who built on the company's reputation for quality optical instruments. Grubb was also known for building accurate electrically driven clock drives for equatorial mounted telescopes. Some of the telescopes produced in the 19th century include the "Great Melbourne Telescope" - a 48-inch-diameter (1.2 m) reflecting telescope with speculum primary mirror, the 27-inch refractor for the Vienna Observatory (1878), the 10-inch refractor at Armagh Observatory (1882), the 28-inch refractor at the Royal Observatory, Greenwich - the UK's largest refractor (1893), and the 10-inch refractor at Coats Observatory, Paisley (1898). In 1887 Grubb's firm built seven normal astrographs for the Carte du Ciel international photographic star catalogue project, 13 inch refracting telescopes all designed to produce uniform photographic plates.

text: The Company was originally founded in

text: Dublin

text: by

text: Thomas Grubb

text: as the Grubb Telescope Company in 1833. Thomas Grubb was joined in 1864 by his son

text: Howard

text: who built on the company's reputation for quality

text: optical instrument

text: s. Grubb was also known for building accurate electrically driven

text: clock drive

text: s for

text: equatorial mount

text: ed telescopes. Some of the telescopes produced in the 19th century include the "

text: Great Melbourne Telescope

text: " - a 48-inch-diameter (1.2 m)

text: reflecting telescope

text: with

text: speculum

text: primary mirror, the 27-inch refractor for the

text: Vienna Observatory

text: (1878), the 10-inch refractor at

text: Armagh Observatory

text: (1882), the 28-inch refractor at the

text: Royal Observatory, Greenwich

text: - the UK's largest refractor (1893), and the 10-inch refractor at

text: Coats Observatory, Paisley

text: (1898). In 1887 Grubb's firm built seven normal

text: astrograph

text: s for the

text: Carte du Ciel

text: international photographic star catalogue project, 13 inch

text: refracting telescope

text: s all designed to produce uniform photographic plates.

text: Bernard Lovell built the Transit Telescope at Jodrell Bank in the late 1940s. This was a -diameter radio telescope that could only point directly upwards; the next logical step was to build a telescope that could look at all parts of the sky so that more sources could be observed, as well as for longer integration times. Although the Transit Telescope had been designed and constructed by the astronomers that used it, a fully steerable telescope would need to be professionally designed and constructed; the first challenge was to find an engineer willing to do the job. This turned out to be Charles Husband, whom Lovell first met on 8 September 1949.

text: Bernard Lovell

text: built the

text: Transit Telescope

text: at Jodrell Bank in the late 1940s. This was a -diameter radio telescope that could only point directly upwards; the next logical step was to build a telescope that could look at all parts of the sky so that more sources could be observed, as well as for longer integration times. Although the Transit Telescope had been designed and constructed by the astronomers that used it, a fully steerable telescope would need to be professionally designed and constructed; the first challenge was to find an engineer willing to do the job. This turned out to be

text: Charles Husband

text: , whom Lovell first met on 8 September 1949.

text: Cosmic Journey features images from NASA's Great Observatories, including the Hubble Space Telescope and the Spitzer Space Telescope.  The show is narrated by astrophysicist, Dr. Stacy Palen.  Cosmic Journey was produced with Blender 3D and uses a 3D adaptation of the Ken Burns Effect.

text: Cosmic Journey features images from

text: NASA's Great Observatories

text: , including the

text: Hubble Space Telescope

text: and the

text: Spitzer Space Telescope

text: .  The show is narrated by astrophysicist, Dr. Stacy Palen.  Cosmic Journey was produced with

text: Blender 3D

text: and uses a 3D adaptation of the

text: Ken Burns Effect

text: The Faulkes Telescope Project (FTP) is supported by the  Dill Faulkes Educational Trust. It provides access to 1,500 hours of observing time on two 2-metre class telescopes located in Hawaii (Faulkes Telescope North in Hawaii) and Australia (Faulkes Telescope South in Australia). This time is dedicated to education and public outreach, mainly in the UK, but also for smaller, selected projects in Europe and the US.

text: The Faulkes Telescope Project (FTP) is supported by the

text: Dill Faulkes

text: Educational Trust. It provides access to 1,500 hours of observing time on two 2-metre class telescopes located in Hawaii (

text: Faulkes Telescope North

text: in

text: Hawaii

text: ) and Australia (

text: Faulkes Telescope South

text: in

text: Australia

text: ). This time is dedicated to education and public outreach, mainly in the UK, but also for smaller, selected projects in

text: Europe

text: and the

text: US

text: There is some evidence against the boundary model. A study by Lee and Brown in 2004 looked at how four different groups dated news events under different conditions. They found that the different boundaries had no effect on date estimation, and the existence of a boundary had no effect on date estimation. This study suggests that telescoping is not due solely to boundaries.

text: A green rim is present at every sunset but it is too thin to be seen with the naked eye. Often a green rim changes to a green flash and back again during the same sunset. The best time to observe a green rim is about 10 minutes before sunset. That is too early to use any magnification like binoculars or a telescope to look directly at the Sun without potential harm to the eyes. (Of course, a magnified image might be projected onto a sheet of paper for safe viewing.) As the sun gets closer to the horizon, the green rim becomes fainter due to atmospheric reddening. According to the above, it is probably correct to conclude that although a green rim is present during every sunset, a green flash is rarer because of the required mirage.

text: A green rim is present at every sunset but it is too thin to be seen with the naked eye. Often a green rim changes to a green flash and back again during the same sunset. The best time to observe a green rim is about 10 minutes before sunset. That is too early to use any

text: magnification

text: like

text: binoculars

text: or a

text: telescope

text: to look directly at the Sun without potential harm to the eyes. (Of course, a magnified image might be projected onto a sheet of paper for safe viewing.) As the sun gets closer to the horizon, the green rim becomes fainter due to atmospheric reddening. According to the above, it is probably correct to conclude that although a green rim is present during every sunset, a green flash is rarer because of the required

text: mirage

text: Light consists of electromagnetic radiation of different wavelengths. Therefore, when the elements or their compounds are heated either on a flame or by an electric arc they emit energy in the form of light. Analysis of this light, with the help of a spectroscope gives us a discontinuous spectrum. A spectroscope or a spectrometer is an instrument which is used for separating the components of light, which have different wavelengths. The spectrum appears in a series of lines called the line spectrum. This line spectrum is called an atomic spectrum when it originates from an atom in elemental form. Each element has a different atomic spectrum. The production of line spectra by the atoms of an element indicate that an atom can radiate only a certain amount of energy. This leads to the conclusion that bound electrons cannot have just any amount of energy but only a certain amount of energy.

text: Light consists of electromagnetic radiation of different wavelengths. Therefore, when the elements or their compounds are heated either on a flame or by an electric arc they emit energy in the form of light. Analysis of this light, with the help of a

text: spectroscope

text: gives us a discontinuous spectrum. A spectroscope or a spectrometer is an instrument which is used for separating the components of light, which have different wavelengths. The spectrum appears in a series of lines called the line spectrum. This line spectrum is called an atomic spectrum when it originates from an atom in elemental form. Each element has a different atomic spectrum. The production of line spectra by the atoms of an element indicate that an atom can radiate only a certain amount of energy. This leads to the conclusion that bound electrons cannot have just any amount of energy but only a certain amount of energy.

text: The primary payload, the Gamma Ray Observatory (GRO), was deployed on flight day 3. GRO's high-gain antenna failed to deploy on command; it was finally freed and manually deployed by Ross and Apt during an unscheduled contingency space walk, the first since April 1985. The following day, the two astronauts performed the first scheduled space walk since November 1985 to test means for astronauts to move themselves and equipment about while maintaining the then-planned Space Station Freedom. GRO science instruments were Burst and Transient Source Experiment (BATSE), Imaging Compton Telescope (COMPTEL), Energetic Gamma Ray Experiment Telescope (EGRET) and Oriented Scintillation Spectrometer Experiment (OSSE). GRO was the second of NASA's four Great Observatories. The Hubble Space Telescope, deployed during Mission STS-31 in April 1990, was the first. GRO was launched on a two-year mission to search for the high-energy celestial gamma ray emissions, which cannot penetrate Earth's atmosphere. At about 35,000 pounds, GRO was the heaviest satellite to be deployed into low-Earth orbit from the Shuttle. It was also designed to be the first satellite that could be refueled in orbit by Shuttle crews. Five months after deployment, NASA renamed the satellite the Arthur Holly Compton Gamma Ray Observatory, or Compton Observatory, after the Nobel Prize-winning physicist who did important work in gamma ray astronomy.

text: The primary payload, the

text: Gamma Ray Observatory

text: (GRO), was deployed on flight day 3. GRO's high-gain antenna failed to deploy on command; it was finally freed and manually deployed by Ross and Apt during an unscheduled contingency

text: space walk

text: , the first since April 1985. The following day, the two astronauts performed the first scheduled space walk since November 1985 to test means for astronauts to move themselves and equipment about while maintaining the then-planned Space Station Freedom. GRO science instruments were Burst and Transient Source Experiment (BATSE), Imaging Compton Telescope (COMPTEL),

entity_name: Energetic Gamma Ray Experiment Telescope

text: Energetic Gamma Ray Experiment Telescope

text: (EGRET) and Oriented Scintillation Spectrometer Experiment (OSSE). GRO was the second of

text: NASA

text: 's four

text: Great Observatories

text: . The

text: Hubble Space Telescope

text: , deployed during Mission

text: in April 1990, was the first. GRO was launched on a two-year mission to search for the high-energy celestial gamma ray emissions, which cannot penetrate Earth's atmosphere. At about 35,000 pounds, GRO was the heaviest

text: satellite

text: to be deployed into low-Earth

text: orbit

text: from the Shuttle. It was also designed to be the first satellite that could be refueled in orbit by Shuttle crews. Five months after deployment, NASA renamed the satellite the

text: Arthur Holly Compton Gamma Ray Observatory

text: , or Compton Observatory, after the

text: Nobel Prize-winning physicist

text: who did important work in

text: gamma ray astronomy

text: The observatory operates several telescopes at three locations in the Flagstaff area. The main facility, located on Mars Hill just west of downtown Flagstaff, houses the original  Clark Refracting Telescope, although its role today is as a public education tool and not research. The telescope, built in 1896 for $20,000, was assembled in Boston by Alvan Clark & Sons and then shipped by train to Flagstaff. Also located on the Mars Hill campus is the  Pluto Discovery Telescope, used by Clyde Tombaugh in 1930 to discover the dwarf planet Pluto.

text: The observatory operates several

text: telescope

text: s at three locations in the Flagstaff area. The main facility, located on Mars Hill just west of downtown Flagstaff, houses the original  Clark Refracting Telescope, although its role today is as a public education tool and not research. The telescope, built in 1896 for $20,000, was assembled in Boston by

text: Alvan Clark & Sons

text: and then shipped by train to Flagstaff. Also located on the Mars Hill campus is the  Pluto Discovery Telescope, used by

text: Clyde Tombaugh

text: in 1930 to discover the dwarf planet

text: Pluto

text: HIP 79431 b is located in orbit around a star whose metallicity had been challenging to be assessed due to the uncertainties within the molecular data line however it has not been typical for M Dwarfs to have strong emissions from the core data lines. This led to the inclusion of the HIP 79431 star to the KECK program in April 2009 as part of the exoplanet studies for low mass stars. During this study, 13 Doppler measurements of the star were done over a 6-month period using the High Resolution Echelle Spectrometer (HIRES). The exposure times used in its observation was 600 seconds which yielded a signal-to-noise ratio of just under 100. Each program observation required the use of iodine absorption lines in order to model the wavelength scale as well as the instrumental profile of the telescope and spectrometer optics. The Doppler experiments derived radial velocities fit the Keplerian model showing an unambiguous signal and orbital parameters which best fit planetary gravitational pull, this revealed the presence of the planet HIP 79431 b. However, there is no evidence that any additional planets was found.

text: HIP 79431 b is located in orbit around a star whose

text: metallicity

text: had been challenging to be assessed due to the uncertainties within the molecular data line however it has not been typical for M Dwarfs to have strong emissions from the core data lines. This led to the inclusion of the HIP 79431 star to the KECK program in April 2009 as part of the exoplanet studies for low mass stars. During this study, 13

text: Doppler measurements

text: of the star were done over a 6-month period using the

text: High Resolution Echelle Spectrometer (HIRES)

text: . The exposure times used in its observation was 600 seconds which yielded a

text: signal-to-noise ratio

text: of just under 100. Each program observation required the use of iodine absorption lines in order to model the wavelength scale as well as the instrumental profile of the telescope and spectrometer optics. The Doppler experiments derived radial velocities fit the

text: Keplerian model

text: showing an unambiguous signal and orbital parameters which best fit planetary gravitational pull, this revealed the presence of the planet HIP 79431 b. However, there is no evidence that any additional planets was found.

text: The observatory has seven major telescopes operating in visible and infrared light: the four  telescopes of the Very Large Telescope, the  VLT Survey Telescope (VST) and the  Visible and Infrared Survey Telescope for Astronomy. In addition, there are four  auxiliary telescopes forming an array used for interferometric observations. In March 2008, Paranal was the location for several scenes of the 22nd James Bond film, Quantum of Solace.

text: The observatory has seven major telescopes operating in visible and infrared light: the four  telescopes of the Very Large Telescope, the  VLT Survey Telescope (VST) and the  Visible and Infrared Survey Telescope for Astronomy. In addition, there are four  auxiliary telescopes forming an array used for

text: interferometric

text: observations. In March 2008, Paranal was the location for several scenes of the 22nd James Bond film,

text: Quantum of Solace

text: 100,000 years later an Atlantean known as Capricia is revived underwater by a strange man. Quickly tossed into a battle by this unknown benefactor Capricia is forced to quickly choose which of her fellow Atlanteans she should nominate for revival. Taking into account the five Atlantean disciplines Capricia chooses five Atlanteans, each of whom have mastery over their chosen discipline. Twin brothers Gammid and Galvan each of whom control one end of the electromagnetic spectrum, Zephyre for her super-speed, Verityn for his insight and Tug for his telekenetic expertise. Together they defeat their first foe in 100,000 years.

text: Far infrared observations including submillimeter astronomy have revealed a number of sources at cosmological distances. With the exception of a few atmospheric windows, most of infrared light is blocked by the atmosphere, the observations generally take place from balloon or space-based instruments. Current observational experiments in the infrared include NICMOS, the Cosmic Origins Spectrograph, the Spitzer Space Telescope, the Keck Interferometer, the Stratospheric Observatory For Infrared Astronomy, and the Herschel Space Observatory. The next large space telescope planned by NASA, the James Webb Space Telescope will also explore in the infrared.

text: Far

text: infrared

text: observations including

text: submillimeter astronomy

text: have revealed a number of sources at cosmological distances. With the exception of a few

text: atmospheric window

text: s, most of infrared light is blocked by the atmosphere, the observations generally take place from balloon or space-based instruments. Current observational experiments in the infrared include

text: NICMOS

text: , the

text: Cosmic Origins Spectrograph

text: , the

text: Spitzer Space Telescope

text: , the

text: Keck Interferometer

text: , the

text: Stratospheric Observatory For Infrared Astronomy

text: , and the

text: Herschel Space Observatory

text: . The next large space telescope planned by NASA, the

text: James Webb Space Telescope

text: will also explore in the infrared.

text: This center is headed by Dr. Noah Brosch from Tel Aviv University and operates the three telescopes of the Wise Observatory. For the purpose of NEO studies, a special wide-field 0.46-m telescope was acquired by Tel Aviv University and is operating at the Wise Observatory located near Mitzpe Ramon. The telescope facilitated the discovery of several tens of new asteroids and is now intensely used to study asteroid rotation and asteroid pair properties. Following the cessation of funding from ISA, the asteroid studies are continuing at the Wise Observatory with no specific financial support.

text: This center is headed by Dr.

text: Noah Brosch

text: from

text: Tel Aviv University

text: and operates the three telescopes of the

text: Wise Observatory

text: . For the purpose of NEO studies, a special wide-field 0.46-m telescope was acquired by

text: Tel Aviv University

text: and is operating at the

text: Wise Observatory

text: located near

text: Mitzpe Ramon

text: . The telescope facilitated the discovery of several tens of new asteroids and is now intensely used to study asteroid rotation and asteroid pair properties. Following the cessation of funding from ISA, the

text: asteroid

text: studies are continuing at the

text: Wise Observatory

text: with no specific financial support.

text: The U.S. Department of Defense's 2009 Annual Report to Congress on "Military Power of thePeople’s Republic of China" defines local wars under conditions of informationization as "high intensity and short duration fighting against high technology adversaries" ... "capable of fighting and winning short-duration, high-intensity conflicts along its periphery against high-tech adversaries".  Additionally, local war under informationization is an effort which seeks to fully develop and link land, air, sea, space and the electromagnetic spectrum into one system. China's military strategy is focused on fighting and winning "informationized local wars."

text: The U.S. Department of Defense's 2009 Annual Report to Congress on "Military Power of thePeople’s Republic of China" defines local wars under conditions of informationization as "high intensity and short duration fighting against

text: high technology

text: adversaries" ... "capable of fighting and winning short-duration, high-intensity conflicts along its periphery against high-tech adversaries".  Additionally, local war under informationization is an effort which seeks to fully develop and link land, air, sea, space and the

text: electromagnetic spectrum

text: into one system. China's military strategy is focused on fighting and winning "informationized local wars."

text: An extremely large telescope (ELT) is an astronomical observatory featuring a telescope with an aperture for its primary mirror from 20 metres up to 100 metres across,when discussing reflecting telescopes of optical wavelengths including ultraviolet (UV), visible, and near infrared wavelengths. Among many planned capabilities, ELTs are planned to increase the chance of finding Earth-like planets around other stars. Telescopes for radio wavelengths can be much bigger physically, such as the  aperture fixed focus radio telescope of the Arecibo Observatory. Freely steerable radio telescopes with diameters up to  have been in operation since the 1970s.

text: An extremely large telescope (ELT) is an

text: astronomical observatory

text: featuring a

text: telescope

text: with an

text: aperture

text: for its

text: primary mirror

text: from 20 metres up to 100 metres across,when discussing reflecting telescopes of optical wavelengths including

text: ultraviolet

text: (UV),

text: visible

text: , and

text: near infrared

text: wavelengths. Among many planned capabilities, ELTs are planned to increase the chance of finding Earth-like planets around other stars. Telescopes for radio wavelengths can be much bigger physically, such as the  aperture fixed focus radio telescope of the

text: Arecibo Observatory

text: . Freely steerable radio telescopes with diameters up to  have been in operation since the 1970s.

text: Aderin-Pocock has worked on many projects, from private industry to government contracts to academic research. She began in the Ministry of Defence and the Defence Evaluation and Research Agency on missile warning systems. She then worked on hand-held instruments to detect landmines. Aderin-Pocock moved back to Imperial College London in 1999 with a fellowship from the Science and Technology Facilities Council to work with the group developing a high-resolution spectrograph for the Gemini telescope in Chile, which probes the heart of stars by converting the starlight gathered by huge telescopes into the spectrum of colours, and then analyses them to work out what's happening billions of miles away.

text: Aderin-Pocock has worked on many projects, from private industry to government contracts to academic research. She began in the

text: Ministry of Defence

text: and the

text: Defence Evaluation and Research Agency

text: on missile warning systems. She then worked on hand-held instruments to detect landmines. Aderin-Pocock moved back to

text: Imperial College London

text: in 1999 with a fellowship from the

entity_name: Science and Technology Facilities Council

text: Science and Technology Facilities Council

text: to work with the group developing a high-resolution

text: spectrograph

text: for the Gemini telescope in Chile, which probes the heart of stars by converting the starlight gathered by huge telescopes into the spectrum of colours, and then analyses them to work out what's happening billions of miles away.

text: The Mars 5 spacecraft carried an array of instruments to study Mars. In addition to cameras, it was equipped with a radio telescope, an IR radiometer, multiple photometers, polarimeters, a magnetometer, plasma traps, an electrostatic analyser, a gamma-ray spectrometer, and a radio probe.

text: The Mars 5 spacecraft carried an array of instruments to study Mars. In addition to cameras, it was equipped with a radio telescope, an IR radiometer, multiple photometers, polarimeters, a magnetometer, plasma traps, an electrostatic analyser, a

text: gamma-ray spectrometer

text: , and a radio probe.

text: The plan for a large telescope was leaked around September 1944 in the form of the University's budget proposals.  Wright and Joseph H. Moore, interim wartime Lick director, imagined an  or  reflector based upon the funds proposed in the budget by Sproul.  Mayall and Gerald E. Kron sent a letter to Sproul representing the younger Lick staff members, in which they requested a meeting to discuss the kind of telescope to be built.  They met with Sproul in December 1944 in Sproul's Los Angeles office.  Mayall spoke of the key need for a telescope exceeding .  At the Caltech optical shop in Pasadena he had seen the nearly completed  Pyrex glass disc that was initially planned to be used as a flat in the auto-collimation test of the  Palomar mirror and urged Sproul to have the Lick telescope use a mirror of that size.  Much to their surprise, Sproul agreed.

text: The plan for a large telescope was leaked around September 1944 in the form of the University's budget proposals.  Wright and Joseph H. Moore, interim wartime Lick director, imagined an  or  reflector based upon the funds proposed in the budget by Sproul.  Mayall and Gerald E. Kron sent a letter to Sproul representing the younger Lick staff members, in which they requested a meeting to discuss the kind of telescope to be built.  They met with Sproul in December 1944 in Sproul's Los Angeles office.  Mayall spoke of the key need for a telescope exceeding .  At the Caltech optical shop in Pasadena he had seen the nearly completed

text: Pyrex

text: glass disc that was initially planned to be used as a

text: flat

text: in the auto-

text: collimation

text: test of the

text: Palomar

text: mirror and urged Sproul to have the Lick telescope use a mirror of that size.  Much to their surprise, Sproul agreed.

text: There are many descriptions of Niccolò Zucchi successfully using his early "reflecting telescope". The French author Bernard le Bovier de Fontenelle's 1700 work History of the Academy of Sciences stated Zucchi used it to observe "celestial and terrestrial objects". There are also modern claims that Zucchi used a reflecting telescope to observe the belts of Jupiter and examine the spots on the planet Mars,

text: There are many descriptions of Niccolò Zucchi successfully using his early "reflecting telescope". The French author

text: Bernard le Bovier de Fontenelle

text: 's 1700 work History of the Academy of Sciences stated Zucchi used it to observe "celestial and terrestrial objects". There are also modern claims that Zucchi used a reflecting telescope to observe the belts of Jupiter and examine the spots on the planet Mars,

text: The same academy of Cimento in Florence was involved in another disputation to compare Divini’s and Campani’s instruments in 1664. First tests were not favourable to either of them, notwithstanding the paragoni had been carefully arranged by Matteo and Giuseppe Campani brothers to put Divini at as much of a disadvantage as possible. In the paragone of April, 30th 1664 Divini used a telescope manufactured by him with a very complex optical system and previously sold to the nephew of Pope Alexander VII, Cardinal Flavio Chigi, for a very high price. Since Divini's instruments was in the possession of Cardinal Chigi, the Campani brothers were able to make all the arrangements and substitutions without notifying Divini beforehand. Then Divini arrived in the test place to find his telescope arranged on chairs and was not allowed to check the conditions of the lenses or to make any changes on it,  while Campani's telescope was beautifully mounted. Divini's telescope gave a worse performance of Campani's, but Divini, rather than making excuses, admitted that Campani's instrument was better than his and begged to be allowed to make the Cardinal a better telescope to replace the manifestly defective one. This easy victory and the humiliation of Divini initiated Campani to the success. The academy of Cimento and Prince Leopold was eager to know if Campani's telescopes were, indeed, better than those of Divini that had served them so well in Florence. So they inquired that the previous paragone in Rome was unfair and commanded specially designed experiments based on the reading of texts at a distance. The first of these does not permitted to establish the winner because the competitors used different telescopes; as Campani refuted to do the experiment in Florence, the test was done in different places and times (autumn 1964), Campani moved a lamp closer to the sheet to be read, whose letters could be recognized also by insight as being made of known words and famous phrases. The Accademia of Cimento devised better criteria, more similar to nowadays ophthalmic characters tables, but in the subsequent paragoni, in the late 1664, no one's telescope was definitely declared as best performer. In 1665 the Grand Duke Ferdinand II and Prince Leopold acquired a number of Campani and new Divini telescopes and subjected them to tests of their own in astronomical observations. Sometimes no clear advantage accrued either to Campani or Divini, until in July a 50-palm Campani telescope made for Cardinal Borromeo resulted to be much better than all other telescopes of similar length. Divini did not take Campani's victory well, arguing a freak or bare luck. Both the antagonists proposed to the Accademia del Cimento an impartial test based on the manufacturing of the best objective lenses with given curvature starting from the same piece of glass  divided in two parts. In this way their skills as lens-makers could have been assessed, but Prince Leopold did not act on the proposal: the dispute was over and Campani was the undisputed winner. Despite the undeniable merits of Divini's telescopes, it was just one of Campani's telescopes that won the day. Rather than this single defeat, they were mainly Cassini’s discoveries that promoted the products by Campani, up to the end of the century. Divini, resigned to leave the top position of his art to the antagonist, wrote with pride in 1666: "my glasses have lost nothing in these paragoni, in fact after the contest and even today I have new orders from Florence" (from letter to C. A. Manzini). There are also witnesses that as late as in 1671 lenses were commissioned to both Campani and Divini from the great Observatoire de Paris, directed by Cassini.

text: An electromagnetic wave consists of two waves that are oscillations of the electric and magnetic fields. An electromagnetic wave travels in a direction that is at right angles to the oscillation direction of both fields. In the 19th century, James Clerk Maxwell showed that, in vacuum, the electric and magnetic fields satisfy the wave equation both with speed equal to that of the speed of light. From this emerged the idea that light is an electromagnetic wave. Electromagnetic waves can have different frequencies (and thus wavelengths), giving rise to various types of radiation such as radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and Gamma rays.

text: An electromagnetic wave consists of two waves that are oscillations of the

text: electric

text: and

text: magnetic

text: fields. An electromagnetic wave travels in a direction that is at right angles to the oscillation direction of both fields. In the 19th century,

text: James Clerk Maxwell

text: showed that, in

text: vacuum

text: , the electric and magnetic fields satisfy the

text: wave equation

text: both with speed equal to that of the

text: speed of light

text: . From this emerged the idea that

text: light

text: is an electromagnetic wave. Electromagnetic waves can have different frequencies (and thus wavelengths), giving rise to various types of radiation such as

text: radio waves

text: microwaves

text: infrared

text: , visible light,

text: ultraviolet

text: X-rays

text: , and

text: Gamma rays

text: Telescopes may also be classified by location: ground telescope, space telescope, or flying telescope.  They may also be classified by whether they are operated by professional astronomers or amateur astronomers.  A vehicle or permanent campus containing one or more telescopes or other instruments is called an observatory.

text: Telescopes may also be classified by location: ground telescope,

text: space telescope

text: , or

text: flying telescope

text: .  They may also be classified by whether they are operated by

text: professional astronomers

text: or

text: amateur astronomer

text: s.  A vehicle or permanent campus containing one or more telescopes or other instruments is called an

text: observatory

text: At nearly  distant, Kepler-186f is too far and its star too faint for current telescopes or the next generation of planned telescopes to determine its mass or whether it has an atmosphere. However, the discovery of Kepler-186f demonstrates conclusively that there are other Earth-sized planets in habitable zones. The Kepler spacecraft focused on a single small region of the sky but next-generation planet-hunting space telescopes, such as TESS and CHEOPS, will examine nearby stars throughout the sky. Nearby stars with planets can then be studied by the upcoming James Webb Space Telescope and future large ground-based telescopes to analyze atmospheres, determine masses and infer compositions. Additionally the Square Kilometer Array would significantly improve radio observations over the Arecibo Observatory and Green Bank Telescope.

text: At nearly  distant, Kepler-186f is too far and its star too faint for current telescopes or the next generation of planned telescopes to determine its mass or whether it has an atmosphere. However, the discovery of Kepler-186f demonstrates conclusively that there are other Earth-sized planets in habitable zones. The Kepler spacecraft focused on a single small region of the sky but next-generation planet-hunting space telescopes, such as

text: TESS

text: and

text: CHEOPS

text: , will examine nearby stars throughout the sky. Nearby stars with planets can then be studied by the upcoming

text: James Webb Space Telescope

text: and future large ground-based telescopes to analyze atmospheres, determine masses and infer compositions. Additionally the

text: Square Kilometer Array

text: would significantly improve radio observations over the

text: Arecibo Observatory

text: and

text: Green Bank Telescope

text: Based only on uncertain descriptions of the first practical telescope, invented by Hans Lippershey in the Netherlands in 1608, Galileo, in the following year, made a telescope with about 3x magnification. He later made improved versions with up to about 30x magnification. With a Galilean telescope the observer could see magnified, upright images on the earth—it was what is commonly known as a terrestrial telescope or a spyglass. He could also use it to observe the sky; for a time he was one of those who could construct telescopes good enough for that purpose. On 25 August 1609, he demonstrated one of his early telescopes, with a magnification of about 8 or 9, to Venetian lawmakers. His telescopes were also a profitable sideline for Galileo selling them to merchants who found them useful both at sea and as items of trade. He published his initial telescopic astronomical observations in March 1610 in a brief treatise entitled Sidereus Nuncius (Starry Messenger).

text: Based only on uncertain descriptions of the first practical telescope, invented by

text: Hans Lippershey

text: in the Netherlands in 1608, Galileo, in the following year, made a telescope with about 3x magnification. He later made improved versions with up to about 30x magnification. With a

text: Galilean telescope

text: the observer could see magnified, upright images on the earth—it was what is commonly known as a terrestrial telescope or a spyglass. He could also use it to observe the sky; for a time he was one of those who could construct telescopes good enough for that purpose. On 25 August 1609, he demonstrated one of his early telescopes, with a magnification of about 8 or 9, to

text: Venetian

text: lawmakers. His telescopes were also a profitable sideline for Galileo selling them to merchants who found them useful both at sea and as items of trade. He published his initial telescopic astronomical observations in March 1610 in a brief treatise entitled

text: Sidereus Nuncius

text: (Starry Messenger).

text: Before the advent of modern mass-produced telescopes the price of even a modest instrument was often beyond the means of an aspiring amateur astronomer. Building your own was the only economical method to obtain a suitable telescope for observing. There were many published works that helped spark an interest in building telescopes such as Irish telescope maker Rev. W. F. A. Ellison's 1920 book "The Amateur's Telescope".

text: Before the advent of modern mass-produced telescopes the price of even a modest instrument was often beyond the means of an aspiring amateur astronomer. Building your own was the only economical method to obtain a suitable telescope for observing. There were many published works that helped spark an interest in building telescopes such as Irish telescope maker

text: Rev. W. F. A. Ellison's

text: 1920 book "The Amateur's Telescope".

text: All of these waves, from the lowest-frequency radio waves to the highest-frequency gamma rays, are fundamentally the same, and they are all called electromagnetic radiation. They all travel through a vacuum at the same speed (the speed of light), giving them wavelengths inversely proportional to their frequencies.

text: All of these waves, from the lowest-frequency radio waves to the highest-frequency gamma rays, are fundamentally the same, and they are all called

text: electromagnetic radiation

text: . They all travel through a vacuum at the same speed (the

text: speed of light

text: ), giving them

text: wavelength

text: s inversely proportional to their frequencies.

text: Some projects to equip telescopes with planet-imaging-capable instruments include the ground-based telescopes Gemini Planet Imager, VLT-SPHERE, Subaru-HiCIAO, Palomar Project 1640, and the space telescope WFIRST-AFTA. The New Worlds Mission proposes a large occulter in space designed to block the light of nearby stars in order to observe their orbiting planets. This could be used with existing, already planned or new, purpose-built, telescopes.

text: Some projects to equip telescopes with planet-imaging-capable instruments include the ground-based telescopes

text: Gemini Planet Imager

entity_name: Spectro-Polarimetric High-Contrast Exoplanet Research

text: VLT-SPHERE

text: Subaru-HiCIAO

text: Palomar Project 1640

text: , and the space telescope

text: WFIRST-AFTA

text: . The

text: New Worlds Mission

text: proposes a large occulter in space designed to block the light of nearby stars in order to observe their orbiting planets. This could be used with existing, already planned or new, purpose-built, telescopes.

text: Automated Patrol Telescope (APT) is operated by the University of NSW (UNSW) is a wide-field CCD imaging telescope. The 0.5m telescope has a 5 degree field of view and can be operated remotely or in a fully automatic mode. The telescope has an optical design that more resembles that of a Schmidt camera, but has a 3-element lens to achieve a wide, corrected field of view. The APT was developed by extensively modifying the optical, mechanical and electronic systems of a Baker-Nunn satellite tracking instrument. The Baker-Nunn telescope had been located at Woomera in South Australia during the 1960's, and afterward was stationed at Orroral Valley near Canberra. The camera was donated by the Smithsonian Institution to UNSW in 1982.

text: When Putt-Putt visits the fireworks factory, a slip of Pep's paw sends him rocketing to the moon. Once there, he needs to gather the pieces of a rocket ship to get himself, Pep, and his new friend, Rover back home to Earth. There was a hidden sneak peek to this game if Fatty Bear looks through a telescope in Fatty Bear's Birthday Surprise. The game was ported from DOS to Windows in 1995, and re-packaged in 1999. It was rereleased on Steam on May 1, 2014

text: When Putt-Putt visits the fireworks factory, a slip of Pep's paw sends him rocketing to the moon. Once there, he needs to gather the pieces of a rocket ship to get himself, Pep, and his new friend, Rover back home to Earth. There was a hidden sneak peek to this game if Fatty Bear looks through a telescope in

text: Fatty Bear's Birthday Surprise

text: . The game was ported from

text: DOS

text: to

text: Windows

text: in 1995, and re-packaged in 1999. It was rereleased on Steam on May 1, 2014

text: Alfvén received his PhD from the University of Uppsala in 1934. His thesis was titled "Investigations of the Ultra-short Electromagnetic Waves."

text: Alfvén received his PhD from the

text: University of Uppsala

text: in 1934. His thesis was titled "Investigations of the Ultra-short Electromagnetic Waves."

text: In late 1668 Isaac Newton built his first reflecting telescope. He chose an alloy (speculum metal) of tin and copper as the most suitable material for his objective  mirror. He later devised means for shaping and grinding the mirror and may have been the first to use a pitch lap to polish the optical surface. He chose a spherical shape for his mirror instead of a parabola to simplify construction; even though it would introduce spherical aberration, it would still correct chromatic aberration. He added to his reflector what is the hallmark of the design of a Newtonian telescope, a secondary diagonally mounted mirror near the primary mirror's focus to reflect the image at a 90° angle to an eyepiece mounted on the side of the telescope. This unique addition allowed the image to be viewed with minimal obstruction of the objective mirror. He also made the tube, mount, and fittings. Newton's first version had a primary mirror diameter of  and a focal ratio of f/5. He found that the telescope worked without colour distortion and that he could see the four Galilean moons of Jupiter and the crescent phase of the planet Venus with it. Newton's friend Isaac Barrow showed a second telescope to a small group from the Royal Society of London at the end of 1671. They were so impressed with it that they demonstrated it to Charles II in January 1672. Newton was admitted as a fellow of the society in the same year.

text: In late 1668 Isaac Newton built his

text: first reflecting telescope

text: . He chose an

text: alloy

text: speculum metal

text: ) of

text: tin

text: and

text: copper

text: as the most suitable material for his

text: objective

text: mirror. He later devised means for shaping and grinding the mirror and may have been the first to use a

text: pitch lap

text: to polish the optical surface. He chose a spherical shape for his mirror instead of a parabola to simplify construction; even though it would introduce

text: spherical aberration

text: , it would still correct chromatic aberration. He added to his reflector what is the hallmark of the design of a Newtonian telescope, a secondary diagonally mounted mirror near the primary mirror's focus to reflect the image at a 90° angle to an

text: eyepiece

text: mounted on the side of the telescope. This unique addition allowed the image to be viewed with minimal obstruction of the objective mirror. He also made the tube,

text: mount

text: , and fittings. Newton's first version had a primary mirror diameter of  and a

text: focal ratio

text: of f/5. He found that the telescope worked without colour distortion and that he could see the four

text: Galilean moons

text: of

text: Jupiter

text: and the

text: crescent phase of the planet Venus

text: with it. Newton's friend

text: Isaac Barrow

text: showed a second telescope to a small group from the

text: Royal Society of London

text: at the end of 1671. They were so impressed with it that they demonstrated it to

text: Charles II

text: in January 1672. Newton was admitted as a fellow of the society in the same year.

text: The idea that curved mirrors behave like lenses dates back at least to Alhazen's 11th century treatise on optics, works that had been widely disseminated in Latin translations in early modern Europe.  Soon after the invention of the refracting telescope, Galileo, Giovanni Francesco Sagredo, and others, spurred on by their knowledge of the principles of curved mirrors, discussed the idea of building a telescope using a mirror as the image forming objective. There were reports that the Bolognese Cesare Caravaggi had constructed one around 1626 and the Italian professor Niccolò Zucchi, in a later work, wrote that he had experimented with a concave bronze mirror in 1616, but said it did not produce a satisfactory image. The potential advantages of using parabolic mirrors, primarily reduction of spherical aberration with no chromatic aberration, led to many proposed designs for reflecting telescopes. The most notable being James Gregory, who published an innovative design for a ‘reflecting’ telescope in 1663. It would be ten years (1673), before the experimental scientist Robert Hooke was able to build this type of telescope, which became known Gregorian telescope.

text: The idea that

text: curved mirrors

text: behave like lenses dates back at least to

text: Alhazen

text: 's 11th century treatise on optics, works that had been widely disseminated in Latin translations in

text: early modern Europe

text: .  Soon after the invention of the

text: refracting telescope

text: Galileo

text: Giovanni Francesco Sagredo

text: , and others, spurred on by their knowledge of the principles of curved mirrors, discussed the idea of building a telescope using a mirror as the image forming objective. There were reports that the

text: Bolognese

text: Cesare Caravaggi

text: had constructed one around 1626 and the Italian professor

text: Niccolò Zucchi

text: , in a later work, wrote that he had experimented with a concave bronze mirror in 1616, but said it did not produce a satisfactory image. The potential advantages of using

text: parabolic mirrors

text: , primarily reduction of

text: spherical aberration

text: with no

text: chromatic aberration

text: , led to many proposed designs for reflecting telescopes. The most notable being

text: James Gregory

text: , who published an innovative design for a ‘reflecting’ telescope in 1663. It would be ten years (1673), before the experimental scientist

text: Robert Hooke

text: was able to build this type of telescope, which became known

text: Gregorian telescope

text: Since 2007, the Department of Physics takes care of the construction of a space telescope called MuSTAnG (Muon Spaceweather Telescope for Anisotropies at Greifswald), which will be part of a worldwide network of telescopes in Japan, Brazil, Australia and Germany. The telescope will enable physicists and astrononomers at Greifswald University to forecast solar activity and has been co-funded by the European Space Agency (ESA) and the Deutsches Zentrum für Luft- und Raumfahrt. In addition to MuSTAnG, the university owns an observatory, which is taken care of by a private initiative and open to the public.

text: Since 2007, the Department of Physics takes care of the construction of a

text: space telescope

text: called MuSTAnG (Muon Spaceweather Telescope for Anisotropies at Greifswald), which will be part of a worldwide network of telescopes in Japan, Brazil, Australia and Germany. The telescope will enable physicists and astrononomers at Greifswald University to forecast

text: solar activity

text: and has been co-funded by the

text: European Space Agency

text: (ESA) and the

text: Deutsches Zentrum für Luft- und Raumfahrt

text: . In addition to MuSTAnG, the university owns an

text: observatory

text: , which is taken care of by a private initiative and open to the public.

text: There is a zone of the atmosphere in which ozone absorbs some 98% of non-ionizing but dangerous UV-C and UV-B. This so-called ozone layer, starts at about  and extends upward. Some of the ultraviolet spectrum that does reach the ground (the part that begins above energies of 3.1 eV, a wavelength less than 400 nm) is non-ionizing, but is still biologically hazardous due to the ability of single photons of this energy to cause electronic excitation in biological molecules, and thus damage them by means of unwanted reactions. An example is the formation of pyrimidine dimers in DNA, which begins at wavelengths below 365 nm (3.4 eV), which is well below ionization energy. This property gives the ultraviolet spectrum some of the dangers of ionizing radiation in biological systems without actual ionization occurring. In contrast, visible light and longer-wavelength electromagnetic radiation, such as infrared, microwaves, and radio waves, consists of photons with too little energy to cause damaging molecular excitation, and thus this radiation is far less hazardous per unit of energy.

text: There is a zone of the atmosphere in which ozone absorbs some 98% of non-ionizing but dangerous UV-C and UV-B. This so-called

text: ozone layer

text: , starts at about  and extends upward. Some of the ultraviolet spectrum that does reach the ground (the part that begins above energies of 3.1 eV, a wavelength less than 400 nm) is non-ionizing, but is still biologically hazardous due to the ability of single photons of this energy to cause electronic excitation in biological molecules, and thus damage them by means of unwanted reactions. An example is the formation of

text: pyrimidine dimer

text: s in DNA, which begins at wavelengths below 365 nm (3.4 eV), which is well below ionization energy. This property gives the ultraviolet spectrum some of the dangers of ionizing radiation in biological systems without actual ionization occurring. In contrast, visible light and longer-wavelength electromagnetic radiation, such as infrared, microwaves, and radio waves, consists of photons with too little energy to cause damaging molecular excitation, and thus this radiation is far less hazardous per unit of energy.

text: Faraday's and Ampère's work showed that a time-varying magnetic field acted as a source of an electric field, and a time-varying electric field was a source of a magnetic field. Thus, when either field is changing in time, then a field of the other is necessarily induced. Such a phenomenon has the properties of a wave, and is naturally referred to as an electromagnetic wave. Electromagnetic waves were analysed theoretically by James Clerk Maxwell in 1864. Maxwell developed a set of equations that could unambiguously describe the interrelationship between electric field, magnetic field, electric charge, and electric current. He could moreover prove that such a wave would necessarily travel at the speed of light, and thus light itself was a form of electromagnetic radiation. Maxwell's Laws, which unify light, fields, and charge are one of the great milestones of theoretical physics.

text: Faraday's and Ampère's work showed that a time-varying magnetic field acted as a source of an electric field, and a time-varying electric field was a source of a magnetic field. Thus, when either field is changing in time, then a field of the other is necessarily induced. Such a phenomenon has the properties of a

text: wave

text: , and is naturally referred to as an

text: electromagnetic wave

text: . Electromagnetic waves were analysed theoretically by

text: James Clerk Maxwell

text: in 1864. Maxwell developed a set of equations that could unambiguously describe the interrelationship between electric field, magnetic field, electric charge, and electric current. He could moreover prove that such a wave would necessarily travel at the

text: speed of light

text: , and thus light itself was a form of electromagnetic radiation.

text: Maxwell's Laws

text: , which unify light, fields, and charge are one of the great milestones of theoretical physics.

text: Due to problems with the mirrors and because the telescope was unwieldy, the telescope did not prove to be a substantial improvement over smaller telescopes. The weather was rarely suitable for the telescope, and most objects observed by Herschel were also visible in his smaller telescopes. The final observation made by the telescope was in 1815.

text: The spacing of the molybdenum and silicon layers on each telescope's mirror is the primary determinant of the telescope's photon energy response function. The ALEXIS multilayer mirrors also employ a "wavetrap" feature to significantly reduce the mirror's reflectance for He II 304 Angstrom geocoronal radiation which can be a significant background source for space borne EUV telescopes. These mirrors, produced by Ovonyx, Inc., are highly curved yet have been shown to have very uniform multilayer coatings and hence have very uniform EUV reflecting properties over their entire surfaces. The efforts in designing, producing and calibrating the ALEXIS telescope mirrors have been previously described in Smith et al., 1990.

text: The SKA is a proposed radio telescope with an unprecedented one million square metres of collecting area, which will make it fiftytimes more sensitive than any other radio instrument. The telescope is currently in its design phase and has been described as "a revolutionary break from traditional radio telescope design" which is expected to "drive technology development, particularly in information and communication technology".

text: Large visible-light optical ground telescopes in 1984:

text: The waterhole, or water hole, is an especially quiet band of the electromagnetic spectrum between 1,420 and 1,666 megahertz, corresponding to wavelengths of 21 and 18 centimeters respectively.  It is a popular observing frequency used by radio telescopes in radio astronomy.   The term was coined by Bernard Oliver in 1971. The strongest hydroxyl radical spectral line radiates at 18 centimeters, and hydrogen at 21 centimeters. These two molecules, which combined form water, are widespread in interstellar gas, and their presence radiates radio noise at these frequencies.  Therefore, the spectrum between these frequencies form a "quiet" channel in the interstellar radio noise background.  Bernard M. Oliver theorized that the waterhole would be an obvious band for communication with extraterrestrial intelligence, hence the name, which is a form of pun: in English, a watering hole is a vernacular reference to a common place to meet and talk. Several programs involved in the search for extraterrestrial intelligence, including SETI@home, search in the waterhole radio frequencies.

text: The waterhole, or water hole, is an especially quiet

text: band

text: of the

text: electromagnetic spectrum

text: between 1,420 and 1,666

text: megahertz

text: , corresponding to wavelengths of 21 and 18 centimeters respectively.  It is a popular observing frequency used by

text: radio telescope

text: s in

text: radio astronomy

text: .   The term was coined by

text: Bernard Oliver

text: in 1971. The strongest

text: hydroxyl radical

text: spectral line

text: radiates at 18 centimeters, and

text: hydrogen

text: at 21 centimeters. These two molecules, which combined form

text: water

text: , are widespread in interstellar gas, and their presence radiates radio noise at these frequencies.  Therefore, the spectrum between these frequencies form a "quiet" channel in the interstellar

text: radio noise

text: background.  Bernard M. Oliver theorized that the waterhole would be an obvious band for

entity_name: Communication with extraterrestrial intelligence

text: communication with extraterrestrial intelligence

text: , hence the name, which is a form of pun: in English, a watering hole is a

text: vernacular

text: reference to a common place to meet and talk. Several programs involved in the

entity_name: Search for extraterrestrial intelligence

text: search for extraterrestrial intelligence

text: , including

text: SETI@home

text: , search in the waterhole radio frequencies.

text: The Netherlands Institute for Space Research (SRON) in collaboration with the University of Geneva provided the filter-wheel and calibration source for the spectrometer.

text: The

text: Netherlands Institute for Space Research

text: (SRON) in collaboration with the

text: University of Geneva

text: provided the filter-wheel and calibration source for the

text: spectrometer

text: The majority of IRTF users prefer to use IRTF remotely.  Observers can use IRTF from any location with a high speed internet connection, such as their office or home, anywhere around the world.  The observer controls the instrument via a VNC session, just as they would at the summit, and communicates with the telescope operator via phone, Polycom, or Skype.  The observer calls in and logs in for their time allocation.  Remote observing has several advantages.  Remote observing spares the observer the time and cost of traveling from their home institution to Hawaii.  In the past, when observers traveled to the telescope, the telescope was scheduled in full nights.  With remote observing, observers only need to submit a request for the amount of time they need, when they need it, instead of asking for whole nights.  Since the observers do not travel to Hawaii, they can also request to use the telescope more frequently.  This has enabled the IRTF to support many programs where frequent observations of targets are necessary, such as weekly monitoring of solar system objects.  Remote observing has also allowed the IRTF to support target-of-opportunity (ToO) programs.  These are programs of high scientific merit where the timing of the observation cannot be predicted at the time that telescope is scheduled.  Examples include supernovae, which explode unexpectedly, or near-earth asteroids that may be discovered shortly before their closest approach to the Earth.  Although the observers are usually remote, the telescope operator is at the summit to ensure the safety of the facility, assist the observer, and troubleshoot problems that may arise during the night.

text: In contrast to a true-color image, a false-color image sacrifices natural color rendition in order to ease the detection of features that are not readily discernible otherwise – for example the use of near infrared for the detection of vegetation in satellite images. While a false-color image can be created using solely the visual spectrum (e.g. to accentuate color differences), typically some or all data used is from electromagnetic radiation (EM) outside the visual spectrum (e.g. infrared, ultraviolet or X-ray). The choice of spectral bands is governed by the physical properties of the object under investigation.

text: In contrast to a true-color image, a false-color image sacrifices natural color rendition in order to ease the detection of features that are not readily discernible otherwise – for example the use of near infrared for the detection of vegetation in satellite images. While a false-color image can be created using solely the visual spectrum (e.g. to accentuate color differences), typically some or all data used is from

text: electromagnetic radiation

text: (EM) outside the

text: visual spectrum

text: (e.g.

text: infrared

text: ultraviolet

text: or

text: X-ray

text: ). The choice of spectral bands is governed by the physical properties of the object under investigation.

text: s that we know of today. It is approximately 13,000 light years away, located near the center of the galaxy. The planet was discovered using a technique called microlensing. In this case it took 150 days. Two telescopes are used to detect the planet and the time difference between identification by each telescope is used to calculate the distance to the planet. This also contributes to determining the mass of the planet which is about half of Jupiter's. The planet orbits a star with a mass of 0.7 solar masses and is 3.1 AU

text: s that we know of today. It is approximately 13,000 light years away, located near the center of the galaxy. The planet was discovered using a technique called

text: microlensing

text: . In this case it took 150 days. Two telescopes are used to detect the planet and the time difference between identification by each telescope is used to calculate the distance to the planet. This also contributes to determining the mass of the planet which is about half of

text: Jupiter

text: 's. The planet orbits a star with a mass of 0.7 solar masses and is 3.1

text: AU

text: Galileo Galilei was an Italian scientist who is sometimes referred to as the “father of modern observational astronomy”. His improvements to the telescope, astronomical observations, and support for Copernicanism were all integral to the Copernican Revolution.

text: Galileo Galilei was an Italian scientist who is sometimes referred to as the “father of modern

text: observational astronomy

text: ”. His improvements to the

text: telescope

text: , astronomical observations, and support for Copernicanism were all integral to the Copernican Revolution.

text: Radio frequencies occupy the range from a 3 kHz to 300 GHz, although commercially important uses of radio use only a small part of this spectrum. Other types of electromagnetic radiation, with frequencies above the RF range, are infrared, visible light, ultraviolet, X-rays and gamma rays. Since the energy of an individual photon of radio frequency is too low to remove an electron from an atom, radio waves are classified as non-ionizing radiation.

text: Radio frequencies occupy the range from a 3 kHz to 300 GHz, although commercially important uses of radio use only a small part of this spectrum. Other types of electromagnetic radiation, with frequencies above the RF range, are

text: infrared

text: , visible

text: light

text: ultraviolet

text: X-ray

text: s and

text: gamma ray

text: s. Since the energy of an individual

text: photon

text: of radio frequency is too low to remove an

text: electron

text: from an

text: atom

text: , radio waves are classified as

text: non-ionizing radiation

text: Polarization-division multiplexing (PDM) is a physical layer method for multiplexing signals carried on electromagnetic waves using the polarization of the electromagnetic waves to distinguish between the different orthogonal signals.

text: Polarization-division multiplexing (PDM) is a

text: physical layer

text: method for

text: multiplexing

text: signals carried on

text: electromagnetic wave

text: s using the

text: polarization

text: of the electromagnetic waves to distinguish between the different orthogonal signals.

text: A Dynamical Theory of the Electromagnetic Field is the third of James Clerk Maxwell's papers regarding electromagnetism, published in 1865.  In the paper, Maxwell derives an electromagnetic wave equation with a velocity for light in close agreement with measurements made by experiment, and deduces that light is an electromagnetic wave.

text: A Dynamical Theory of the Electromagnetic Field is the third of

text: James Clerk Maxwell

text: 's papers regarding

text: electromagnetism

text: , published in 1865.  In the paper, Maxwell derives an electromagnetic wave equation with a velocity for light in close agreement with measurements made by experiment, and deduces that light is an electromagnetic wave.

text: The Great Observatories Origins Deep Survey or GOODS is an astronomical survey combining deep observations from three of NASA's Great Observatories: the Hubble Space Telescope, the Spitzer Space Telescope , and the Chandra X-ray Observatory, along with data from other space-based telescopes, such as XMM Newton, and some of the worlds most powerful ground-based telescopes.

text: The Great Observatories Origins Deep Survey or GOODS is an

text: astronomical survey

text: combining deep observations from three of

text: NASA

text: 's

text: Great Observatories

text: : the

text: Hubble Space Telescope

text: , the

text: Spitzer Space Telescope

text: , and the

text: Chandra X-ray Observatory

text: , along with data from other

text: space-based telescopes

text: , such as

text: XMM Newton

text: , and some of the worlds most powerful ground-based telescopes.

text: The terahertz gap is an engineering term for a band of frequencies in the terahertz region of the electromagnetic spectrum between radio waves and infrared light for which practical technologies for generating and detecting the radiation do not exist. It is defined as 0.1 to 10 THz (wavelengths of 3 mm to 30 µm). Currently, at frequencies within this range, useful power generation and receiver technologies are inefficient and impractical. Mass production of devices in this range and operation at room temperature (at which kT is equal to the energy of a photon with a frequency of 6.2 THz) are mostly unfeasible. Hence, a gap exists between mature microwave technologies in the highest frequencies of the radio spectrum and the well developed optical engineering of infrared detector

text: The terahertz gap is an engineering term for a band of

text: frequencies

text: in the

text: terahertz

text: region of the

text: electromagnetic spectrum

text: between

text: radio wave

text: s and

text: infrared light

text: for which practical technologies for generating and detecting the radiation do not exist. It is defined as 0.1 to 10 THz (

text: wavelength

text: s of 3 mm to 30 µm). Currently, at frequencies within this range, useful power generation and receiver technologies are inefficient and impractical. Mass production of devices in this range and operation at

text: room temperature

text: (at which

text: kT

text: is equal to the

text: energy of a photon

text: with a frequency of 6.2 THz) are mostly unfeasible. Hence, a gap exists between mature

text: microwave

text: technologies in the highest frequencies of the

text: radio spectrum

text: and the well developed

text: optical engineering

text: of

text: infrared detector

text: To find an object, such as globular cluster NGC 6712, one does not need to look up the RA and Dec coordinates in a book, and then move the telescope to those numerical readings.  Rather, the object is chosen from the database and arrow markers appear in the display which indicate the direction to move the telescope.  The telescope is moved until the distance value reaches zero. When both the RA and Dec axes are thus "zeroed out", the object should be in the eyepiece. The user therefore does not have to go back and forth from some other database (such as a book or laptop) to match the desired object's listed coordinates to the coordinates on the telescope. However, many DSCs, and also go-to systems, can work in conjunction with laptop sky programs.

text: To find an object, such as globular cluster

text: NGC 6712

text: , one does not need to look up the RA and Dec coordinates in a book, and then move the telescope to those numerical readings.  Rather, the object is chosen from the database and arrow markers appear in the display which indicate the direction to move the telescope.  The telescope is moved until the distance value reaches zero. When both the RA and Dec axes are thus "zeroed out", the object should be in the eyepiece. The user therefore does not have to go back and forth from some other database (such as a book or laptop) to match the desired object's listed coordinates to the coordinates on the telescope. However, many DSCs, and also go-to systems, can work in conjunction with laptop sky programs.

text: Ten Bruggencate became chief astronomer at the Potsdam Observatory in 1935. The most valuable equipment at that time at Potsdam was the solar telescope in the Einstein Tower. From that time on, the main focus of ten Bruggencate's research became the Sun. In 1941, during World War II, ten Bruggencate became the director at the Göttingen University Observatory. In pursuing his interest in observing the Sun, he looked for a new solar telescope. The already existing observatory at the Hainberg, south east of Göttingen, provided the best location within the surrounding area. The interest of the military in the effect of the Sun on short wave radio communication made it possible to build this observatory during the war. Military patronage and ten Bruggencate's profound knowledge of the solar telescope in Potsdam assisted construction of the new telescope.

text: Ten Bruggencate became chief astronomer at the

entity_name: Leibniz Institute for Astrophysics Potsdam

text: Potsdam Observatory

text: in 1935. The most valuable equipment at that time at Potsdam was the

text: solar telescope

text: in the

text: Einstein Tower

text: . From that time on, the main focus of ten Bruggencate's research became the

text: Sun

text: . In 1941, during World War II, ten Bruggencate became the director at the

text: Göttingen University Observatory

text: . In pursuing his interest in observing the Sun, he looked for a new

text: solar telescope

text: . The already existing observatory at the Hainberg, south east of Göttingen, provided the best location within the surrounding area. The interest of the military in the

text: effect of the Sun

text: on

text: short wave

text: radio communication made it possible to build this observatory during the war. Military patronage and ten Bruggencate's profound knowledge of the solar telescope in Potsdam assisted construction of the new telescope.

text: Radiation from all regions of the electromagnetic spectrum has now been detected from galaxies. These observations have utilized telescopes at ground-based observatories (many located at high altitude mountain sites), telescopes in aircraft (≥10 km altitude), detectors on balloons that voyaged to the upper atmosphere (30–40 km altitude), instrument payloads on rockets that reached space, observatory satellites in Earth and Solar orbit as well as instruments aboard planetary missions journeying through the Solar System.

text: Modern Radio interferometers consist of widely separated radio telescopes observing the same object that are connected together using coaxial cable, waveguide, optical fiber, or other type of transmission line. This not only increases the total signal collected, it can also be used in a process called Aperture synthesis to vastly increase resolution. This technique works by superposing ("interfering") the signal waves from the different telescopes on the principle that waves that coincide with the same phase will add to each other while two waves that have opposite phases will cancel each other out. This creates a combined telescope that is the size of the antennas furthest apart in the array. In order to produce a high quality image, a large number of different separations between different telescopes are required (the projected separation between any two telescopes as seen from the radio source is called a "baseline") - as many different baselines as possible are required in order to get a good quality image. For example, the Very Large Array has 27 telescopes giving 351 independent baselines at once.

text: Modern

text: Radio interferometers

text: consist of widely separated radio telescopes observing the same object that are connected together using

text: coaxial cable

text: waveguide

text: optical fiber

text: , or other type of

text: transmission line

text: . This not only increases the total signal collected, it can also be used in a process called

text: Aperture synthesis

text: to vastly increase resolution. This technique works by superposing ("

text: interfering

text: ") the signal

text: wave

text: s from the different telescopes on the principle that

text: wave

text: s that coincide with the same

text: phase

text: will add to each other while two waves that have opposite phases will cancel each other out. This creates a combined telescope that is the size of the antennas furthest apart in the array. In order to produce a high quality image, a large number of different separations between different telescopes are required (the projected separation between any two telescopes as seen from the radio source is called a "baseline") - as many different baselines as possible are required in order to get a good quality image. For example, the

text: Very Large Array

text: has 27 telescopes giving 351 independent baselines at once.

text: is a triple system consisting of a central primary, which is itself a binary, and a small moon (component B). The combined observations by the infrared Spitzer Space Telescope, Herschel Space Telescope and the Hubble Space Telescope (HST) make it possible to estimate the sizes of the components and consequently provide the range of possible values for the objects’ bulk density. The single-body diameter (effective system size) of  is currently estimated at .

text: is a

text: triple system

text: consisting of a central primary, which is itself a binary, and a small moon (component B). The combined observations by the infrared

text: Spitzer Space Telescope

text: Herschel Space Telescope

text: and the

text: Hubble Space Telescope

text: (HST) make it possible to estimate the sizes of the components and consequently provide the range of possible values for the objects’ bulk

text: density

text: . The single-body diameter (effective system size) of  is currently estimated at .

text: Surface-wave-sustained plasmas (SWP) can be operated in a large variety of recipient geometries.  The pressure range accessible for surface-wave-excited plasmas depends on the process gas and the diameter of the recipient.  The larger the chamber diameter, the lower the minimal pressure necessary for the SWP mode. Analogously, the maximal pressure where a stable SWP can be operated decreases with increasing diameter.  The numerical modelling of SWPs is quite involved. The plasma is created by the electromagnetic wave, but it also reflects and guides this same wave. Therefore, a truly self-consistent description is necessary.

text: Surface-wave-sustained plasmas (SWP) can be operated in a large variety of recipient geometries.  The pressure range accessible for surface-wave-excited plasmas depends on the process gas and the diameter of the recipient.  The larger the chamber diameter, the lower the minimal pressure necessary for the SWP mode. Analogously, the maximal pressure where a stable SWP can be operated decreases with increasing diameter.  The

text: numerical modelling

text: of SWPs is quite involved. The plasma is created by the

text: electromagnetic wave

text: , but it also reflects and guides this same wave. Therefore, a truly

text: self-consistent

text: description is necessary.

text: Scientists at the B612 Foundation are planning to use Venus's L point to position their planned Sentinel telescope, which aims to look back towards Earth's orbit and compile a catalogue of near-Earth asteroids.

text: Scientists at the

text: B612 Foundation

text: are planning to use

text: Venus

text: 's L point to position their planned

text: Sentinel telescope

text: , which aims to look back towards Earth's orbit and compile a catalogue of

text: near-Earth asteroids

text: The main telescope at the observatory is the Lovell Telescope, which is the third largest steerable radio telescope in the world. There are three other active telescopes located at the observatory; the Mark II, as well as 42ft and 7m-diameter radio telescopes. Jodrell Bank Observatory is also the base of the Multi-Element Radio Linked Interferometer Network (MERLIN), a National Facility run by the University of Manchester on behalf of the Science and Technology Facilities Council.

text: The main telescope at the observatory is the

text: Lovell Telescope

text: , which is the third largest steerable radio telescope in the world. There are three other active telescopes located at the observatory; the

text: Mark II

text: , as well as 42ft and 7m-diameter radio telescopes. Jodrell Bank Observatory is also the base of the

text: Multi-Element Radio Linked Interferometer Network

text: (MERLIN), a National Facility run by the

text: University of Manchester

text: on behalf of the

text: The above equations are, in fact, the general functions  sought, but they are in their general form; whilst  we want to actually find their exact forms and solutions, so now is the time to look back at the information given to us, the so-called initial value problem. We chose

text: The above equations are, in fact, the general functions  sought, but they are in their general form; whilst  we want to actually find their exact forms and solutions, so now is the time to look back at the information given to us, the so-called

text: initial value problem

text: . We chose

text: SN 2002cx was discovered on 2002 May 12.21 UT by W. M. Wood-Vasey, G. Aldering, and P. Nugent of LBL with the Oschin 1.2-m telescope at Palomar.  On 2002 May 17.2 a spectrum taken by T. Matheson, S. Jha, P. Challis, and R. Kirshner of the CfA with the 1.5-m telescope at FLWO suggested it was a peculiar SN 1991T like type Ia. SN 2002cx had photometric follow up taken at Lick using KAIT and the Nickel telescope, and further spectra were taken at FLWO and Keck.

text: SN 2002cx was discovered on 2002 May 12.21 UT by W. M. Wood-Vasey,

text: G. Aldering

text: , and P. Nugent of LBL with the

text: Oschin 1.2-m telescope

text: at

text: Palomar

text: .  On 2002 May 17.2 a spectrum taken by T. Matheson, S. Jha, P. Challis, and R. Kirshner of the

entity_name: Harvard–Smithsonian Center for Astrophysics

text: CfA

text: with the 1.5-m telescope at

text: FLWO

text: suggested it was a peculiar SN 1991T like type Ia. SN 2002cx had photometric follow up taken at

text: Lick

text: using

text: KAIT

text: and the

text: Nickel telescope

text: , and further spectra were taken at FLWO and

text: Keck

text: The Nançay decimetric radio telescope (Le radiotélescope décimétrique de Nançay (NRT)) is located in the small commune of Nançay, two hours' drive south of Paris, France.  The radio telescope saw first light in 1965, after an inauguration by the then French president, Charles de Gaulle.  It is one of the largest radio telescopes in the world.

text: The Nançay decimetric radio telescope (Le radiotélescope décimétrique de Nançay (NRT)) is located in the small

text: commune

text: of

text: Nançay

text: , two hours' drive south of

text: Paris

text: France

text: .  The

text: radio telescope

text: saw

text: first light

text: in 1965, after an inauguration by the then

text: French president

text: Charles de Gaulle

text: .  It is one of the largest radio telescopes in the world.

text: The light from the stars was captured with optical fibres, precisely positioned by a robot. The robot picks up optical fibres, one by one, and places them on a metal plate in the telescope. Each fibre is in the right place to catch the light from a single star. By using many fibres, more than 100 stars can be studied at the same time. Travelling down the tiny glass threads, the starlight enters an instrument that spreads it out into its component wavelengths or 'colours', the way a prism does. These colours tell astronomers about the chemical elements a star contains and how it is moving. From that, the astronomers can work out how old the stars are, where they came from, and how they are related. And that's the key that unlocks the history of our Galaxy.

text: With the exception of the Bolshoi Teleskop Azimutalnyi (BTA-6) and William Herschel's 40-foot telescope, major optical telescopes prior to the MMT used equatorial mounts. The MMT heralded a change in telescope design; all major optical telescopes since the MMT have been built with alt-azimuth mounts. Several technologies pioneered at the MMT contributed to the success of the subsequent generation of large telescopes. These included: high dynamic-range servos for the alt-azimuth mount; highly accurate pointing that eliminated the need for sky charts; co-alignment and co-phasing of multiple telescopes; improvements to optical performance by attention to thethermal environment of the facility; contributions to vacuum coatings deposition, optics cleaning, and maintenance; and early experiments in co-phased adaptive optics.

text: With the exception of the

text: Bolshoi Teleskop Azimutalnyi (BTA-6)

text: and William Herschel's

text: 40-foot telescope

text: , major optical telescopes prior to the MMT used

text: equatorial mount

text: s. The MMT heralded a change in telescope design; all major optical telescopes since the MMT have been built with alt-azimuth mounts. Several technologies pioneered at the MMT contributed to the success of the subsequent generation of large telescopes. These included: high dynamic-range servos for the

text: alt-azimuth

text: mount; highly accurate pointing that eliminated the need for sky charts; co-alignment and co-phasing of multiple telescopes; improvements to optical performance by attention to thethermal environment of the facility; contributions to vacuum coatings deposition, optics cleaning, and maintenance; and early experiments in co-phased adaptive optics.

text: Follow-up observations were conducted at observatories at the W.M. Keck Observatory's Keck 1 telescope in Hawaii; the Shane and Hale telescopes in California; the Harlan J. Smith and Hobby-Eberly telescopes in Texas; telescopes at the WIYN (including MMT) and Whipple observatories in Arizona; and the Nordic Optical Telescope in the Canary Islands. The Spitzer Space Telescope was also used. According to NASA, Kepler-11's system is the most compact and the flattest system yet discovered, surpassing even the Solar System.

text: Follow-up observations were conducted at observatories at the

text: W.M. Keck Observatory

text: 's Keck 1 telescope in Hawaii; the

text: Shane

text: and

text: Hale

text: telescopes in California; the

text: Harlan J. Smith

text: and

text: Hobby-Eberly

text: telescopes in Texas; telescopes at the

text: WIYN

text: (including

text: MMT

text: ) and

text: Whipple

text: observatories in Arizona; and the

text: Nordic Optical Telescope

text: in the Canary Islands. The

text: Spitzer Space Telescope

text: was also used. According to NASA, Kepler-11's system is the most compact and the flattest system yet discovered, surpassing even the Solar System.

text: The radio telescopes are sensitive enough to detect "Earth-leakage" levels of radio transmission for stars within 5 parsecs, and can detect a transmitter of the same power as a common aircraft radar for the 1,000 nearest stars. The Green Bank Telescope began operations in January 2016, with the Parkes Telescope due to join it in October 2016. The FAST radiotelescope in China also joined forces in October 2016 with the Breakthrough Initiatives to launch a coordinated search, including the rapid sharing of promising new signals for additional observation and analysis.

text: The radio telescopes are sensitive enough to detect "Earth-leakage" levels of radio transmission for stars within 5

text: parsec

text: s, and can detect a transmitter of the same power as a common aircraft

text: radar

text: for the 1,000 nearest stars. The Green Bank Telescope began operations in January 2016, with the Parkes Telescope due to join it in October 2016. The

entity_name: Five hundred meter Aperture Spherical Telescope

text: FAST

text: radiotelescope in China also joined forces in October 2016 with the Breakthrough Initiatives to launch a coordinated search, including the rapid sharing of promising new signals for additional observation and analysis.

text: Maze of Moonlight is a novel written by Gael Baudino in 1993.  It is the second in the Strands of Starlight tetralogy.  The other novels are Strands of Starlight, Shroud of Shadow, and Strands of Sunlight.

text: Maze of Moonlight is a novel written by

text: Gael Baudino

text: in 1993.  It is the second in the

text: Strands of Starlight

text: tetralogy

text: .  The other novels are

text: Strands of Starlight

text: Shroud of Shadow

text: , and

text: Strands of Sunlight

text: The first optical instruments were telescopes used for magnification of distant images, and microscopes used for magnifying very tiny images. Since the days of Galileo and Van Leeuwenhoek, these instruments have been greatly improved and extended into other portions of the electromagnetic spectrum. The binocular device is a generally compact instrument for both eyes designed for mobile use. A camera could be considered a type of optical instrument, with the pinhole camera and camera obscura being very simple examples of such devices.

text: The first optical instruments were

text: telescope

text: s used for magnification of distant images, and

text: microscope

text: s used for magnifying very tiny images. Since the days of

text: Galileo

text: and

text: Van Leeuwenhoek

text: , these instruments have been greatly improved and extended into other portions of the

text: electromagnetic spectrum

text: . The

text: binocular

text: device is a generally compact instrument for both eyes designed for mobile use. A

text: camera

text: could be considered a type of optical instrument, with the

text: pinhole camera

text: and

text: camera obscura

text: being very simple examples of such devices.

text: The absence of air makes outer space an ideal location for astronomy at all wavelengths of the electromagnetic spectrum. This is evidenced by the spectacular pictures sent back by the Hubble Space Telescope, allowing light from more than 13 billion years ago—almost to the time of the Big Bang—to be observed. However, not every location in space is ideal for a telescope. The interplanetary zodiacal dust emits a diffuse near-infrared radiation that can mask the emission of faint sources such as extrasolar planets. Moving an infrared telescope out past the dust will increase the effectiveness of the instrument. Likewise, a site like the Daedalus crater on the far side of the Moon could shield a radio telescope from the radio frequency interference that hampers Earth-based observations.

text: The absence of air makes outer space an ideal location for astronomy at all wavelengths of the

text: electromagnetic spectrum

text: . This is evidenced by the spectacular pictures sent back by the

text: Hubble Space Telescope

text: , allowing light from more than 13 billion years ago—almost to the time of the Big Bang—to be observed. However, not every location in space is ideal for a telescope. The

text: interplanetary zodiacal dust

text: emits a diffuse near-infrared radiation that can mask the emission of faint sources such as extrasolar planets. Moving an

text: infrared telescope

text: out past the dust will increase the effectiveness of the instrument. Likewise, a site like the

text: Daedalus crater

text: on the

text: far side of the Moon

text: could shield a

text: radio telescope

text: from the

text: radio frequency interference

text: that hampers Earth-based observations.

text: Through his career T. W. Webb served as a clergyman at various places including Gloucester, and finally in 1852 was assigned to the parish of Hardwicke near the border with Wales.  In addition to serving faithfully the members of his parish, T. W. Webb pursued astronomical observation in his spare time.  On the grounds of the vicarage or parsonage he built a small canvas and wood observatory that was home to instruments including a small 3.7" (94mm) refractor. Webb acquired progressively larger refractors and reflectors with which the observations in the guide were made. The largest telescope was a 9-1/3" (225mm) silver on glass reflector used from 1866 until his last observation in March 1885.  It was at Hardwick that he wrote his classic astronomical observing guide Celestial Objects for Common Telescopes (2 vols) in 1859 for which he is best known today.  This two volume work was written as a guide for the amateur astronomer, containing instructions on the use of a telescope as well as detailed descriptions of what could be observed with it. This work became the standard observing guide of amateur astronomers worldwide, and remained so until well into the 20th Century, gradually supplanted by more modern guides such as Burnham's Celestial Handbook.

text: Through his career T. W. Webb served as a clergyman at various places including

text: Gloucester

text: , and finally in 1852 was assigned to the parish of

text: Hardwicke

text: near the border with

text: Wales

text: .  In addition to serving faithfully the members of his parish, T. W. Webb pursued

text: astronomical observation

text: in his spare time.  On the grounds of the

text: vicarage

text: or

text: parsonage

text: he built a small canvas and wood observatory that was home to instruments including a small 3.7" (94mm) refractor. Webb acquired progressively larger

text: refractors

text: and reflectors with which the observations in the guide were made. The largest telescope was a 9-1/3" (225mm) silver on glass reflector used from 1866 until his last observation in March 1885.  It was at Hardwick that he wrote his classic astronomical observing guide Celestial Objects for Common Telescopes (2

text: vol

text: s) in 1859 for which he is best known today.  This two volume work was written as a guide for the amateur astronomer, containing instructions on the use of a telescope as well as detailed descriptions of what could be observed with it. This work became the standard observing guide of amateur astronomers worldwide, and remained so until well into the 20th Century, gradually supplanted by more modern guides such as

text: Burnham's

text: Celestial Handbook.

text: The largest optical telescope currently in regular use is a  open truss Newtonian on a mount inspired by the designs of John Dobson. A  mirror blank is available for a future enhancement of the facilities but construction of the UK's largest reflector since the destruction of the  original Isaac Newton Telescope at Herstmonceux Castle is currently suspended due to commercial development around the observatory. Pre- and post-construction studies have shown that these turbines interfere with observations in certain parts of the sky in the visual, infra-red and radio parts of the electromagnetic spectrum.

text: The largest optical telescope currently in regular use is a  open truss Newtonian on a mount inspired by the designs of

text: John Dobson

text: . A  mirror blank is available for a future enhancement of the facilities but construction of the UK's largest reflector since the destruction of the  original

text: Isaac Newton Telescope

text: at

text: Herstmonceux Castle

text: is currently suspended due to commercial development around the observatory. Pre- and post-construction studies have shown that these turbines interfere with observations in certain parts of the sky in the visual, infra-red and radio parts of the electromagnetic spectrum.

text: For observation purposes, the optimal location for an optical telescope is undoubtedly in outer space. There the telescope can make observations without being affected by the atmosphere. However, at present it remains costly to lift telescopes into orbit. Thus the next best locations are certain mountain peaks that have a high number of cloudless days and generally possess good atmospheric conditions (with good seeing conditions). The peaks of the islands of Mauna Kea, Hawaii and La Palma possess these properties, as to a lesser extent do inland sites such as Llano de Chajnantor, Paranal, Cerro Tololo and La Silla in Chile. These observatory locations have attracted an assemblage of powerful telescopes, totalling many billion US dollars of investment.

text: For observation purposes, the optimal location for an optical telescope is undoubtedly in

text: outer space

text: . There the telescope can make observations without being affected by the

text: atmosphere

text: . However, at present it remains costly to lift telescopes into

text: orbit

text: . Thus the next best locations are certain mountain peaks that have a high number of cloudless days and generally possess good atmospheric conditions (with good

text: seeing

text: conditions). The peaks of the islands of

text: Mauna Kea, Hawaii

text: and

text: La Palma

text: possess these properties, as to a lesser extent do inland sites such as

text: Llano de Chajnantor

text: Paranal

text: Cerro Tololo

text: and

text: La Silla

text: in

text: Chile

text: . These observatory locations have attracted an assemblage of powerful telescopes, totalling many billion US dollars of investment.

text: For reflecting telescopes, which use a curved mirror in place of the objective lens, theory preceded practice. The theoretical basis for curved mirrors behaving similar to lenses was probably established by Alhazen, whose theories had been widely disseminated in Latin translations of his work. Soon after the invention of the refracting telescope Galileo, Giovanni Francesco Sagredo, and others, spurred on by their knowledge that curved mirrors had similar properties as lenses, discussed the idea of building a telescope using a mirror as the image forming objective. The potential advantages of using parabolic mirrors (primarily a reduction of spherical aberration with elimination of chromatic aberration) led to several proposed designs for reflecting telescopes, the most notable of which was published in 1663 by James Gregory and came to be called the Gregorian telescope, but no working models were built. Isaac Newton has been generally credited with constructing the first practical reflecting telescopes, the Newtonian telescope, in 1668 although due to their difficulty of construction and the poor performance of the speculum metal mirrors used it took over 100 years for reflectors to become popular. Many of the advances in reflecting telescopes included the perfection of parabolic mirror fabrication in the 18th century, silver coated glass mirrors in the 19th century, long-lasting aluminum coatings in the 20th century, segmented mirrors to allow larger diameters, and active optics to compensate for gravitational deformation. A mid-20th century innovation was catadioptric telescopes such as the Schmidt camera, which uses both a lens (corrector plate) and mirror as primary optical elements, mainly used for wide field imaging without spherical aberration.

text: For

text: reflecting telescope

text: s, which use a

text: curved mirror

text: in place of the objective lens, theory preceded practice. The theoretical basis for

text: curved mirrors

text: behaving similar to lenses was probably established by

text: Alhazen

text: , whose theories had been widely disseminated in Latin translations of his work. Soon after the invention of the refracting telescope Galileo,

text: Giovanni Francesco Sagredo

text: , and others, spurred on by their knowledge that curved mirrors had similar properties as lenses, discussed the idea of building a telescope using a mirror as the image forming objective. The potential advantages of using

text: parabolic mirrors

text: (primarily a reduction of

text: spherical aberration

text: with elimination of

text: chromatic aberration

text: ) led to several proposed designs for reflecting telescopes, the most notable of which was published in 1663 by

text: James Gregory

text: and came to be called the

text: Gregorian telescope

text: , but no working models were built.

text: Isaac Newton

text: has been generally credited with constructing the first practical reflecting telescopes, the

text: Newtonian telescope

text: , in 1668 although due to their difficulty of construction and the poor performance of the

text: speculum metal

text: mirrors used it took over 100 years for reflectors to become popular. Many of the advances in reflecting telescopes included the perfection of

text: parabolic mirror

text: fabrication in the 18th century, silver coated glass mirrors in the 19th century, long-lasting aluminum coatings in the 20th century,

text: segmented mirror

text: s to allow larger diameters, and

text: active optics

text: to compensate for gravitational deformation. A mid-20th century innovation was

text: catadioptric

text: telescopes such as the

text: Schmidt camera

text: , which uses both a lens (corrector plate) and mirror as primary optical elements, mainly used for wide field imaging without spherical aberration.

text: The ASC has led the development and deployment of an international VLBI project. It is called the RadioAstron. VLBI stands for (Very Long Baseline Interferometry), for radio astronomy. It allows observations of an object that are made simultaneously by many telescopes to be combined, emulating a telescope with a size equal to the maximum separation between the telescopes.

text: The ASC has led the development and deployment of an international

text: VLBI

text: project. It is called the

text: RadioAstron

text: . VLBI stands for (

text: Very Long Baseline Interferometry

text: ), for radio astronomy. It allows observations of an object that are made simultaneously by many telescopes to be combined, emulating a telescope with a size equal to the maximum separation between the telescopes.

text: The  refracting telescope on Mt. Hamilton was Earth's largest refracting telescope during the period from when it saw first light on January 3, 1888, until the construction of Yerkes Observatory in 1897. Warner & Swasey designed and built the telescope mounting, with the  lens manufactured by one of the Clark sons, Alvan Graham. E. E. Barnard used the telescope in 1892 to discover a fifth moon of Jupiter, Amalthea. This was the first addition to Jupiter's known moons since Galileo observed the planet through his parchment tube and spectacle lens. The telescope provided spectra for W. W. Campbell's work on the radial velocities of stars.

text: The

text: refracting telescope

text: on Mt. Hamilton was Earth's largest refracting telescope during the period from when it saw

text: first light

text: on January 3, 1888, until the construction of

text: Yerkes Observatory

text: in 1897.

text: Warner & Swasey

text: designed and built the telescope mounting, with the  lens manufactured by one of the

text: Clark sons

text: Alvan Graham

text: E. E. Barnard

text: used the telescope in 1892 to discover a fifth

text: moon of Jupiter

text: Amalthea

text: . This was the first addition to Jupiter's known moons since

text: Galileo

text: observed the planet through his parchment tube and

text: spectacle lens

text: . The telescope provided

text: spectra

text: for

text: W. W. Campbell's

text: work on the

text: radial velocities

text: of

text: star

text: s.

text: Jim is an observational cosmologist who uses the world's largest telescopes (including telescopes in space such as the Hubble Space Telescope) to study the chronology of the universe back to the formation and birth of the first galaxies. His research has been funded by the Science and Technology Facilities Council (STFC), a Royal Society Wolfson Research Merit Award and the European Research Council.

text: Jim is an

text: observational cosmologist

text: who uses the

text: world's largest telescopes

text: (including telescopes in space such as the

text: Hubble Space Telescope

text: ) to study the

text: chronology of the universe

text: back to the formation and birth of the first

text: galaxies

text: . His research has been funded by the

text: Science and Technology Facilities Council (STFC)

text: , a

entity_name: Royal Society Wolfson Research Merit Award

text: Royal Society Wolfson Research Merit Award

text: and the

text: European Research Council

text: Other instruments include a swivel chair for vestibular function tests, lower body negative pressure gear for cardiovascular studies, bicycle ergometer integrated physical trainer (electrically driven running track 1 m X .3 m with elastic cords providing 50 kg load), penguin suits and alternate athletic suit, sensors for temperature and characteristics of upper atmosphere, ITS-K infrared telescope spectrometer and ultraviolet spectrometer for study of earth's infrared radiation,  multispectral earth resources camera, cosmic ray detector, embryological studies, new engineering instruments tested for orientation of station by celestial objects and in darkness and a teletypewriter.

text: Other instruments include a swivel chair for vestibular function tests, lower body negative pressure gear for cardiovascular studies, bicycle ergometer integrated physical trainer (electrically driven running track 1 m X .3 m with elastic cords providing 50 kg load),

text: penguin suits

text: and alternate athletic suit, sensors for temperature and characteristics of upper atmosphere, ITS-K infrared telescope spectrometer and ultraviolet spectrometer for study of earth's infrared radiation,  multispectral earth resources camera, cosmic ray detector, embryological studies, new engineering instruments tested for orientation of station by celestial objects and in darkness and a teletypewriter.

text: As a variation of standard web-based assessment methods, the SAPA methodology borrows by analogy a technique used in radio and optical astronomy: Synthetic Aperture Measurement. The resolution of a telescope is limited by its diameter which may be functionally increased a great deal by combining input from multiple, linked sites into one coherent image. Effectively, a very large telescope is created by synthesizing the input of many smaller ones. A classic example in radio astronomy is the Very Large Array, part of the National Radio Astronomy Observatory in Socorro, New Mexico, where 27 relatively small (≈ 25 meter) radio telescopes are spread out in a Y-shaped configuration to simulate the resolution of a 36 km telescope. The configuration is adjustable so that the telescope can either emphasize resolution (by maximizing the distance covered) or sensitivity (by concentrating the telescopes close to each other). In optical astronomy similar techniques are used in inferometry at the W. M. Keck Observatory in Hawaii with "outriggers" to supplement the main telescope. Similar techniques are available for "telemetric assessment" of psychological constructs. Rather than combining signals from the same source using different telescopes as is done in astronomy, the structure of personality can be studied by combining the responses of many people across more items than any one person is willing to take. This is not an entirely novel procedure.  The Educational Testing Service, for example, has long used the very large samples available when students take the SAT or GRE to develop new items by randomly giving small subsets of items to much smaller (but still quite large) subsamples of students. The SAPA methodology allows for these techniques to be used by a broader population of researchers by making use of open source and public domain software.

text: As a variation of standard web-based assessment methods, the SAPA methodology borrows by analogy a technique used in radio and optical astronomy: Synthetic Aperture Measurement. The resolution of a telescope is limited by its diameter which may be functionally increased a great deal by combining input from multiple, linked sites into one coherent image. Effectively, a very large telescope is created by synthesizing the input of many smaller ones. A classic example in radio astronomy is the

text: Very Large Array

text: , part of the

text: National Radio Astronomy Observatory

text: in Socorro, New Mexico, where 27 relatively small (≈ 25 meter) radio telescopes are spread out in a Y-shaped configuration to simulate the resolution of a 36 km telescope. The configuration is adjustable so that the telescope can either emphasize resolution (by maximizing the distance covered) or sensitivity (by concentrating the telescopes close to each other). In optical astronomy similar techniques are used in inferometry at the

text: W. M. Keck Observatory

text: in Hawaii with "outriggers" to supplement the main telescope. Similar techniques are available for "telemetric assessment" of psychological constructs. Rather than combining signals from the same source using different telescopes as is done in astronomy, the structure of personality can be studied by combining the responses of many people across more items than any one person is willing to take. This is not an entirely novel procedure.  The

text: Educational Testing Service

text: , for example, has long used the very large samples available when students take the SAT or GRE to develop new items by randomly giving small subsets of items to much smaller (but still quite large) subsamples of students. The SAPA methodology allows for these techniques to be used by a broader population of researchers by making use of open source and public domain software.

text: Sexton High School was not only an engineering marvel, it was a piece of architectural art. The school was designed at the very end of the Art Deco period. Had it been designed just a few years later, it probably would have been in the International Style. The geometric characteristics of the Art Deco style are quite prominent in Sexton's exterior.  When one first looks at the building, the eye is immediately drawn to the eight-story clock tower flanking the north end of the building. At the top, the corners have a stepped look, which is common among Art Deco buildings. As the tower grows in height, there are step backs, providing a telescope effect. Below the clock face, narrow glass block windows and chrome spandrels give an extra sense of height to the tower.

text: Classically, electromagnetic radiation consists of electromagnetic waves, which are synchronized oscillations of electric and magnetic fields that propagate at the speed of light through a vacuum.  The oscillations of the two fields are perpendicular to each other and perpendicular to the direction of energy and wave propagation, forming a transverse wave. Electromagnetic waves can be characterized by either the frequency or wavelength of their oscillations, which determines their position in the electromagnetic spectrum, which includes, in order of increasing frequency and decreasing wavelength: radio waves, microwaves, infrared radiation, visible light, ultraviolet radiation, X-rays and gamma rays.

text: Classically

text: , electromagnetic radiation consists of electromagnetic waves, which are synchronized

text: oscillation

text: s of

text: electric

text: and

text: magnetic

text: fields that propagate at the

text: speed of light

text: through a

text: vacuum

text: .  The oscillations of the two fields are perpendicular to each other and perpendicular to the direction of energy and wave propagation, forming a

text: transverse wave

text: . Electromagnetic waves can be characterized by either the

text: frequency

text: or

text: wavelength

text: of their oscillations, which determines their position in the

text: electromagnetic spectrum

text: , which includes, in order of increasing frequency and decreasing wavelength:

text: radio wave

text: s,

text: microwave

text: s,

text: infrared

text: radiation,

text: visible light

text: ultraviolet radiation

text: X-ray

text: s and

text: gamma ray

text: s.

text: The 1.3 m (51-inch) large-field R-C telescope was produced by DFM Engineering and then corrected and automated by NOFS staff. Corning Glass Works and Kodak made the primary mirror. The hyperbolic secondary has an advanced, computer-controlled collimation (alignment) system in order to permit very precise positions of stars and satellites (milliarcsecond astrometry) across its wide field of view. This system analyzes optical aberrations of the optical path, modeled by taking slope fits of the wavefront deviations revealed using a Hartmann mask. The telescope also now sports a state-of-the art, cryogenic wide-field mosaic CCD camera. It will also permit employment of the new "Microcam", an orthogonal transfer array (OTA), with Pan-STARRS heritage. Other advanced camera systems are also deployed for use on this telescope, such as the LANL-produced RULLI single photon counter, nCam. Using the telescope's special software controls, the telescope can track both stars and man-made satellites orbiting the Earth, while the camera images both. The 1.3 m dome itself is compact, owing to the fast overall optics at f/4. It is located near by and southwest of, the very large 61-inch dome. In addition to astrometric studies (such as for Space Situational Awareness, SDSS and SST), research on this telescope includes the study of blue and K-Giant stars, celestial mechanics and dynamics of multiple star systems, characterizations of artificial satellites, and the astrometry and transit photometry of exoplanets. Astrometrically, exoplanets also confuse centroid of a parent star's PSF—and there are many exoplanets—so the impact of their not-bland dynamics must be understood.

text: The 1.3 m (51-inch) large-field

text: R-C

text: telescope was produced by

text: DFM Engineering

text: and then corrected and automated by NOFS staff.

text: Corning Glass Works

text: and

text: Kodak

text: made the primary mirror. The hyperbolic secondary has an advanced, computer-controlled collimation (alignment) system in order to permit very precise positions of stars and satellites (

text: milliarcsecond

text: astrometry) across its wide field of view. This system analyzes

text: optical aberrations

text: of the optical path, modeled by taking

text: slope fits

text: of the

text: wavefront

text: deviations revealed using a

text: Hartmann mask

text: . The telescope also now sports a state-of-the art,

text: cryogenic

text: wide-field mosaic CCD camera. It will also permit employment of the new "Microcam", an

text: orthogonal transfer array

text: (OTA), with

text: Pan-STARRS

text: heritage. Other advanced camera systems are also deployed for use on this telescope, such as the

text: LANL

text: -produced RULLI single photon counter, nCam. Using the telescope's special software controls, the telescope can track both

text: stars

text: and man-made

text: satellites

text: orbiting the Earth, while the camera images both. The 1.3 m dome itself is compact, owing to the

text: fast overall optics

text: at f/4. It is located near by and southwest of, the very large 61-inch dome. In addition to astrometric studies (such as for

text: Space Situational Awareness

text: SDSS

text: and

text: SST

text: ), research on this telescope includes the study of

text: blue

text: and

text: K-Giant

text: stars,

text: celestial mechanics

text: and dynamics of multiple star systems, characterizations of

text: artificial satellite

text: s, and the astrometry and

text: transit photometry

text: of

text: exoplanets

text: . Astrometrically, exoplanets also confuse centroid of a parent star's PSF—and there are many exoplanets—so the impact of their not-bland dynamics must be understood.

text: NRAO is the operator of the world's largest fully steerable radio telescope, the Robert C. Byrd Green Bank Telescope, which stands near Green Bank, West Virginia. The observatory contains several other telescopes, among them the  telescope that utilizes an equatorial mount uncommon for radio telescopes, three  telescopes forming the Green Bank Interferometer, a  telescope used by school groups and organizations for small scale research, a fixed radio 'horn' built to observe the radio source Cassiopeia A, as well as a reproduction of the original antenna built by Karl Jansky while he worked for Bell Labs to detect the interference that was discovered to be previously unknown natural radio waves emitted by the universe.

text: NRAO is the operator of the world's largest fully steerable

text: radio telescope

text: , the Robert C. Byrd

text: Green Bank Telescope

text: , which stands near

text: Green Bank, West Virginia

text: . The observatory contains several other telescopes, among them the  telescope that utilizes an

text: equatorial mount

text: uncommon for radio telescopes, three  telescopes forming the

text: Green Bank Interferometer

text: , a  telescope used by school groups and organizations for small scale research, a fixed radio '

text: horn

text: ' built to observe the radio source Cassiopeia A, as well as a reproduction of the original antenna built by

text: Karl Jansky

text: while he worked for Bell Labs to detect the

text: interference

text: that was discovered to be previously unknown natural

text: radio waves

text: emitted by the universe.

text: The Huygens contrived some ingenious arrangements for aiming these "aerial telescopes" at an object visible in the night sky. The telescope could be aimed at bright objects such as planets by looking for their image cast on a white pasteboard ring or oiled translucent paper screen and then centering them in the eyepiece. Fainter objects could be found by looking for the reflection of a lamp held in the observer's hand being bounced back by the objective and then centering that reflection on the object. Other contrivances for the same purpose are described by Philippe de la Hire and by Nicolaas Hartsoeker. The objectives for aerial telescopes sometimes had very long focal lengths. Christiaan Huygens states that in 1686 he and his brother made objectives of 8 inch (200 mm) and 8.5 inch (220 mm) diameter and 170 and 210 ft (52 and 64 m) focal length, respectively. Constantijn Huygens, Jr. presented a 7.5 inch (190 mm) diameter 123 ft (37.5 m) focal length objective to the Royal Society of London in 1690. Adrien Auzout and others made telescopes of from 300 to 600 ft (90 to 180 m) focal length, and Auzout proposed a huge aerial telescope 1,000 ft in length that he would use "to observe animals on the Moon".

text: The Huygens contrived some ingenious arrangements for aiming these "aerial telescopes" at an object visible in the night sky. The telescope could be aimed at bright objects such as planets by looking for their image cast on a white pasteboard ring or oiled translucent paper screen and then centering them in the eyepiece. Fainter objects could be found by looking for the reflection of a lamp held in the observer's hand being bounced back by the objective and then centering that reflection on the object. Other contrivances for the same purpose are described by

text: Philippe de la Hire

text: and by

text: Nicolaas Hartsoeker

text: . The objectives for aerial telescopes sometimes had very long focal lengths. Christiaan Huygens states that in 1686 he and his brother made objectives of 8 inch (200 mm) and 8.5 inch (220 mm) diameter and 170 and 210 ft (52 and 64 m) focal length, respectively. Constantijn Huygens, Jr. presented a 7.5 inch (190 mm) diameter 123 ft (37.5 m) focal length objective to the

text: Royal Society of London

text: in 1690. Adrien Auzout and others made telescopes of from 300 to 600 ft (90 to 180 m) focal length, and Auzout proposed a huge aerial telescope 1,000 ft in length that he would use "to observe animals on the Moon".

text: Each of the individual telescopes have a 39 feet aperture, 350 mirrors on each dish, and a 3.5 degree field of view. The telescopes are built on a Davies-Cotton optical design, which uses a spherical reflector and is easy to construct and align. This design does cause a small time spread in the signal, but this spread is very small (~ 4 nanoseconds). The camera on each telescope has 499 individual photomultiplier tubes. VERITAS, like other IACTs, are most sensitive to the highest energy cosmic rays. Its full range of sensitivity is from 85 GeV to over 30 TeV (although the spectral reconstruction does not start until at least 100 GeV). The energy and angular resolution depend on the energy of the incident gamma ray but at 1 TeV the energy resolution is ~17%, and the angular resolution is 0.08 degrees. The entire array has an effective area of 100,000 square meters.

text: Each of the individual telescopes have a 39 feet aperture, 350 mirrors on each dish, and a 3.5 degree field of view. The telescopes are built on a Davies-Cotton optical design, which uses a spherical reflector and is easy to construct and align. This design does cause a small time spread in the signal, but this spread is very small (~ 4 nanoseconds). The camera on each telescope has 499 individual

text: photomultiplier tubes

text: . VERITAS, like other

text: IACT

text: s, are most sensitive to the highest energy cosmic rays. Its full range of sensitivity is from 85 GeV to over 30 TeV (although the spectral reconstruction does not start until at least 100 GeV). The energy and angular resolution depend on the energy of the incident gamma ray but at 1 TeV the energy resolution is ~17%, and the angular resolution is 0.08 degrees. The entire array has an effective area of 100,000 square meters.

text: At nearly  distant, Kepler-438b is too remote and its star too far for current telescopes or the next generation of planned telescopes to determine its mass or whether it has an atmosphere. The Kepler spacecraft focused on a single small region of the sky but next-generation planet-hunting space telescopes, such as TESS and CHEOPS, will examine nearby stars throughout the sky. Nearby stars with planets can then be studied by the upcoming James Webb Space Telescope and future large ground-based telescopes to analyze atmospheres, determine masses and infer compositions. Additionally the Square Kilometer Array would significantly improve radio observations over the Arecibo Observatory and Green Bank Telescope.

text: At nearly  distant, Kepler-438b is too remote and its star too far for current telescopes or the next generation of planned telescopes to determine its mass or whether it has an atmosphere. The Kepler spacecraft focused on a single small region of the sky but next-generation planet-hunting space telescopes, such as

text: TESS

text: and

text: CHEOPS

text: James Webb Space Telescope

text: Square Kilometer Array

text: Arecibo Observatory

text: and

text: Green Bank Telescope

text: Even before the end of the war, the Soviet government made a decision to restore the Observatory. In 1946, it began the construction after having cleared the territory. In May 1954, the Observatory was re-opened, not only having been restored but considerably expanded in terms of instruments, employees and research subjects. New departments had been created, such as the Department of Radio Astronomy and Department of Instrument Making (with its own optical and mechanical workshop). The surviving old instruments were repaired, modernized and put into service once again. Also installed were new instruments, such as the  refractor, a horizontal meridian device, a photographic polar telescope, a big zenith telescope, stellar interferometer, 2 solar telescopes, coronagraph, a big radio telescope and all kinds of labware.The 65 cm Zeiss refractor was originally intended as a gift from then Chancellor of Germany Adolf Hitler to the Italian Benito Mussolini, but it was not delivered and instead was taken by the Soviet Union.

text: Even before the end of the war, the Soviet

text: government

text: made a decision to restore the Observatory. In 1946, it began the construction after having cleared the territory. In May 1954, the Observatory was re-opened, not only having been restored but considerably expanded in terms of instruments,

text: employee

text: s and research subjects. New departments had been created, such as the Department of

text: Radio Astronomy

text: and Department of Instrument Making (with its own

text: optic

text: al and mechanical workshop). The surviving old instruments were repaired, modernized and put into service once again. Also installed were new instruments, such as the  refractor, a horizontal meridian device, a photographic polar telescope, a big zenith telescope, stellar

text: interferometer

text: , 2 solar telescopes,

text: coronagraph

text: , a big

text: radio telescope

text: and all kinds of labware.The 65 cm

text: Zeiss

text: refractor was originally intended as a gift from then

text: Chancellor of Germany

text: Adolf Hitler

text: to the Italian

text: Benito Mussolini

text: , but it was not delivered and instead was taken by the Soviet Union.

text: A team at the University of California, Irvine, led by Asantha Cooray, was the first to detect and characterize HXMM01 in data from the Herschel space telescope's HerMES instrument. Initially noticed as an "amazing, bright blob" in an otherwise cold region of the cosmos, the galaxy was revealed to be an extremely bright submillimeter galaxy (SMG) after an extensive series of observations across the electromagnetic spectrum. Analyses of the data, published in May 2013, revealed the galaxy to be a merging pair with a mass at least ten times that of the Milky Way.

text: A team at the University of California, Irvine, led by Asantha Cooray, was the first to detect and characterize HXMM01 in data from the

text: Herschel

text: space telescope's HerMES instrument. Initially noticed as an "amazing, bright blob" in an otherwise cold region of the cosmos, the galaxy was revealed to be an extremely bright

text: submillimeter galaxy

text: (SMG) after an extensive series of observations across the

text: electromagnetic spectrum

text: . Analyses of the data, published in May 2013, revealed the galaxy to be a merging pair with a mass at least ten times that of the Milky Way.

text: Focal Plane Arrays are arrays of receivers placed at the focus of a radio-telescope. Traditional radio-telescopes have only one receiver at the focus of the telescope, but radio-telescopes are now starting to be equipped with focal plane arrays, which are of three different types: multi-beam feed arrays, bolometer arrays, and the experimental phased-array feeds.

text: Focal Plane Arrays are arrays of

text: receivers

text: placed at the

text: focus

text: of a

text: radio-telescope

text: . Traditional radio-telescopes have only one receiver at the focus of the telescope, but radio-telescopes are now starting to be equipped with focal plane arrays, which are of three different types: multi-beam feed arrays, bolometer arrays, and the experimental phased-array feeds.

text: Like Gregory before him, Newton found it hard to construct an effective reflector. It was difficult to grind the speculum metal to a regular curvature. The surface also tarnished rapidly; the consequent low reflectivity of the mirror and also its small size meant that the view through the telescope was very dim compared to contemporary refractors. Because of these difficulties in construction, the Newtonian reflecting telescope was  initially not widely adopted. In 1721 John Hadley showed a much-improved model to the Royal Society. Hadley had solved many of the problems of making a parabolic mirror. His Newtonian with a mirror diameter of  compared favourably with the large aerial refracting telescopes of the day. The size of reflecting telescopes subsequently grew rapidly, with designs doubling in primary mirror diameter about every 50 years.

text: Like Gregory before him, Newton found it hard to construct an effective reflector. It was difficult to grind the speculum metal to a regular curvature. The surface also

text: tarnish

text: ed rapidly; the consequent low reflectivity of the mirror and also its small size meant that the view through the telescope was very dim compared to contemporary refractors. Because of these difficulties in construction, the Newtonian reflecting telescope was  initially not widely adopted. In 1721

text: John Hadley

text: showed a much-improved model to the Royal Society. Hadley had solved many of the problems of making a

text: parabolic

text: mirror. His Newtonian with a mirror diameter of  compared favourably with the large

text: aerial refracting telescopes

text: of the day. The size of reflecting telescopes subsequently grew rapidly, with designs doubling in primary mirror diameter about every 50 years.

text: Bandi Observatory, a 3-story building established in area covering 752.47㎡, is located in Bandi Land and equipped with Exhibition Room, Video Room and Observation Room. It is also equipped with 13 small telescopes including a 305mm RC Telescope enabling visitors to experience telescopes, and the Korea’s first 800mm satellite tracking and monitoring telescope enables visitors to observe planets including the Sun, nebula and a cluster of stars.

text: The OSO and OAO missions demonstrated the important role space-based observations could play in astronomy, and in 1968, NASA developed firm plans for a space-based reflecting telescope with a mirror 3 m in diameter, known provisionally as the Large Orbiting Telescope or Large Space Telescope (LST), with a launch slated for 1979. These plans emphasized the need for manned maintenance missions to the telescope to ensure such a costly program had a lengthy working life, and the concurrent development of plans for the reusable space shuttle indicated that the technology to allow this was soon to become available.

text: The OSO and OAO missions demonstrated the important role space-based observations could play in astronomy, and in 1968, NASA developed firm plans for a space-based

text: reflecting telescope

text: with a mirror 3 m in diameter, known provisionally as the Large Orbiting Telescope or Large Space Telescope (LST), with a launch slated for 1979. These plans emphasized the need for manned maintenance missions to the telescope to ensure such a costly program had a lengthy working life, and the concurrent development of plans for the reusable

text: space shuttle

text: indicated that the technology to allow this was soon to become available.

text: The James Webb Space Telescope is the next generation in deep space imaging systems. The James Webb Space Telescope seeks to provide a better understanding of the origins of the earth and life in the universe. This telescope is significant to future scientific breakthroughs and through the RealWorld-InWorld Engineering Design Challenge students use the engineering design process to solve problems related to the James Webb Space Telescope.

text: At the library clock tower, Greg (Ethan Embry) and Tamara (Sonequa Martin-Green) remove Hook's (Colin O'Donoghue) hood, begin their plot to take magic from Storybrooke, and look for Greg's father. The outsiders offer Hook a chance to help them, but Hook says that he already succeeded in his mission in killing Rumplestiltskin. But the two show Hook that his mission failed by giving him his telescope to show him that Mr. Gold and Lacey are still alive. Hook reluctantly gives in to their demands. At the same time, at the docks, David (Josh Dallas) and Mary Margaret discuss what to do about Regina, knowing that every time they tried to trust her she kept breaking those promises, unaware that Regina, posing as a fisherman, is hearing the conversation and vows that she will not be locked away. The following morning, Regina approaches Henry at the park and tries to manipulate him into believing that his family is about to take him away from her by showing off the magic beans that would transport them back to the Enchanted Forest. However, when Regina tells Henry that she plans to solve the problem by unleashing a fail-safe trigger that would wipe out Storybrooke, Henry tells Regina that she has not changed. Before he can warn the family, Regina takes out her book of spells and gives him a short-term memory block to make him forget about the conversation and they start over as if nothing happened.

text: At the library clock tower, Greg (

text: Ethan Embry

text: ) and Tamara (

text: Sonequa Martin-Green

text: ) remove Hook's (

text: Colin O'Donoghue

text: ) hood, begin their plot to take magic from Storybrooke, and look for Greg's father. The outsiders offer Hook a chance to help them, but Hook says that he already succeeded in his mission in killing Rumplestiltskin. But the two show Hook that his mission failed by giving him his telescope to show him that Mr. Gold and Lacey are still alive. Hook reluctantly gives in to their demands. At the same time, at the docks, David (

text: Josh Dallas

text: ) and Mary Margaret discuss what to do about Regina, knowing that every time they tried to trust her she kept breaking those promises, unaware that Regina, posing as a fisherman, is hearing the conversation and vows that she will not be locked away. The following morning, Regina approaches Henry at the park and tries to manipulate him into believing that his family is about to take him away from her by showing off the magic beans that would transport them back to the Enchanted Forest. However, when Regina tells Henry that she plans to solve the problem by unleashing a fail-safe trigger that would wipe out Storybrooke, Henry tells Regina that she has not changed. Before he can warn the family, Regina takes out her book of spells and gives him a short-term memory block to make him forget about the conversation and they start over as if nothing happened.

text: When making observations, scientists look through telescopes, study images on electronic screens, record meter readings, and so on. Generally, on a basic level, they can agree on what they see, e.g., the thermometer shows 37.9 degrees C. But, if these scientists have different ideas about the theories that have been developed to explain these basic observations, they may disagree about what they are observing. For example, before Albert Einstein's general theory of relativity, observers would have likely interpreted the image at left as five different objects in space. In light of that theory, however, astronomers will tell you that is actually only two objects, one in the center and four different images of the same object around the sides. Alternatively, if other scientists suspect that something is wrong with the telescope and only one object is actually being observed, they are operating under yet another theory. Observations that cannot be separated from theoretical interpretation are said to be theory-laden.

text: When making observations, scientists look through telescopes, study images on electronic screens, record meter readings, and so on. Generally, on a basic level, they can agree on what they see, e.g., the thermometer shows 37.9 degrees C. But, if these scientists have different ideas about the theories that have been developed to explain these basic observations, they may disagree about what they are observing. For example, before

text: Albert Einstein

text: 's

text: general theory of relativity

text: , observers would have likely interpreted the image at left as five different objects in space. In light of that theory, however, astronomers will tell you that is actually only two objects, one in the center and

text: four different images

text: of the same object around the sides. Alternatively, if other scientists suspect that something is wrong with the telescope and only one object is actually being observed, they are operating under yet another theory. Observations that cannot be separated from theoretical interpretation are said to be

text: theory-laden

text: A telescope like the Large Millimeter Telescope (active since 2006) observes from , bridging between the far-infrared/submillimeter telescopes and longer wavelength radio telescopes including the microwave band from about  to  in wavelength.

text: A telescope like the

text: Large Millimeter Telescope

text: (active since 2006) observes from , bridging between the far-infrared/

text: submillimeter telescopes

text: and longer wavelength radio telescopes including the microwave band from about  to  in wavelength.

text: The study of galaxies and our current understanding of the formation and evolution of the large and small scale structures are to a large extend based on the observations carried out by mid‐size telescopes. Even at the era of large and very large telescopes, such observations are still pursued thanks to advances in the instrumentation. While there are new frontiers to be explored by very large and extremely large telescopes, there are still enormous details which require further explorations. For economic and flexibility reasons there are still demands for 2‐4m class telescopes. These telescopes can complement others observing facilities to address some of the most fundamental questions related to galaxies such as the evolution of the cosmic web of galaxies, metal production and distribution within and between galaxies, formation of the present day Hubble sequence and also understanding our own galaxy.

text: At the time this was considered a long gap between albums, but Scholz still considered Don't Look Back to be a rush job and was unhappy with the album's second side in particular. Overall, Don't Look Back sold about half as well as the debut album, eventually selling over 7 million records.

text: Radio telescopes are directional radio antennas used for radio astronomy. The dishes are sometimes constructed of a conductive wire mesh whose openings are smaller than the wavelength being observed. Multi-element Radio telescopes are constructed from pairs or larger groups of these dishes to synthesize large 'virtual' apertures that are similar in size to the separation between the telescopes; this process is known as aperture synthesis. As of 2005, the current record array size is many times the width of the Earth—utilizing space-based Very Long Baseline Interferometry (VLBI) telescopes such as the Japanese HALCA (Highly Advanced Laboratory for Communications and Astronomy) VSOP (VLBI Space Observatory Program) satellite. Aperture synthesis is now also being applied to optical telescopes using optical interferometers (arrays of optical telescopes) and aperture masking interferometry at single reflecting telescopes. Radio telescopes are also used to collect microwave radiation, which is used to collect radiation when any visible light is obstructed or faint, such as from quasars. Some radio telescopes are used by programs such as SETI and the Arecibo Observatory to search for extraterrestrial life.

text: Radio telescopes are

text: directional

text: radio antennas

text: used for

text: radio astronomy

text: . The dishes are sometimes constructed of a conductive wire mesh whose openings are smaller than the

text: wavelength

text: being observed. Multi-element

text: Radio telescope

text: s are constructed from pairs or larger groups of these dishes to synthesize large 'virtual' apertures that are similar in size to the separation between the telescopes; this process is known as

text: aperture synthesis

text: . As of 2005, the current record array size is many times the width of the

text: Earth

text: —utilizing space-based

text: Very Long Baseline Interferometry

text: (VLBI) telescopes such as the

text: Japan

text: ese

text: HALCA

text: (Highly Advanced Laboratory for Communications and Astronomy) VSOP (VLBI Space Observatory Program) satellite. Aperture synthesis is now also being applied to optical telescopes using

text: optical interferometers

text: (arrays of optical telescopes) and

text: aperture masking interferometry

text: at single reflecting telescopes. Radio telescopes are also used to collect

text: microwave radiation

text: , which is used to collect radiation when any visible light is obstructed or faint, such as from

text: quasar

text: s. Some radio telescopes are used by programs such as

text: SETI

text: and the

text: Arecibo Observatory

text: to search for extraterrestrial life.

text: The Demonstration of a Compact X-ray Spectrometer was an X-ray telescope for the identification of chemical elements on the lunar surface. It detected the x-ray fluorescence (XRF) of crystal compounds created through the interaction of the electron shell with the solar wind particles to measure the abundance of the three main components: magnesium, silicon and aluminium. The detection of iron, calcium and titanium depended on the solar activity. The detection range for x-rays was 0.5 to 10 keV. The spectrometer and XSM (described below) together weighed 5.2 kg and had a power consumption of 18 watts.

text: The Demonstration of a Compact X-ray Spectrometer was an

text: X-ray telescope

text: for the identification of chemical elements on the lunar surface. It detected the

text: x-ray fluorescence

text: (XRF) of crystal compounds created through the interaction of the electron shell with the solar wind particles to measure the abundance of the three main components:

text: magnesium

text: silicon

text: and

text: aluminium

text: . The detection of

text: iron

text: calcium

text: and

text: titanium

text: depended on the solar activity. The detection range for x-rays was 0.5 to 10 keV. The spectrometer and XSM (described below) together weighed 5.2 kg and had a power consumption of 18 watts.

text: Varying accounts are cited to support Janssen as a possible inventor of the telescope. German astronomer Simon Marius wrote an account to his patron Johan Philip Fuchs von Bimbach about meeting an unnamed Dutchman at the 1608 Autumn Frankfurt Fair (which ran the month of September) who tried to sell him a device that sounded like a telescope. Given his history as a street seller, there is speculation this unnamed Dutchman could have been Zacharias Janssen, which would mean Janssen had a telescope at least a month before Lippershey's October 2, 1608 patent date. William de Boreel, who visited Middelburg to research the invention in 1655, interviewed Janssen's son Johannes. Boreel concluded that Janssen's telescope was finished about 1610. His research was referenced by Pierre Borel in De vero telescopii inventore. There are other claims that Janssen constructed the first telescope in 1604, or even earlier. Janssen's son Johannes testified under oath that Hans Lippershey had stolen his father's invention of the telescope, and that his father had invented the device in 1590.

text: Varying accounts are cited to support Janssen as a possible inventor of the telescope. German astronomer

text: Simon Marius

text: wrote an account to his patron

text: Johan Philip Fuchs von Bimbach

text: about meeting an unnamed Dutchman at the 1608 Autumn Frankfurt Fair (which ran the month of September) who tried to sell him a device that sounded like a telescope. Given his history as a street seller, there is speculation this unnamed Dutchman could have been Zacharias Janssen, which would mean Janssen had a telescope at least a month before Lippershey's October 2, 1608 patent date.

text: William de Boreel

text: , who visited Middelburg to research the invention in 1655, interviewed Janssen's son Johannes. Boreel concluded that Janssen's telescope was finished about 1610. His research was referenced by

text: Pierre Borel

text: in De vero telescopii inventore. There are other claims that Janssen constructed the first telescope in 1604, or even earlier. Janssen's son Johannes testified under oath that Hans Lippershey had stolen his father's invention of the telescope, and that his father had invented the device in 1590.

text: A telescopic sight is an optical telescope equipped with some form of graphic image pattern reticle mounted in an optically appropriate position in the optical system to give an accurate aiming point. Telescopic sights are used on a wide range of devices including guns, surveying equipment, and even as sights on larger telescopes (called a finderscope).

text: A

text: telescopic sight

text: is an

text: optical telescope

text: equipped with some form of graphic image pattern reticle mounted in an optically appropriate position in the optical system to give an accurate aiming point. Telescopic sights are used on a wide range of devices including

text: gun

text: s,

text: surveying

text: equipment, and even as sights on larger telescopes (called a

text: finderscope

text: When tracing human lineage back in time, most people look at parents, grandparents, great-grandparents and so on. The same approach is often taken when tracing descendants via children and grandchildren. Dawkins shows that this approach is misguided, as the numbers of ancestors and descendants seem to grow exponentially as generations are added to the lineage tree. In just 80 generations, the number of ancestors can exceed a trillion trillion.

text: When tracing human

text: lineage

text: back in time, most people look at parents, grandparents, great-grandparents and so on. The same approach is often taken when tracing descendants via children and grandchildren. Dawkins shows that this approach is misguided, as the numbers of ancestors and descendants seem to

text: grow exponentially

text: as generations are added to the lineage tree. In just 80 generations, the number of ancestors can exceed a trillion trillion.

text: To detect dark matter and answer other fundamental questions about our universe, engineers and scientists from all over the world built the Alpha Magnetic Spectrometer (AMS), which NASA compares to the Hubble space telescope, and says could not be accommodated on a free flying satellite platform partly because of its power requirements and data bandwidth needs. On 3 April 2013, NASA scientists reported that hints of dark matter may have been detected by the Alpha Magnetic Spectrometer. According to the scientists, "The first results from the space-borne Alpha Magnetic Spectrometer confirm an unexplained excess of high-energy positrons in Earth-bound cosmic rays."

text: To detect dark matter and answer other fundamental questions about our universe, engineers and scientists from all over the world built the

text: Alpha Magnetic Spectrometer

text: (AMS), which NASA compares to the

text: Hubble space telescope

text: , and says could not be accommodated on a free flying satellite platform partly because of its power requirements and data bandwidth needs. On 3 April 2013,

text: NASA

text: scientists reported that hints of

text: dark matter

text: may have been detected by the Alpha Magnetic Spectrometer. According to the scientists, "

text: The first results

text: from the space-borne Alpha Magnetic Spectrometer confirm an unexplained excess of high-energy positrons in Earth-bound cosmic rays."

text: As wavelengths become longer, it becomes easier to use antenna technology to interact with electromagnetic radiation (although it is possible to make very tiny antenna). The near-infrared can be collected much like visible light, however in the far-infrared and submillimetre range,  telescopes can operate more like a radio telescope. For example, the James Clerk Maxwell Telescope observes from wavelengths from 3 μm (0.003 mm) to 2000 μm (2 mm), but uses a parabolic aluminum antenna. On the other hand, the Spitzer Space Telescope, observing from about 3 μm (0.003 mm) to 180 μm (0.18 mm) uses a mirror (reflecting optics). Also using reflecting optics, the Hubble Space Telescope with Wide Field Camera 3 can observe in the frequency range from about 0.2 μm (0.0002 mm) to 1.7 μm (0.0017 mm) (from ultra-violet to infrared light).

text: As wavelengths become longer, it becomes easier to use antenna technology to interact with electromagnetic radiation (although it is possible to make very tiny antenna). The near-infrared can be collected much like visible light, however in the far-infrared and submillimetre range,  telescopes can operate more like a radio telescope. For example, the

text: James Clerk Maxwell Telescope

text: observes from wavelengths from 3 μm (0.003 mm) to 2000 μm (2 mm), but uses a parabolic aluminum antenna. On the other hand, the

text: Spitzer Space Telescope

text: , observing from about 3 μm (0.003 mm) to 180 μm (0.18 mm) uses a mirror (reflecting optics). Also using reflecting optics, the

text: Hubble Space Telescope

text: with

text: Wide Field Camera 3

text: can observe in the frequency range from about 0.2 μm (0.0002 mm) to 1.7 μm (0.0017 mm) (from ultra-violet to infrared light).

text: Balle, Campbell, Keenan  and Flygare demonstrated that the FTMW technique can be applied within a "free space cell" comprising an evacuated chamber containing a Fabry-Perot cavity. This technique allows a sample to be probed only milliseconds after it undergoes rapid cooling to only a few kelvins in the throat of an expanding gas jet. This was a revolutionary development because (i) cooling molecules to low temperatures concentrates the available population in the lowest rotational energy levels. Coupled with benefits conferred by the use of a Fabry-Perot cavity, this brought a great enhancement in the sensitivity and resolution of spectrometers along with a reduction in the complexity of observed spectra; (ii) it became possible to isolate and study molecules that are very weakly bound because there is insufficient energy available for them to undergo fragmentation or chemical reaction at such low temperatures. William Klemperer was a pioneer in using this instrument for the exploration of weakly bound interactions. While the Fabry-Perot cavity of a Balle-Flygare FTMW spectrometer can typically be tuned into resonance at any frequency between 6 and 18 GHz, the bandwidth of individual measurements is restricted to about 1 MHz. An animation illustrates the operation of this instrument which is currently the most widely used tool for microwave spectroscopy.

text: Balle, Campbell, Keenan  and Flygare demonstrated that the FTMW technique can be applied within a "free space cell" comprising an evacuated chamber containing a

text: Fabry-Perot cavity

text: . This technique allows a sample to be probed only milliseconds after it undergoes rapid cooling to only a few

text: kelvin

text: s in the throat of an expanding gas jet. This was a revolutionary development because (i) cooling molecules to low temperatures concentrates the available population in the lowest rotational energy levels. Coupled with benefits conferred by the use of a Fabry-Perot cavity, this brought a great enhancement in the sensitivity and resolution of spectrometers along with a reduction in the complexity of observed spectra; (ii) it became possible to isolate and study molecules that are very weakly bound because there is insufficient energy available for them to undergo fragmentation or chemical reaction at such low temperatures.

text: William Klemperer

text: was a pioneer in using this instrument for the exploration of weakly bound interactions. While the Fabry-Perot cavity of a Balle-Flygare FTMW spectrometer can typically be tuned into resonance at any frequency between 6 and 18 GHz, the bandwidth of individual measurements is restricted to about 1 MHz. An animation illustrates the operation of this instrument which is currently the most widely used tool for microwave spectroscopy.

text: The VeSpR telescope is a special-purpose Cassegrain design to accomplish observations that other missions are not able to perform.<ref name='VeSpR Homepage'/> The use of a pre-dispersing prism to prevent long wavelengths from entering the spectrograph permits a long-aperture approach to echelle spectroscopy, and the chosen combination of imaging and dispersion scales provides high spectral resolution of emission line profiles with a several arc sec wide aperture for good sensitivity. For comparable spectral resolution the HST/STIS uses a 0.2 arc sec aperture, which provides 375 times less solid angle on the sky than a 3 x 5 arc sec region observed by this rocket telescope. For comparison, the ratio of telescope areas HST/rocket is roughly 50 times. With equivalent efficiencies, Hubble Space Telescope would need 4 hours of observing time to achieve the same S/N that the rocket obtains in 5 minutes.<ref name='VeSpR Homepage'/> However, Hubble telescope is not allowed to point too close to the Sun to avoid damaging its instruments, so it cannot be used for this.

text: The VeSpR telescope is a special-purpose

text: Cassegrain

text: design to accomplish observations that other missions are not able to perform.<ref name='VeSpR Homepage'/> The use of a pre-dispersing

text: prism

text: to prevent long wavelengths from entering the spectrograph permits a long-aperture approach to

text: echelle spectroscopy

text: , and the chosen combination of imaging and dispersion scales provides high spectral resolution of emission line profiles with a several arc sec wide aperture for good sensitivity. For comparable spectral resolution the HST/STIS uses a 0.2 arc sec aperture, which provides 375 times less solid angle on the sky than a 3 x 5 arc sec region observed by this rocket telescope. For comparison, the ratio of telescope areas HST/rocket is roughly 50 times. With equivalent efficiencies,

text: Hubble Space Telescope

text: would need 4 hours of observing time to achieve the same S/N that the rocket obtains in 5 minutes.<ref name='VeSpR Homepage'/> However, Hubble telescope is not allowed to point too close to the Sun to avoid damaging its instruments, so it cannot be used for this.

text: Joshua Bloom of the University of California, Berkeley, who was able to observe the location of the GRB at the Gemini South telescope in Chile, called the discovery of GRB 090423 a "watershed event" as it marked "the beginning of the study of the universe as it was before most of the structure that we know about today came into being."<ref name='New Scientist' /> Nial Tanvir, who was part of the VLT team, suggests that gamma-ray bursts provide a unique tool to study the universe at early times because everything else is too faint to be observed. For instance, the first generation of stars have yet to be directly observed, but the progenitor of GRB 090423 may belong to this class. These early stars are expected to contribute to the reionisation of the universe, a process which ended at a redshift of about 6. As more powerful telescopes begin operation, such as the James Webb Space Telescope that is set to launch in 2018, astronomers hope to pinpoint the locations of faint GRB host galaxies by observing blasts similar to that of GRB 090423.<ref name='New Scientist' />

text: Joshua Bloom of the

text: University of California, Berkeley

text: , who was able to observe the location of the GRB at the

text: Gemini South telescope

text: in

text: Chile

text: , called the discovery of GRB 090423 a "watershed event" as it marked "the beginning of the study of the universe as it was before most of the structure that we know about today came into being."<ref name='New Scientist' /> Nial Tanvir, who was part of the VLT team, suggests that gamma-ray bursts provide a unique tool to study the universe at early times because everything else is too faint to be observed. For instance,

text: the first generation of stars

text: have yet to be directly observed, but the progenitor of GRB 090423 may belong to this class. These early stars are expected to contribute to the

text: reionisation

text: of the universe, a process which ended at a redshift of about 6. As more powerful telescopes begin operation, such as the

text: James Webb Space Telescope

text: that is set to launch in 2018,

text: astronomer

text: s hope to pinpoint the locations of faint GRB host galaxies by observing blasts similar to that of GRB 090423.<ref name='New Scientist' />

text: The Víctor M. Blanco Telescope, also known as the Blanco 4m, is a 4-metre aperture telescope located at the Cerro Tololo Inter-American Observatory, Chile. Commissioned in 1974 and completed in 1976, this telescope is similar to the Mayall 4m telescope located on Kitt Peak. In 1995 it was dedicated and named in honour of Puerto Rican astronomer Víctor Manuel Blanco.It was the largest optical telescope in the Southern hemisphere from 1976 until 1998, when the first 8-metre telescope of the ESO Very Large Telescope opened.

text: The Víctor M. Blanco Telescope, also known as the Blanco 4m, is a 4-metre aperture

text: telescope

text: located at the

text: Cerro Tololo Inter-American Observatory

text: Chile

text: . Commissioned in 1974 and completed in 1976, this telescope is similar to the

text: Mayall 4m telescope

text: located on

text: Kitt Peak

text: . In 1995 it was dedicated and named in honour of

text: Puerto Rican

text: astronomer

text: Víctor Manuel Blanco

text: .It was the largest optical telescope in the Southern hemisphere from 1976 until 1998, when the first 8-metre telescope of the ESO

text: Very Large Telescope

text: opened.

text: More detailed observations were made with the Einstein Observatory, ROSAT X-ray telescope, Advanced Satellite for Cosmology and Astrophysics (ASCA), and Chandra X-ray Observatory.  There are multiple sources at various wavelengths right across the high energy electromagnetic spectrum: hard X-rays and gamma rays within 1 light-month of the Eta Carinae; hard X-rays from a central region about 3 light-months wide; a distinct partial ring "horse-shoe" structure in low energy X-rays 0.67 parsec (2.2 light-years) across corresponding to the main shockfront from the Great Eruption; diffuse X-ray emission across the whole area of the Homunculus; and numerous condensations and arcs outside the main ring.

text: More detailed observations were made with the

text: Einstein Observatory

text: ROSAT

text: X-ray telescope,

entity_name: Advanced Satellite for Cosmology and Astrophysics

text: Advanced Satellite for Cosmology and Astrophysics

text: (ASCA), and

text: Chandra X-ray Observatory

text: .  There are multiple sources at various wavelengths right across the high energy electromagnetic spectrum: hard X-rays and gamma rays within 1 light-month of the Eta Carinae; hard X-rays from a central region about 3 light-months wide; a distinct partial ring "horse-shoe" structure in low energy X-rays 0.67 parsec (2.2 light-years) across corresponding to the main shockfront from the Great Eruption; diffuse X-ray emission across the whole area of the Homunculus; and numerous condensations and arcs outside the main ring.

text: MOP drew the attention of the United States Congress, where the program was ridiculed and canceled one year after its start. SETI advocates continued without government funding, and in 1995 the nonprofit SETI Institute of Mountain View, California resurrected the MOP program under the name of Project "Phoenix", backed by private sources of funding. Project Phoenix, under the direction of Jill Tarter, is a continuation of the targeted search program from MOP and studies roughly 1,000 nearby Sun-like stars. From 1995 through March 2004, Phoenix conducted observations at the  Parkes radio telescope in Australia, the  radio telescope of the National Radio Astronomy Observatory in Green Bank, West Virginia, and the  radio telescope at the Arecibo Observatory in Puerto Rico. The project observed the equivalent of 800 stars over the available channels in the frequency range from 1200 to 3000 MHz. The search was sensitive enough to pick up transmitters with 1 GW EIRP to a distance of about 200 light-years. According to Prof. Tarter, in 2012 it costs around "$2 million per year to keep SETI research going at the SETI Institute" and approximately 10 times that to support "all kinds of SETI activity around the world."

text: MOP drew the attention of the

text: United States Congress

text: , where the program was ridiculed and canceled one year after its start. SETI advocates continued without government funding, and in 1995 the nonprofit SETI Institute of

text: Mountain View, California

text: resurrected the MOP program under the name of Project "Phoenix", backed by private sources of funding.

text: Project Phoenix

text: , under the direction of

text: Jill Tarter

text: , is a continuation of the targeted search program from MOP and studies roughly 1,000 nearby

text: Sun

text: -like stars. From 1995 through March 2004, Phoenix conducted observations at the

text: Parkes radio telescope

text: in

text: Australia

text: , the  radio telescope of the

text: National Radio Astronomy Observatory

text: in Green Bank, West Virginia, and the  radio telescope at the Arecibo Observatory in Puerto Rico. The project observed the equivalent of 800 stars over the available channels in the frequency range from 1200 to 3000 MHz. The search was sensitive enough to pick up transmitters with 1 GW

text: EIRP

text: to a distance of about 200

text: light-year

text: s. According to Prof. Tarter, in 2012 it costs around "$2 million per year to keep SETI research going at the SETI Institute" and approximately 10 times that to support "all kinds of SETI activity around the world."

text: Shortly after the telescope was originally completed, Lovell and Husband started contemplating the idea of upgrading the telescope so that it had a more accurate surface, and was controlled by a digital computer. Plans for this upgrade were created by Husband and Co., and were presented to Lovell in April 1964. Their plans became more urgent when fatigue cracks were discovered in the elevation drive system in September 1967. The telescope was only expected to have an operational lifespan of 10 years, and Husband had been warning about the decay of the telescope since 1963. The appearance of fatigue cracks was the first of these problems that threatened to stop the telescope working; had they been left in place, then the elevation system could have failed and perhaps jammed. The telescope was therefore repaired and upgraded to become the Mark IA; the £400,000 of funding to do this was announced on 8 July 1968 by the SRC to upgrade and repair the telescope to the Mark IA. The upgrade was carried out in three phases, phase 1 lasting between September 1968 and February 1969, phase 2 between September and November 1969 and phase 3 between August 1970 and November 1971.

text: Shortly after the telescope was originally completed, Lovell and Husband started contemplating the idea of upgrading the telescope so that it had a more accurate surface, and was controlled by a digital computer. Plans for this upgrade were created by Husband and Co., and were presented to Lovell in April 1964. Their plans became more urgent when fatigue cracks were discovered in the elevation drive system in September 1967. The telescope was only expected to have an operational lifespan of 10 years, and Husband had been warning about the decay of the telescope since 1963. The appearance of fatigue cracks was the first of these problems that threatened to stop the telescope working; had they been left in place, then the elevation system could have failed and perhaps jammed. The telescope was therefore repaired and upgraded to become the Mark IA; the £400,000 of funding to do this was announced on 8 July 1968 by the

entity_name: Science and Engineering Research Council

text: SRC

text: to upgrade and repair the telescope to the Mark IA. The upgrade was carried out in three phases, phase 1 lasting between September 1968 and February 1969, phase 2 between September and November 1969 and phase 3 between August 1970 and November 1971.

text: ESO operates three major optical and near infrared telescopes at the La Silla site: the New Technology Telescope (NTT), the 3.6-m ESO Telescope, and the 2.2-m Max-Planck-ESO Telescope (MPG/ESO Telescope). In addition La Silla hosts several other national and project telescopes such as the ESO 1-metre Schmidt Telescope, the 1.54-m Danish Telescope, the 1.2-m Leonhard Euler Telescope, the Rapid Eye Mount telescope, TRAPPIST and TAROT. These telescopes are not operated by ESO and hence do not fall under the responsibility of La Silla Science Operations.

text: For snipers, Karabiner 98k rifles selected for being exceptionally accurate during factory tests were fitted with a telescopic sight as sniper rifles. Karabiner 98k sniper rifles had an effective range of up to  when used by a skilled sniper. The German Zeiss Zielvier 4x (ZF39) telescopic sight had bullet drop compensation in  increments for ranges from  or in some variations from . There were ZF42, Zeiss Zielsechs 6x and Zielacht 8x telescopic sights by various manufacturers like the Ajack 4x and 6x, Hensoldt Dialytan 4x and Kahles Heliavier 4x with similar features employed on Karabiner 98k sniper rifles. Several different mountings produced by various manufacturers were used. The Karabiner 98k was not designed to accept telescopic sights. Attaching such sights to a Karabiner 98k required machining by a skilled armourer. A telescopic sight mounted low above the center axis of the receiver will not leave enough space between the rifle and the telescopic sight body for unimpaired operation of the bolt handle or the three-position safety catch lever. This ergonomic problem was solved by mounting the telescopic sight relatively high above the receiver and sometimes modifying or replacing the safety operating lever or using an offset mounting to position the telescopic sight axis to the left side in relation to the receiver center axis. A common minor modification was replacing the stock buttplate with a waffled anti-slip "sniper" buttplate. Approximately 132,000 of these sniper rifles were produced by Germany.

text: For

text: snipers

text: , Karabiner 98k rifles selected for being exceptionally accurate during factory tests were fitted with a

text: telescopic sight

text: as

text: sniper rifle

text: s. Karabiner 98k sniper rifles had an effective range of up to  when used by a skilled sniper. The German Zeiss Zielvier 4x (ZF39)

text: telescopic sight

text: had

text: bullet drop compensation

text: in  increments for ranges from  or in some variations from . There were ZF42, Zeiss Zielsechs 6x and Zielacht 8x telescopic sights by various manufacturers like the Ajack 4x and 6x, Hensoldt Dialytan 4x and Kahles Heliavier 4x with similar features employed on Karabiner 98k sniper rifles. Several different

text: mountings

text: produced by various manufacturers were used. The Karabiner 98k was not designed to accept telescopic sights. Attaching such sights to a Karabiner 98k required

text: machining

text: by a skilled armourer. A telescopic sight mounted low above the center axis of the receiver will not leave enough space between the rifle and the telescopic sight body for unimpaired operation of the bolt handle or the three-position

text: safety catch lever

text: . This ergonomic problem was solved by mounting the telescopic sight relatively high above the receiver and sometimes modifying or replacing the safety operating lever or using an offset mounting to position the telescopic sight axis to the left side in relation to the receiver center axis. A common minor modification was replacing the stock buttplate with a waffled anti-slip "sniper" buttplate. Approximately 132,000 of these sniper rifles were produced by Germany.

text: Square waves are universally encountered in digital switching circuits and are naturally generated by binary (two-level) logic devices. They are used as timing references or "clock signals", because their fast transitions are suitable for triggering synchronous logic circuits at precisely determined intervals. However, as the frequency-domain graph shows, square waves contain a wide range of harmonics; these can generate electromagnetic radiation or pulses of current that interfere with other nearby circuits, causing noise or errors. To avoid this problem in very sensitive circuits such as precision analog-to-digital converters, sine waves are used instead of square waves as timing references.

text: Square waves are universally encountered in

text: digital

text: switching circuits and are naturally generated by binary (two-level) logic devices. They are used as timing references or "

text: clock signal

text: s", because their fast transitions are suitable for triggering

text: synchronous logic

text: circuits at precisely determined intervals. However, as the frequency-domain graph shows, square waves contain a wide range of harmonics; these can generate

text: electromagnetic radiation

text: or pulses of current that interfere with other nearby circuits, causing

text: noise

text: or errors. To avoid this problem in very sensitive circuits such as precision

text: analog-to-digital converter

text: s,

text: sine wave

text: s are used instead of square waves as timing references.

text: Some people who fall into this category can use their considerable residual vision – their remaining sight – to complete daily tasks without relying on alternative methods. The role of a low vision specialist (optometrist or ophthalmologist) is to maximize the functional level of a patient's vision by optical or non-optical means. Primarily, this is by use of magnification in the form of telescopic systems for distance vision and optical or electronic magnification for near tasks.

text: With the advent and growth of organized amateur astronomical groups,  sidewalk astronomy has come to be associated with public education about astronomy via free public viewing for anyone who wishes to look through the telescope. This usually involves individual or a groups of amateur astronomers with small-to-medium-sized telescopes. Organizations such as the San Francisco Sidewalk Astronomers, founded by John Dobson, are organized around the idea of educating people about the universe they live in by having them look through telescopes. Dobson even promoted a design for large inexpensive reflecting telescope that he called a "Sidewalk Telescope", more commonly referred to as the Dobsonian telescope.

text: With the advent and growth of organized

text: amateur astronomical groups

text: ,  sidewalk astronomy has come to be associated with public education about astronomy via free public viewing for anyone who wishes to look through the telescope. This usually involves individual or a groups of amateur astronomers with small-to-medium-sized telescopes. Organizations such as the San Francisco Sidewalk Astronomers, founded by

text: John Dobson

text: , are organized around the idea of educating people about the universe they live in by having them look through telescopes. Dobson even promoted a design for large inexpensive

text: reflecting telescope

text: that he called a "Sidewalk Telescope", more commonly referred to as the

text: Dobsonian telescope

text: This Zeiss di Merate is a reflecting telescope on an equatorial mount and is one of the largest telescopes funded by the Regno d'Italia ("Kingdom of Italy") before Italy became republic in 1946.

text: This Zeiss di Merate is a

text: reflecting telescope

text: on an

text: equatorial mount

text: and is one of the largest telescopes funded by the Regno d'Italia ("

text: Kingdom of Italy

text: ") before Italy became republic in 1946.

text: Radio frequency radiation is usually measured in kilohertz (kHz), megahertz (MHz), or gigahertz (GHz). Light is electromagnetic radiation that is even higher in frequency, and has frequencies in the range of tens (infrared) to thousands (ultraviolet) of terahertz. Electromagnetic radiation with frequencies in the low terahertz range, (intermediate between those of the highest normally usable radio frequencies and long-wave infrared light), is often called terahertz radiation. Even higher frequencies exist, such as that of gamma rays, which can be measured in exahertz. (For historical reasons, the frequencies of light and higher frequency electromagnetic radiation are more commonly specified in terms of their wavelengths or photon energies: for a more detailed treatment of this and the above frequency ranges, see electromagnetic spectrum.)

text: Radio frequency radiation is usually measured in kilohertz (kHz), megahertz (MHz), or gigahertz (GHz).

text: Light

text: is electromagnetic radiation that is even higher in frequency, and has frequencies in the range of tens (

text: infrared

text: ) to thousands (

text: ultraviolet

text: ) of terahertz. Electromagnetic radiation with frequencies in the low terahertz range, (intermediate between those of the highest normally usable radio frequencies and long-wave infrared light), is often called

text: terahertz radiation

text: . Even higher frequencies exist, such as that of

text: gamma ray

text: s, which can be measured in exahertz. (For historical reasons, the frequencies of light and higher frequency electromagnetic radiation are more commonly specified in terms of their

text: wavelength

text: s or

text: photon

text: energies

text: : for a more detailed treatment of this and the above frequency ranges, see

text: electromagnetic spectrum

text: , it should be emphasized that Bradley's result does not merely give the classical limit of the relativistic case, in the sense that it gives incorrect predictions even at low relative velocities. Bradley's explanation cannot account for situations such as the water telescope, nor for many other optical effects (such as interference) that might occur within the telescope. This is because in the Earth's frame it predicts that the direction of propagation of the light beam in the telescope is not normal to the wavefronts of the beam, in contradiction with Maxwell's theory of electromagnetism. It also does not preserve the speed of light c between frames. However, Bradley did correctly infer that the effect was due to relative velocities.

text: , it should be emphasized that Bradley's result does not merely give the classical limit of the relativistic case, in the sense that it gives incorrect predictions even at low relative velocities. Bradley's explanation cannot account for situations such as the water telescope, nor for many other optical effects (such as interference) that might occur within the telescope. This is because in the Earth's frame it predicts that the direction of propagation of the light beam in the telescope is not normal to the wavefronts of the beam, in contradiction with

text: Maxwell's theory of electromagnetism

text: . It also does not preserve the speed of light c between frames. However, Bradley did correctly infer that the effect was due to relative velocities.

text: Skynet has proven to be an attractive option for non-PROMPT telescope owners because (1) they no longer need to staff their telescopes at night, or in the case of campus telescopes they no longer need to keep their students awake night after night if they want to do observational astronomy curricula, research, or research training; and (2) Skynet allows telescope owners to queue observations on the other telescopes on the network when these systems are not otherwise in use, giving them free access to different and often better telescopes, instrumentation, regions of the sky, and site and weather conditions.  Skynet has now taken over 8.4 million exposures, currently at a rate of about 170,000 per month and this rate is increasing by about 4,600 per month.  All Skynet observations are publicly available after one year:  https://skynet.unc.edu/archive.

text: Phobos probes carried several instruments:  solar x-ray and ultraviolet telescopes, a neutron spectrometer and the Grunt radar experiment designed to study the surface relief of Phobos.The lander had an x-ray/alpha spectrometer to provide information on the chemical element composition of the surface of Phobos, a seismometer to determine the internal structure of Phobos, and the "Razrez" penetrator with temperature sensors and an accelerometer for testing the physical and mechanical properties of the surface.

text: Phobos probes carried several instruments:  solar

text: x-ray

text: and

text: ultraviolet

text: telescopes, a

text: neutron spectrometer

text: and the Grunt radar experiment designed to study the surface relief of Phobos.The lander had an

text: x-ray/alpha spectrometer

text: to provide information on the chemical element composition of the surface of Phobos, a

text: seismometer

text: to determine the internal structure of Phobos, and the "

text: Razrez

text: " penetrator with temperature sensors and an

text: accelerometer

text: for testing the physical and mechanical properties of the surface.

text: List of X-ray space telescopes is a listing of "telescopes" in outer space that can observe X-ray wavelengths.

text: List of X-ray space telescopes is a listing of "telescopes" in

text: outer space

text: that can observe

text: X-ray

text: wavelengths.

text: The Shane telescope saw first light to a different world for large telescopes in 1959:

text: One of the key aims of the astronomers who designed the Hubble Space Telescope was to use its high optical resolution to study distant galaxies to a level of detail that was not possible from the ground. Positioned above the atmosphere, Hubble avoids atmospheric airglow allowing it to take more sensitive visible and ultraviolet light images than can be obtained with seeing-limited ground-based telescopes (when good adaptive optics correction at visible wavelengths becomes possible, 10 m ground-based telescopes may become competitive). Although the telescope's mirror suffered from spherical aberration when the telescope was launched in 1990, it could still be used to take images of more distant galaxies than had previously been obtainable. Because light takes billions of years to reach Earth from very distant galaxies, we see them as they were billions of years ago; thus, extending the scope of such research to increasingly distant galaxies allows a better understanding of how they evolve.

text: One of the key aims of the astronomers who designed the Hubble Space Telescope was to use its high

text: optical resolution

text: to study distant galaxies to a level of detail that was not possible from the ground. Positioned above the

text: atmosphere

text: , Hubble avoids atmospheric

text: airglow

text: allowing it to take more sensitive

text: visible

text: and

text: ultraviolet light

text: images than can be obtained with seeing-limited ground-based telescopes (when good

text: adaptive optics

text: correction at visible wavelengths becomes possible, 10 m ground-based telescopes may become competitive). Although the telescope's mirror suffered from

text: spherical aberration

text: when the telescope was launched in 1990, it could still be used to take images of more distant galaxies than had previously been obtainable. Because

text: light takes billions of years

text: to reach Earth from very distant galaxies, we see them as they were billions of years ago; thus, extending the scope of such research to increasingly distant galaxies allows a better understanding of how they evolve.

text: A fine guidance sensor (FGS) is an interferometric instrument on board a space telescope that provides high-precision pointing information as input to the observatory's attitude control systems. FGSs have been deployed on the Hubble Space Telescope, and will be deployed with a different technical approach on the James Webb Space Telescope.

text: A fine guidance sensor (FGS) is an interferometric instrument on board a space telescope that provides high-precision pointing information as input to the observatory's attitude control systems. FGSs have been deployed on the

text: Hubble Space Telescope

text: , and will be deployed with a different technical approach on the

text: James Webb Space Telescope

text: The Effelsberg 100-m Radio Telescope is a radio telescope in the Ahrgebirge (part of the Eifel) in Bad Münstereifel, Germany. For 29 years the Effelsberg Radio Telescope was the largest fully steerable radio telescope on Earth. In 2000 it was surpassed by the Robert C. Byrd Green Bank Telescope in Green Bank, US which has a slightly larger elliptical 100 by 110-metre aperture.

text: The Effelsberg 100-m Radio Telescope is a

text: radio telescope

text: in the Ahrgebirge (part of the

text: Eifel

text: ) in

text: Bad Münstereifel

text: Germany

text: . For 29 years the Effelsberg Radio Telescope was the largest fully steerable radio telescope on Earth. In 2000 it was surpassed by the

text: Robert C. Byrd Green Bank Telescope

text: in

text: Green Bank

text: , US which has a slightly larger elliptical 100 by 110-metre aperture.

text: is the density of seawater.

text: is the density of seawater.

text: Radio astronomy began in 1931 when Karl Jansky discovered that the Milky Way was a source of radio emission while doing research on terrestrial static with a direction antenna. Building on Jansky's work, Grote Reber built a more sophisticated purpose-built radio telescope in 1937, with a  dish; using this, he discovered various unexplained radio sources in the sky. Interest in radio astronomy grew after the Second World War when much larger dishes were built including: the  Jodrell bank telescope (1957), the  Green Bank Telescope (1962), and the  Effelsberg telescope (1971). The huge  Arecibo telescope (1963) is so large that it is fixed into a natural depression in the ground; the central antenna can be steered to allow the telescope to study objects up to twenty degrees from the zenith. However, not every radio telescope is of the dish type. For example, the Mills Cross Telescope (1954) was an early example of an array which used two perpendicular lines of antennae  in length to survey the sky.

text: Radio astronomy began in 1931 when

text: Karl Jansky

text: discovered that the

text: Milky Way

text: was a source of radio emission while doing research on terrestrial static with a direction antenna. Building on Jansky's work,

text: Grote Reber

text: built a more sophisticated purpose-built radio telescope in 1937, with a  dish; using this, he discovered various unexplained radio sources in the sky. Interest in radio astronomy grew after the Second World War when much larger dishes were built including: the

text: Jodrell bank

text: telescope (1957), the

text: Green Bank Telescope

text: (1962), and the

text: Effelsberg

text: telescope (1971). The huge

text: Arecibo telescope

text: (1963) is so large that it is fixed into a natural depression in the ground; the central antenna can be steered to allow the telescope to study objects up to twenty degrees from the

text: zenith

text: . However, not every radio telescope is of the dish type. For example, the

text: Mills Cross Telescope

text: (1954) was an early example of an array which used two perpendicular lines of antennae  in length to survey the sky.

text: Auction theory is an applied branch of economics which deals with how people act in auction markets and researches the properties of auction markets. There are many possible designs (or sets of rules) for an auction and typical issues studied by auction theorists include the efficiency of a given auction design, optimal and equilibrium bidding strategies, and revenue comparison. Auction theory is also used as a tool to inform the design of real-world auctions; most notably auctions for the privatization of public-sector companies or the sale of licenses for use of the electromagnetic spectrum.

text: Auction theory is an applied branch of

text: economics

text: which deals with how people act in

text: auction

text: markets and researches the properties of auction markets. There are many possible designs (or sets of rules) for an auction and typical issues studied by auction theorists include the

text: efficiency

text: of a given auction design,

text: optimal

text: and equilibrium bidding strategies, and revenue comparison. Auction theory is also used as a tool to inform the design of real-world auctions; most notably auctions for the privatization of public-sector companies or the sale of licenses for use of the electromagnetic spectrum.

text: We can represent an electromagnetic wave in the form of a 2 by 1 matrix

text: In optical astronomy the air mass provides an indication of the deterioration of the observed image, not only as regards direct effects of spectral absorption, scattering and reduced brightness, but also an aggregation of visual aberrations, e.g. resulting from atmospheric turbulence, collectively referred to as the quality of the seeing. On bigger telescopes, such as the WHT (Wynne and Warsick 1988) and VLT (Avila, Rupprecht, and Becker 1997), the atmospheric dispersion can be so severe that it affects the pointing of the telescope to the target. In such cases an atmospheric dispersion compensator is used, which usually consists of two The Greenwood frequency and Fried parameter, both relevant for adaptive optics depend on the air mass above them (or more specifically, on the zenith angle).

text: In

text: optical astronomy

text: the air mass provides an indication of the deterioration of the observed image, not only as regards direct effects of spectral absorption, scattering and reduced brightness, but also an aggregation of visual aberrations, e.g. resulting from atmospheric turbulence, collectively referred to as the quality of the

text: seeing

text: . On bigger telescopes, such as the

text: WHT

text: Wynne and Warsick 1988

text: ) and

text: VLT

text: Avila, Rupprecht, and Becker 1997

text: ), the atmospheric dispersion can be so severe that it affects the pointing of the telescope to the target. In such cases an atmospheric dispersion compensator is used, which usually consists of two The

text: Greenwood frequency

text: and

text: Fried parameter

text: , both relevant for

text: adaptive optics

text: depend on the air mass above them (or more specifically, on the

text: zenith angle

text: The telescopic pixel design is based on the optical telescope. 'Telescopic' indicates that each pixel acts as a miniature telescope consisting of a primary and secondary mirror that can both be deformed by application of specific voltage.

text: The telescopic pixel design is based on the

text: optical telescope

text: . 'Telescopic' indicates that each

text: pixel

text: acts as a miniature telescope consisting of a primary and secondary mirror that can both be deformed by application of specific voltage.

text: A typical size of the single antenna of a radio telescope is 25 meters. Dozens of radio telescopes with comparable sizes are operated in radio observatories all over the world.

text: He used a wide variety of optical telescopes, having learnt about optical observing using the Isaac Newton Telescope, before being one of the first western astronomers to use the Soviet BTA-6 telescope.

text: He used a wide variety of

text: optical telescope

text: s, having learnt about optical observing using the

text: Isaac Newton Telescope

text: , before being one of the first western astronomers to use the Soviet

text: telescope.

text: By 1895 Crossley had deemed the rainy English weather and the industrial air pollution at his observatory site unsuitable for astronomy, so he donated his  telescope to the Lick Observatory in California.  Though extensively modified, it was used for research until 2010 and is known as the Crossley reflector. This telescope was used by Charles Dillon Perrine to discover two moons of Jupiter. The 36 in. Crossley reflector was used extensively before the 120 in. Shane Reflecting Telescope (C. Donald Shane Telescope) was built in 1959.

text: By 1895 Crossley had deemed the rainy English weather and the industrial air pollution at his observatory site unsuitable for astronomy, so he donated his  telescope to the

text: Lick Observatory

text: in

text: California

text: .  Though extensively modified, it was used for research until 2010 and is known as the

text: Crossley reflector

text: . This telescope was used by

text: Charles Dillon Perrine

text: to discover two

text: moon

text: s of

text: Jupiter

text: . The 36 in.

text: Crossley reflector

text: was used extensively before the 120 in. Shane Reflecting Telescope (

text: C. Donald Shane Telescope

text: ) was built in 1959.

text: The planet is typically discovered by using Doppler spectrometer by looking for shifts in the spectrum of the star. In Australia, Jones et al. found this planet in 2002 by using the telescope in Anglo-Australian Observatory.

text: The planet is typically discovered by using

text: Doppler spectrometer

text: by looking for shifts in the spectrum of the star. In

text: Australia

text: , Jones et al. found this planet in 2002 by using the

text: telescope

text: in

text: Anglo-Australian Observatory

text: In other experiments that spring and summer Lodge put a series of spark gaps along two 29 meter long wires and noticed he was getting a very large spark in the gap near the end of the wires, which seemed to be consistent with the oscillation wavelength produced by the Leyden jar meeting with the wave being reflected at the end of the wire. In a darkened room, he also noted a glow at intervals along the wire at one half wavelength intervals. He took this as evidence that he was generating and detecting Maxwell's electromagnetic waves. While on summer vacation Lodge learned that Heinrich Hertz in Germany had been conducting his own electromagnetic research and published a series of papers proving the existence of electromagnetic waves and their propagation in free space. Lodge presented his own paper on electromagnetic waves along wires in September 1888 at the British Science Association meeting in Bath, England, adding a postscript acknowledging Hertz's work and saying: "The whole subject of electrical radiation seems working itself out splendidly."

text: In other experiments that spring and summer Lodge put a series of spark gaps along two 29 meter long wires and noticed he was getting a very large spark in the gap near the end of the wires, which seemed to be consistent with the oscillation wavelength produced by the Leyden jar meeting with the wave being reflected at the end of the wire. In a darkened room, he also noted a glow at intervals along the wire at one half wavelength intervals. He took this as evidence that he was generating and detecting Maxwell's electromagnetic waves. While on summer vacation Lodge learned that

text: Heinrich Hertz

text: in Germany had been conducting

text: his own electromagnetic research

text: and published a series of papers proving the existence of electromagnetic waves and their propagation in free space. Lodge presented his own paper on electromagnetic waves along wires in September 1888 at the

text: British Science Association

text: meeting in

text: Bath, England

text: , adding a postscript acknowledging Hertz's work and saying: "The whole subject of electrical radiation seems working itself out splendidly."

text: For the 2006 observing season, the telescopes involved were (apart from the RoboNet telescopes):

text: For the 2006 observing season, the telescopes involved were (apart from the

text: RoboNet

text: telescopes):

text: The TNG is an altazimuthal reflecting telescope with a Ritchey-Chretien optical configuration and a flat tertiary mirror feeding two opposite Nasmyth foci. It has a design derived from the New Technology Telescope (NTT), an ESO 4-meters class telescope located in La Silla (Chile). Therefore, the optical quality of the telescope is ensured by an active optics system performing real-time corrections of the optical components and compensating, in particular, for the deformations of the primary mirror, which is too thin to be completely rigid.

text: The TNG is an altazimuthal reflecting telescope with a

text: Ritchey-Chretien

text: optical configuration and a flat tertiary mirror feeding two opposite

text: Nasmyth

text: foci. It has a design derived from the

text: New Technology Telescope

text: (NTT), an

text: ESO

text: 4-meters class telescope located in La Silla (Chile). Therefore, the optical quality of the telescope is ensured by an

text: active optics

text: system performing real-time corrections of the optical components and compensating, in particular, for the deformations of the primary mirror, which is too thin to be completely rigid.

text: The observatory has two main telescopes. The 1.5 metre Cassegrain reflector, which is the largest optical telescope in Northern Europe, is used for spectroscopic observations. The second telescope is a 0.6 metre reflector for photometric observations. There is also a pitch for a collection of meteorological instruments on the observatory grounds.

text: The observatory has two main telescopes. The 1.5 metre

text: Cassegrain reflector

text: , which is the largest optical telescope in

text: Northern Europe

text: , is used for

text: spectroscopic

text: observations. The second telescope is a 0.6 metre reflector for

text: photometric

text: observations. There is also a pitch for a collection of

text: meteorological

text: instruments

text: on the observatory grounds.

text: The 3.67-meter telescope, known as the Advanced Electro-Optical System (AEOS), owned by the Department of Defense, is the United States' largest optical telescope designed for tracking satellites. The 75-ton AEOS telescope points and tracks very accurately, yet is fast enough to track both low-Earth satellites and ballistic missiles. AEOS can be used simultaneously by many groups or institutions because its light can be channeled through a series of mirrors to seven independent coudé rooms below the telescope. Employing sophisticated sensors that include an adaptive optics system, radiometer, spectrograph, and long-wave infrared imager, the telescope tracks man-made objects in deep space and performs space object identification data collection.

text: The 3.67-meter telescope, known as the

entity_name: 3.67 m Advanced Electro Optical System Telescope

text: Advanced Electro-Optical System

text: (AEOS), owned by the

text: Department of Defense

text: , is the United States' largest optical telescope designed for tracking satellites. The 75-ton AEOS telescope points and tracks very accurately, yet is fast enough to track both low-Earth satellites and

text: ballistic missile

text: s. AEOS can be used simultaneously by many groups or institutions because its light can be channeled through a series of mirrors to seven independent coudé rooms below the telescope. Employing sophisticated sensors that include an adaptive optics system,

text: radiometer

text: spectrograph

text: , and long-wave infrared imager, the telescope tracks man-made objects in deep space and performs space object identification data collection.

text: During the development of radio, many scientists and inventors contributed to radio technology and electronics. The mathematical work of James Clerk Maxwell during the 1850s had shown the relationship of different forms of electromagnetic radiation including possibility of invisible airborne waves (later called "radio waves"). In his classic physics experiments of 1888, Heinrich Hertz proved Maxwell's theory by transmitting radio waves with a spark-gap transmitter, and detected them by using simple electrical devices. Other physicists experimented with these new waves and in the process developed devices for transmitting and detecting them. In 1895, Guglielmo Marconi began work on a way to adapt the known methods of transmitting and detecting these "Hertzian waves" into a purpose built commercial wireless telegraphic system. Early on, he sent wireless signals over a distance of one and a half miles. In December 1901, he sent wireless waves that were not affected by the curvature of the Earth. Marconi later transmitted the wireless signals across the Atlantic between Poldhu, Cornwall, and St. John's, Newfoundland, a distance of .

text: During the

text: development of radio

text: , many scientists and

text: inventor

text: s contributed to

text: radio technology

text: and electronics. The mathematical work of

text: James Clerk Maxwell

text: during the 1850s had shown the relationship of different forms of

text: electromagnetic radiation

text: including possibility of invisible airborne waves (later called "radio waves"). In his classic physics experiments of 1888,

text: Heinrich Hertz

text: proved Maxwell's theory by transmitting

text: radio wave

text: s with a

text: spark-gap transmitter

text: , and detected them by using simple electrical devices. Other physicists experimented with these new waves and in the process developed devices for transmitting and detecting them. In 1895,

text: Guglielmo Marconi

text: began work on a way to adapt the known methods of transmitting and detecting these "Hertzian waves" into a purpose built commercial

text: wireless telegraphic

text: system. Early on, he sent wireless signals over a distance of one and a half miles. In December 1901, he sent wireless waves that were not affected by the curvature of the Earth. Marconi later transmitted the wireless signals across the Atlantic between Poldhu, Cornwall, and St. John's, Newfoundland, a distance of .

text: Galileo Galilei was recently selected as a main motif for a high value collectors' coin: the €25 International Year of Astronomy commemorative coin, minted in 2009. This coin also commemorates the 400th anniversary of the invention of Galileo's telescope. The obverse shows a portion of his portrait and his telescope. The background shows one of his first drawings of the surface of the moon. In the silver ring other telescopes are depicted: the Isaac Newton Telescope, the observatory in Kremsmünster Abbey, a modern telescope, a radio telescope and a space telescope. In 2009, the Galileoscope was also released. This is a mass-produced, low-cost educational  telescope with relatively high quality.

text: Galileo Galilei was recently selected as a main motif for a high value collectors' coin: the €25

entity_name: Euro gold and silver commemorative coins (Austria)

text: International Year of Astronomy commemorative coin

text: , minted in 2009. This coin also commemorates the 400th anniversary of the invention of

text: Galileo's telescope

text: . The obverse shows a portion of his portrait and his telescope. The background shows one of his first drawings of the surface of the moon. In the silver ring other telescopes are depicted: the

text: Isaac Newton Telescope

text: , the observatory in

text: Kremsmünster Abbey

text: , a modern telescope, a

text: radio telescope

text: and a

text: space telescope

text: . In 2009, the

text: Galileoscope

text: was also released. This is a mass-produced, low-cost educational  telescope with relatively high quality.

text: In addition, Maxwell's equations required that all electromagnetic waves in vacuum propagate at a fixed speed, c. As this can only occur in one reference frame in Newtonian physics (see Galilean-Newtonian relativity), the aether was hypothesized as the absolute and unique frame of reference in which Maxwell's equations hold. That is, the aether must be "still" universally, otherwise c would vary along with any variations that might occur in its supportive medium. Maxwell himself proposed several mechanical models of aether based on wheels and gears, and George Francis FitzGerald even constructed a working model of one of them. These models had to agree with the fact that the electromagnetic waves are transverse but never longitudinal.

text: In addition, Maxwell's equations required that all electromagnetic waves in

text: vacuum

text: propagate at a fixed speed,

text: c

text: . As this can only occur in one

text: reference frame

text: in Newtonian physics (see

text: Galilean-Newtonian relativity

text: ), the aether was hypothesized as the absolute and unique frame of reference in which Maxwell's equations hold. That is, the aether must be "still" universally, otherwise c would vary along with any variations that might occur in its supportive medium. Maxwell himself proposed several mechanical models of aether based on wheels and gears, and

text: George Francis FitzGerald

text: even constructed a working model of one of them. These models had to agree with the fact that the electromagnetic waves are

text: transverse

text: but never

text: longitudinal

text: Giovanni Demisiani (; died 1614), a Greek from Zakynthos, was a theologian, chemist, mathematician to Cardinal Gonzaga, and member of the Accademia dei Lincei. Demisiani is noted for  coining the name telescope (from the Greek τῆλε, tele "far" and σκοπεῖν, skopein "to look or see") for a version of the instrument presented by Galileo Galilei to the Accademia dei Lincei at a banquet honoring Galileo’s induction into the Accademia in 1611.

text: Giovanni Demisiani (; died 1614), a

text: Greek

text: from

text: Zakynthos

text: , was a

text: theologian

text: chemist

text: mathematician

text: to

text: Cardinal Gonzaga

text: , and member of the

text: Accademia dei Lincei

text: . Demisiani is noted for  coining the name

text: telescope

text: (from the

text: Greek

text: τῆλε

text: , tele "far" and

text: σκοπεῖν

text: , skopein "to look or see") for a version of the instrument presented by

text: Galileo Galilei

text: to the

text: Accademia dei Lincei

text: at a banquet honoring Galileo’s induction into the Accademia in 1611.

text: Optical telescopes can be classified by three primary optical designs (refractor, reflector, or catadioptric), by sub-designs of these types, by how they are constructed, or by the task they perform. They all have their different advantages and disadvantages and they are used in different areas of professional and amateur astronomy.

text: Optical telescope

text: s can be classified by three primary optical designs (refractor, reflector, or catadioptric), by sub-designs of these types, by how they are constructed, or by the task they perform. They all have their different advantages and disadvantages and they are used in different areas of

text: professional

text: and

text: amateur astronomy

text: Although specialized and experienced amateur astronomers tend to acquire more specialized and more powerful equipment over time, relatively simple equipment is often preferred for certain tasks.  Binoculars, for instance, although generally of lower power than the majority of telescopes, also tend to provide a wider field of view, which is preferable for looking at some objects in the night sky.

text: Although specialized and experienced amateur astronomers tend to acquire more specialized and more powerful equipment over time, relatively simple equipment is often preferred for certain tasks.  Binoculars, for instance, although generally of lower power than the majority of telescopes, also tend to provide a wider

text: field of view

text: , which is preferable for looking at some objects in the night sky.

text: Reber Radio Telescope is a parabolic radio telescope built by astronomer Grote Reber in his back yard in Illinois in 1937, implementing an earlier proposal of Karl Jansky, the discoverer (1931) of radio waves emanating from the Milky Way.   It was the second radio telescope ever built (after Jansky's dipole array), and the first parabolic radio telescope, serving as a prototype for the first large dish radio telescopes such as the Green Bank Telescope and Lovell Telescope constructed after World War 2.  Made of sheet metal with a 31.4 foot (9 meter) aperture and 20 foot (6 meter) focal length, it was the largest parabolic dish in existence at the time.   Reber was the world's only radio astronomer at the time, and his construction of the telescope and the sky surveys he did with it helped found the field of radio astronomy, revealing radio sources such as Cassiopeia A and Cygnus X-1 for the first time.

text: Reber Radio Telescope is a

text: parabolic

text: radio telescope

text: built by astronomer

text: Grote Reber

text: in his back yard in Illinois in 1937, implementing an earlier proposal of

text: Karl Jansky

text: , the discoverer (1931) of radio waves emanating from the Milky Way.   It was the second

text: radio telescope

text: ever built (after Jansky's dipole array), and the first parabolic radio telescope, serving as a prototype for the first large dish radio telescopes such as the

text: Green Bank Telescope

text: and

text: Lovell Telescope

text: constructed after World War 2.  Made of sheet metal with a 31.4 foot (9 meter) aperture and 20 foot (6 meter)

text: focal length

text: , it was the largest parabolic dish in existence at the time.   Reber was the world's only

text: radio astronomer

text: at the time, and his construction of the telescope and the sky surveys he did with it helped found the field of

text: radio astronomy

text: , revealing radio sources such as

text: Cassiopeia A

text: and

text: Cygnus X-1

text: for the first time.

text: The speed of the star around the system's center of mass is much smaller than that of the planet, because the radius of its orbit around the center of mass is so small. However, velocity variations down to 1 m/s or even somewhat less can be detected with modern spectrometers, such as the HARPS (High Accuracy Radial Velocity Planet Searcher) spectrometer at the ESO 3.6 meter telescope in La Silla Observatory, Chile, or the HIRES spectrometer at the Keck telescopes.An especially simple and inexpensive method for measuring radial velocity is "externally dispersed interferometry".<ref>

text: The speed of the star around the system's

text: center of mass

text: is much smaller than that of the planet, because the radius of its orbit around the center of mass is so small. However, velocity variations down to 1 m/s or even somewhat less can be detected with modern

text: spectrometer

text: s, such as the HARPS (

text: ) spectrometer at the

text: ESO

text: 3.6 meter telescope in

text: La Silla Observatory

text: , Chile, or the

text: HIRES

text: spectrometer at the

text: Keck telescopes

text: .An especially simple and inexpensive method for measuring radial velocity is "externally dispersed interferometry".<ref>

text: The JWST is a collaborative effort between NASA,the European Space Agency, and the Canadian Space Agency. The project is currently being managed by the NASA Goddard Space Center. The contracting company involved in the development is Northrup Grumman. After launch the telescope will be operated by the Space Telescope Science Institute. The project was formerly known as the "Next Generation Space Telescope" but was renamed after James Webb in 2002.

text: The JWST is a collaborative effort between

text: NASA

text: ,the

text: European Space Agency

text: , and the

text: Canadian Space Agency

text: . The project is currently being managed by the

text: NASA Goddard Space Center

text: . The contracting company involved in the development is

text: Northrup Grumman

text: . After launch the telescope will be operated by the

text: Space Telescope Science Institute

text: . The project was formerly known as the "

text: Next Generation Space Telescope

text: " but was renamed after James Webb in 2002.

text: Looking back Hume commented in The Times:

text: The difficulty of construction is another factor in an amateur’s choice of project. For a given design the difficulty of construction grows roughly as the square  of the diameter of the objective. For example, a Newtonian telescope of  aperture is a moderately easy science fair project. A  Newtonian is considered a good compromise size since construction is not difficult and results in an instrument that would be expensive to purchase commercially. A  reflecting telescope is difficult, but still within the ability of the average amateur who has had experience building smaller instruments. Amateurs have constructed telescopes as large as  across, but usually small groups or astronomy clubs take on such projects.

text: Back in the Red kingdom, the princess looks at the Golden Kingdom in the sky, pining for the Yellow boy. The Red king is concerned though, and does not approve of her feelings for him, as he fears for her safety. The Red king is then called away, and through a giant red telescope, he spots the Blue Kingdom and Golden Kingdom's soldiers and leaders coming to his land... with paintbrushes! He rallies his men, and they prepare for war.

text: The observatory has seven permanently mounted main optical telescopes, the first and largest being the 20-inch J.C.D Marsh Cassegrain Telescope. The other telescopes include five equatorially mounted, robotic 16-inch Meade LX200s as well as a  14-inch Meade LX200. These telescopes are equipped with research-grade CCD cameras, spectrographs, video cameras and a high-sensitivity Lucky imaging camera. A number of smaller telescopes are co-mounted to the main telescopes to act as guidescopes, widefield telescopes or H-alpha solar telescopes.

text: The observatory has seven permanently mounted main

text: optical telescopes

text: , the first and largest being the 20-inch J.C.D Marsh

text: Cassegrain Telescope

text: . The other telescopes include five equatorially mounted,

text: robotic

text: Meade LX200

text: s as well as a  14-inch Meade LX200. These telescopes are equipped with research-grade

text: CCD

text: cameras,

text: spectrograph

text: s,

text: video

text: cameras and a high-sensitivity

text: Lucky imaging

text: camera. A number of smaller telescopes are co-mounted to the main telescopes to act as

text: guidescopes

text: , widefield telescopes or

text: H-alpha

text: solar telescope

text: s.

text: Largest optical telescopes 1967:

text: Largest optical telescopes 1967:

text: The Institut de radioastronomie millimétrique (IRAM) operates two radio astronomy telescopes at millimeter wavelengths, which are open to the international astronomical community: the 30 m single-dish radio telescope located on Pico Veleta (2850 m) in the Spanish Sierra Nevada (Andalucia, Spain), and the six-antenna Plateau de Bure Interferometer (2550 m) in the French Alps. Both sites are at high altitude to reduce the absorption by water vapor. The telescopes are supported by the IRAM offices and laboratories in Granada and Grenoble, respectively. IRAM, which is directed by Karl Schuster, has its headquarters in Grenoble.

text: The Institut de radioastronomie millimétrique (IRAM) operates two

text: radio astronomy

text: telescopes at

text: millimeter wavelengths

text: , which are open to the international astronomical community: the

text: 30 m single-dish

text: radio

text: telescope

text: located on

text: Pico Veleta

text: (2850 m) in the Spanish

text: Sierra Nevada

text: Andalucia

text: Spain

text: ), and the six-antenna

text: Plateau de Bure Interferometer

text: (2550 m) in the

text: French Alps

text: . Both sites are at high

text: altitude

text: to reduce the absorption by

text: water vapor

text: . The telescopes are supported by the IRAM offices and laboratories in

text: Granada

text: and

text: Grenoble

text: , respectively. IRAM, which is directed by Karl Schuster, has its headquarters in

text: Grenoble

text: On the longer term, after accomplishing the primary goal of discovering gravitational waves, Virgo aims at being part of the birth of a new branch of astronomy by observing the Universe with a different and complementary perspective than current telescopes and detectors. Information brought by gravitational waves will be added to those provided by the study of the electromagnetic spectrum (microwaves, radio waves, infrared, the visible spectrum, ultraviolet, X rays and gamma rays), of cosmic rays and of neutrinos. In order to correlate a gravitational wave detection with visible and localized events in the sky, the LIGO and VIRGO collaborations have signed bilateral agreements with many teams operating telescopes to quickly inform (on the timescale of a few days or a few hours) these partners that a potential gravitational wave signal has been observed. These alerts must be sent before knowing whether the signal is real or not, because the source (if it is real) may only remain visible during a short amount of time.

text: On the longer term, after accomplishing the primary goal of discovering gravitational waves, Virgo aims at being part of the birth of a new branch of astronomy by observing the Universe with a different and complementary perspective than current telescopes and detectors. Information brought by gravitational waves will be added to those provided by the study of the electromagnetic spectrum (

text: microwave

text: s,

text: radio wave

text: s,

text: infrared

text: the visible spectrum

text: ultraviolet

text: X rays

text: and

text: gamma ray

text: s), of

text: cosmic ray

text: s and of

text: neutrino

text: s. In order to correlate a gravitational wave detection with visible and localized events in the sky, the LIGO and VIRGO collaborations have signed bilateral agreements with many teams operating telescopes to quickly inform (on the timescale of a few days or a few hours) these partners that a potential gravitational wave signal has been observed. These alerts must be sent before knowing whether the signal is real or not, because the source (if it is real) may only remain visible during a short amount of time.

text: In the fiscal year 2014 budget, the US Congress did not recommend divesting the Green Bank Telescope. The Telescope is looking for partners to help fund its $10 million annual operating costs.

text: At present, observations can be made on the 2 m telescopes either by remote control, where an observer directly controls the telescope, or by robotic scheduler, where observations are submitted to a queue and the observations are taken robotically. The first remote 1-meter telescope achieved first light at the McDonald Observatory on April 1, 2012.

text: At present, observations can be made on the 2 m telescopes either by

text: remote control

text: , where an observer directly controls the telescope, or by robotic scheduler, where observations are submitted to a queue and the observations are taken

text: robotically

text: . The first remote 1-meter telescope achieved first light at the McDonald Observatory on April 1, 2012.

text: The Submillimeter Telescope (SMT), formerly known as the Heinrich Hertz Submillimeter Telescope, is a submillimeter wavelength radio telescope located on Mount Graham, Arizona.  It is a 10-meter-wide parabolic dish inside a building to protect it from bad weather. The building front doors and roof are opened when the telescope is in use.  The telescope's construction was finished in 1993.  Along with the 12 Meter Telescope on Kitt Peak, this telescope is maintained by the Arizona Radio Observatory, a division of Steward Observatory at the University of Arizona.

text: The Submillimeter Telescope (SMT), formerly known as the Heinrich Hertz Submillimeter Telescope, is a

text: submillimeter wavelength

text: radio telescope

text: located on

text: Mount Graham

text: Arizona

text: .  It is a 10-meter-wide parabolic dish inside a building to protect it from bad weather. The building front doors and roof are opened when the telescope is in use.  The telescope's construction was finished in

text: .  Along with the

text: 12 Meter Telescope

text: on

text: Kitt Peak

text: , this telescope is maintained by the

text: Arizona Radio Observatory

text: , a division of

text: Steward Observatory

text: at the

text: University of Arizona

text: At nearly  distant, Kepler-452b is too remote and its star too far for current telescopes or the next generation of planned telescopes to determine its true mass or whether it has an atmosphere. The Kepler spacecraft focused on a single small region of the sky but next-generation planet-hunting space telescopes, such as TESS and CHEOPS, will examine nearby stars throughout the sky. Nearby stars with planets can then be studied by the upcoming James Webb Space Telescope and future large ground-based telescopes to analyze atmospheres, determine masses and infer compositions. Additionally the Square Kilometer Array would significantly improve radio observations over the Arecibo Observatory and Green Bank Telescope.

text: At nearly  distant, Kepler-452b is too remote and its star too far for current telescopes or the next generation of planned telescopes to determine its true mass or whether it has an atmosphere. The Kepler spacecraft focused on a single small region of the sky but next-generation planet-hunting space telescopes, such as

text: TESS

text: and

text: CHEOPS

text: James Webb Space Telescope

text: Square Kilometer Array

text: Arecibo Observatory

text: and

text: Green Bank Telescope

text: Mt. Abu Observatory is equipped with a 1.2m Infrared Telescope along with the following back-end instruments: NICMOS Infrared Camera and Spectrograph, Imaging Fabry-Perot Spectrometer, large format optical CCDs, Optical Imaging Polarimeter and Fibre-linked Grating Spectrograph. A new high resolution optical spectrometer, PRL Advanced Radial-velocity All-sky Search (PARAS) to detect extrasolar planets using the radial velocity technique began observation in April 2012.In addition to these, a 50 cm telescope, Automated Telescope for Variability Study (ATVS), is now functional to monitor variable sources, eg AGNs, variable stars, Comets etc. MIRO has its own aluminizing plant for polishing of the telescope mirrors, a liquid nitrogen plant for providing liquid nitrogen to cool the IR detectors to reduce thermal noise.A new facility, created by LEOS, ISRO will become operational next year. This facility will have a one-metre diameter telescope with sophisticated optics and back-end instruments assembled by the Laboratory for Electro-Optics Systems (LEOS), Bengaluru.  The new facility, known as the Electro-Optical Deep Space Surveillance (EODSS) system, will track space debris,  mainly consisting of inactive satellites, electronic parts of instruments, leftovers from rocket launch and other such junk in space.  It will help ISRO to better handle their future missions, including re-entry capable space shuttles.

text: The observatory is also equipped with a more modern and more powerful instrument - a Celestron C14. It is a telescope which works with mirrors, as is generally the case with per-formant instruments. This one is a Schmidt-Cassegrain - that is, it has a hyperbolic and concave secondary mirror in the same axis as the primary mirror, which reflects light back through a hole pierced in the primary mirror itself. The image can then be observed through an eyepiece at the end of the tube. This instrument, with a primary mirror of 40 cm diameter can capture about 1800 times more light than the naked eye; the diameter of the eye's pupil is only 5 mm. In order to increase the stability of the instrument we have opted for a German mount. The electronic pilot automatically follows observed objects by compensating for the rotation of the Earth. Our NGC-Max guiding system contains the coordinates of thousands of objects and greatly helps with the aiming of the telescope.

text: The Synthesis Telescope consists of seven nine-metre, metal-mesh reflector antennas along a 600-m east-west baseline. The antennas are equipped with single-circular polarisation receivers at 408 MHz and dual circular receivers at 1420 MHz, from which all four Stokes parameters may be formed. A spectrometer may also be employed at 1420 MHz for study of the 21-cm hydrogen line. Maps of the sky are formed using the technique of aperture synthesis.

text: The Synthesis Telescope consists of seven nine-metre, metal-mesh reflector antennas along a 600-m east-west baseline. The antennas are equipped with single-circular

text: polarisation

text: receivers at 408

text: MHz

text: and dual circular receivers at 1420 MHz, from which all four

text: Stokes parameters

text: may be formed. A

text: spectrometer

text: may also be employed at 1420 MHz for study of the

text: 21-cm hydrogen line

text: . Maps of the sky are formed using the technique of

text: aperture synthesis

text: Some of the largest optical telescopes in the world use segmented primary mirrors. These include, but are not limited to the following telescopes:

text: Some of the

text: largest optical telescopes

text: in the world use segmented primary mirrors. These include, but are not limited to the following telescopes:

text: The Hilda Lindley House was built by the Army at a cost of about $22,000. The two-story structure, standing on a hill about 87 feet above mean low tide and approximately a half-mile back from the beach, contained two instrument rooms on the ground floor and another instrument room on the second floor, where soldiers used azimuth telescopes to look for enemy shipping on Block Island Sound. The soldiers looked through the fire control station’s characteristic mullioned observation slots — long, narrow windows with vertical supports.

text: In spectroscopy, optical fiber bundles transmit light from a spectrometer to a substance that cannot be placed inside the spectrometer itself, in order to analyze its composition. A spectrometer analyzes substances by bouncing light off and through them. By using fibers, a spectrometer can be used to study objects remotely.

text: In

text: spectroscopy

text: , optical fiber bundles transmit light from a spectrometer to a substance that cannot be placed inside the spectrometer itself, in order to analyze its composition. A spectrometer analyzes substances by bouncing light off and through them. By using fibers, a spectrometer can be used to study objects remotely.

text: A 2009 report in The New York Times looking back at the Dinkins administration summarized its achievements, noting:

text: A 2009 report in

text: The New York Times

text: looking back at the Dinkins administration summarized its achievements, noting:

text: John Dobson was most notable for being the originator and promoter of a design for a large, portable, low-cost reflecting telescope, the "Dobsonian telescope". The design is a very simple, low cost alt-azimuth mounted Newtonian telescope that employs common materials such as plywood, formica, PVC closet flanges, cardboard construction tubes, recycled porthole glass, and indoor-outdoor carpet. This type of simplified altazimuth mount is also commonly referred to in amateur astronomical circles as a "Dobsonian mount". Using this construction method makes the typical Dobsonian telescope large, portable, inexpensive, very stable, and easy to manufacture. The design revolutionized the sheer size of telescopes available to amateur astronomers with the optical diameters unheard of before their appearance.

text: John Dobson was most notable for being the originator and promoter of a design for a large, portable, low-cost

text: reflecting telescope

text: , the "Dobsonian telescope". The design is a very simple, low cost

text: alt-azimuth mount

text: ed

text: Newtonian telescope

text: that employs common materials such as

text: plywood

text: formica

text: , PVC

text: closet flange

text: s, cardboard construction tubes, recycled porthole glass, and indoor-outdoor carpet. This type of simplified altazimuth

text: mount

text: is also commonly referred to in amateur astronomical circles as a "Dobsonian mount". Using this construction method makes the typical Dobsonian telescope large, portable, inexpensive, very stable, and easy to manufacture. The design revolutionized the sheer size of telescopes available to amateur astronomers with the optical diameters unheard of before their appearance.

text: A main feature on the grounds of the castle is the "Great Telescope" or Leviathan (aka The Rosse Telescope) of the third Earl of Rosse, an astronomical telescope with a 183-cm (72 in) reflector. It was completed in 1845 and was used for several decades before the last observations were made in the first years of the 20th century. Its record size was not surpassed until the completion of the 100-inch (2.5-meter) Hooker Telescope at Mount Wilson Observatory in 1917. It was dismantled in 1914, but the structure was restored and the telescope reconstructed in the 1990s and is open to the public.

text: A main feature on the grounds of the castle is the "Great

text: Telescope

text: " or

text: Leviathan

text: (aka The Rosse Telescope) of the

text: third Earl of Rosse

text: , an

text: astronomical

text: telescope with a 183-cm (72 in) reflector. It was completed in 1845 and was used for several decades before the last observations were made in the first years of the 20th century. Its record size was not surpassed until the completion of the 100-inch (2.5-meter)

text: Hooker Telescope

text: at Mount Wilson Observatory in 1917. It was dismantled in 1914, but the structure was restored and the telescope reconstructed in the 1990s and is open to the public.

text: The telescopes amateur telescope makers build range from backyard variety to sophisticated instruments that make meaningful contributions to the field of astronomy. Instruments built by amateurs have been employed in planetary study, astrometry, photometry, comet and asteroid discovery to name just a few. Even the “hobbyist” end of the field can break down into several distinct categories such as: observing deep sky objects, observing the planets, solar observing, lunar observation, and astrophotography of all those classes of objects. Therefore, the design, size, and construction of the telescopes vary as well. Some amateur telescope makers build instruments that, while looking crude, are wholly suited to the purpose they are designed for. Others may strive for a more aesthetic look with high levels of mechanical “finish”. Since some amateur telescope makers do not have access to high-precision machining equipment, many elegant designs such as the Poncet Platform, Crayford focuser, and the Dobsonian telescope have evolved, which achieve functionality and stability without requiring precision machining.

text: The telescopes amateur telescope makers build range from backyard variety to sophisticated instruments that make meaningful contributions to the field of

text: astronomy

text: . Instruments built by amateurs have been employed in planetary study,

text: astrometry

text: photometry

text: , comet and asteroid discovery to name just a few. Even the “hobbyist” end of the field can break down into several distinct categories such as: observing

text: deep sky

text: objects, observing the planets, solar observing, lunar observation, and

text: astrophotography

text: of all those classes of objects. Therefore, the design, size, and construction of the telescopes vary as well. Some amateur telescope makers build instruments that, while looking crude, are wholly suited to the purpose they are designed for. Others may strive for a more aesthetic look with high levels of mechanical “finish”. Since some amateur telescope makers do not have access to high-precision machining equipment, many elegant designs such as the

text: Poncet Platform

text: Crayford focuser

text: , and the

text: Dobsonian telescope

text: have evolved, which achieve functionality and stability without requiring precision machining.

text: A spectrum (plural spectra or spectrums) is a condition that is not limited to a specific set of values but can vary infinitely within a continuum. The word was first used scientifically within the field of optics to describe the rainbow of colors in visible light when separated using a prism. As scientific understanding of light advanced, it came to apply to the entire electromagnetic spectrum.

text: A spectrum (plural spectra or spectrums) is a condition that is not limited to a specific set of values but can vary infinitely within a

text: continuum

text: . The word was first used scientifically within the field of

text: optics

text: to describe the

text: rainbow

text: of colors in

text: visible light

text: when separated using a

text: prism

text: . As scientific understanding of light advanced, it came to apply to the entire

text: electromagnetic spectrum

text: Kepler-10b's discovery was based on eight months of data collected with the Kepler telescope from May 2009 to January 2010. The planet's first transits were observed in July 2009. According to the collected data, Kepler-10 dimmed by one part in ten thousand every 0.83 days. Kepler-10 was the first star in the field of view of the Kepler telescope identified as capable of harboring a small transiting planet, and was considered a high priority target for ground based radial velocity observations intended to confirm the mass of Kepler-10b. Radial velocity measurements with the Keck I telescope taken intermittently between August 2009 and August 2010 revealed a periodic Doppler shift in the spectrum of Kepler-10 consistent with a planet of the nature observed by Kepler, confirming the planet's existence and allowing its mass to be determined. The planet's discovery was announced to the public on January 10, 2011.

text: Kepler-10b's discovery was based on eight months of data collected with the Kepler telescope from May 2009 to January 2010. The planet's first transits were observed in July 2009. According to the collected data, Kepler-10 dimmed by one part in ten thousand every 0.83 days. Kepler-10 was the first star in the

text: field of view

text: of the Kepler telescope identified as capable of harboring a small transiting planet, and was considered a high priority target for ground based radial velocity observations intended to confirm the mass of Kepler-10b. Radial velocity measurements with the

text: Keck I

text: telescope taken intermittently between August 2009 and August 2010 revealed a periodic

text: Doppler shift

text: in the spectrum of Kepler-10 consistent with a planet of the nature observed by Kepler, confirming the planet's existence and allowing its mass to be determined. The planet's discovery was announced to the public on January 10, 2011.

text: VoC is also rapidly gaining use in electronic news-gathering and remote broadcasting, where it is used in place of remote pickup units (RPUs), which must be temporarily fixed in a certain position, with an antenna often on a telescoping pole or satellite dish atop an outside broadcast van.  RPUs are also limiting in terms of setup time and space, safety regarding overhead powerlines, and the requirement for a line of sight back to the TV station or a remote receiving antenna.

text: VoC is also rapidly gaining use in

text: electronic news-gathering

text: and

text: remote broadcast

text: ing, where it is used in place of

text: remote pickup unit

text: s (RPUs), which must be temporarily fixed in a certain position, with an

text: antenna

text: often on a

text: telescoping

text: pole or

text: satellite dish

text: atop an

text: outside broadcast

text: van

text: .  RPUs are also limiting in terms of setup time and space, safety regarding overhead

text: powerlines

text: , and the requirement for a

text: line of sight

text: back to the

text: TV station

text: or a remote receiving antenna.

text: Based only on uncertain descriptions of the first practical telescope which Hans Lippershey tried to patent in the Netherlands in 1608, Galileo, in the following year, made a telescope with about 3x magnification. He later made improved versions with up to about 30x magnification. With a Galilean telescope, the observer could see magnified, upright images on the earth—it was what is commonly known as a terrestrial telescope or a spyglass. He could also use it to observe the sky; for a time he was one of those who could construct telescopes good enough for that purpose. On 25 August 1609, he demonstrated one of his early telescopes, with a magnification of about 8 or 9, to Venetian lawmakers. His telescopes were also a profitable sideline for Galileo, who sold them to merchants who found them useful both at sea and as items of trade. He published his initial telescopic astronomical observations in March 1610 in a brief treatise entitled Sidereus Nuncius (Starry Messenger).

text: Based only on uncertain descriptions of the first practical telescope which

text: Hans Lippershey

text: tried to patent in the Netherlands in 1608, Galileo, in the following year, made a telescope with about 3x magnification. He later made improved versions with up to about 30x magnification. With a

text: Galilean telescope

text: , the observer could see magnified, upright images on the earth—it was what is commonly known as a terrestrial telescope or a spyglass. He could also use it to observe the sky; for a time he was one of those who could construct telescopes good enough for that purpose. On 25 August 1609, he demonstrated one of his early telescopes, with a magnification of about 8 or 9, to

text: Venetian

text: lawmakers. His telescopes were also a profitable sideline for Galileo, who sold them to merchants who found them useful both at sea and as items of trade. He published his initial telescopic astronomical observations in March 1610 in a brief treatise entitled

text: Sidereus Nuncius

text: (Starry Messenger).

text: In 1972 he became Head of the Optics and Telescopes Group at the European Southern Observatory (ESO), where he worked for the next 21 years, first in Geneva and then in Garching, Germany. His major contributions have been in telescope optics and technology. In particular, he developed the concept of active optics, which is now the basic principle on which modern large telescopes are constructed.  The concept of active optics was developed first in ESO's New Technology Telescope (first light 1988), and then in ESO's Very Large Telescope (VLT). (first light 1998).

text: In 1972 he became Head of the Optics and Telescopes Group at the European Southern Observatory (

text: ESO

text: ), where he worked for the next 21 years, first in

text: Geneva

text: and then in

text: Garching

text: , Germany. His major contributions have been in telescope optics and technology. In particular, he developed the concept of

text: active optics

text: , which is now the basic principle on which modern large telescopes are constructed.  The concept of active optics was developed first in ESO's

text: New Technology Telescope

text: (first light 1988), and then in ESO's

text: Very Large Telescope

text: (VLT). (first light 1998).

text: On the ESO Schmidt telescope image, taken in 1984, the source looks elongated with a position angle of 138°. The similarity of this position angle with that of the resolved pair in the GMOS image (epoch 2013) in Fig. 1 of Luhman (2013) suggests that the time period between 1984 and 2013 may be close to the orbital period of the system (not far from original orbital period estimate by Luhman (2013)).

text: On the ESO Schmidt telescope image, taken in 1984, the source looks elongated with a

text: position angle

text: of 138

text: . The similarity of this position angle with that of the resolved pair in the GMOS image (epoch 2013) in Fig. 1 of Luhman (2013) suggests that the time period between 1984 and 2013 may be close to the orbital period of the system (not far from original orbital period estimate by Luhman (2013)).

text: In cognitive psychology, the telescoping effect (or telescoping bias) refers to the temporal displacement of an event whereby people perceive recent events as being more remote than they are and distant events as being more recent than they are. The former is known as backward telescoping or time expansion, and the latter as is known as forward telescoping. Three years is approximately the time frame in which events switch from being displaced backwards in time to forwards in time, with events occurring three years in the past being equally likely to be reported with forward telescoping bias as with backward telescoping bias. Although telescoping occurs in both the forward and backward directions, in general the effect is to increase the number of events reported too recently. This net effect in the forward direction is because of forces that impair memory, such as lack of salience, also impair time perception. Telescoping leads to an over reporting of the frequency of events. This over reporting is because participants include events beyond the period, either events that are too recent for the target time period (backward telescoping) or events that are too old for the target time period (forward telescoping).

text: In

text: cognitive psychology

text: , the telescoping effect (or telescoping bias) refers to the temporal displacement of an event whereby people perceive recent events as being more remote than they are and distant events as being more recent than they are. The former is known as backward telescoping or time expansion, and the latter as is known as forward telescoping. Three years is approximately the time frame in which events switch from being displaced backwards in time to forwards in time, with events occurring three years in the past being equally likely to be reported with forward telescoping bias as with backward telescoping bias. Although telescoping occurs in both the forward and backward directions, in general the effect is to increase the number of events reported too recently. This net effect in the forward direction is because of forces that impair memory, such as lack of

text: salience

text: , also impair

text: time perception

text: . Telescoping leads to an over reporting of the frequency of events. This over reporting is because participants include events beyond the period, either events that are too recent for the target time period (backward telescoping) or events that are too old for the target time period (forward telescoping).

text: Then on October 18, 1916, University President Rufus von KleinSmid announced that an anonymous donor had given the University $60,000 “…to be used to buy a telescope of huge size.”  That donor was later revealed to be Mrs. Lavinia Steward of Oracle, Arizona.  Mrs. Steward was a wealthy widow who had an interest in astronomy and a desire to memorialize her late husband, Mr. Henry Steward.  Douglass made plans to use the Steward gift to construct a 36-inch diameter Newtonian reflecting telescope.  The Warner & Swasey Company of Cleveland, Ohio was contracted to build the telescope, but the United States entry into World War I delayed the contract since Warner & Swayze had war contracts that took priority.  The situation was further delayed by the fact that up until this time, the expertise in large telescope mirror making was in Europe.  The war made it impossible to contract with a European company.  So Douglass had to find an American glass company that was willing to develop this expertise.  After a couple of failed castings, the Spencer Lens Co. of Buffalo, New York ultimately produced a 36-inch mirror for the Steward Telescope.

text: Then on October 18, 1916, University President

text: Rufus von KleinSmid

text: announced that an anonymous donor had given the University $60,000 “…to be used to buy a telescope of huge size.”  That donor was later revealed to be Mrs. Lavinia Steward of

text: Oracle, Arizona

text: .  Mrs. Steward was a wealthy widow who had an interest in astronomy and a desire to memorialize her late husband, Mr. Henry Steward.  Douglass made plans to use the Steward gift to construct a 36-inch diameter Newtonian reflecting telescope.  The

text: Warner & Swasey Company

text: of

text: Cleveland, Ohio

text: was contracted to build the telescope, but the United States entry into

text: World War I

text: delayed the contract since Warner & Swayze had war contracts that took priority.  The situation was further delayed by the fact that up until this time, the expertise in large telescope mirror making was in Europe.  The war made it impossible to contract with a European company.  So Douglass had to find an American glass company that was willing to develop this expertise.  After a couple of failed castings, the Spencer Lens Co. of

text: Buffalo, New York

text: ultimately produced a 36-inch mirror for the Steward Telescope.

text: One of the equations governing electromagnetic wave propagation is the Maxwell-Ampere law:

text: One of the equations governing electromagnetic wave propagation is the

text: Maxwell-Ampere law

text: AUT maintains a number of facilities off campus, including the AUT Radio Telescope, New Zealand's first radio telescope. The 12m telescope is located near Warkworth and is part of New Zealand and Australia's involvement in the international mega-science project, the Square Kilometre Array......

text: AUT maintains a number of facilities off campus, including the

entity_name: Warkworth Radio Astronomical Observatory

text: AUT Radio Telescope

text: , New Zealand's first radio telescope. The 12m telescope is located near Warkworth and is part of New Zealand and Australia's involvement in the international mega-science project, the

text: Square Kilometre Array

text: Isaac Newton (1643–1727) investigated the refraction of light, demonstrating that a prism could decompose white light into a spectrum of colours, and that a lens and a second prism could recompose the multicoloured spectrum into white light. He also showed that the coloured light does not change its properties by separating out a coloured beam and shining it on various objects. Newton noted that regardless of whether it was reflected or scattered or transmitted, it stayed the same colour. Thus, he observed that colour is the result of objects interacting with already-coloured light rather than objects generating the colour themselves. This is known as Newton's theory of colour. From this work he concluded that any refracting telescope would suffer from the dispersion of light into colours, and invented a reflecting telescope (today known as a Newtonian telescope) to bypass that problem. By grinding his own mirrors, using Newton's rings to judge the quality of the optics for his telescopes, he was able to produce a superior instrument to the refracting telescope, due primarily to the wider diameter of the mirror. In 1671 the Royal Society asked for a demonstration of his reflecting telescope. Their interest encouraged him to publish his notes On Colour, which he later expanded into his Opticks. Newton argued that light is composed of particles or corpuscles and were refracted by accelerating toward the denser medium, but he had to associate them with waves to explain the diffraction of light (Opticks Bk. II, Props. XII-L). Later physicists instead favoured a purely wavelike explanation of light to account for diffraction. Today's quantum mechanics, photons and the idea of wave-particle duality bear only a minor resemblance to Newton's understanding of light.

text: Isaac Newton

text: (1643–1727) investigated the

text: refraction

text: of light, demonstrating that a

text: prism

text: could decompose

text: white light

text: into a

text: spectrum

text: of colours, and that a

text: lens

text: and a second prism could recompose the multicoloured spectrum into white light. He also showed that the coloured light does not change its properties by separating out a coloured beam and shining it on various objects. Newton noted that regardless of whether it was reflected or scattered or transmitted, it stayed the same colour. Thus, he observed that colour is the result of objects interacting with already-coloured light rather than objects generating the colour themselves. This is known as

text: Newton's theory of colour

text: . From this work he concluded that any refracting

text: telescope

text: would suffer from the

text: dispersion

text: of light into colours, and invented a reflecting telescope (today known as a

text: Newtonian telescope

text: ) to bypass that problem. By grinding his own mirrors, using

text: Newton's rings

text: to judge the quality of the optics for his telescopes, he was able to produce a superior instrument to the refracting telescope, due primarily to the wider diameter of the mirror. In 1671 the Royal Society asked for a demonstration of his reflecting telescope. Their interest encouraged him to publish his notes On Colour, which he later expanded into his Opticks. Newton argued that light is composed of particles or corpuscles and were refracted by accelerating toward the denser medium, but he had to associate them with

text: wave

text: s to explain the

text: diffraction

text: of light (Opticks Bk. II, Props. XII-L). Later physicists instead favoured a purely wavelike explanation of light to account for diffraction. Today's

text: quantum mechanics

text: photons

text: and the idea of

text: wave-particle duality

text: bear only a minor resemblance to Newton's understanding of light.

text: The telescope was calibrated to only record gamma rays entering the telescope at certain angles. As these gamma rays entered the telescope, the rays went through the telescopes spark chamber and started the production of an electron and positron. The calorimeter then detected the electron or positron and recorded its data, such as energy level.

text: The facilities include two radio telescopes, a solar tower, an astrograph and a Gravimeter. The most powerful telescope is the 40 m telescope.

text: The facilities include two radio telescopes, a

text: solar tower

text: , an

text: astrograph

text: and a

text: Gravimeter

text: . The most powerful telescope is the

text: 40 m telescope

text: 1991 – Buckyballs studied by μSR, Second arm spectrometer SASP completed

text: 1991 –

text: Buckyballs

text: studied by μSR, Second arm spectrometer SASP completed

text: Nyquist's formula is essentially the same as that derived by Planck in 1901 for electromagnetic radiation of a blackbody in one dimension—i.e., it is the one-dimensional version of Planck's law of blackbody radiation. In other words, a hot resistor will create electromagnetic waves on a transmission line just as a hot object will create electromagnetic waves in free space.

text: Nyquist's formula is essentially the same as that derived by Planck in 1901 for electromagnetic radiation of a blackbody in one dimension—i.e., it is the one-dimensional version of

text: Planck's law of blackbody radiation

text: . In other words, a hot resistor will create electromagnetic waves on a

text: transmission line

text: just as a hot object will create electromagnetic waves in free space.

text: Four largest telescopes in 1939:

text: Four largest telescopes in 1939:

text: Some telescopes use deliberately astigmatic optics.

text: Some

text: telescope

text: s use deliberately astigmatic optics.

text: Space-based observatories are telescopes or other instruments that are located in outer space, many in orbit around the Earth. Space telescopes can be used to observe astronomical objects at wavelengths of the electromagnetic spectrum that cannot penetrate the Earth's atmosphere and are thus impossible to observe using ground-based telescopes. The Earth's atmosphere is opaque to ultraviolet radiation, X-rays, and gamma rays and is partially opaque to infrared radiation so observations in these portions of the electromagnetic spectrum are best carried out from a location above the atmosphere of our planet. Another advantage of space-based telescopes is that, because of their location above the Earth's atmosphere, their images are free from the effects of atmospheric turbulence that plague ground-based observations. As a result, the angular resolution of space telescopes such as the Hubble Space Telescope is often much smaller than a ground-based telescope with a similar aperture. However, all these advantages do come with a price. Space telescopes are much more expensive to build than ground-based telescopes. Due to their location, space telescopes are also extremely difficult to maintain. The Hubble Space Telescope was serviced by the Space Shuttle while many other space telescopes cannot be serviced at all.

text: Space-based observatories are telescopes or other instruments that are located in

text: outer space

text: , many in

text: orbit

text: around the Earth. Space telescopes can be used to observe astronomical objects at wavelengths of the electromagnetic spectrum that cannot penetrate the

text: Earth's atmosphere

text: and are thus impossible to observe using ground-based telescopes. The Earth's atmosphere is

text: opaque

text: to

text: ultraviolet

text: radiation,

text: X-rays

text: , and

text: gamma rays

text: and is partially opaque to

text: infrared

text: radiation so observations in these portions of the electromagnetic spectrum are best carried out from a location above the atmosphere of our planet. Another advantage of space-based telescopes is that, because of their location above the Earth's atmosphere, their images are free from the effects of atmospheric turbulence that plague ground-based observations. As a result, the

text: angular resolution

text: of space telescopes such as the

text: Hubble Space Telescope

text: is often much smaller than a ground-based telescope with a similar

text: aperture

text: . However, all these advantages do come with a price. Space telescopes are much more expensive to build than ground-based telescopes. Due to their location, space telescopes are also extremely difficult to maintain. The Hubble Space Telescope was serviced by the

text: Space Shuttle

text: while many other space telescopes cannot be serviced at all.

text: Most amateur astronomers work at visible wavelengths, but a small minority experiment with wavelengths outside the visible spectrum.  An early pioneer of radio astronomy was Grote Reber, an  amateur astronomer who constructed the first purpose built radio telescope in the late 1930s to follow up on the discovery of radio wavelength emissions from space by Karl Jansky.  Non-visual amateur astronomy includes the use of infrared filters on conventional telescopes, and also the use of radio telescopes.  Some amateur astronomers use home-made radio telescopes, while others use radio telescopes that were originally built for astronomy research but have since been made available for use by amateurs.  The One-Mile Telescope is one such example.

text: Most amateur astronomers work at

text: visible wavelengths

text: , but a small minority experiment with wavelengths outside the visible spectrum.  An early pioneer of

text: radio astronomy

text: was

text: Grote Reber

text: , an  amateur astronomer who constructed the first purpose built

text: radio telescope

text: in the late 1930s to follow up on the discovery of

text: radio wavelength

text: emissions from space by

text: Karl Jansky

text: .  Non-visual amateur astronomy includes the use of

text: infrared filter

text: s on conventional telescopes, and also the use of

text: radio telescope

text: s.  Some amateur astronomers use home-made radio telescopes, while others use radio telescopes that were originally built for astronomy research but have since been made available for use by amateurs.  The

text: One-Mile Telescope

text: is one such example.

text: Afocal systems are used in laser optics, for instance as beam expanders, Infrared and forward looking infrared systems, camera zoom lenses and telescopic lens attachments such as teleside converters, and photography setups combining cameras and telescopes (Afocal photography).

text: Afocal systems are used in laser optics, for instance as

text: beam expander

text: s,

text: Infrared

text: and

text: forward looking infrared

text: systems, camera

text: zoom lens

text: es and telescopic lens attachments such as

text: teleside converter

text: s, and photography setups combining cameras and telescopes (

text: Afocal photography

text: The device was invented by Brett Marut, a resident of Santa Monica, California, after he suffered from pain and embarrassment while having his back professionally waxed at a salon full of female customers. It first went on sale in 2006 and quickly gained popularity through online retailers. The Mangroomer is an electric razor which The New York Times remarked "resembles a futuristic kung fu weapon." When it is folded open and its telescoping handle is extended to its maximum length, the  Mangroomer is almost two feet long.

text: The device was invented by Brett Marut, a resident of

text: Santa Monica

text: California

text: , after he suffered from pain and embarrassment while having his back professionally

text: waxed

text: at a

text: salon

text: full of female customers. It first went on sale in 2006 and quickly gained popularity through online retailers. The Mangroomer is an electric razor which The New York Times remarked "resembles a futuristic kung fu weapon." When it is folded open and its telescoping handle is extended to its maximum length, the  Mangroomer is almost two feet long.

text: There are many applications for ULE, but by far the most common is for mirrors and lenses for telescopes in both space and terrestrial settings. One of the most well known examples of the use of ULE is in the Hubble telescope's mirror. Another good example of its application is in the Gemini telescope's mirror bank. this type of material is needed for this application because the mirrors on telescopes, especially the very large and precise ones, cannot bend or lose their shape even slightly. If this were to happen, the telescope would be out of focus. some other examples and uses of ULE are:

text: There are many applications for ULE, but by far the most common is for mirrors and lenses for telescopes in both space and terrestrial settings. One of the most well known examples of the use of ULE is in the

text: Hubble telescope

text: 's mirror. Another good example of its application is in the

text: Gemini telescope

text: 's mirror bank. this type of material is needed for this application because the mirrors on telescopes, especially the very large and precise ones, cannot bend or lose their shape even slightly. If this were to happen, the telescope would be out of focus. some other examples and uses of ULE are:

text: In his 1663 Optica Promota, James Gregory described his reflecting telescope which has come to be known by his name, the Gregorian telescope. Gregory pointed out that a reflecting telescope with a parabolic mirror would correct spherical aberration as well as the chromatic aberration seen in refracting telescopes. In his design he also placed a concave secondary mirror with an elliptical surface past the focal point of the parabolic primary mirror, reflecting the image back through a hole in the primary mirror where it could be conveniently viewed. According to his own confession, Gregory had no practical skill and he could find no optician capable of actually constructing one.

text: In his 1663 Optica Promota, James Gregory described his

text: reflecting telescope

text: which has come to be known by his name, the Gregorian telescope. Gregory pointed out that a reflecting telescope with a

text: parabolic mirror

text: would correct

text: spherical aberration

text: as well as the

text: chromatic aberration

text: seen in

text: refracting telescope

text: s. In his design he also placed a concave

text: secondary mirror

text: with an elliptical surface past the focal point of the parabolic

text: primary mirror

text: , reflecting the image back through a hole in the primary mirror where it could be conveniently viewed. According to his own confession, Gregory had no practical skill and he could find no optician capable of actually constructing one.

text: Space telescopes. Since the beginning of space exploration, telescopes have been sent to space, where they work at wavelengths shorter than UV, which are completely absorbed by the atmosphere, and where flares may be very bright. Since the 1970s, the GOES series of satellites observe the Sun in soft X-rays, and their observations became the standard measure of flares, diminishing the importance of the Hα classification. Hard X-rays were observed by many different instruments, the most important today being the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI). Nonetheless, UV observations are today the stars of solar imaging with their incredible fine details that reveal the complexity of the solar corona. Spacecraft may also bring radio detectors at extremely long wavelengths (as long as a few kilometers) that cannot propagate through the ionosphere.

text: Space telescopes. Since the beginning of

text: space exploration

text: , telescopes have been sent to space, where they work at wavelengths shorter than UV, which are completely absorbed by the atmosphere, and where flares may be very bright. Since the 1970s, the

entity_name: Geostationary Operational Environmental Satellite

text: GOES

text: series of satellites observe the Sun in soft X-rays, and their observations became the standard measure of flares, diminishing the importance of the

text: Hα

text: classification. Hard X-rays were observed by many different instruments, the most important today being the Reuven Ramaty High Energy Solar Spectroscopic Imager (

entity_name: Reuven Ramaty High Energy Solar Spectroscopic Imager

text: RHESSI

text: ). Nonetheless, UV observations are today the stars of solar imaging with their incredible fine details that reveal the complexity of the

text: solar corona

text: . Spacecraft may also bring radio detectors at extremely long wavelengths (as long as a few kilometers) that cannot propagate through the

text: ionosphere

text: The Ritchey-Chrétien is a specialized Cassegrain reflector which has two hyperbolic mirrors (instead of a parabolic primary). It is free of coma and spherical aberration at a flat focal plane, making it well suited for wide field and photographic observations. It was invented by George Willis Ritchey and Henri Chrétien in the early 1910s. This design is very common in large professional research telescopes, including the Hubble Space Telescope, Keck Telescopes and VLT telescope; it is also found in high-grade amateur telescopes.

text: The Ritchey-Chrétien is a specialized Cassegrain reflector which has two hyperbolic mirrors (instead of a parabolic primary). It is free of

text: coma

text: and spherical aberration at a flat focal plane, making it well suited for wide field and photographic observations. It was invented by

text: George Willis Ritchey

text: and

text: Henri Chrétien

text: in the early 1910s. This design is very common in large professional research telescopes, including the

text: Hubble Space Telescope

text: Keck Telescopes

text: and

text: VLT telescope

text: ; it is also found in high-grade amateur telescopes.

text: The UV Stellar Spectrometer was operated by the Astronomical Institute of Utrecht University. It consisted of a grating spectrometer attached to a  Cassegrain reflector telescope. UV measurements at 216, 255 & 286nm.

text: The

text: UV Stellar Spectrometer

text: was operated by the Astronomical Institute of

text: Utrecht University

text: . It consisted of a grating

text: spectrometer

text: attached to a

text: Cassegrain reflector

text: telescope. UV measurements at 216, 255 & 286nm.

text: The scientific instruments consisted of an ion chamber and Geiger-Müller tube to measure total radiation flux, a proportional radiation counter telescope to measure high energy radiation, a scintillation counter to monitor low-energy radiation, a VLF receiver for natural radio waves, a transponder to study electron density, and part of the flux-gate and search coil magnetometers mounted on the instrument platform. The micrometeorite detector and sun scanner were mounted on the sphere. The difference between the payload of Pioneer P-30 and the earlier Pioneer P-3 was the replacement of the TV facsimile system on P-3 with a scintillation spectrometer to study the Earth's (and possible lunar) radiation belts, mounted on the instrument platform, and a plasma probe mounted on the sphere to measure energy and momentum distribution of protons above a few kilovolts to study the radiation effect of solar flares. The total mass of the science package including electronics and power supply was roughly . Total cost of the mission was estimated at 9-10 million dollars.

text: ion chamber

text: and

text: Geiger-Müller tube

text: to measure total radiation flux, a proportional radiation counter telescope to measure high energy radiation, a

text: scintillation counter

text: to monitor low-energy radiation, a VLF receiver for natural radio waves, a transponder to study electron density, and part of the flux-gate and search coil magnetometers mounted on the instrument platform. The micrometeorite detector and sun scanner were mounted on the sphere. The difference between the payload of Pioneer P-30 and the earlier Pioneer P-3 was the replacement of the TV facsimile system on P-3 with a scintillation spectrometer to study the Earth's (and possible lunar) radiation belts, mounted on the instrument platform, and a plasma probe mounted on the sphere to measure energy and momentum distribution of protons above a few kilovolts to study the radiation effect of solar flares. The total mass of the science package including electronics and power supply was roughly . Total cost of the mission was estimated at 9-10 million dollars.

text: The world's second largest filled-aperture telescope is the Arecibo radio telescope located in Arecibo, Puerto Rico. Another stationary dish telescope like FAST, whose  dish is built into a natural depression in the landscape, the antenna is steerable within an angle of about 20° of the zenith by moving the suspended feed antenna. The largest individual radio telescope of any kind is the RATAN-600 located near Nizhny Arkhyz, Russia, which consists of a 576-meter circle of rectangular radio reflectors, each of which can be pointed towards a central conical receiver.

text: The world's second largest filled-aperture telescope is the

text: Arecibo radio telescope

text: located in

text: Arecibo, Puerto Rico

text: . Another stationary dish telescope like FAST, whose  dish is built into a natural depression in the landscape, the antenna is steerable within an angle of about 20° of the

text: zenith

text: by moving the suspended

text: feed antenna

text: . The largest individual radio telescope of any kind is the

text: located near

text: Nizhny Arkhyz

text: Russia

text: , which consists of a 576-meter circle of rectangular radio reflectors, each of which can be pointed towards a central conical receiver.

text: The following is a list of largest single mount optical telescopes sorted by total objective diameter (aperture), including segmented and multi-mirror configurations. It is a historical list, with the instruments listed in chronological succession by objective size. By itself, the diameter of the primary optics can be a poor measure of a telescope's historical or scientific significance; for example, William Parsons, 3rd Earl of Rosse's 72-inch (1.8 m) reflecting telescope did not perform as well (i.e. gather as much light) as the smaller silvered glass mirror telescopes that succeeded it because of the poor performance of its speculum metal mirror.

text: The following is a list of largest single

text: mount

text: optical telescope

text: s sorted by total

text: objective

text: diameter (aperture), including

text: segmented

text: and multi-mirror configurations. It is a historical list, with the instruments listed in chronological succession by objective size. By itself, the diameter of the primary optics can be a poor measure of a telescope's historical or scientific significance; for example,

text: William Parsons, 3rd Earl of Rosse

text: 's

text: 72-inch (1.8 m) reflecting telescope

text: did not perform as well (i.e.

text: gather as much light

text: ) as the smaller silvered glass mirror telescopes that succeeded it because of the poor performance of its

text: speculum metal

text: mirror.

text: Another way to measure the speed of light is to independently measure the frequency f and wavelength λ of an electromagnetic wave in vacuum. The value of c can then be found by using the relation c = fλ. One option is to measure the resonance frequency of a cavity resonator. If the dimensions of the resonance cavity are also known, these can be used to determine the wavelength of the wave. In 1946, Louis Essen and A.C. Gordon-Smith established the frequency for a variety of normal modes of microwaves of a microwave cavity of precisely known dimensions. The dimensions were established to an accuracy of about ±0.8 μm using gauges calibrated by interferometry. As the wavelength of the modes was known from the geometry of the cavity and from electromagnetic theory, knowledge of the associated frequencies enabled a calculation of the speed of light.

text: Another way to measure the speed of light is to independently measure the frequency f and wavelength λ of an electromagnetic wave in vacuum. The value of c can then be found by using the relation c = fλ. One option is to measure the resonance frequency of a

text: cavity resonator

text: . If the dimensions of the resonance cavity are also known, these can be used to determine the wavelength of the wave. In 1946,

text: Louis Essen

text: and A.C. Gordon-Smith established the frequency for a variety of

text: normal mode

text: s of microwaves of a

text: microwave cavity

text: of precisely known dimensions. The dimensions were established to an accuracy of about ±0.8 μm using gauges calibrated by interferometry. As the wavelength of the modes was known from the geometry of the cavity and from

text: electromagnetic theory

text: , knowledge of the associated frequencies enabled a calculation of the speed of light.

text: The ALFALFA survey is a blind extragalactic survey in neutral atomic hydrogen (HI) utilizing the ALFA at Arecibo Observatory. The telescope is not directed at preselected targets, but at one location for one night, allowing the sky to pass. This is called drift-scan. The goal is to find up to 25,000 galaxies in the course of 6–7 years. Some of the detected objects should be dark galaxies, consisting largely of dark matter and in this case hydrogen gas, but no or very few stars. These galaxies are not visible with optical telescopes and yet (March 2009) undiscovered.

text: The ALFALFA survey is a blind extragalactic survey in

text: neutral atomic hydrogen (HI)

text: utilizing the ALFA at Arecibo Observatory. The telescope is not directed at preselected targets, but at one location for one night, allowing the sky to pass. This is called drift-scan. The goal is to find up to 25,000

text: galaxies

text: in the course of 6–7 years. Some of the detected objects should be

text: dark galaxies

text: , consisting largely of

text: dark matter

text: and in this case

text: hydrogen gas

text: , but no or very few

text: star

text: s. These galaxies are not visible with

text: optical telescopes

text: and yet (March 2009) undiscovered.

text: Electronic Warfare supports any military action using electromagnetic energy to control the electromagnetic spectrum or attack an adversary

text: Until the 1940s, Bonn astronomical observations were carried out mainly from Argelander's old observatory in Bonn itself. With more and more electrical lights in the city, the night sky in town became increasingly brighter, making observations difficult. In search for an alternative location, in 1950, the hill of Hoher List above the village of Schalkenmehren was found to be well suited for astronomical observation. The rural surrounds meant very low sky brightness. It was decided to relocate the Bonn telescopes. The new observatory was inaugurated in 1954, after the 50 cm Schmidt telescope had been installed in the first dome. A major extension in 1964 included the relocation of the Double Refractor, which dates from 1899. The final dome to be erected contains a 1 m Cassegrain telescope, the largest and most modern of the observatory's telescopes. Today, there are six telescopes at the observatory. The Double Refractor aside, there is also the 16 cm Schröder Refractor, which was used for the Cordoba Durchmusterung (the southern extension of the Bonner Durchmusterung).

text: Until the 1940s, Bonn astronomical observations were carried out mainly from

text: Argelander

text: 's old observatory in Bonn itself. With more and more electrical lights in the city, the night sky in town became increasingly brighter, making observations difficult. In search for an alternative location, in 1950, the hill of

text: Hoher List

text: above the village of

text: Schalkenmehren

text: was found to be well suited for astronomical observation. The rural surrounds meant very low sky brightness. It was decided to relocate the Bonn telescopes. The new observatory was inaugurated in 1954, after the 50 cm

text: Schmidt telescope

text: had been installed in the first dome. A major extension in 1964 included the relocation of the Double

text: Refractor

text: , which dates from 1899. The final dome to be erected contains a 1 m

text: Cassegrain telescope

text: , the largest and most modern of the observatory's telescopes. Today, there are six telescopes at the observatory. The Double Refractor aside, there is also the 16 cm Schröder Refractor, which was used for the Cordoba Durchmusterung (the southern extension of the

text: Bonner Durchmusterung

text: The electromagnetic spectrum is the range of all possible electromagnetic radiation frequencies. The electromagnetic spectrum (usually just spectrum) of an object is the characteristic distribution of electromagnetic radiation emitted by, or absorbed by, that particular object.

text: The

text: electromagnetic spectrum

text: is the range of all possible electromagnetic radiation frequencies. The electromagnetic spectrum (usually just spectrum) of an object is the characteristic distribution of electromagnetic radiation emitted by, or absorbed by, that particular object.

text: Ground-based observatories, located on the surface of Earth, are used to make observations in the radio and visible light portions of the electromagnetic spectrum. Most optical telescopes are housed within a dome or similar structure, to protect the delicate instruments from the elements. Telescope domes have a slit or other opening in the roof that can be opened during observing, and closed when the telescope is not in use. In most cases, the entire upper portion of the telescope dome can be rotated to allow the instrument to observe different sections of the night sky. Radio telescopes usually do not have domes.

text: Ground-based observatories, located on the surface of Earth, are used to make observations in the

text: radio

text: and

text: visible light

text: portions of the

text: electromagnetic spectrum

text: . Most

text: optical telescope

text: s are housed within a

text: dome

text: or similar structure, to protect the delicate instruments from the elements. Telescope domes have a slit or other opening in the roof that can be opened during observing, and closed when the telescope is not in use. In most cases, the entire upper portion of the telescope dome can be rotated to allow the instrument to observe different sections of the night sky. Radio telescopes usually do not have domes.

text: Following a TV programme, lecture, and book by Patrick Moore, there was renewed interest in the six-foot telescope in the 1970s. Gradually, the telescope became a visitor attraction. But it was not before the 1990s that plans to actually rebuild the telescope came to fruition. In 1994 the retired structural engineer and amateur astronomer Michael Tubridy was called in to research and re-design the Rosse six-foot telescope. The original plans were lost, and so it took detective work to review the remains of the telescope, incidental comments in observing logs, and contemporary photographs taken by Mary Rosse, wife of the 3rd Earl. Reconstruction work lasted from early 1996 to early 1997. It had been planned to include a working mirror, but due to budget constraints this had to be left for a separate project.

text: Following a TV programme, lecture, and book by

text: Patrick Moore

text: , there was renewed interest in the six-foot telescope in the 1970s. Gradually, the telescope became a visitor attraction. But it was not before the 1990s that plans to actually rebuild the telescope came to fruition. In 1994 the retired

text: structural engineer

text: and

text: amateur astronomer

text: Michael Tubridy

text: was called in to research and re-design the Rosse six-foot telescope. The original plans were lost, and so it took detective work to review the remains of the telescope, incidental comments in observing logs, and contemporary photographs taken by

text: Mary Rosse

text: , wife of the 3rd Earl. Reconstruction work lasted from early 1996 to early 1997. It had been planned to include a working mirror, but due to budget constraints this had to be left for a separate project.

text: The 60-inch telescope is used for a variety of projects including follow-up observations for the Palomar Transient Factory and is a rapid response telescope for gamma-ray bursts.

text: The 60-inch telescope is used for a variety of projects including follow-up observations for the Palomar Transient Factory and is a rapid response telescope for

text: gamma-ray bursts

text: The KSAR Telescope's 60-foot diameter steel dome is quite large for the telescope's aperture, owing to its telescope's long f/9.8 focal ratio (favorable for very accurate optical collimation, or alignment, needed for astrometric observation). It uses a very wide 2-shutter, vertical slit. Development studies have taken place to successfully show that planned life-cycle replacement of this venerable instrument can be efficiently done within the original dome, for a future telescope with an aperture of up to 3.6-meters, by using fast, modern-day optics. However, the 61-inch telescope remains unique in its ability to operationally conduct both very high-accuracy relative astrometry to the milliarcsecond level, and close-separation, PSF photometry. Several key programs take advantage of this capability to this day.

text: The KSAR Telescope's 60-foot diameter steel dome is quite large for the telescope's aperture, owing to its telescope's long f/9.8

text: focal ratio

text: (favorable for very accurate

text: optical collimation

text: , or alignment, needed for astrometric observation). It uses a very wide 2-shutter, vertical slit. Development studies have taken place to successfully show that planned life-cycle replacement of this venerable instrument can be efficiently done within the original dome, for a future telescope with an aperture of up to 3.6-meters, by using fast, modern-day optics. However, the 61-inch telescope remains unique in its ability to operationally conduct both very high-accuracy relative astrometry to the

text: milliarcsecond

text: level, and close-separation,

text: PSF

text: photometry

text: . Several key programs take advantage of this capability to this day.

text: The two observatories consist of three domed telescopes. The Vestal street location houses research offices as well as the 17-inch Plane Wave Dall-Kirkham telescope. This telescope was installed in 2008 after the completion of the Loines Observatory. The Loines Observatory houses the historic 7.5-inch Alvan Clark refractor, which is used for public stargazing. At this location there is also the larger 24-inch Richey-Chretian reflecting telescope, installed in 2006, which has been made accessible for public tours. Both the 17-inch and the 24-inch telescopes are also used for research year round.

text: The two observatories consist of three domed

text: telescopes

text: . The Vestal street location houses research offices as well as the 17-inch Plane Wave Dall-Kirkham telescope. This telescope was installed in 2008 after the completion of the Loines Observatory. The Loines Observatory houses the historic 7.5-inch

text: Alvan Clark

text: refractor, which is used for public stargazing. At this location there is also the larger 24-inch Richey-Chretian reflecting telescope, installed in 2006, which has been made accessible for public tours. Both the 17-inch and the 24-inch telescopes are also used for research year round.

text: This unification, which was observed by Michael Faraday, extended by James Clerk Maxwell, and partially reformulated by Oliver Heaviside and Heinrich Hertz, is one of the key accomplishments of 19th century mathematical physics. It has had far-reaching consequences, one of which was the understanding of the nature of light. Unlike what was proposed by electromagnetic theory of that time, light and other electromagnetic waves are at present seen as taking the form of quantized, self-propagating oscillatory electromagnetic field disturbances called photons. Different frequencies of oscillation give rise to the different forms of electromagnetic radiation, from radio waves at the lowest frequencies, to visible light at intermediate frequencies, to gamma rays at the highest frequencies.

text: This unification, which was observed by

text: Michael Faraday

text: , extended by

text: James Clerk Maxwell

text: , and partially reformulated by

text: Oliver Heaviside

text: and

text: Heinrich Hertz

text: , is one of the key accomplishments of 19th century

text: mathematical physics

text: . It has had far-reaching consequences, one of which was the understanding of the nature of

text: light

text: . Unlike what was proposed by electromagnetic theory of that time, light and other

text: electromagnetic waves

text: are at present seen as taking the form of

text: quantized

text: , self-propagating

text: oscillatory

text: electromagnetic field disturbances called

text: photon

text: s. Different

text: frequencies

text: of oscillation give rise to the different forms of

text: electromagnetic radiation

text: , from

text: radio wave

text: s at the lowest frequencies, to visible light at intermediate frequencies, to

text: gamma ray

text: s at the highest frequencies.

text: Soundwaves are not electromagnetic radiation. At the lower end of the electromagnetic spectrum, about 20 Hz to about 20 kHz, are frequencies that might be considered in the audio range. However, electromagnetic waves cannot be directly perceived by human ears. Sound waves are instead the oscillating compression of molecules. To be heard, electromagnetic radiation must be converted to pressure waves of the fluid in which the ear is located (whether the fluid is air, water or something else).

text: Soundwaves are not electromagnetic radiation. At the lower end of the electromagnetic spectrum, about 20 Hz to about 20 kHz, are frequencies that might be considered in the audio range. However, electromagnetic waves cannot be directly perceived by human

text: ears

text: . Sound waves are instead the oscillating compression of molecules. To be heard, electromagnetic radiation must be converted to pressure waves of the fluid in which the

text: ear

text: is located (whether the fluid is air, water or something else).

text: Yerkes Observatory's  refracting telescope was built by the refracting telescope company Alvan Clark & Sons. It is the largest refracting telescope used for scientific research. (A larger demonstration refractor, the Great Paris Exhibition Telescope of 1900, was exhibited at the Paris Universal Exhibition of 1900.) The mounting and tube for the  telescope was exhibited at the 1893 World's Columbian Exposition in Chicago before being installed in the observatory. The grinding of the lens was completed later.

text: Yerkes Observatory's

text: refracting telescope

text: was built by the refracting telescope company

text: Alvan Clark & Sons

text: . It is the largest refracting telescope used for scientific research. (A larger demonstration refractor, the

entity_name: Great Paris Exhibition Telescope of 1900

text: Great Paris Exhibition Telescope of 1900

text: , was exhibited at the

text: Paris Universal Exhibition of 1900

text: .) The mounting and tube for the  telescope was exhibited at the 1893

text: World's Columbian Exposition

text: in Chicago before being installed in the observatory. The grinding of the lens was completed later.

text: At the microscale, an electromagnetic wave's phase velocity is slowed in a material because the electric field creates a disturbance in the charges of each atom (primarily the electrons) proportional to the electric susceptibility of the medium. (Similarly, the magnetic field creates a disturbance proportional to the magnetic susceptibility.) As the electromagnetic fields oscillate in the wave, the charges in the material will be "shaken" back and forth at the same frequency. The charges thus radiate their own electromagnetic wave that is at the same frequency, but usually with a phase delay, as the charges may move out of phase with the force driving them (see sinusoidally driven harmonic oscillator). The light wave traveling in the medium is the macroscopic superposition (sum) of all such contributions in the material: the original wave plus the waves radiated by all the moving charges. This wave is typically a wave with the same frequency but shorter wavelength than the original, leading to a slowing of the wave's phase velocity. Most of the radiation from oscillating material charges will modify the incoming wave, changing its velocity. However, some net energy will be radiated in other directions or even at other frequencies (see scattering).

text: At the microscale, an electromagnetic wave's phase velocity is slowed in a material because the

text: electric field

text: creates a disturbance in the charges of each atom (primarily the

text: electron

text: s) proportional to the

text: electric susceptibility

text: of the medium. (Similarly, the

text: magnetic field

text: creates a disturbance proportional to the

text: magnetic susceptibility

text: .) As the electromagnetic fields oscillate in the wave, the charges in the material will be "shaken" back and forth at the same frequency. The charges thus radiate their own electromagnetic wave that is at the same frequency, but usually with a

text: phase delay

text: , as the charges may move out of phase with the force driving them (see

text: sinusoidally driven harmonic oscillator

text: ). The light wave traveling in the medium is the macroscopic

text: superposition (sum)

text: of all such contributions in the material: the original wave plus the waves radiated by all the moving charges. This wave is typically a wave with the same frequency but shorter wavelength than the original, leading to a slowing of the wave's phase velocity. Most of the radiation from oscillating material charges will modify the incoming wave, changing its velocity. However, some net energy will be radiated in other directions or even at other frequencies (see

text: scattering

text: Coronagraphs in outer space are much more effective than the same instruments would be if located on the ground. This is because the complete absence of atmospheric scattering eliminates the largest source of glare present in a terrestrial coronagraph. Several space missions such as NASA-ESA's SOHO, and NASA's SPARTAN, Solar Maximum Mission, and Skylab have used coronagraphs to study the outer reaches of the solar corona. The Hubble Space Telescope (HST) is able to perform coronagraphy using the Near Infrared Camera and Multi-Object Spectrometer (NICMOS), and there are plans to have this capability on the James Webb Space Telescope (JWST) using its Near Infrared Camera (NIRCam) and Mid Infrared Instrument (MIRI).

text: Coronagraphs in

text: outer space

text: are much more effective than the same instruments would be if located on the ground. This is because the complete absence of atmospheric scattering eliminates the largest source of glare present in a terrestrial coronagraph. Several space missions such as

text: NASA

text: ESA

text: 's

text: SOHO

text: , and NASA's SPARTAN,

text: Solar Maximum Mission

text: , and

text: Skylab

text: have used coronagraphs to study the outer reaches of the solar corona. The

text: Hubble Space Telescope

text: (HST) is able to perform coronagraphy using the

text: (NICMOS), and there are plans to have this capability on the

text: James Webb Space Telescope

text: (JWST) using its Near Infrared Camera (

text: NIRCam

text: ) and Mid Infrared Instrument (MIRI).

text: NIRCam and MIRI feature starlight-blocking coronagraphs for observation of faint targets such as extrasolar planets and circumstellar disks very close to bright stars.

text: NIRCam and MIRI feature starlight-blocking

text: coronagraph

text: s for observation of faint targets such as

text: extrasolar planets

text: and

text: circumstellar disks

text: very close to bright stars.

text: In the field of astrophysics, the university is a member of a consortium engaged in the construction and operation of the Large Binocular Telescope in the Mount Graham International Observatory of the Pinaleno Mountains of southeastern Arizona. It is also a member of both the Astrophysical Research Consortium, which operates telescopes at Apache Point Observatory in New Mexico, and the Association of Universities for Research in Astronomy which operates the National Optical Astronomy Observatory, the Gemini Observatory and the Space Telescope Science Institute. The University of Virginia hosts the headquarters of the National Radio Astronomy Observatory, which operates the Green Bank Telescope in West Virginia and the Very Large Array radio telescope made famous in the Carl Sagan television documentary Cosmos and film Contact. The North American Atacama Large Millimeter Array Science Center is also located at the Charlottesville NRAO site.

text: In the field of

text: astrophysics

text: , the university is a member of a consortium engaged in the construction and operation of the

text: Large Binocular Telescope

text: in the

text: Mount Graham International Observatory

text: of the

text: Pinaleno Mountains

text: of southeastern

text: Arizona

text: . It is also a member of both the Astrophysical Research Consortium, which operates telescopes at

text: Apache Point Observatory

text: in

text: New Mexico

text: , and the

entity_name: Association of Universities for Research in Astronomy

text: Association of Universities for Research in Astronomy

text: which operates the

text: National Optical Astronomy Observatory

text: , the

text: Gemini Observatory

text: and the

text: Space Telescope Science Institute

text: . The University of Virginia hosts the headquarters of the

text: National Radio Astronomy Observatory

text: , which operates the

text: Green Bank Telescope

text: in

text: West Virginia

text: and the

text: Very Large Array

text: radio telescope made famous in the

text: Carl Sagan

text: television documentary

text: Cosmos

text: and film

text: Contact

text: . The North American

text: Atacama Large Millimeter Array

text: Science Center is also located at the Charlottesville NRAO site.

text: To some it may be more desirable to utilize a telescope in which case far more options for observing the Moon exist. Even a small, well-made telescope will show the observer much greater detail than is visible with the naked eye or small binoculars. As the aperture of the telescope mirror (in the case of a reflecting telescope) or lens (in the case of a refracting telescope) increases, smaller and smaller features will begin to appear. With large amateur telescopes, features as small as 0.6 miles (1 km) in diameter can be observed depending on atmospheric conditions.

text: To some it may be more desirable to utilize a telescope in which case far more options for observing the Moon exist. Even a small, well-made telescope will show the observer much greater detail than is visible with the naked eye or small binoculars. As the

text: aperture

text: of the telescope mirror (in the case of a

text: reflecting telescope

text: ) or lens (in the case of a

text: refracting telescope

text: ) increases, smaller and smaller features will begin to appear. With large amateur telescopes, features as small as 0.6 miles (1 km) in diameter can be observed depending on atmospheric conditions.

text: "Before the War, we were only a fistful. Pierre Rousseau was a modest person, almost too modest, deep, an excellent writer and an excellent popularizer. His books on astronomy are admirable! I read them avidly. To illustrate his Mars, Mysterious Earth, I think he obtained the images from the telescope of Antoniadi himself."

text: "Before the War, we were only a fistful. Pierre Rousseau was a modest person, almost too modest, deep, an excellent writer and an excellent popularizer. His books on astronomy are admirable! I read them avidly. To illustrate his Mars, Mysterious Earth, I think he obtained the images from the telescope of

text: Antoniadi

text: himself."

text: The Earth's atmosphere is opaque over most of the far-infrared, so that ground-based observations are limited to submillimetre wavelengths using high-altitude telescopes such as the James Clerk Maxwell Telescope, the Caltech Submillimeter Observatory, and the Submillimeter Array. Most far-infrared astronomy is performed by satellites such as the Herschel Space Observatory, Spitzer, IRAS, and ISO. Upper-atmosphere observations are also possible, as conducted by the airborne SOFIA telescope.

text: The Earth's atmosphere is opaque over most of the far-infrared, so that ground-based observations are limited to submillimetre wavelengths using high-altitude telescopes such as the

text: James Clerk Maxwell Telescope

text: , the

text: Caltech Submillimeter Observatory

text: , and the

text: Submillimeter Array

text: . Most far-infrared astronomy is performed by satellites such as the

text: Herschel Space Observatory

text: Spitzer

text: IRAS

text: , and

text: ISO

text: . Upper-atmosphere observations are also possible, as conducted by the airborne

text: SOFIA

text: telescope.

text: In addition to telescopes, astronomers have begun using other instruments to make observations.

text: In the order of increasing frequency or decreasing wavelength of electromagnetic waves;

text: In the order of increasing frequency or decreasing wavelength of

text: electromagnetic waves

text: In the mid 1980s, members calling themselves the "scientific faction", and warning of the evils of electromagnetic waves (which the group claimed were causing catastrophic environmental destruction and climate change) built the Pana-Wave Laboratory in Fukui Prefecture in an area they believed was less at risk from electromagnetic pollution. Members started to dress only in white in the mid 1990s, in the belief that this would protect them from harmful "scalar electromagnetic waves", which they claimed were being used against them by communists to try to kill their leader.

text: In the mid 1980s, members calling themselves the "scientific faction", and warning of the evils of

text: electromagnetic waves

text: (which the group claimed were causing catastrophic environmental destruction and climate change) built the Pana-Wave Laboratory in

text: Fukui Prefecture

text: in an area they believed was less at risk from electromagnetic pollution. Members started to dress only in white in the mid 1990s, in the belief that this would protect them from harmful "

text: scalar

text: electromagnetic waves", which they claimed were being used against them by

text: communist

text: s to try to kill their leader.

text: Because of its closeness to its star and its apparent magnitude of +11.7, the exoplanet cannot be seen in a telescope, only its gravitational effect can be detected by Doppler–Fizeau effect on its electromagnetic spectrum (radial speed method).

text: Because of its closeness to its star and its

text: apparent magnitude

text: of +11.7, the

text: exoplanet

text: cannot be seen in a

text: telescope

text: , only its gravitational effect can be detected by

text: Doppler–Fizeau effect

text: on its electromagnetic spectrum (radial speed method).

text: OMI produced the 60 cm, f/10 telescope for TUBITAK National Observatory in Turkey. OMI built the telescope mount for the SuperWASP telescope. The Robotic telescope Rigel Telescope was finished in 2002, a Talon program controlled 0.37-meter (14.5 in) F/14 telescope.

text: OMI produced the 60 cm, f/10 telescope for

text: TUBITAK National Observatory

text: in

text: Turkey

text: . OMI built the telescope mount for the

text: SuperWASP

text: telescope. The

text: Robotic telescope

text: Rigel Telescope

text: was finished in 2002, a Talon program controlled 0.37-meter (14.5 in) F/14 telescope.

text: Radio telescopes included in the ATNF:

text: Radio telescopes included in the ATNF:

text: Combining the detection in infrared by the Spitzer Space Telescope and Herschel Space Telescope with the similarities of spectrum with Pluto yielded an estimated diameter from 1,360 to 1,480 km. From the 2011 stellar occultation by Makemake, its dimensions have been initially measured to be . However, this analysis of the occultation data was later reanalyzed, which led to the dimension estimate of  without a pole-orientation constraint. This means that Makemake is slightly larger than that of , making it likely the fourth-largest known trans-Neptunian object after Pluto, , and , though the error bars with the latter overlap. Makemake was the fourth dwarf planet recognized, because it has a bright V-band absolute magnitude of −0.44. Makemake has a high geometrical albedo of .

text: Combining the detection in infrared by the

text: Spitzer Space Telescope

text: and

text: Herschel Space Telescope

text: with the similarities of spectrum with Pluto yielded an estimated diameter from 1,360 to 1,480 km. From the 2011 stellar occultation by Makemake, its dimensions have been initially measured to be . However, this analysis of the occultation data was later reanalyzed, which led to the dimension estimate of  without a pole-orientation constraint. This means that Makemake is slightly larger than that of , making it likely the fourth-largest known trans-Neptunian object after Pluto, , and , though the error bars with the latter overlap. Makemake was the fourth

text: dwarf planet

text: recognized, because it has a bright

text: V-band

text: absolute magnitude

text: of −0.44. Makemake has a high geometrical albedo of .

text: Interferometry is a technique pioneered by Albert A. Michelson in the 19th century. Optical interferometry, which has matured within the last two decades, combines the light of multiple telescopes so that precise measurements can be made, akin to what might be accomplished with a single, much larger telescope. It is the interaction of light waves, called interference, that makes this possible. Interference can be used to cancel out the glare of bright stars or to measure distances and angles accurately. The construction of the word partially illustrates this: interfere + measure = interfer-o-metry. At radio wavelengths of the electromagnetic spectrum, interferometry has been used for more than 50 years to measure the structure of distant galaxies.

text: Interferometry is a technique pioneered by

text: Albert A. Michelson

text: in the 19th century. Optical interferometry, which has matured within the last two decades, combines the light of multiple telescopes so that precise measurements can be made, akin to what might be accomplished with a single, much larger telescope. It is the interaction of

text: light wave

text: s, called

text: interference

text: , that makes this possible. Interference can be used to cancel out the glare of bright stars or to measure distances and angles accurately. The construction of the word partially illustrates this: interfere + measure = interfer-o-metry. At

text: radio wave

text: lengths of the

text: electromagnetic spectrum

text: , interferometry has been used for more than 50 years to measure the structure of distant galaxies.

text: After 1640, the Dutch continued to inform the Japanese about the evolution of telescope technology. Until 1676 more than 150 telescopes were brought to Nagasaki.  In 1831, after having spent several months in Edo where he could get accustomed with Dutch wares, Kunitomo Ikkansai (a former gun manufacturer) built Japan’s first reflecting telescope of the Gregorian type. Kunitomo’s telescope had a magnification of 60, and allowed him to make very detailed studies of sun spots and lunar topography. Four of his telescopes remain to this day.

text: After 1640, the Dutch continued to inform the Japanese about the evolution of telescope technology. Until 1676 more than 150 telescopes were brought to Nagasaki.  In 1831, after having spent several months in Edo where he could get accustomed with Dutch wares,

text: Kunitomo Ikkansai

text: (a former gun manufacturer) built Japan’s first

text: reflecting telescope

text: of the

text: Gregorian

text: type. Kunitomo’s telescope had a

text: magnification

text: of 60, and allowed him to make very detailed studies of

text: sun spot

text: s and lunar topography. Four of his telescopes remain to this day.

text: During the past century, astronomy has been revolutionized by the use of new methods for observing the universe. Astronomical observations were originally made using visible light. Galileo Galilei pioneered the use of telescopes to enhance these observations. However, visible light is only a small portion of the electromagnetic spectrum, and not all objects in the distant universe shine strongly in this particular band. More useful information may be found, for example, in radio wavelengths. Using radio telescopes, astronomers have found pulsars, quasars, and other extreme objects that push the limits of our understanding of physics. Observations in the microwave band have opened our eyes to the faint imprints of the Big Bang, a discovery Stephen Hawking called the "greatest discovery of the century, if not all time". Similar advances in observations using gamma rays, x-rays, ultraviolet light, and infrared light have also brought new insights to astronomy. As each of these regions of the spectrum has opened, new discoveries have been made that could not have been made otherwise. Astronomers hope that the same holds true of gravitational waves.

text: During the past century,

text: astronomy

text: has been revolutionized by the use of new methods for observing the universe. Astronomical observations were originally made using

text: visible light

text: Galileo Galilei

text: pioneered the use of telescopes to enhance these observations. However, visible light is only a small portion of the

text: electromagnetic spectrum

text: , and not all objects in the distant universe shine strongly in this particular band. More useful information may be found, for example, in radio wavelengths. Using

text: radio telescopes

text: , astronomers have found

text: pulsars

text: quasars

text: , and other extreme objects that push the limits of our understanding of physics. Observations in the

text: microwave

text: band have opened our eyes to the

text: faint imprints

text: of the

text: Big Bang

text: , a discovery

text: Stephen Hawking

text: called the "greatest discovery of the century, if not all time". Similar advances in observations using

text: gamma ray

text: s,

text: x-ray

text: s,

text: ultraviolet light

text: , and

text: infrared light

text: have also brought new insights to astronomy. As each of these regions of the spectrum has opened, new discoveries have been made that could not have been made otherwise. Astronomers hope that the same holds true of gravitational waves.

text: The ESO New Technology Telescope (NTT) is an Alt-Az, 3.58m Richey-Chretien telescope which pioneered the use of active optics. The telescope and its enclosure had a revolutionary design for optimal image quality. NTT saw first light in March 1989. The telescope chamber is ventilated by a system of flaps which optimize the air flow across the NTT minimizing the dome and mirror seeing. To prevent heat input to the building, all motors in the telescope are water cooled and all the electronics boxes are insulated and cooled. The primary mirror of the NTT is actively controlled to preserve its figure at all telescope positions. The secondary mirror position is also actively controlled in three directions. The optimized airflow, the thermal controls, and the active optics give the excellent image quality of the NTT. Note that the NTT has active instead of adaptive optics: it corrects the defects and deformation of the telescope and mirror, but does not correct the turbulence; it ensures that the optics is always in perfect shape. Together with the thermal control, it allows the NTT to reach the ambient seeing, but it does not improve it.

text: The ESO New Technology Telescope (NTT) is an Alt-Az, 3.58m Richey-Chretien telescope which pioneered the use of

text: active optics

text: . The telescope and its enclosure had a revolutionary design for optimal image quality. NTT saw first light in March 1989. The telescope chamber is ventilated by a system of flaps which optimize the air flow across the NTT minimizing the dome and mirror

text: seeing

text: . To prevent heat input to the building, all motors in the telescope are water cooled and all the electronics boxes are insulated and cooled. The primary mirror of the NTT is actively controlled to preserve its figure at all telescope positions. The secondary mirror position is also actively controlled in three directions. The optimized airflow, the thermal controls, and the active optics give the excellent image quality of the NTT. Note that the NTT has active instead of adaptive optics: it corrects the defects and deformation of the telescope and mirror, but does not correct the turbulence; it ensures that the optics is always in perfect shape. Together with the thermal control, it allows the NTT to reach the ambient seeing, but it does not improve it.

text: On the top of the hill, the Stockert Radio Telescope is built.

text: On the top of the hill, the

text: Stockert Radio Telescope

text: is built.

text: SWAS was designed to study the composition and structure of interstellar clouds and investigate the processes of stellar and planetary formation. Its sole instrument is a telescope operating in the submillimeter wavelengths of far infrared and microwave radiation. The telescope is composed of three main components: a  elliptical off-axis Cassegrain reflector, two Schottky diode receivers, and an acousto-optical spectrometer. The system is sensitive to frequencies between 487–557 GHz (538–616 μm), which allows it to focus on the spectral lines of molecular oxygen (O) at 487.249 GHz; neutral carbon () at 492.161 GHz; isotopic water (HO) at 548.676 GHz; isotopic carbon monoxide (CO) at 550.927 GHz; and water (HO) at 556.936 GHz.

text: SWAS was designed to study the composition and structure of

text: interstellar cloud

text: s and investigate the processes of

text: stellar and planetary formation

text: . Its sole instrument is a telescope operating in the submillimeter wavelengths of

text: far infrared

text: and

text: microwave

text: radiation. The telescope is composed of three main components: a  elliptical off-axis

text: Cassegrain reflector

text: , two

text: Schottky diode

text: receivers, and an

text: acousto-optical spectrometer

text: . The system is sensitive to frequencies between 487–557

text: GHz

text: μm

text: ), which allows it to focus on the

text: spectral line

text: s of molecular

text: oxygen

text: (O) at 487.249 GHz; neutral

text: carbon

text: () at 492.161 GHz; isotopic

text: water

text: (HO) at 548.676 GHz; isotopic

text: carbon monoxide

text: (CO) at 550.927 GHz; and water (HO) at 556.936 GHz.

text: It is hard to classify the Dobsonian Telescope as a single invention. In the field of amateur telescope making most, if not all, of its design features had been used before. John Dobson, credited as having invented this design in the 1950s, points out that "for hundreds of years, wars were fought using cannon on 'Dobsonian' mounts". Dobson himself identified the characteristic features of the design as lightweight objective mirrors made of porthole glass, and mountings constructed from plywood, Teflon strips and other low-cost materials. Since he built these telescopes as aids in his avocation of instructional sidewalk astronomy, he prefers to call the design a "sidewalk telescope". It appears that John Dobson simply combined all these innovations in a design that is focused towards one goal: building a very large, inexpensive, easy to use, portable telescope for the sole purpose of visual observing of astronomical objects as a way to bring astronomy to the masses.

text: It is hard to classify the Dobsonian Telescope as a single invention. In the field of amateur telescope making most, if not all, of its design features had been used before. John Dobson, credited as having invented this design in the 1950s, points out that "for hundreds of years, wars were fought using cannon on 'Dobsonian' mounts". Dobson himself identified the characteristic features of the design as lightweight objective mirrors made of

text: porthole glass

text: , and mountings constructed from

text: plywood

text: Teflon

text: strips and other low-cost materials. Since he built these telescopes as aids in his

text: avocation

text: of instructional

text: sidewalk astronomy

text: , he prefers to call the design a "sidewalk telescope". It appears that John Dobson simply combined all these innovations in a design that is focused towards one goal: building a very large, inexpensive, easy to use, portable telescope for the sole purpose of visual observing of astronomical objects as a way to bring astronomy to the masses.

text: Today the Mauna Kea Science Reserve has 13 observation facilities, each funded by as many as 11 countries. It is one of the world's premier observatories for optical, infrared, and submillimeter astronomy,  and in 2009 was the largest measured by light gathering power. There are nine telescopes working in the visible and infrared spectrum, three in the submillimeter spectrum, and one in the radio spectrum, with mirrors or dishes ranging from . In comparison, the Hubble Space Telescope has a  mirror, similar in size to the UH88, now the second smallest telescope on the mountain. Planned new telescopes, including the Thirty Meter Telescope, have attracted controversy due to their potential cultural and ecological impact. The multi-telescope "outrigger" extension to the Keck telescopes, which required new sites, was eventually canceled. Three or four of the mountain’s 13 existing telescopes must be dismantled over the next decade and the TMT will be the last area on Mauna Kea on which any telescope will ever be built.

text: Today the Mauna Kea Science Reserve has 13 observation facilities, each funded by as many as 11 countries. It is one of the world's premier observatories for optical, infrared, and submillimeter astronomy,  and in 2009 was the largest measured by light gathering power. There are nine telescopes working in the visible and infrared spectrum, three in the submillimeter spectrum, and one in the radio spectrum, with mirrors or dishes ranging from . In comparison, the

text: Hubble Space Telescope

text: has a  mirror, similar in size to the UH88, now the second smallest telescope on the mountain. Planned new telescopes, including the

text: Thirty Meter Telescope

text: , have attracted controversy due to their potential cultural and ecological impact. The multi-telescope "outrigger" extension to the

text: Keck telescopes

text: , which required new sites, was eventually canceled. Three or four of the mountain’s 13 existing telescopes must be dismantled over the next decade and the

text: TMT

text: will be the last area on Mauna Kea on which any telescope will ever be built.

text: Channels are available in several frequency ranges to suit the users' requirements for propagation and protection from interference. The electromagnetic spectrum between approximately 450 and 470 MHz is used largely for UHF business communications, although this spectrum is not exclusively for business use. In some large metropolitan areas, such as New York, the UHF-T band (between 470 and 512 MHz) is also used, due to congestion on the standard VHF or UHF bands. There are also a number of specific frequencies, in both the VHF and UHF spectrum, that are for business use; some of these have color-coded names, such as Blue Dot or Red Star.

text: Channels are available in several frequency ranges to suit the users' requirements for

text: propagation

text: and protection from interference. The

text: electromagnetic spectrum

text: between approximately 450 and 470

text: MHz

text: is used largely for UHF business communications, although this spectrum is not exclusively for business use. In some large metropolitan areas, such as New York, the UHF-T band (between 470 and 512 MHz) is also used, due to congestion on the standard VHF or UHF bands. There are also a number of specific frequencies, in both the VHF and UHF spectrum, that are for business use; some of these have color-coded names, such as Blue Dot or Red Star.

text: False color is used (among others) for satellite and space images: Examples are remote sensing satellites (e.g. Landsat, see example above), space telescopes (e.g. the Hubble Space Telescope) or space probes (e.g. Cassini-Huygens). Some spacecraft, with rovers (e.g. the Mars Science Laboratory "Curiosity") being the most prominent examples, have the ability to capture approximate true-color images as well. Weather satellites produce, in contrast the spacecrafts mentioned previously, grayscale images from the visible or infrared spectrum.

text: False color is used (among others) for satellite and space images: Examples are

text: remote sensing

text: satellites (e.g.

text: Landsat

text: , see example above),

text: space telescope

text: s (e.g. the

text: Hubble Space Telescope

text: ) or

text: space probe

text: s (e.g.

text: Cassini-Huygens

text: ). Some spacecraft, with

text: rovers

text: (e.g. the

text: Mars Science Laboratory

text: "Curiosity") being the most prominent examples, have the ability to capture approximate true-color images as well.

text: Weather satellite

text: s produce, in contrast the spacecrafts mentioned previously, grayscale images from the visible or infrared spectrum.

text: DFM Engineering is an American telescope and optics manufacturer. DFM Engineering was founded in 1979 by Dr. Frank Melsheimer. DFM makes medium size Cassegrain telescopes and their associated systems including telescope optics, control systems, and mounts. A range of pre-designed telescopes are made, as are various custom installations. In 2005 the base DFM 16"(40 cm) telescope system cost roughly 95 thousand USD.

text: DFM Engineering is an American

text: telescope

text: and optics manufacturer. DFM Engineering was founded in 1979 by Dr. Frank Melsheimer. DFM makes medium size

text: Cassegrain

text: telescopes and their associated systems including telescope optics, control systems, and mounts. A range of pre-designed telescopes are made, as are various custom installations. In 2005 the base DFM 16"(40 cm) telescope system cost roughly 95 thousand

text: USD

text: The ion mass spectrometers measured the concentrations of different types of ions in the topside ionosphere, principally atomic hydrogen, helium, nitrogen, and oxygen.  The concentrations were recorded as a function of time, location, and solar and geomagnetic activity.  The satellite was able to perform a global study of the diurnal variation of the atmosphere during nearly two complete diurnal cycles, since the orbit plane precessed one revolution each 5.5 months. The data from the ion mass spectrometers allowed for studies of: (1) the diurnal and seasonal variation of atmospheric ion composition, (2) the effect of atmospheric winds on the atomic hydrogen-atomic oxygen ion transition level, (3) the density and temporal variation of thermospheric atomic hydrogen, and (4) the altitude variation of ion composition in the midlatitude trough region.

text: The ion

text: mass spectrometer

text: s measured the concentrations of different types of

text: ion

text: s in the topside

text: ionosphere

text: , principally atomic

text: hydrogen

text: helium

text: nitrogen

text: , and

text: oxygen

text: .  The concentrations were recorded as a function of time, location, and

text: solar

text: and

text: geomagnetic

text: activity.  The satellite was able to perform a global study of the

text: diurnal

text: variation of the atmosphere during nearly two complete diurnal cycles, since the orbit plane

text: precessed

text: one revolution each 5.5 months. The data from the ion mass spectrometers allowed for studies of: (1) the diurnal and seasonal variation of atmospheric ion composition, (2) the effect of atmospheric winds on the atomic hydrogen-atomic oxygen ion transition level, (3) the density and temporal variation of thermospheric atomic hydrogen, and (4) the altitude variation of ion composition in the midlatitude trough region.

text: Visible light is an electromagnetic wave, consisting of oscillating electric and magnetic fields traveling through space. The frequency of the wave determines its color:  is red light,  is violet light, and between these (in the range 4-) are all the other colors of the visible spectrum. An electromagnetic wave can have a frequency less than , but it will be invisible to the human eye; such waves are called infrared (IR) radiation. At even lower frequency, the wave is called a microwave, and at still lower frequencies it is called a radio wave. Likewise, an electromagnetic wave can have a frequency higher than , but it will be invisible to the human eye; such waves are called ultraviolet (UV) radiation. Even higher-frequency waves are called X-rays, and higher still are gamma rays.

text: Visible light is an

text: electromagnetic wave

text: , consisting of oscillating

text: electric

text: and

text: magnetic field

text: s traveling through space. The frequency of the wave determines its color:  is red light,  is violet light, and between these (in the range 4-) are all the other colors of the

text: visible spectrum

text: . An electromagnetic wave can have a frequency less than , but it will be invisible to the human eye; such waves are called

text: infrared

text: (IR) radiation. At even lower frequency, the wave is called a

text: microwave

text: , and at still lower frequencies it is called a

text: radio wave

text: . Likewise, an electromagnetic wave can have a frequency higher than , but it will be invisible to the human eye; such waves are called

text: ultraviolet

text: (UV) radiation. Even higher-frequency waves are called

text: X-ray

text: s, and higher still are

text: gamma ray

text: s.

text: In "Wrath of The First Lantern", the First Lantern's origins are revealed as of being a mysterious explorer named Volthoom from a parallel world (implied to be Earth-Three), brought to Oa by Krona's first attempt to uncover the origins of the universe. Taken before the Guardians of the Universe, Volthoom was shown to be able to harness the power of the Emotional Electromagnetic Spectrum to warp reality. As they scrambled to learn everything they could about the Emotional Spectrum they also try to copy his gifts using technology until they were finally able to create the original Lantern and Ring. However, over time Volthoom grew proud and when the Guardians considered sharing the power of the lights with the rest of the universe, Volthoom disagreed. He left the Guardians and began wreaking havoc across the universe, killing millions. The Manhunters are then created to stop the rampage, but he could not be destroyed. Instead, the Guardians imprisoned the First Lantern as well as their own emotions and wrote him out of their history. A number of Oans (who kept their emotions) remained behind to ensure that the First Lantern was kept imprisoned and became known as The Hidden Ones.

text: In "

text: Wrath of The First Lantern

text: ", the First Lantern's origins are revealed as of being a mysterious explorer named Volthoom from a parallel world (implied to be Earth-Three), brought to Oa by

text: Krona

text: 's first attempt to uncover the origins of the universe. Taken before the Guardians of the Universe, Volthoom was shown to be able to harness the power of the Emotional Electromagnetic Spectrum to warp reality. As they scrambled to learn everything they could about the Emotional Spectrum they also try to copy his gifts using technology until they were finally able to create the original Lantern and Ring. However, over time Volthoom grew proud and when the Guardians considered sharing the power of the lights with the rest of the universe, Volthoom disagreed. He left the Guardians and began wreaking havoc across the universe, killing millions. The Manhunters are then created to stop the rampage, but he could not be destroyed. Instead, the Guardians imprisoned the First Lantern as well as their own emotions and wrote him out of their history. A number of Oans (who kept their emotions) remained behind to ensure that the First Lantern was kept imprisoned and became known as The Hidden Ones.

text: SAO's pioneering efforts in the development of orbiting observatories and large ground-based telescopes, the application of computers to astrophysical problems, and the integration of laboratory measurements, theoretical astrophysics, and observations across the electromagnetic spectrum have contributed much to our current understanding of the universe.

text: SAO's pioneering efforts in the development of orbiting observatories and large ground-based telescopes, the application of computers to astrophysical problems, and the integration of laboratory measurements, theoretical astrophysics, and observations across the

text: electromagnetic spectrum

text: have contributed much to our current understanding of the universe.

text: Electromagnetic waves in free space must be solutions of Maxwell's electromagnetic wave equation. Two main classes of solutions are known, namely plane waves and spherical waves. The plane waves may be viewed as the limiting case of spherical waves at a very large (ideally infinite) distance from the source.  Both types of waves can have a waveform which is an arbitrary time function (so long as it is sufficiently differentiable to conform to the wave equation).  As with any time function, this can be decomposed by means of Fourier analysis into its frequency spectrum, or individual sinusoidal components, each of which contains a single frequency, amplitude and phase. Such a component wave is said to be monochromatic.  A monochromatic electromagnetic wave can be characterized by its frequency or wavelength, its peak amplitude, its phase relative to some reference phase, its direction of propagation and its polarization.

text: Electromagnetic waves in free space must be solutions of Maxwell's

text: electromagnetic wave equation

text: . Two main classes of solutions are known, namely plane waves and spherical waves. The plane waves may be viewed as the limiting case of spherical waves at a very large (ideally infinite) distance from the source.  Both types of waves can have a waveform which is an arbitrary time function (so long as it is sufficiently differentiable to conform to the wave equation).  As with any time function, this can be decomposed by means of

text: Fourier analysis

text: into its

text: frequency spectrum

text: , or individual sinusoidal components, each of which contains a single frequency, amplitude and phase. Such a component wave is said to be monochromatic.  A monochromatic electromagnetic wave can be characterized by its frequency or wavelength, its peak amplitude, its phase relative to some reference phase, its direction of propagation and its polarization.

text: The SZA is not a single telescope, but an array of 8 telescopes operating together as an interferometer. An interferometer does not detect light in quite the same way as an ordinary telescope, by measuring the total power collected by a single dish; instead, it looks at differences between the light falling on pairs of telescopes. Like water waves, light waves can interfere with each other, producing a complex pattern of intensity enhancements where the waves constructively interfere, and nulls where they destructively interfere.

text: The SZA is not a single telescope, but an array of 8 telescopes operating together as an

text: interferometer

text: . An interferometer does not detect light in quite the same way as an ordinary telescope, by measuring the total power collected by a single dish; instead, it looks at differences between the light falling on pairs of telescopes. Like water waves, light waves can interfere with each other, producing a complex pattern of intensity enhancements where the waves constructively interfere, and nulls where they destructively interfere.

text: In 2004, the group spoke against an environmental study that came out in favor of an expansion to the Keck telescope, called outrigger.

text: The Planetarium Granny Murray's children look at stars through Mickey John's telescope.

text: The satellite was three-axis stabilized and in a near-circular orbit. It carried four instruments: a Soft X-ray Telescope (SXT), a Hard X-ray Telescope (HXT), a Bragg Crystal Spectrometer (BCS), and a Wide Band Spectrometer (WBS). About 50 MB were generated each day and this was stored on board by a 10.5 MB bubble memory recorder.

text: The satellite was three-axis stabilized and in a near-circular orbit. It carried four instruments: a Soft X-ray Telescope (SXT), a Hard X-ray Telescope (HXT), a Bragg Crystal Spectrometer (BCS), and a Wide Band Spectrometer (WBS). About 50

text: MB

text: were generated each day and this was stored on board by a 10.5 MB

text: bubble memory

text: recorder.

text: The continuing success of the OAO program encouraged increasingly strong consensus within the astronomical community that the LST should be a major goal. In 1970, NASA established two committees, one to plan the engineering side of the space telescope project, and the other to determine the scientific goals of the mission. Once these had been established, the next hurdle for NASA was to obtain funding for the instrument, which would be far more costly than any Earth-based telescope. The U.S. Congress questioned many aspects of the proposed budget for the telescope and forced cuts in the budget for the planning stages, which at the time consisted of very detailed studies of potential instruments and hardware for the telescope. In 1974, public spending cuts led to Congress deleting all funding for the telescope project.

text: The continuing success of the OAO program encouraged increasingly strong consensus within the astronomical community that the LST should be a major goal. In 1970, NASA established two committees, one to plan the engineering side of the space telescope project, and the other to determine the scientific goals of the mission. Once these had been established, the next hurdle for NASA was to obtain funding for the instrument, which would be far more costly than any Earth-based telescope. The

text: U.S. Congress

text: questioned many aspects of the proposed budget for the telescope and forced cuts in the budget for the planning stages, which at the time consisted of very detailed studies of potential instruments and hardware for the telescope. In 1974,

text: public spending

text: cuts led to Congress deleting all funding for the telescope project.

text: Researchers on the project suggested that photographs taken through a telescope at Ridge A could be nearly as good as those taken by the Hubble Space Telescope. Despite the difficult conditions on Antarctica and the remote location of Ridge A, construction costs for an observatory there that could match the Hubble telescope could be built at a fraction of the cost of sending Hubble into space.

text: Researchers on the project suggested that photographs taken through a telescope at Ridge A could be nearly as good as those taken by the

text: Hubble Space Telescope

text: . Despite the difficult conditions on Antarctica and the remote location of Ridge A, construction costs for an observatory there that could match the Hubble telescope could be built at a fraction of the cost of sending Hubble into space.

text: Darnhall is home to one of the radio telescopes that make up the Jodrell Bank MERLIN (Multi-Element Radio Linked Interferometer Network) radio telescope array linking six observing stations that together form a powerful telescope with an effective aperture of over 217 kilometres.

text: Darnhall is home to one of the radio telescopes that make up the

text: Jodrell Bank

text: MERLIN

text: (Multi-Element Radio Linked Interferometer Network)

text: radio telescope

text: array linking six observing stations that together form a powerful telescope with an effective aperture of over 217 kilometres.

text: The James Clerk Maxwell Telescope (JCMT) is a submillimetre-wavelength telescope at Mauna Kea Observatory in Hawaii. The telescope is near the summit of Mauna Kea at . Its primary mirror is 15 metres (16.4 yards) across: it is the largest single-dish telescope that operates in submillimetre wavelengths of the electromagnetic spectrum (far-infrared to microwave). Scientists use it to study the Solar System, interstellar dust and gas, and distant galaxies.

text: The James Clerk Maxwell Telescope (JCMT) is a

text: submillimetre-wavelength

text: telescope at

text: Mauna Kea Observatory

text: in

text: Hawaii

text: . The telescope is near the summit of

text: Mauna Kea

text: at . Its primary mirror is 15 metres (16.4 yards) across: it is the largest single-dish telescope that operates in submillimetre wavelengths of the electromagnetic spectrum (

text: far-infrared

text: to

text: microwave

text: ). Scientists use it to study the

text: Solar System

text: interstellar dust

text: and

text: gas

text: , and distant

text: galaxies

text: Orion sells a range of telescopes that they characterize as "beginner", "intermediate" or "advanced", including Newtonians, Maksutovs, Schmidt-Cassegrains, Ritchey-Chrétiens and refractors with or without (sold as optical tube assemblies or "OTA") a variety of mounts. Orion also sells a series of Dobsonian telescopes that come in "Classic" and "IntelliScope" versions, the latter with upgraded accessories and the ability to indicate astronomical objects to the observer aided by a computerized object database. Orion also sells Dobsonians with GoTo and tracking capabilities.

text: Orion sells a range of telescopes that they characterize as "beginner", "intermediate" or "advanced", including

text: Newtonians

text: Maksutov

text: s,

text: Schmidt-Cassegrain

text: s,

text: Ritchey-Chrétien

text: s and

text: refractor

text: s with or without (sold as optical tube assemblies or "OTA") a variety of mounts. Orion also sells a series of

text: Dobsonian telescope

text: s that come in "Classic" and "IntelliScope" versions, the latter with upgraded accessories and the ability to indicate astronomical objects to the observer aided by a computerized object database. Orion also sells Dobsonians with GoTo and tracking capabilities.

text: He has also written the young adult series "Dragons of Starlight" with four books, and the adult series "Tales of Starlight" with three books. Also, he is writing a third dragon series called "Children of the Bard".  The first installment is titled The Song of the Ovulum, and was released in July 2011.

text: Peter Theophil Riess (27 June 1804 – 22 October 1883) was a German physicist, known mostly for his work in electricity, particularly friction electricity, but also in the field of electromagnetic induction.  In the latter work he developed two devices, the spark micrometer (sometimes called the Riess micrometer) and the Riess spiral coils, both of which were used by Heinrich Hertz in his experiments to prove the propagation of electromagnetic waves.

text: Peter Theophil Riess (27 June 1804 – 22 October 1883) was a German physicist, known mostly for his work in electricity, particularly

text: friction electricity

text: , but also in the field of

text: electromagnetic induction

text: .  In the latter work he developed two devices, the

text: spark micrometer

text: (sometimes called the Riess micrometer) and the Riess spiral coils, both of which were used by

text: Heinrich Hertz

text: in his experiments to prove the propagation of

text: electromagnetic waves

text: The Hubble Space Telescope (HST) is a space telescope that was carried into orbit by a Space Shuttle in April 1990. It is named after American astronomer Edwin Hubble. Although not the first space telescope, Hubble is one of the largest and most versatile, and is well known as both a vital research tool and a public relations boon for astronomy. The HST is a collaboration between NASA and the European Space Agency, and is one of NASA's Great Observatories, along with the Compton Gamma Ray Observatory, the Chandra X-ray Observatory, and the Spitzer Space Telescope. The HST's success has paved the way for greater collaboration between the agencies.

text: The Hubble Space Telescope (HST) is a

text: space telescope

text: that was carried into

text: orbit

text: by a Space Shuttle in April 1990. It is named after American

text: astronomer

text: Edwin Hubble

text: . Although not the first space telescope, Hubble is one of the largest and most versatile, and is well known as both a vital research tool and a public relations boon for

text: astronomy

text: . The HST is a collaboration between NASA and the

text: European Space Agency

text: , and is one of NASA's

text: Great Observatories

text: , along with the

text: Compton Gamma Ray Observatory

text: , the

text: Chandra X-ray Observatory

text: , and the

text: Spitzer Space Telescope

text: . The HST's success has paved the way for greater collaboration between the agencies.

text: Sky mode is the main feature of the software. It allows users to view high quality images of outer space with images from many space and Earth-based telescopes. Each image is shown at its actual position in the sky. There are over 200 full-sky images in spectral bands ranging from radio to gamma-rays There are also thousands of individual study images of various astronomical objects from space telescopes such as the Hubble Space Telescope, the Spitzer Space Telescope in infrared, the Chandra X-ray Observatory, COBE, WMAP, ROSAT, IRAS, GALEX as well as many other space and ground based telescopes. Sky mode also shows the Sun, Moon, planets, and their moons in their current positions.

text: Sky mode is the main feature of the software. It allows users to view high quality images of outer space with images from many space and Earth-based telescopes. Each image is shown at its actual position in the sky. There are over 200 full-sky images in spectral bands ranging from

text: radio

text: to

text: gamma-rays

text: There are also thousands of individual study images of various astronomical objects from space telescopes such as the

text: Hubble Space Telescope

text: , the

text: Spitzer Space Telescope

text: in

text: infrared

text: , the

text: Chandra X-ray Observatory

text: COBE

text: WMAP

text: ROSAT

text: IRAS

text: GALEX

text: as well as many other space and ground based telescopes. Sky mode also shows the Sun, Moon, planets, and their moons in their current positions.

text: SOHO is managed by scientists from the European Space Agency (ESA) and NASA. Containing more instruments than both TRACE and Yohkoh, this large solar mission was designed to look at the chain from the solar interior, the solar corona to the solar wind. SOHO has 12 instruments on board, including the Coronal Diagnostic Spectrometer (CDS), the Extreme ultraviolet Imaging Telescope (EIT), the Solar Ultraviolet Measurements of Emitted Radiation (SUMER) and the UltraViolet Coronagraph Spectrometer (UVCS), which are all used extensively in the study of the transition region and corona.

text: SOHO is managed by scientists from the

text: European Space Agency

text: (ESA) and NASA. Containing more instruments than both TRACE and Yohkoh, this large solar mission was designed to look at the chain from the solar interior, the solar corona to the solar wind. SOHO has 12 instruments on board, including the Coronal Diagnostic Spectrometer (CDS), the Extreme ultraviolet Imaging Telescope (EIT), the Solar Ultraviolet Measurements of Emitted Radiation (SUMER) and the UltraViolet Coronagraph Spectrometer (UVCS), which are all used extensively in the study of the transition region and corona.

text: As well as using optical wavelengths, the observatory also has extensive radio astronomy capabilities. The largest radio telescope is the 4.5m R.W. Forrest telescope which is used for receiving the 21cm Hydrogen line and continuum emission. A further three 3m radio telescopes are soon to operate together as a 115 metre baseline interferometer.

text: As well as using optical wavelengths, the observatory also has extensive

text: radio astronomy

text: capabilities. The largest

text: radio telescope

text: is the 4.5m R.W. Forrest telescope which is used for receiving the

text: 21cm Hydrogen line

text: and continuum emission. A further three 3m radio telescopes are soon to operate together as a 115 metre baseline

text: interferometer

text: Apart from fossil digging, the Coon Creek Science Center offers fields and forests for hiking tours and wildlife watching as well as five ponds at which aquatic life can be studied. A telescope site is available for studies of the night sky.

text: Apart from fossil digging, the Coon Creek Science Center offers fields and forests for hiking tours and wildlife watching as well as five ponds at which aquatic life can be studied. A

text: telescope

text: site is available for studies of the night sky.

text: In June 2010, Hammel participated in the World Science Festival held in New York City, (June 2–6, 2010), along with other celebrities: Alan Alda, Michael York, (the actor), Oliver Sacks and James D. Watson. On Friday, June 4, 2010, Hammel joined professional and amateur astronomers at the base of the full-scale, tennis court-sized James Webb Space Telescope model for a free evening of star-gazing in Battery Park, New York City. Hammel talked about the discoveries anticipated in 2014 with the launching of the James Webb Space Telescope, which will be the world's most powerful space telescope, being the successor to the Hubble Space Telescope. She was joined by Dr. John C. Mather, Nobel laureate and the Webb telescope's senior project scientist; Dr. John Grunsfeld, astronaut, physicist and "chief repairman" of the Hubble Telescope.

text: In June 2010, Hammel participated in the

text: World Science Festival

text: held in

text: New York City

text: , (June 2–6, 2010), along with other celebrities:

text: Alan Alda

text: Michael York

text: , (the actor),

text: Oliver Sacks

text: and

text: James D. Watson

text: . On Friday, June 4, 2010, Hammel joined professional and amateur astronomers at the base of the full-scale, tennis court-sized

text: James Webb Space Telescope

text: model for a free evening of star-gazing in

text: Battery Park

text: , New York City. Hammel talked about the discoveries anticipated in 2014 with the launching of the

text: James Webb Space Telescope

text: , which will be the world's most powerful space telescope, being the successor to the

text: Hubble

text: Space Telescope. She was joined by Dr.

text: John C. Mather

text: Nobel laureate

text: and the Webb telescope's senior project scientist; Dr.

text: John Grunsfeld

text: , astronaut, physicist and "chief repairman" of the

text: Hubble Telescope

text: The 2.56m Nordic Optical Telescope (NOT) at the Canary Islands' Roque de los Muchachos Observatory was used to collected radial velocity measurements. The Fibre-Fed Echelle Spectrograph, or FIES, was the instrument that collected these observations between December 2008 and April 2009; also used was the CORALIE spectrograph on the Leonhard Euler Telescope at Chile's La Silla Observatory, which collected additional radial velocity and spectral measurements. Analysis of WASP-24's spectrum ruled out the possibility that WASP-24 is a rapidly rotating star, which could make confirmation of a planet difficult, or that it is a spectroscopic binary star system. Use of a span bisector analysis revealed that the star is not very active. WASP-24 was then observed using Hawaii's Faulkes Telescope North and Australia's Faulkes Telescope South, searching for a period at which the discovered planet WASP-24b might transit, or cross in front of, its star, over various days in 2009 and 2010.

text: The 2.56m

text: Nordic Optical Telescope

text: (NOT) at the Canary Islands'

text: Roque de los Muchachos Observatory

text: was used to collected

text: radial velocity

text: measurements. The

text: Fibre-Fed Echelle Spectrograph

text: , or FIES, was the instrument that collected these observations between December 2008 and April 2009; also used was the

entity_name: Swiss 1.2-metre Leonhard Euler Telescope

text: CORALIE spectrograph

text: on the

text: Leonhard Euler Telescope

text: at Chile's

text: La Silla Observatory

text: , which collected additional radial velocity and spectral measurements. Analysis of WASP-24's spectrum ruled out the possibility that WASP-24 is a rapidly rotating star, which could make confirmation of a planet difficult, or that it is a

text: spectroscopic binary

text: star system. Use of a span bisector analysis revealed that the star is not very active. WASP-24 was then observed using Hawaii's

text: Faulkes Telescope North

text: and Australia's

text: Faulkes Telescope South

text: , searching for a period at which the discovered planet

text: might

text: transit

text: , or cross in front of, its star, over various days in 2009 and 2010.

text: The ability of DES to observe cosmic shear is limited by the systematics of the telescope, the number of galaxies observed, and the intrinsic correlation between ellipse directions of galaxies. The primary systematics of the telescope are described by the point spread function of the telescope. Distortions in the point spread function caused by the mirror, optics, or geometry of the various telescope components will act to produce a false cosmic shear image. These distortions can be caused by wind, thermal contraction, misalignment, or a variety of other effects. Fortunately, most of these effects can be corrected for by actively measuring the point spread function of the telescope. The point spread function of the telescope can be measured by observing stars within our own galaxy. When the telescope observes these stars, their images ideally would be perfectly round. However, real star images have aberrations. Measuring the aberrations of point-like stars enables corrections to be applied to the images of galaxies during processing.

text: The ability of DES to observe cosmic shear is limited by the

text: systematics

text: of the telescope, the number of galaxies observed, and the intrinsic correlation between ellipse directions of galaxies. The primary systematics of the telescope are described by the

text: point spread function

text: of the telescope. Distortions in the point spread function caused by the mirror, optics, or geometry of the various telescope components will act to produce a false cosmic shear image. These distortions can be caused by wind, thermal contraction, misalignment, or a variety of other effects. Fortunately, most of these effects can be corrected for by actively measuring the point spread function of the telescope. The point spread function of the telescope can be measured by observing stars within our own galaxy. When the telescope observes these stars, their images ideally would be perfectly round. However, real star images have aberrations. Measuring the aberrations of point-like stars enables corrections to be applied to the images of galaxies during processing.

text: Nançay Radio Telescope and The Big Ear are Kraus-type telescope, and the southern section of the RATAN-600 ring can operate as a Kraus-type telescope.

text: Nançay Radio Telescope

text: and

text: The Big Ear

text: are Kraus-type telescope, and the southern section of the

text: ring can operate as a Kraus-type telescope.

text: Formally opened by the Vice-Chancellor of Cambridge University, Leszek Borysiewicz, on 7 February 2013, the museum was opened to the public on 8 February 2013. Its first exhibition dealt with the electromagnetic spectrum and principles of sound and hearing. Its target audience is families and schools, particularly children between 7 and 14 years old.

text: Formally opened by the

text: Vice-Chancellor

text: of

text: Cambridge University

text: Leszek Borysiewicz

text: , on 7 February 2013, the museum was opened to the public on 8 February 2013. Its first exhibition dealt with the

text: electromagnetic spectrum

text: and principles of

text: sound

text: and

text: hearing

text: . Its target audience is families and schools, particularly children between 7 and 14 years old.

text: The term photonic molecule has been also used since 1998 for an unrelated phenomenon involving electromagnetically-interacting optical microcavities. The properties of quantized confined photon states in optical micro- and nanocavities are very similar to those of confined electron states in atoms. Owing to this similarity, optical microcavities can be termed ‘photonic atoms’. Taking this analogy even further, a cluster of several mutually-coupled photonic atoms forms a photonic molecule. When individual photonic atoms are brought into close proximity, their optical modes interact and give rise to a spectrum of hybridized super-modes of photonic molecules.

text: Aperture Masking Interferometry is a form of speckle interferometry, that allows diffraction limited imaging from ground-based telescopes, and is a planned high contrast imaging mode on the James Webb Space Telescope. This technique allows ground based telescopes to reach the maximum possible resolution, allowing ground-based telescopes with large diameters to produce far greater resolution than does the Hubble Space Telescope. The principal limitation of the technique is that it is applicable only to relatively bright astronomical objects. A mask is placed over the telescope which only allows light through a small number of holes. This array of holes acts as a miniature astronomical interferometer. The method was developed by John E. Baldwin and collaborators in the Cavendish Astrophysics Group.

text: Aperture Masking Interferometry is a form of

text: speckle interferometry

text: , that allows

text: diffraction limited

text: imaging from ground-based

text: telescopes

text: , and is a planned high contrast imaging mode on the

text: James Webb Space Telescope

text: . This technique allows ground based telescopes to reach the maximum possible resolution, allowing ground-based telescopes with large diameters to produce far greater resolution than does the

text: Hubble Space Telescope

text: . The principal limitation of the technique is that it is applicable only to relatively bright astronomical objects. A mask is placed over the telescope which only allows light through a small number of holes. This array of holes acts as a miniature

text: astronomical interferometer

text: . The method was developed by

text: John E. Baldwin

text: and collaborators in the

text: Cavendish Astrophysics Group

text: 1932 Radio telescope

text: Radio telescope

text: The selected disk candidates will eventually become the future targets for NASA's Hubble Space Telescope and its successor, the James Webb Space Telescope. They also will be the topic for future publications in the scientific literature.

text: The selected disk candidates will eventually become the future targets for NASA's

text: Hubble Space Telescope

text: and its successor, the

text: James Webb Space Telescope

text: . They also will be the topic for future publications in the scientific literature.

text: An image of an object can be defined as a tangible or visible representation  of the features of that object. A requirement for image formation is interaction with fields of  electromagnetic radiation. Furthermore, the level of feature detail, or image resolution, is limited to a length of a wave of radiation. For example, with optical microscopy, image production and resolution depends on the length of a wave of visible light. However, with a superlens, this limitation may be removed, and a new class of image generated.

text: An image of an object can be defined as a tangible or visible representation  of the features of that object. A requirement for image formation is interaction with fields of

text: electromagnetic radiation

text: . Furthermore, the level of feature detail, or image

text: resolution

text: , is limited to a

text: length of a wave of radiation

text: . For example, with

text: optical microscopy

text: , image production and resolution depends on the length of a wave of

text: visible light

text: . However, with a superlens, this limitation may be removed, and a new class of image generated.

text: The EETT is responsible for managing numbering resources, controlling and licensing the electromagnetic spectrum in Greece as well as regulating the telecom markets having exclusive rights over the competition in the telecoms market. Thus, all issues concerning competition in the Greek telecom market are resolved by the EETT and not by the Competition Committee which is responsible for ensuring competition in the Greek market (with the exception of telecommunications market).

text: The Isaac Newton Group of Telescopes or ING operates the William Herschel Telescope, Isaac Newton Telescope and Jacobus Kapteyn Telescope optical telescopes for the Science and Technology Facilities Council (STFC), the NWO and the IAC. The telescopes are located at Roque de los Muchachos Observatory on La Palma in the Canary Islands.

text: The Isaac Newton Group of Telescopes or ING operates the

text: William Herschel Telescope

text: Isaac Newton Telescope

text: and

text: Jacobus Kapteyn Telescope

text: optical

text: telescopes

text: for the

text: (STFC), the

entity_name: Netherlands Organisation for Scientific Research

text: NWO

text: and the

text: IAC

text: . The telescopes are located at

text: Roque de los Muchachos Observatory

text: on

text: La Palma

text: in the

text: Canary Islands

text: With its high altitude, dry environment, and stable airflow, Mauna Kea's summit is one of the best sites in the world for astronomical observation. Since the creation of an access road in 1964, thirteen telescopes funded by eleven countries have been constructed at the summit. The Mauna Kea Observatories are used for scientific research across the electromagnetic spectrum from visible light to radio, and comprise the largest such facility in the world. Their construction on a "sacred landscape" continues to be a topic of debate.

text: With its high altitude, dry environment, and stable airflow, Mauna Kea's summit is one of the best sites in the world for astronomical observation. Since the creation of an access road in 1964, thirteen telescopes funded by eleven countries have been constructed at the summit. The

text: Mauna Kea Observatories

text: are used for scientific research across the

text: electromagnetic spectrum

text: from

text: visible

text: light to

text: radio

text: , and comprise the largest such facility in the world. Their construction on a "sacred landscape" continues to be a topic of debate.

text: This method is used by, among others, the Nordic Optical Telescope, the New Technology Telescope, the Telescopio Nazionale Galileo and the Keck telescopes, as well as all of the largest telescopes built in the last decade.

text: This method is used by, among others, the

text: Nordic Optical Telescope

text: , the

text: New Technology Telescope

text: , the

text: Telescopio Nazionale Galileo

text: and the

text: Keck telescope

text: s, as well as all of the largest telescopes built in the last decade.

text: Although other pre-existing telescopes such as the Nordic Optical Telescope had lightweight mirrors supported by actuators, the NTT is claimed to be the first telescope using full active optics. Its design as well as the design of its enclosure (the building protecting it) included many revolutionary features, from whence it was named. In particular, great care was taken to ensure a good ventilation of the telescope, and to avoid heat sources in around the telescope. Since its construction, the NTT has undergone several upgrades which continued to improve its quality. It was used as a real-life test bench for the engineering concepts and software used for the Very Large Telescope.

text: Although other pre-existing telescopes such as the

text: Nordic Optical Telescope

text: had lightweight mirrors supported by actuators, the NTT is claimed to be the first telescope using full active optics. Its design as well as the design of its enclosure (the building protecting it) included many revolutionary features, from whence it was named. In particular, great care was taken to ensure a good ventilation of the telescope, and to avoid heat sources in around the telescope. Since its construction, the NTT has undergone several upgrades which continued to improve its quality. It was used as a real-life test bench for the engineering concepts and software used for the

text: Very Large Telescope

text: The time T a point of the electromagnetic wave needs to cover a path between the points A and B is given by:

text: Electromagnetic radiation composed of photons that carry minimum-ionization energy, or more, (which includes the entire spectrum with shorter wavelengths), is therefore termed ionizing radiation. (Many other kinds of ionizing radiation are made of non-EM particles). Electromagnetic-type ionizing radiation extends from the extreme ultraviolet to all higher frequencies and shorter wavelengths, which means that all X-rays and gamma rays qualify. These are capable of the most severe types of molecular damage, which can happen in biology to any type of biomolecule, including mutation and cancer, and often at great depths below the skin, since the higher end of the X-ray spectrum, and all of the gamma ray spectrum, penetrate matter.

text: Electromagnetic radiation composed of photons that carry minimum-ionization energy, or more, (which includes the entire spectrum with shorter wavelengths), is therefore termed

text: ionizing radiation

text: . (Many other kinds of ionizing radiation are made of non-EM particles). Electromagnetic-type ionizing radiation extends from the extreme ultraviolet to all higher frequencies and shorter wavelengths, which means that all

text: X-rays

text: and

text: gamma rays

text: qualify. These are capable of the most severe types of molecular damage, which can happen in biology to any type of biomolecule, including mutation and cancer, and often at great depths below the skin, since the higher end of the X-ray spectrum, and all of the gamma ray spectrum, penetrate matter.

text: The three FGSs are located at 90-degree intervals around the circumference of the telescope's field of view. To achieve the very high pointing accuracy Hubble needs, the FGSs have been constructed as interferometers to exploit the wavelike features of the in-coming starlight. With this kind of accuracy and precision, the sensors can search for a wobble in the motion of nearby stars that could indicate the presence of a planetary companion, determine if certain stars really are double stars, measure the angular diameter of stars, galaxies, etc.

text: The Telescopio InfraRosso del Gornergrat (TIRGO), or the Gornergrat Infrared Telescope, is located on the northern tower of the Kulm Hotel at Gornergrat ( altitude) near Zermatt, Switzerland. It was a  Cassegrain telescope with a tip-tilt correcting secondary and optimized for infrared observations, but was decommissioned in March 2005. The telescope and related instrumentation were run by the Istituto di Radioastronomia (IRA - C.N.R.), sezione di Firenze (former CAISMI), with the assistance of the Osservatorio Astrofisico di Arcetri and the Dipartimento di Astronomia e Scienza dello Spazio of the University of Florence.

text: The Telescopio InfraRosso del Gornergrat (TIRGO), or the Gornergrat Infrared Telescope, is located on the northern tower of the

text: Kulm Hotel

text: at

text: Gornergrat

text: ( altitude) near

text: Zermatt

text: Switzerland

text: . It was a

text: Cassegrain

text: telescope

text: with a tip-tilt correcting secondary and optimized for infrared observations, but was decommissioned in March 2005. The telescope and related instrumentation were run by the Istituto di Radioastronomia (IRA - C.N.R.), sezione di Firenze (former CAISMI), with the assistance of the

text: Osservatorio Astrofisico di Arcetri

text: and the Dipartimento di Astronomia e Scienza dello Spazio of the

text: University of Florence

text: 2015: Looking Towards Our Origins. The mission of the large ESO telescopes in Chile

text: 2015: Looking Towards Our Origins. The mission of the large

text: ESO

text: telescopes in Chile

text: The 1990s saw a new generation of giant telescopes appear using active optics, beginning with the construction of the first of the two  Keck telescopes in 1993. Other giant telescopes built since then include: the two Gemini telescopes, the four separate telescopes of the Very Large Telescope, and the Large Binocular Telescope.

text: The 1990s saw a new generation of giant telescopes appear using active optics, beginning with the construction of the first of the two

text: Keck telescope

text: s in 1993. Other giant telescopes built since then include: the two

text: Gemini telescope

text: s, the four separate telescopes of the

text: Very Large Telescope

text: , and the

text: Large Binocular Telescope

text: Also in 1891, Patrick Alexander acquired an  aperture refractor telescope which was erected in Bath. The telescope was a substantial instrument, which together with its mounting, must have weighed several tons. The telescope was fully equipped for astronomical observations and Patrick was a member of the Royal Astronomical Society until 1921. Although he enjoyed showing his telescope to friends and distinguished visitors, any interest he had in astronomy was overshadowed by his other passions; the telescope was probably a scientific toy. Barry Bellinger suggests that the telescope was used to track pilot balloons released into the air, before releasing any main balloons; however, a telescope of this size and type seems unsuited to such a task.

text: Also in 1891, Patrick Alexander acquired an  aperture refractor telescope which was erected in Bath. The telescope was a substantial instrument, which together with its mounting, must have weighed several tons. The telescope was fully equipped for astronomical observations and Patrick was a member of the

text: Royal Astronomical Society

text: until 1921. Although he enjoyed showing his telescope to friends and distinguished visitors, any interest he had in astronomy was overshadowed by his other passions; the telescope was probably a scientific toy. Barry Bellinger suggests that the telescope was used to track pilot balloons released into the air, before releasing any main balloons; however, a telescope of this size and type seems unsuited to such a task.

text: Many optical telescopes are monitoring  in anticipation of another multi-day dimming event, with planned follow-up observations of a dimming event using large telescopes equipped with spectrographs to determine if the eclipsing mass is a solid object, or if composed of dust or gas. Additional follow-up observations may involve the ground-based Green Bank Telescope, the Very Large Array Radio Telescope, and future orbital telescopes dedicated to exoplanetology such as WFIRST, TESS, and PLATO.

text: Many

text: optical telescope

text: s are monitoring  in anticipation of another multi-day dimming event, with planned follow-up observations of a dimming event using large telescopes equipped with

text: spectrographs

text: to determine if the eclipsing mass is a solid object, or if composed of dust or gas. Additional follow-up observations may involve the ground-based

text: Green Bank Telescope

text: , the

text: Very Large Array Radio Telescope

text: , and future orbital telescopes dedicated to

text: exoplanetology

text: such as

text: WFIRST

text: TESS

text: , and

text: PLATO

text: By November 2014, the Wall Street Journal was reporting that Musk and Wyler were considering options for building a factory to manufacture high-volume low-cost satellites, and that "initial talks have been held with state officials in Florida and Colorado" about potentially locating a factory in those states, as well as that SpaceX would likely launch the satellites.Also in November, WorldVu issued a tender "to satellite manufacturers for 640 125-kilogram satellites", asking for responses by mid-December, having secured regulatory approval for use of the requisite electromagnetic spectrum communication frequencies in mid-2014.

text: By November 2014, the

text: Wall Street Journal

text: was reporting that Musk and Wyler were considering options for building a

text: factory

text: to manufacture high-volume low-cost satellites, and that "initial talks have been held with state officials in

text: Florida

text: and

text: Colorado

text: " about potentially locating a factory in those states, as well as that SpaceX would likely launch the satellites.Also in November, WorldVu issued a tender "to satellite manufacturers for 640 125-kilogram satellites", asking for responses by mid-December, having secured regulatory approval for use of the requisite electromagnetic spectrum communication frequencies in mid-2014.

text: An auroral chorus is a series of electromagnetic waves at frequencies which resemble chirps, whistles, and quasi-musical sounds in predominantly rising tones when played as pressure waves (sound), which are created by geomagnetic storms also responsible for the auroras.  The electromagnetic waves are a type of natural radio waves, vibrations of electric and magnetic energy occurring at the same frequency as sound.

text: An auroral chorus is a series of

text: electromagnetic wave

text: s at frequencies which resemble chirps, whistles, and quasi-musical sounds in predominantly rising tones when played as pressure waves (sound), which are created by

text: geomagnetic storm

text: s also responsible for the

text: aurora

text: s.  The electromagnetic waves are a type of

text: natural radio waves

text: , vibrations of electric and magnetic energy occurring at the same frequency as sound.

text: The satellite will carry a single instrument designed to take the most precise measurements of atmospheric carbon dioxide ever made from space. The instrument consists of three parallel, high-resolution spectrometers, integrated into a common structure and fed by a common telescope. The spectrometers will make simultaneous measurements of the carbon dioxide and molecular oxygen absorption of sunlight reflected off the same location on Earth's surface when viewed in the near-infrared part of the electromagnetic spectrum, invisible to the human eye.

text: The satellite will carry a single instrument designed to take the most precise measurements of atmospheric carbon dioxide ever made from space. The instrument consists of three parallel, high-resolution

text: spectrometer

text: s, integrated into a common structure and fed by a common

text: telescope

text: . The spectrometers will make simultaneous measurements of the carbon dioxide and

text: molecular oxygen

text: absorption of sunlight reflected off the same location on Earth's surface when viewed in the near-

text: infrared

text: part of the

text: electromagnetic spectrum

text: , invisible to the human eye.

text: According to Jonathan Bate, Shakespeare relied heavily on these sections of Ovid's Metamorphoses while composing Sonnet 60, and these passages from Ovid roughly correspond to the three quatrains of the sonnet. Shakespeare would have looked back to ancient sources like many Renaissance writers of his time. In the book Shakespeare and Ovid, Johnathan Bate states that persons of the Renaissance period "believed passionately that the present could learn from the past"  and that this belief "was the starting-point of education and a formative influence on the writing of the period". There was a strong belief in Shakespeare's day that, though times change—changes which are the result of the passing pf time—the essentials of human nature, "the foundations of the affections of the human mind,"  did not change. To look into the past, therefore, meant also for Shakespeare to look more deeply into the meaning of the present.By looking back to Book XV of Ovid's Metamorphoses, Shakespeare also gives a modern view (one that includes minutes) of an ancient view of time, one that provides a contrast to the more mechanized time of the 1590s. Time, in Ovid's work and in the first three quatrains of Sonnet 60, is intertwined with the processes of nature, looking back to a time before time and nature were fractured.  Just as the poem struggles with time, so Shakespeare's modernized use of Ovid struggles to reconcile the past view of time and the present view of time, the world as it was, and the world as it is.

text: Cima Ekar is a ridge located about 4 km east of and about 350 m higher than the Italian town of Asiago.  On the crest of this ridge sits the Asiago Astrophysical Observatory, home of a 67/92-cm Schmidt telescope and the 182-cm telescope dedicated to Nicholas Copernicus, the largest telescope in Italy.

text: Cima Ekar is a

text: ridge

text: located about 4 km east of and about 350 m higher than the

text: Italian

text: town of

text: Asiago

text: .  On the crest of this ridge sits the

text: Asiago Astrophysical Observatory

text: , home of a 67/92-cm

text: Schmidt telescope

text: and the 182-cm telescope dedicated to

text: Nicholas Copernicus

text: , the largest telescope in Italy.

text: Maxwell's contribution to science in producing these equations lies in the correction he made to Ampère's circuital law in his 1861 paper On Physical Lines of Force. He added the displacement current term to Ampère's circuital law and this enabled him to derive the electromagnetic wave equation in his later 1865 paper A Dynamical Theory of the Electromagnetic Field and to demonstrate the fact that light is an electromagnetic wave. This fact was later confirmed experimentally by Heinrich Hertz in 1887. The physicist Richard Feynman predicted that, "From a long view of the history of mankind, seen from, say, ten thousand years from now, there can be little doubt that the most significant event of the 19th century will be judged as Maxwell's discovery of the laws of electrodynamics. The American Civil War will pale into provincial insignificance in comparison with this important scientific event of the same decade."

text: Maxwell's contribution to science in producing these equations lies in the correction he made to

text: Ampère's circuital law

text: in his 1861 paper

text: On Physical Lines of Force

text: . He added the

text: displacement current

text: term to Ampère's circuital law and this enabled him to derive the

text: electromagnetic wave equation

text: in his later 1865 paper

text: and to demonstrate the fact that light is an

text: electromagnetic wave

text: . This fact was later confirmed experimentally by

text: Heinrich Hertz

text: in 1887. The physicist

text: Richard Feynman

text: predicted that, "From a long view of the history of mankind, seen from, say, ten thousand years from now, there can be little doubt that the most significant event of the 19th century will be judged as Maxwell's discovery of the laws of electrodynamics. The American Civil War will pale into provincial insignificance in comparison with this important scientific event of the same decade."

text: Telescopes that operate in the electromagnetic spectrum:

text: Telescopes that operate in the

text: electromagnetic spectrum

text: Beckers was born on 14 February 1934 in Arnhem. He studied at Utrecht University, where he obtained a PhD under Marcel Minnaert in 1964. Beckers then moved to the United States, where he obtained American nationality in 1968. He was director of the Multiple Mirror Telescope at Mount Hopkins in Arizona from 1979 to 1984. Afterwards Beckers served as head of the National New Technology Telescope (NNTT) project. Although initially enthousiastic Beckers became frustrated when the director of the National Optical Astronomy Observatory limited the scope of his project. In 1988 he started as research leader of the Interferometry Group at the Very Large Telescope of the European Southern Observatory in Chile. In 1993 Beckers moved back to the United States to become director of the National Solar Observatory, which he was between 1993 and 1998. He worked a further three years as researcher at the observatory. In 2001 Beckers started as scientist at the University of Chicago.

text: Beckers was born on 14 February 1934 in

text: Arnhem

text: . He studied at

text: Utrecht University

text: , where he obtained a PhD under

text: Marcel Minnaert

text: in 1964. Beckers then moved to the United States, where he obtained American nationality in 1968. He was director of the

text: Multiple Mirror Telescope

text: at

text: Mount Hopkins

text: in Arizona from 1979 to 1984. Afterwards Beckers served as head of the National New Technology Telescope (NNTT) project. Although initially enthousiastic Beckers became frustrated when the director of the

text: National Optical Astronomy Observatory

text: limited the scope of his project. In 1988 he started as research leader of the Interferometry Group at the

text: Very Large Telescope

text: of the

text: European Southern Observatory

text: in Chile. In 1993 Beckers moved back to the United States to become director of the

text: National Solar Observatory

text: , which he was between 1993 and 1998. He worked a further three years as researcher at the observatory. In 2001 Beckers started as scientist at the

text: University of Chicago

text: The m/45 has been manufactured under license in Egypt as the Port Said and the Akaba. The tooling needed for production, as well as technical assistance,  was sold by Sweden to Egypt during the 1950s. The Port Said looks and functions exactly as the M/45 while the Akaba is a modified and simplified version. The Akaba has no barrel jacket and a slightly shorter barrel and the folding butt stock has been replaced by a telescoping wire butt stock similar to the one used on the US M3A1 and the French MAT-49 sub machine guns. The simplified sights of the Akaba were moved to the front (unprotected post) and back (protected peep) of the receiver.

text: The m/45 has been manufactured under license in

text: Egypt

text: as the Port Said and the Akaba. The tooling needed for production, as well as technical assistance,  was sold by Sweden to Egypt during the 1950s. The Port Said looks and functions exactly as the M/45 while the Akaba is a modified and simplified version. The Akaba has no barrel jacket and a slightly shorter barrel and the folding butt stock has been replaced by a telescoping wire butt stock similar to the one used on the US

text: and the French

text: sub machine guns. The simplified sights of the Akaba were moved to the front (unprotected post) and back (protected peep) of the receiver.

text: Variable power telescopic sights with FFP reticles have no problems with point of impact shifts. Variable power telescopic sights with SFP reticles can have slight point-of-impact shifts through their magnification range, caused by the positioning of the reticle in the mechanical zoom mechanism in the rear part of the telescopic sight. Normally these impact shifts are insignificant, but accuracy-oriented users, who wish to use their telescopic sight trouble-free at several magnification levels, often opt for FFP reticles. Around the year 2005 Zeiss was the first high-end European telescopic sight manufacturer who brought out variable magnification military grade telescopic sight models with rear SFP mounted reticles. They get around impermissible impact shifts by laboriously hand-adjusting every military grade telescopic sight. The American high-end telescopic sight manufacturer U.S. Optics Inc. also offers variable magnification military grade telescopic sight models with SFP mounted reticles.

text: Variable power telescopic sights with FFP reticles have no problems with point of impact shifts. Variable power telescopic sights with SFP reticles can have slight point-of-impact shifts through their magnification range, caused by the positioning of the reticle in the mechanical zoom mechanism in the rear part of the telescopic sight. Normally these impact shifts are insignificant, but accuracy-oriented users, who wish to use their telescopic sight trouble-free at several magnification levels, often opt for FFP reticles. Around the year 2005

text: Zeiss

text: was the first high-end European telescopic sight manufacturer who brought out variable magnification military grade telescopic sight models with rear SFP mounted reticles. They get around impermissible impact shifts by laboriously hand-adjusting every military grade telescopic sight. The American high-end telescopic sight manufacturer U.S. Optics Inc. also offers variable magnification military grade telescopic sight models with SFP mounted reticles.

text: Modojo said "OK, so War Pinball looks and sounds outstanding, but how does it play? Perfect. In-game missions, smooth play and tight controls put it in a whole other league. The fact that it runs without a hitch with the ball zipping all over the place is impressive, no question. " SlideToPlay deemed it "A Must Have app for any portable pinball wizard." 148Apps said "Gameprom is back doing what they have proven themselves proficient at time and time again: making stellar pinball games. " IGN noted "The ball physics are fast, smooth, and reliable. If you fancy yourself a digital pinball wizard, grab this download. " Gamezebo said "Everything you loved about their previous effort is back, and the tables are even better than before. If you're a fan of video game pinball, it's time to soldier up; looks like you're going to war. " TouchArcade wrote "While all of Gameprom's pinball games are very good, War Pinball is definitely the cream of the crop. If you're already of fan of their previous work, this latest game is an easy purchase decision as it contains 3 fun new tables that make great use of their movie licenses. " Pocketgamer UK said "War Pinball looks and sounds fantastic, but there's still room for improvement when it comes to table design. "

text: In 1991, the primary was found to have an excess of infrared emission, implying that it has a circumstellar debris disk. Observations using the Near-Infrared Multi-Object Spectrometer aboard the Hubble Space Telescope in 2007 indicated that the dust had a reddish spectrum similar to that of tholins. The disk was resolved with the Hubble Space Telescope in 2009, confirming that it exists. Based on these images, the disk has a radius of 75 AU and a width of less than 18.5 AU. It may have some asymmetries and the center appears to be slightly offset from the star. The dust in the disk is likely the result of collisions between larger particles. In 2011, observations of the ring offset by the Subaru Telescope implies that one or more planets would likely exist within gaps tugging at its dust grains. With a new image in 2014, the configuration and alignment of the dust ring and HR4796A has been nicknamed "Eye of Sauron".

text: In 1991, the primary was found to have an

text: excess of infrared emission

text: , implying that it has a circumstellar

text: debris disk

text: . Observations using the Near-Infrared Multi-Object Spectrometer aboard the

text: Hubble Space Telescope

text: in 2007 indicated that the dust had a reddish spectrum similar to that of

text: tholin

text: s. The disk was resolved with the Hubble Space Telescope in 2009, confirming that it exists. Based on these images, the disk has a radius of 75 AU and a width of less than 18.5 AU. It may have some asymmetries and the center appears to be slightly offset from the star. The dust in the disk is likely the result of collisions between larger particles. In 2011, observations of the ring offset by the

text: Subaru Telescope

text: implies that one or more planets would likely exist within gaps tugging at its dust grains. With a new image in 2014, the configuration and alignment of the dust ring and HR4796A has been nicknamed "

text: Eye of Sauron

text: The VLT Survey Telescope (VST) is the latest telescope to be added to ESO’s Paranal Observatory in the Atacama Desert of northern Chile. It is housed in an enclosure immediately adjacent to the four Very Large Telescope (VLT) Unit Telescopes on the summit of Cerro Paranal. The VST is a wide-field survey telescope with a field of view twice as broad as the full Moon. It is the largest telescope in the world designed to exclusively survey the sky in visible light.

text: The VLT Survey Telescope (VST) is the latest telescope to be added to

text: ESO

text: ’s

text: Paranal Observatory

text: in the

text: Atacama Desert

text: of northern

text: Chile

text: . It is housed in an enclosure immediately adjacent to the four

text: Very Large Telescope

text: (VLT) Unit Telescopes on the summit of

text: Cerro Paranal

text: . The VST is a wide-field survey telescope with a field of view twice as broad as the full Moon. It is the largest telescope in the world designed to exclusively survey the sky in visible light.

text: Radio astronomy is conducted using large radio antennas referred to as radio telescopes, that are either used singularly, or with multiple linked telescopes utilizing the techniques of radio interferometry and aperture synthesis. The use of interferometry allows radio astronomy to achieve high angular resolution, as the resolving power of an interferometer is set by the distance between its components, rather than the size of its components.

text: Radio astronomy is conducted using large

text: radio antennas

text: referred to as

text: radio telescope

text: s, that are either used singularly, or with multiple linked telescopes utilizing the techniques of

text: radio interferometry

text: and

text: aperture synthesis

text: . The use of interferometry allows radio astronomy to achieve high

text: angular resolution

text: , as the resolving power of an interferometer is set by the distance between its components, rather than the size of its components.

text: Now with both of them tied up (labeled as "Two disgruntled Martians"), Bugs tries turning the ship back home. After a brief out-of-control spin, he starts to fly back, but throws out an anchor to steady the ship. The anchor then pulls on a crescent moon, which in turn pulls on Saturn's rings, a large planet (presumably Jupiter) and other assorted stars. Back on Earth, a small man in an observatory looks into his telescope, only to see the spaceship and the planets directly in front of him. The man then writes a note ("I resign! When I begin to see things like this, it's time to take up turkey farming." Signed, I. Frisby (a reference to Friz Freleng, whose caricature was indeed used for the character) and leaves. Outside, Bugs asks the man if he knows where he can sell a "slightly used flying saucer — it's only got 3 billion miles on it." The man then starts to have a mental breakdown in a goofy matter, causing Bugs with an annoyed look to ask the audience,: "Huh, what's biting him?"

text: Now with both of them tied up (labeled as "Two disgruntled Martians"), Bugs tries turning the ship back home. After a brief out-of-control spin, he starts to fly back, but throws out an

text: anchor

text: to steady the ship. The anchor then pulls on a crescent moon, which in turn pulls on

text: Saturn's rings

text: , a large planet (presumably Jupiter) and other assorted stars. Back on Earth, a small man in an observatory looks into his telescope, only to see the spaceship and the planets directly in front of him. The man then writes a note ("I resign! When I begin to see things like this, it's time to take up turkey farming." Signed, I. Frisby (a reference to

text: Friz Freleng

text: , whose caricature was indeed used for the character) and leaves. Outside, Bugs asks the man if he knows where he can sell a "slightly used flying saucer — it's only got 3 billion miles on it." The man then starts to have a mental breakdown in a goofy matter, causing Bugs with an annoyed look to ask the audience,: "Huh, what's biting him?"

text: Active optics is a technology used with reflecting telescopes developed in the 1980s, which actively shapes a telescope's mirrors to prevent deformation due to external influences  such as wind, temperature, mechanical stress. Without active optics, the construction of 8 metre class telescopes is not possible, nor would telescopes with segmented mirrors be feasible.

text: Active optics is a

text: technology

text: used with

text: reflecting telescope

text: s developed in the 1980s, which actively shapes a telescope's

text: mirror

text: s to prevent deformation due to external influences  such as wind, temperature, mechanical stress. Without active optics, the construction of 8 metre class telescopes is not possible, nor would telescopes with segmented mirrors be feasible.

text: Because the far side of the Moon is shielded from radio transmissions from the Earth, it is considered a good location for placing radio telescopes for use by astronomers. Small, bowl-shaped craters provide a natural formation for a stationary telescope similar to Arecibo in Puerto Rico. For much larger-scale telescopes, the  diameter crater Daedalus is situated near the center of the far side, and the -high rim would help to block stray communications from orbiting satellites. Another potential candidate for a radio telescope is the Saha crater.

text: Because the far side of the Moon is shielded from radio transmissions from the Earth, it is considered a good location for placing

text: radio telescope

text: s for use by

text: astronomer

text: s. Small, bowl-shaped craters provide a natural formation for a stationary

text: telescope

text: similar to

text: Arecibo

text: in

text: Puerto Rico

text: . For much larger-scale telescopes, the  diameter

text: crater Daedalus

text: is situated near the center of the far side, and the -high rim would help to block stray communications from orbiting satellites. Another potential candidate for a radio telescope is the

text: Saha crater

text: The twentieth century saw the construction of telescopes which could produce images using wavelengths other than visible light starting in 1931 when Karl Jansky discovered astronomical objects gave off radio emissions; this prompted a new era of observational astronomy after World War II, with telescopes being developed for other parts of the electromagnetic spectrum from radio to gamma-rays.

text: The twentieth century saw the construction of telescopes which could produce images using wavelengths other than

text: visible light

text: starting in 1931 when

text: Karl Jansky

text: discovered astronomical objects gave off radio emissions; this prompted a new era of observational astronomy after World War II, with telescopes being developed for other parts of the

text: electromagnetic spectrum

text: from radio to

text: gamma-rays

text: Morison joined the University of Manchester's Jodrell Bank Observatory as a research student in 1965 before becoming a staff member in 1970.  Initially working on data acquisition systems for the observatory's own instruments including the Lovell and Mk II radio telescopes, he went on to play a key role in the development of MERLIN, an array of radio telescopes with a resolution in the radio spectrum comparable to that of the Hubble Space Telescope in the optical.

text: Morison joined the

text: University of Manchester's

text: Jodrell Bank Observatory

text: as a research student in 1965 before becoming a staff member in 1970.  Initially working on data acquisition systems for the observatory's own instruments including the

text: Lovell

text: and

text: Mk II

text: radio telescopes, he went on to play a key role in the development of

text: MERLIN

text: , an array of radio telescopes with a resolution in the radio spectrum comparable to that of the

text: Hubble Space Telescope

text: in the optical.

text: In telecommunications, a carrier wave, carrier signal, or just carrier, is a waveform (usually sinusoidal) that is modulated (modified) with an  input signal for the purpose of conveying information. This carrier wave is usually a much higher frequency than the input signal.  The purpose of the carrier is usually either to transmit the information through space as an electromagnetic wave (as in radio communication), or to allow several carriers at different frequencies to share a common physical transmission medium by frequency division multiplexing (as, for example, a cable television system). The term is also used for an unmodulated emission in the absence of any modulating signal.

text: In

text: telecommunications

text: , a carrier wave, carrier signal, or just carrier, is a

text: waveform

text: (usually

text: sinusoidal

text: ) that is

text: modulated

text: (modified) with an

text: input signal

text: for the purpose of conveying information. This carrier wave is usually a much higher

text: frequency

text: than the input signal.  The purpose of the carrier is usually either to transmit the information through space as an

text: electromagnetic wave

text: (as in radio communication), or to allow several carriers at different frequencies to share a common physical transmission medium by

text: frequency division multiplexing

text: (as, for example, a

text: cable television

text: system). The term is also used for an unmodulated

text: emission

text: in the absence of any modulating signal.

text: Because solar telescopes operate during the day, seeing is generally worse than for night-time telescopes, because the ground around the telescope is heated which causes turbulence and degrades the resolution. To alleviate this, solar telescopes are usually built on towers and the structures are painted white. The Dutch Open Telescope is built on an open framework to allow the wind to pass through the complete structure and provide cooling around the telescope's main mirror.

text: Because solar telescopes operate during the day, seeing is generally worse than for night-time telescopes, because the ground around the telescope is heated which causes

text: turbulence

text: and degrades the resolution. To alleviate this, solar telescopes are usually built on towers and the structures are painted white. The

text: Dutch Open Telescope

text: is built on an open framework to allow the wind to pass through the complete structure and provide cooling around the telescope's main mirror.

text: 3 Doors Down lead singer Brad Arnold said of the song, "I think it's a song that a lot of people can identify with. There's somebody out there who needs to hear this song, and I hope they hear it. So many times, older people look at young kids and say, "Enjoy this time! It's the best time of your life," when it's really not. Being young is hard. Everything's in front of you for the first time. Those things that are in front of you seem so much bigger than they do when you're looking back on them. I'm 32 now and looking back on my teenage years and before, a lot of it doesn't seem as hard as it did then because now it's behind me and I hardly remember it. You get the responsibilities of the world as an adult. However, when you were in high school, there was nothing bigger than that test on Friday. Now, you don't even remember what test it was. It's hard to be young. The song discusses that."

text: A special type of pp-wave spacetime, the plane wave spacetimes, provide the most general analogue in general relativity of the plane waves familiar to students of electromagnetism.In particular, in general relativity, we must take into account the gravitational effects of the energy density of the electromagnetic field itself.  When we do this, purely electromagnetic plane waves provide the direct generalization of ordinary plane wave solutions in Maxwell's theory.

text: A special type of pp-wave spacetime, the

text: plane wave spacetimes

text: , provide the most general analogue in general relativity of the

text: plane waves

text: familiar to students of

text: electromagnetism

text: .In particular, in general relativity, we must take into account the gravitational effects of the energy density of the

text: electromagnetic field

text: itself.  When we do this, purely electromagnetic plane waves provide the direct generalization of ordinary plane wave solutions in

text: Maxwell's theory

text: The landers were identical to that of the previous five Venera missions and were to study the atmosphere and surface, each had instruments to study temperature, pressure, a UV spectrometer, a water concentration meter, a gas-phase chromatograph, an X-ray spectrometer, a mass spectrometer and a surface sampling device.

text: The landers were identical to that of the previous five

text: Venera

text: missions and were to study the atmosphere and surface, each had instruments to study temperature, pressure, a UV spectrometer, a water concentration meter, a

text: gas-phase chromatograph

text: , an

text: X-ray

text: spectrometer

text: , a

text: mass spectrometer

text: and a surface sampling device.

text: Other telescopes at OHP are operated by other organizations, including a 1 m telescope belonging to Geneva Observatory, a 0.5 m telescope operated by the French Space Agency for satellite tracking, and the Berlin Exoplanet Search Telescope, a 0.2 m telescope used to search for exoplanets by observing transits across solar-type stars.

text: Other telescopes at OHP are operated by other organizations, including a 1 m telescope belonging to

text: Geneva Observatory

text: , a 0.5 m telescope operated by the

text: French Space Agency

text: for satellite tracking, and the Berlin Exoplanet Search Telescope, a 0.2 m telescope used to search for

text: exoplanet

text: s by observing

text: transits

text: across solar-type stars.

text: Particularly noteworthy operations include: the James Webb Space Telescope which will try to study the history of the universe.

text: Particularly noteworthy operations include: the

text: James Webb Space Telescope

text: which will try to study the history of the universe.

text: To measure TDS, one needs a mass spectrometer, such as a quadrupole mass spectrometer or a time-of-flight (TOF) mass spectrometer, under ultrahigh vacuum (UHV) conditions. The amount of adsorbed molecules is measured by increasing the temperature at a heating rate of typically 2 K/s to 10 K/s. Several masses may be simultaneously measured by the mass spectrometer, and the intensity of each mass as a function of temperature is obtained as a TDS spectrum.

text: To measure TDS, one needs a mass spectrometer, such as a

text: quadrupole mass spectrometer

text: or a time-of-flight (TOF) mass spectrometer, under ultrahigh vacuum (UHV) conditions. The amount of adsorbed molecules is measured by increasing the temperature at a heating rate of typically 2 K/s to 10 K/s. Several masses may be simultaneously measured by the mass spectrometer, and the intensity of each mass as a function of temperature is obtained as a TDS spectrum.

text: The Brazilian Decimetric Array radio telescope is situated in Cachoeira Paulista.

text: The

text: Brazilian Decimetric Array

text: radio telescope

text: is situated in Cachoeira Paulista.

text: The telescope also tracked the Soviet moon probes, including Lunik II from 13 to 14 September 1959 as it hit the moon; this was proven by the telescope by measuring the effect of the moon's gravity on the probe, and Luna 3 around 4 October 1959. Also, the telescope tracked Luna 9 in February 1966, the first spacecraft to make a soft landing on the Moon. The telescope listened in on its facsimile transmission of photographs from the moon's surface. The photos were sent to the British press - the probe transmitted, likely intentionally to increase chances of reception, in the international format for image transmission by newswire - and published before the Soviets themselves had made the photos public.

text: The telescope also tracked the

text: Soviet

text: moon probes, including

text: Lunik II

text: from 13 to 14 September 1959 as it hit the moon; this was proven by the telescope by measuring the effect of the moon's gravity on the probe, and

text: Luna 3

text: around 4 October 1959. Also, the telescope tracked

text: Luna 9

text: in February 1966, the first spacecraft to make a soft landing on the

text: Moon

text: . The telescope listened in on its

text: facsimile

text: transmission of photographs from the moon's surface. The photos were sent to the British press - the probe transmitted, likely intentionally to increase chances of reception, in the international format for image transmission by newswire - and published before the Soviets themselves had made the photos public.

text: Reber sold his telescope to the National Bureau of Standards, and it was erected on a turntable at their field station in Sterling, Virginia. Eventually the telescope made its way to NRAO in Green Bank, West Virginia, and Reber supervised its reconstruction at that site.  Reber also helped with a reconstruction of Jansky's original telescope.

text: Reber sold his telescope to the

entity_name: National Institute of Standards and Technology

text: National Bureau of Standards

text: , and it was erected on a turntable at their field station in

text: Sterling, Virginia

text: . Eventually the telescope made its way to

text: NRAO

text: in

text: Green Bank, West Virginia

text: , and Reber supervised its reconstruction at that site.  Reber also helped with a reconstruction of Jansky's original telescope.

text: The telescopes are equipped with a suite of instruments, both cameras and spectrometers that allow observations across much of the visible and near infrared spectrum.

text: The telescopes are equipped with a suite of instruments, both

text: camera

text: s and

text: spectrometers

text: that allow observations across much of the visible and near infrared spectrum.

text: The BMW R1100RS had a frameless design, using the engine as a stressed member, an approach used by BMW for all subsequent oilheads (except the R1100S). Instead of having conventional telescopic forks, the R1100RS used BMW's own Telelever suspension which bolted directly to the engine. The Telelever design has a superficially similar appearance to telescopic forks, but braking forces are taken back horizontally, minimising "fork dive". A rear subframe supported the rider, passenger and luggage. Both fully faired and half-faired variants were available.

text: The BMW R1100RS had a frameless design, using the engine as a

text: stressed member

text: , an approach used by BMW for all subsequent oilheads (except the R1100S). Instead of having conventional

text: telescopic fork

text: s, the R1100RS used BMW's own

text: Telelever

text: suspension which bolted directly to the engine. The Telelever design has a superficially similar appearance to telescopic forks, but braking forces are taken back horizontally, minimising "fork dive". A rear

text: subframe

text: supported the rider, passenger and luggage. Both fully faired and half-faired variants were available.

text: Other than Pluto, Ixion was the first trans-Neptunian object (TNO) discovered that was originally estimated to be larger than dwarf planet Ceres, Even in 2002, a year after its discovery, Ixion was still believed to be more than 1000 km in diameter, though the 2002 estimate was a result of a spurious detection at 250 GHz that was not confirmed by later observations. More recent estimates suggest that Ixion has a high albedo and is smaller than Ceres. Observations of Ixion by Herschel Space Telescope and Spitzer Space Telescope in the far-infrared part of the spectrum revealed that its size is about 620 km.

text: Other than

text: Pluto

text: , Ixion was the first

text: trans-Neptunian object

text: (TNO) discovered that was originally estimated to be larger than

text: dwarf planet

text: Ceres

text: , Even in 2002, a year after its discovery, Ixion was still believed to be more than 1000 km in diameter, though the 2002 estimate was a result of a spurious detection at 250 GHz that was not confirmed by later observations. More recent estimates suggest that Ixion has a high albedo and is smaller than Ceres. Observations of Ixion by

text: Herschel Space Telescope

text: and

text: Spitzer Space Telescope

text: in the

text: far-infrared

text: part of the spectrum revealed that its size is about 620 km.

text: The consensus for the usage of the telescopes is to follow the NASA Astronomy and Astrophysics Decadal Survey of 2010, which lists the Wide Field Infrared Survey Telescope (WFIRST) as its highest priority. Observing in the infrared section of the electromagnetic spectrum, WFIRST will be used to study the role of dark energy in the Universe, as well as to directly image Jupiter-sized extrasolar planets.

text: The consensus for the usage of the telescopes is to follow the NASA

entity_name: Astronomy and Astrophysics Decadal Survey

text: Astronomy and Astrophysics Decadal Survey

text: of 2010, which lists the

text: Wide Field Infrared Survey Telescope

text: (WFIRST) as its highest priority. Observing in the

text: infrared

text: section of the electromagnetic spectrum, WFIRST will be used to study the role of

text: dark energy

text: in the Universe, as well as to

text: directly image

text: Jupiter-sized

text: extrasolar planet

text: s.

text: There are many properties of optical telescopes and the complexity of observation using one can be a daunting task, experience and experimentation are the major contributors to understanding how to maximize your observations. In practice, only two main properties of a telescope determine how observation differs: the focal length and aperture. These relate as to how the optical system views an object or range and how much light is gathered through an ocular eyepiece. Eyepieces further determine how the field of view and magnification of the observable world change.

text: There are many properties of optical telescopes and the complexity of observation using one can be a daunting task, experience and experimentation are the major contributors to understanding how to maximize your observations. In practice, only two main properties of a telescope determine how observation differs: the

text: focal length

text: and

text: aperture

text: . These relate as to how the optical system views an object or range and how much light is gathered through an ocular

text: eyepiece

text: Eyepiece

text: s further determine how the

text: field of view

text: and

text: magnification

text: of the observable world change.

text: The Stellar UV Radiation Experiment, operated by University College London and the University of Liège, consisted of a  ultraviolet telescope, attached to a spectrometer. It was used to study extinction and to produce a star catalogue using ultraviolet observations. UV range 135 to 255 nm.

text: The

text: Stellar UV Radiation Experiment

text: , operated by

text: University College London

text: and the

text: University of Liège

text: , consisted of a  ultraviolet telescope, attached to a

text: spectrometer

text: . It was used to study

text: extinction

text: and to produce a

text: star catalogue

text: using ultraviolet observations. UV range 135 to 255 nm.

text: |-id=307| 129307 Tomconnors ||  || Thomas Connors (b. 1959) served as a lead mechanical engineer on the OSIRIS-REx Asteroid Sample Return Mission OCAMS camera. He also worked as systems engineer on the LBTI and Kepler Technology Demonstration projects, as well as future telescope architecture studies. He is the proud grandfather of Mills and Ellie. |-id=312| 129312 Drouetdaubigny ||  || Christian Drouet d'Aubigny (b. 1972) served as the deputy instrument scientist and lead optical designer for OSIRIS-REx Asteroid Sample Return Mission OCAMS camera. He also worked on technology development for terahertz imaging radars, imaging spectrometers, and for NASA's proposed Terrestrial Planet Finder. |-id=314| 129314 Dathongolish ||  || Dathon Golish (b. 1979) was the lead image analyst on the OSIRIS-REx Asteroid Sample Return Mission OCAMS camera. He also worked on terahertz astronomical receivers for telescopes in Arizona and at the South Pole, as well as image formation software for the DARPA AWARE gigapixel camera. |-id=318| 129318 Sarahschlieder ||  || Sarah Elizabeth Schlieder (b. 1995) is a science communications specialist. She worked as a Public Affairs Specialist for the OSIRIS-REx Asteroid Sample Return Mission.|-id=321| 129321 Tannercampbell ||  || Tanner S. Campbell (b. 1991) worked on the OSIRIS-REx Asteroid Sample Return Mission as a Stereophotoclinometry Scientist and Programmer, working to test and develop the mission-critical digital terrain mapping software.|-id=324| 129324 Johnweirich ||  || John R. Weirich (b. 1979) is a researcher at the Planetary Science Institute. Currently his research focus is testing and preparing code that will be used to build a shape model of asteroid Bennu for the OSIRIS-REx Asteroid Sample Return Mission. He also conducts age dating on impact-melted meteorites.|-id=325| 129325 Jedhancock ||  || Jed Hancock (b. 1977) served as the detector assembly lead on the OSIRIS-REx Asteroid Sample Return Mission OCAMS camera. He was Civil Space Division director at the Utah State University Space Dynamics Laboratory and managed development of camera assemblies on NASA's Ionospheric Connect Explorer mission. |-id=328| 129328 Loriharrison ||  || Lori Harrison (b. 1978) worked as the Integration and Test Lead Engineer for the OSIRIS-REx Asteroid Sample Return Mission OCAMS camera. She was a Test Engineer for the Phoenix Mars Mission. She enjoys hiking, traveling, taking pictures in space and playing the bagpipes. |-id=330| 129330 Karlharshman ||  || Karl Harshman (b. 1957) served as the lead software engineer on the OCAMS camera and as the Science Processing Operations Center Manager for the OSIRIS-REx Asteroid Sample Return Mission. |-id=332| 129332 Markhunten ||  || Mark Hunten (b. 1954) worked as a senior electrical engineer on the OSIRIS-REx Asteroid Sample Return Mission OCAMS camera. He also worked on the Gemini 8-m telescopes and the MONSOON CCD and IR array controller. |-id=333| 129333 Ashleylancaster ||  || Ashley Lancaster (b. 1990) worked as a test engineer on the OSIRIS-REx Asteroid Sample Return Mission OCAMS camera. She also worked on the ATST Solar Telescope. |-id=335| 129335 Edwardlittle ||  || Edward Little (b. 1978) worked as a calibration and test engineer on the OSIRIS-REx Asteroid Sample Return Mission OCAMS camera. He is an avid amateur astronomer and optical designer. |-id=338| 129338 Andrewlowman ||  || 129338 Andrewlowman Discovered 2005 Oct. 23 by the Catalina Sky Survey. Andrew Lowman (b. 1967) worked as an optical designer on OSIRIS-REx Asteroid Sample Return Mission OCAMS camera. He also worked as an optical engineer on the Lick Automated Planet Finder, SkyMapper, the Magdalena Ridge telescopes and on the Optical Navigation Camera for the Mars Reconnaissance Orbiter.|-id=342| 129342 Ependes ||  || Ependes, Fribourg, Switzerland |}

text: 129307 Tomconnors

text: ||  || Thomas Connors (b. 1959) served as a lead mechanical engineer on the OSIRIS-REx Asteroid Sample Return Mission OCAMS camera. He also worked as systems engineer on the LBTI and Kepler Technology Demonstration projects, as well as future telescope architecture studies. He is the proud grandfather of Mills and Ellie. |-id=312|

text: 129312 Drouetdaubigny

text: ||  || Christian Drouet d'Aubigny (b. 1972) served as the deputy instrument scientist and lead optical designer for OSIRIS-REx Asteroid Sample Return Mission OCAMS camera. He also worked on technology development for terahertz imaging radars, imaging spectrometers, and for NASA's proposed Terrestrial Planet Finder. |-id=314|

text: 129314 Dathongolish

text: ||  || Dathon Golish (b. 1979) was the lead image analyst on the OSIRIS-REx Asteroid Sample Return Mission OCAMS camera. He also worked on terahertz astronomical receivers for telescopes in Arizona and at the South Pole, as well as image formation software for the DARPA AWARE gigapixel camera. |-id=318|

text: 129318 Sarahschlieder

text: ||  || Sarah Elizabeth Schlieder (b. 1995) is a science communications specialist. She worked as a Public Affairs Specialist for the OSIRIS-REx Asteroid Sample Return Mission.|-id=321|

text: 129321 Tannercampbell

text: ||  || Tanner S. Campbell (b. 1991) worked on the OSIRIS-REx Asteroid Sample Return Mission as a Stereophotoclinometry Scientist and Programmer, working to test and develop the mission-critical digital terrain mapping software.|-id=324|

text: 129324 Johnweirich

text: ||  || John R. Weirich (b. 1979) is a researcher at the Planetary Science Institute. Currently his research focus is testing and preparing code that will be used to build a shape model of asteroid Bennu for the OSIRIS-REx Asteroid Sample Return Mission. He also conducts age dating on impact-melted meteorites.|-id=325|

text: 129325 Jedhancock

text: ||  || Jed Hancock (b. 1977) served as the detector assembly lead on the OSIRIS-REx Asteroid Sample Return Mission OCAMS camera. He was Civil Space Division director at the Utah State University Space Dynamics Laboratory and managed development of camera assemblies on NASA's Ionospheric Connect Explorer mission. |-id=328|

text: 129328 Loriharrison

text: ||  || Lori Harrison (b. 1978) worked as the Integration and Test Lead Engineer for the OSIRIS-REx Asteroid Sample Return Mission OCAMS camera. She was a Test Engineer for the Phoenix Mars Mission. She enjoys hiking, traveling, taking pictures in space and playing the bagpipes. |-id=330|

text: 129330 Karlharshman

text: ||  || Karl Harshman (b. 1957) served as the lead software engineer on the OCAMS camera and as the Science Processing Operations Center Manager for the OSIRIS-REx Asteroid Sample Return Mission. |-id=332|

text: 129332 Markhunten

text: ||  || Mark Hunten (b. 1954) worked as a senior electrical engineer on the OSIRIS-REx Asteroid Sample Return Mission OCAMS camera. He also worked on the Gemini 8-m telescopes and the MONSOON CCD and IR array controller. |-id=333|

text: 129333 Ashleylancaster

text: ||  || Ashley Lancaster (b. 1990) worked as a test engineer on the OSIRIS-REx Asteroid Sample Return Mission OCAMS camera. She also worked on the ATST Solar Telescope. |-id=335|

text: 129335 Edwardlittle

text: ||  || Edward Little (b. 1978) worked as a calibration and test engineer on the OSIRIS-REx Asteroid Sample Return Mission OCAMS camera. He is an avid amateur astronomer and optical designer. |-id=338|

text: 129338 Andrewlowman

text: ||  || 129338 Andrewlowman Discovered 2005 Oct. 23 by the Catalina Sky Survey. Andrew Lowman (b. 1967) worked as an optical designer on OSIRIS-REx Asteroid Sample Return Mission OCAMS camera. He also worked as an optical engineer on the Lick Automated Planet Finder, SkyMapper, the Magdalena Ridge telescopes and on the Optical Navigation Camera for the Mars Reconnaissance Orbiter.|-id=342|

text: 129342 Ependes

text: Ependes, Fribourg

text: , Switzerland |}

text: SERENDIP (Search for Extraterrestrial Radio Emissions from Nearby Developed Intelligent Populations) is a SETI program launched in 1979 by the University of California, Berkeley. SERENDIP takes advantage of ongoing "mainstream" radio telescope observations as a "piggy-back" or "commensal" program, using large radio telescopes including the NRAO 90m telescope at Green Bank and the Arecibo 305m telescope. Rather than having its own observation program, SERENDIP analyzes deep space radio telescope data that it obtains while other astronomers are using the telescopes.

text: SERENDIP (Search for Extraterrestrial Radio Emissions from Nearby Developed Intelligent Populations) is a SETI program launched in 1979 by the

text: University of California, Berkeley

text: . SERENDIP takes advantage of ongoing "mainstream"

text: radio telescope

text: observations as a "

text: piggy-back

text: " or "

text: commensal

text: " program, using large radio telescopes including the NRAO 90m telescope at Green Bank and the

text: Arecibo 305m telescope

text: . Rather than having its own observation program, SERENDIP analyzes

text: deep space

text: radio telescope data that it obtains while other

text: astronomer

text: s are using the telescopes.

text: Her current research involves using high spatial resolution imaging techniques, such as the adaptive optics system at the Keck telescopes, to study star-forming regions and the supermassive black hole at the center of the Milky Way known as Sagittarius A*. She uses the kinematics of stars near the center of the Milky Way as a probe to investigate this region. The high resolution of the Keck telescopes gave a significant improvement over the first major study of galactic center kinematics by Reinhard Genzel's group.

text: Her current research involves using high spatial resolution imaging techniques, such as the

text: adaptive optics

text: system at the

text: Keck telescopes

text: , to study star-forming regions and the

text: supermassive black hole

text: at the center of the

text: Milky Way

text: known as

text: Sagittarius A*

text: . She uses the

text: kinematics

text: of stars near the center of the Milky Way as a probe to investigate this region. The high resolution of the Keck telescopes gave a significant improvement over the first major study of galactic center kinematics by

text: Reinhard Genzel

text: 's group.

text: List largest optical telescopes in the continental United States ranks optical telescopes located in the Continental United States by aperture.

text: List largest optical telescopes in the continental United States ranks optical telescopes located in the

text: Continental United States

text: by aperture.

text: In order to produce a high quality image, a large number of different separations between different telescopes are required (the projected separation between any two telescopes as seen from the radio source is called a baseline) - as many different baselines as possible are required in order to get a good quality image. The number of baselines (n) for an array of n telescopes is given by n=(n- n)/2.  For example the Very Large Array has 27 telescopes giving 351 independent baselines at once, and can give high quality images.

text: In order to produce a high quality image, a large number of different separations between different telescopes are required (the projected separation between any two telescopes as seen from the radio source is called a baseline) - as many different baselines as possible are required in order to get a good quality image. The number of baselines (n) for an array of n telescopes is given by n=(n- n)/2.  For example the

text: Very Large Array

text: has 27 telescopes giving 351 independent baselines at once, and can give high quality images.

text: The Molonglo Observatory Synthesis Telescope (MOST) is a radio telescope operating at 843 MHz. It is operated by the School of Physics of the University of Sydney. The telescope is located near the Molonglo River near Canberra, Australian Capital Territory, and was constructed by modification of the East-West arm of the former Molonglo Cross Telescope, a larger version of the Mills Cross Telescope.

text: The Molonglo Observatory Synthesis Telescope (MOST) is a

text: radio telescope

text: operating at 843 MHz. It is operated by the School of Physics of the

text: University of Sydney

text: . The telescope is located near the

text: Molonglo River

text: near

text: Canberra, Australian Capital Territory

text: , and was constructed by modification of the East-West arm of the former Molonglo Cross Telescope, a larger version of the

text: Mills Cross Telescope

text: matched the location of "the radio telescope at Kitt Peak". This is despite there being several radio telescopes at Kitt Peak, such as the Very Long Baseline Array, but that telescope does not match the description as given. DeBakcsy contends that the ARO 12m Radio Telescope perhaps fits the best, but it was also different in several aspects to the described object. DeBakcsy further commented that, considering this is the best example out of 653 possible other tests made at Princeton, it is quite poor. Noting the spread of meta-analyses of the same studies (where the individual studies are weighted differently), have wildly varying odds returned (from trillions to one, to indistinguishable from chance), DeBakcsy argues that this undermines the reliance on meta-analysis in the work since they lack standardization.

text: matched the location of "the

text: radio telescope at Kitt Peak

text: ". This is despite there being several radio telescopes at

text: Kitt Peak

text: , such as the

text: Very Long Baseline Array

text: , but that telescope does not match the description as given. DeBakcsy contends that the

text: ARO 12m Radio Telescope

text: perhaps fits the best, but it was also different in several aspects to the described object. DeBakcsy further commented that, considering this is the best example out of 653 possible other tests made at Princeton, it is quite poor. Noting the spread of meta-analyses of the same studies (where the individual studies are weighted differently), have wildly varying odds returned (from trillions to one, to indistinguishable from chance), DeBakcsy argues that this undermines the reliance on meta-analysis in the work since they lack standardization.

text: By focusing on super-Earth- to Neptune-sized targets orbiting cool, small, but bright stars of K and early-M spectral type, over an area considerably larger than that covered by space missions, NGTS is intended to provide prime targets for further scrutiny by telescopes such as the Very Large Telescope (VLT), European Extremely Large Telescope (E-ELT), and the James Webb Space Telescope (JWST). Such targets are more readily characterized in terms of their atmospheric composition, planetary structure, and evolution than smaller targets orbiting larger stars.

text: By focusing on super-Earth- to Neptune-sized targets orbiting cool, small, but bright stars of K and early-M spectral type, over an area considerably larger than that covered by space missions, NGTS is intended to provide prime targets for further scrutiny by telescopes such as the

text: Very Large Telescope

text: (VLT),

text: European Extremely Large Telescope

text: (E-ELT), and the

text: James Webb Space Telescope

text: (JWST). Such targets are more readily characterized in terms of their atmospheric composition, planetary structure, and evolution than smaller targets orbiting larger stars.

text: Thomson scattering is the result of a collision between a photon (an electromagnetic wave) and a charged particle, such as an electron. When an electron and photon "collide" the electron feels a Lorentz force from the oscillating electric and magnetic fields of the photon and is accelerated. This acceleration causes the electron to emit a different photon in a different direction. This emitted photon has a wavelength shifted from that of the incident photon by an amount dependent on the electron energy. Another way of looking at this is that the electron absorbs the energy of the photon and re emits the energy in the form of a different electromagnetic wave. This scattering of a photon by an electron is called Thomson Scattering.

text: Leuschner Observatory houses two optical telescopes, one with a  diameter and the other with a  diameter. As of 2010, the  telescope is not usable, and the  telescope is undergoing upgrades. The  telescope is of Ritchey-Chretien design, and is equipped with both a charge coupled device (CCD) for observations in visible light and an infrared detector that was fabricated in 2000 in order to create an infrared laboratory course for undergraduate students at UC Berkeley. Both optical telescopes are also outfitted with control systems which allow them be automated, meaning observations are made with minimal human intervention.

text: Leuschner Observatory houses two

text: optical telescope

text: s, one with a  diameter and the other with a  diameter. As of 2010, the  telescope is not usable, and the  telescope is undergoing upgrades. The  telescope is of Ritchey-Chretien design, and is equipped with both a

text: charge coupled device

text: (CCD) for observations in

text: visible light

text: and an

text: infrared

text: detector that was fabricated in 2000 in order to create an infrared laboratory course for undergraduate students at UC Berkeley. Both optical telescopes are also outfitted with control systems which allow them be automated, meaning observations are made with minimal human intervention.

text: Calls for proposals are issued roughly annually, with time allocated for a cycle lasting about one year. Proposals are divided into several categories; "general observer" proposals are the most common, covering routine observations. "Snapshot observations" are those in which targets require only 45 minutes or less of telescope time, including overheads such as acquiring the target. Snapshot observations are used to fill in gaps in the telescope schedule that cannot be filled by regular GO programs.

text: The Solar Isotope Spectrometer (SIS) provides high resolution measurements of the isotopiccomposition of energetic nuclei from He to Zn (Z = 2 to 30) over the energy range from ~10 to ~100 MeV/nucleon. During large solar events SIS measures the isotopic abundances of solar energetic particles to determine directly the composition of the solar corona and tostudy particle acceleration processes. During solar quiet times SIS measures the isotopesof low-energy cosmic rays from the Galaxy and isotopes of the anomalous cosmic ray component, which originates in the nearby interstellar medium. SIS has two telescopes composed of silicon solid-state detectors that provide measurements of the nuclear charge, mass, andkinetic energy of incident nuclei. Within each telescope, particle trajectories are measuredwith a pair of two-dimensional silicon strip detectors instrumented with custom very-large-scale integrated (VLSI) electronics to provide both position and energy-loss measurements.SIS was especially designed to achieve excellent mass resolution under the extreme, high fluxconditions encountered in large solar particle events. It provides a geometry factor of 40 cm sr, significantly greater than earlier solar particle isotope spectrometers.

text: The Solar Isotope Spectrometer (SIS) provides high resolution measurements of the isotopiccomposition of energetic nuclei from He to Zn (Z = 2 to 30) over the energy range from ~10 to ~100 MeV/nucleon. During large solar events SIS measures the isotopic abundances of

text: solar energetic particles

text: to determine directly the composition of the solar

text: corona

text: and tostudy particle acceleration processes. During solar quiet times SIS measures the isotopesof low-energy cosmic rays from the Galaxy and isotopes of the anomalous

text: cosmic ray

text: component, which originates in the nearby interstellar medium. SIS has two telescopes composed of silicon solid-state detectors that provide measurements of the nuclear charge, mass, andkinetic energy of incident nuclei. Within each telescope, particle trajectories are measuredwith a pair of two-dimensional silicon strip detectors instrumented with custom very-large-scale integrated (VLSI) electronics to provide both position and energy-loss measurements.SIS was especially designed to achieve excellent mass resolution under the extreme, high fluxconditions encountered in large solar particle events. It provides a geometry factor of 40 cm sr, significantly greater than earlier solar particle isotope spectrometers.

text: He published several articles in German-language journals, such as in the Annalen der Physik in 1872 and 1875.He published several works in the Rad journal of the Yugoslav Academy of Sciences and Arts, such as Fluorescencija i calcescencija (1871) and Iztraživanje sunčane duge (1873). In the 1871 treatise, he explains the effect of the luminescence in some elements and in the 1873 one he talks about the visible spectrum of the sun's light. In the 1871 treatise, Sekulić also predicted the existence of electromagnetic oscillations at different frequencies.

text: He published several articles in German-language journals, such as in the

text: Annalen der Physik

text: in 1872 and 1875.He published several works in the

text: Rad journal

text: of the

text: Yugoslav Academy of Sciences and Arts

text: , such as Fluorescencija i calcescencija (1871) and Iztraživanje sunčane duge (1873). In the 1871 treatise, he explains the effect of the luminescence in some elements and in the 1873 one he talks about the visible spectrum of the sun's light. In the 1871 treatise, Sekulić also predicted the existence of electromagnetic oscillations at different frequencies.

text: Fomalhaut b and three companions around HR 8799, whose discovery was announced simultaneously, were described as the first directly imaged extrasolar planets  (among earlier claims such as e.g. 2M1207 b, GQ Lup b, DH Tau b, AB Pic b, CHXR 73 b, UScoCTIO 108 b, CT Cha b, 1RXS 1609 b) in that their emission was thought to originate at least in part from a planetary atmosphere.  However, subsequent studies from the Spitzer Space Telescope and a reanalysis of the original HST datainstead suggest that Fomalhaut b's light is scattered starlight, not planet thermal emission.

text: Fomalhaut b and three companions around

text: HR 8799

text: , whose discovery was announced simultaneously, were described as the first directly imaged extrasolar planets  (among earlier claims such as e.g.

text: 2M1207 b

text: GQ Lup b

text: DH Tau b

text: AB Pic b

text: CHXR 73 b

text: UScoCTIO 108 b

text: CT Cha b

text: 1RXS 1609 b

text: ) in that their emission was thought to originate at least in part from a planetary atmosphere.  However, subsequent studies from the Spitzer Space Telescope and a reanalysis of the original HST datainstead suggest that Fomalhaut b's light is scattered starlight, not planet thermal emission.

text: Electromagnetic waves are a type of wave that originate from charged particles, are characterized by varying wavelength and are categorized along the electromagnetic spectrum. Any device that uses electricity will emit electromagnetic radiation due to the magnetic field created by charged particles moving along a medium. For example, radio waves are emitted by electricity moving along a radio transmitter, or even from a satellite.

text: Electromagnetic wave

text: s are a type of wave that originate from

text: charged particles

text: , are characterized by varying

text: wavelength

text: and are categorized along the

text: electromagnetic spectrum

text: . Any device that uses electricity will emit electromagnetic radiation due to the

text: magnetic field

text: created by charged particles moving along a

text: medium

text: . For example,

text: radio wave

text: s are emitted by

text: electricity

text: moving along a

text: radio transmitter

text: , or even from a

text: satellite

text: In a 1995 interview, Marcus said "Naturally we would have preferred that things had gone differently. But it was our wish at the time to make this type of record. For that reason the situation was perfectly OK for us. Looking back today, we would have liked to have had better advice at the time, recommending against this drastic stylistic change in our music. But things went the way they did...."

text: The seeing statistics at ORM make it the second-best location for optical and infrared astronomy in the Northern Hemisphere, after Mauna Kea Observatory, Hawaii. The site also has some of the most extensive astronomical facilities in the Northern Hemisphere; its fleet of telescopes includes the 10.4 m Gran Telescopio Canarias, the world's largest single-aperture optical telescope as of July 2009.; the William Herschel Telescope (second largest in Europe),  and the adaptive optics corrected Swedish 1-m Solar Telescope, which provides the highest resolution solar imaging of any telescope.

text: The

text: seeing

text: statistics at ORM make it the second-best location for optical and infrared astronomy in the

text: Northern Hemisphere

text: , after

text: Mauna Kea Observatory

text: Hawaii

text: . The site also has some of the most extensive astronomical facilities in the Northern Hemisphere; its fleet of telescopes includes the 10.4 m

text: Gran Telescopio Canarias

text: , the

text: world's largest single-aperture optical telescope

text: as of July 2009.; the

text: William Herschel Telescope

text: (second largest in Europe),  and the

text: adaptive optics

text: corrected

text: Swedish 1-m Solar Telescope

text: , which provides the highest resolution solar imaging of any telescope.

text: As a student at the ENS, Henri Abraham was fascinated by the pioneering experiments of Heinrich Hertz in 1888 on radio waves which confirmed the predictions of Maxwell's equations, established in 1864.  His entire scientific career was devoted to developing applications of electromagnetic theory.  In his thesis, he created a new measure of the relationship between units of electric charge used at that time in the electrostatic and the electromagnetic CGS systems of units.  The ratio of these units was equal to the speed of wave propagation c, according to Maxwell.  His work inferred a value of this speed with an uncertainty of 1/2000 that of experiments performed by the best physicists of the time.

text: As a student at the ENS, Henri Abraham was fascinated by the pioneering experiments of

text: Heinrich Hertz

text: in 1888 on

text: radio wave

text: s which confirmed the predictions of Maxwell's equations, established in 1864.  His entire scientific career was devoted to developing applications of electromagnetic theory.  In his thesis, he created a new measure of the relationship between units of

text: electric charge

text: used at that time in the electrostatic and the electromagnetic CGS systems of units.  The ratio of these units was equal to the speed of wave propagation c, according to Maxwell.  His work inferred a value of this speed with an uncertainty of 1/2000 that of experiments performed by the best physicists of the time.

text: Using radar echo measurements at the Arecibo radio telescope the rotational period of  could be determined. In this radar astronomy procedure radio waves of known wavelength are emitted from a radio telescope aimed at an asteroid. There they are reflected, and because of the Doppler effect the part of the surface that is moving towards the observer (because of the asteroid's rotation) shortens the wavelength of the reflected waves, whilst the other part which is turning away from the observer lengthens the reflected wavelength. As a result, the wavelength of the reflected waves is “smeared out”. The extent of the wavelength smearing and the diameter of the asteroid allow the rotational period to be narrowed down. 33 minutes is thus calculated as the upper limit of the rotational period for ; it probably rotates more quickly. This rapid rotation together with the small diameter and therefore low mass leads to some interesting conclusions:

text: Using radar echo measurements at the Arecibo radio telescope the rotational period of  could be determined. In this radar astronomy procedure

text: radio waves

text: of known

text: wavelength

text: are emitted from a radio telescope aimed at an asteroid. There they are reflected, and because of the

text: Doppler effect

text: the part of the surface that is moving towards the observer (because of the asteroid's rotation) shortens the wavelength of the reflected waves, whilst the other part which is turning away from the observer lengthens the reflected wavelength. As a result, the wavelength of the reflected waves is “smeared out”. The extent of the wavelength smearing and the diameter of the asteroid allow the rotational period to be narrowed down. 33 minutes is thus calculated as the upper limit of the rotational period for ; it probably rotates more quickly. This rapid rotation together with the small diameter and therefore low mass leads to some interesting conclusions:

text: CLAES was a spectrometer that determined the concentrations and distributions of nitrogen and chlorine compounds, ozone, water vapor and methane. It did this by inferring the amount of gases in the atmosphere by measuring the unique infrared signature of each gas.

text: CLAES was a

text: spectrometer

text: that determined the concentrations and distributions of

text: nitrogen

text: and

text: chlorine

text: compounds,

text: ozone

text: water vapor

text: and

text: methane

text: . It did this by inferring the amount of gases in the atmosphere by measuring the unique

text: infrared

text: signature of each gas.

text: Oracle invites Kimiyo to join the Birds of Prey (issue #100), but she was not selected to take part in the first mission. She does, however, appear in Birds of Prey #113 (January 2008), assisting Oracle by scanning the electromagnetic spectrum for any evidence that might lead her to the parties responsible for an influx of hi-tech weaponry being smuggled into Metropolis. She is, however, unable to locate any such evidence.

text: Oracle

text: invites Kimiyo to join the

text: Birds of Prey

text: (issue #100), but she was not selected to take part in the first mission. She does, however, appear in Birds of Prey #113 (January 2008), assisting Oracle by scanning the electromagnetic spectrum for any evidence that might lead her to the parties responsible for an influx of hi-tech weaponry being smuggled into Metropolis. She is, however, unable to locate any such evidence.

text: The Spectrometer/Telescope for Imaging X-rays (STIX) is one of the 10 instruments that are part of the scientific payload for the ESASolar Orbiter Mission. The STIX instrument is an X-ray imager whose purpose is to study the extremely hot solar plasma and flare-accelerated high-energy electrons accelerated. It can detect solar X-rays from 4 to 150 keV. It is currently in development for a targeted launch of Solar Orbiter in October 2018. It is being built by the University of Applied Sciences and Arts Northwestern Switzerland.

text: The Spectrometer/Telescope for Imaging X-rays (STIX) is one of the 10 instruments that are part of the scientific payload for the

text: ESA

text: Solar Orbiter Mission

text: . The STIX instrument is an X-ray imager whose purpose is to study the extremely hot solar plasma and flare-accelerated high-energy electrons accelerated. It can detect solar X-rays from 4 to 150 keV. It is currently in development for a targeted launch of Solar Orbiter in October 2018. It is being built by the

text: University of Applied Sciences and Arts Northwestern Switzerland

text: An optical telescope is a telescope that gathers and focuses light, mainly from the visible part of the electromagnetic spectrum, to create a magnified image for direct view, or to make a photograph, or to collect data through electronic image sensors.

text: An optical telescope is a

text: telescope

text: that gathers and

text: focuses

text: light, mainly from the

text: visible

text: part of the

text: electromagnetic spectrum

text: , to create a

text: magnified

text: image for direct view, or to make a

text: photograph

text: , or to collect data through electronic

text: image sensor

text: s.

text: The Hexapod-Telescope (HPT) is a telescope located at Cerro Armazones Observatory in northern Chile.  The  Ritchey-Chrétien reflecting telescope is notable for the design of telescope mount.  Instead of the typical mounting where the telescope moves on two rotating axes, the mirror end of the telescope is supported by six extensible struts, an arrangement known as a Stewart platform.  This configuration allows the telescope to move in all six spatial degrees of freedom and also provides strong structural integrity.  As a result, the ratio of bearing pressure and its own weight is very high.  Furthermore, the six-leg structure allows for a very precise positioning and repeatability.  The disadvantage of the system is that controlling and aiming a hexapod-mounted telescope is much more complex than with conventional telescope mounts.

text: The Hexapod-Telescope (HPT) is a telescope located at

text: Cerro Armazones Observatory

text: in northern

text: Chile

text: .  The

text: Ritchey-Chrétien

text: reflecting telescope

text: is notable for the design of

text: telescope mount

text: .  Instead of the typical mounting where the telescope moves on two rotating axes, the mirror end of the telescope is supported by six extensible struts, an arrangement known as a

text: Stewart platform

text: .  This configuration allows the telescope to move in all six spatial degrees of freedom and also provides strong structural integrity.  As a result, the ratio of bearing pressure and its own weight is very high.  Furthermore, the six-leg structure allows for a very precise positioning and repeatability.  The disadvantage of the system is that controlling and aiming a hexapod-mounted telescope is much more complex than with conventional telescope mounts.

text: Space telescopes were proposed as early as 1923. Hubble was funded in the 1970s, with a proposed launch in 1983, but the project was beset by technical delays, budget problems, and the Challenger disaster (1986). When finally launched in 1990, Hubble's main mirror was found to have been ground incorrectly, compromising the telescope's capabilities. The optics were corrected to their intended quality by a servicing mission in 1993.

text: Space telescopes were proposed as early as 1923. Hubble was funded in the 1970s, with a proposed launch in 1983, but the project was beset by technical delays, budget problems, and the

text: Challenger disaster

text: (1986). When finally launched in 1990, Hubble's main mirror was found to have been ground incorrectly, compromising the telescope's capabilities. The optics were corrected to their intended quality by a

text: servicing mission

text: in 1993.

text: First, the earlier theory which originated from the concept of a hypothetical medium referred as ether. Ether supposedly fills all evacuated or non evacuated spaces.  The transmission of light or of radiant heat are allowed by the propagation of electromagnetic waves in the ether. Electromagnetic waves have similar characteristics to television and radio broadcasting waves they only differ in wavelength. All electromagnetic waves travel at the same speed; therefore, shorter wavelengths are associated with high frequencies. Since every body or fluid is submerged in the ether, due to the vibration of the molecules, any body or fluid can potentially initiate an electromagnetic wave.  All bodies generate and receive electromagnetic waves at the expense of its stored energy  The second theory of radiation is best known as the quantum theory and was first offered by Max Planck in 1900. According to this theory, energy emitted by a radiator is not continuous but is in the form of quanta. Planck claimed that quantities had different sizes and frequencies of vibration similarly to the wave theory. The energy E is found by the expression E = hν, where h is the Planck's constant and ν is the frequency. Higher frequencies are originated by high temperatures and create an increase of energy in the quantum.While the propagation of electromagnetic waves of all wavelengths is often referred as "radiation," thermal radiation is often constrained to the visible and infrared regions. For engineering purposes, it may be stated that thermal radiation is a form of electromagnetic radiation which varies on the nature of a surface and its temperature. Radiation waves may travel in unusual patterns compared to conduction heat flow. Radiation allows waves to travel from a heated body through a cold nonabsorbing or partially absorbing medium and reach a warmer body again. This is the case of the radiation waves that travel from the sun to the earth.

text: First, the earlier theory which originated from the concept of a hypothetical medium referred as

text: ether

text: . Ether supposedly fills all evacuated or non evacuated spaces.  The transmission of light or of

text: radiant heat

text: are allowed by the propagation of

text: electromagnetic waves

text: in the

text: ether

text: . Electromagnetic waves have similar characteristics to

text: television

text: and

text: radio

text: broadcasting waves they only differ in

text: wavelength

text: . All

text: electromagnetic waves

text: travel at the same speed; therefore, shorter

text: wavelengths

text: are associated with high frequencies. Since every body or fluid is submerged in the ether, due to the vibration of the molecules, any body or fluid can potentially initiate an electromagnetic wave.  All bodies generate and receive electromagnetic waves at the expense of its stored energy  The second theory of radiation is best known as the quantum theory and was first offered by Max Planck in 1900. According to this theory, energy emitted by a radiator is not continuous but is in the form of quanta. Planck claimed that quantities had different sizes and frequencies of vibration similarly to the wave theory. The energy E is found by the expression E = hν, where h is the Planck's constant and ν is the frequency. Higher frequencies are originated by high temperatures and create an increase of energy in the quantum.While the propagation of electromagnetic waves of all wavelengths is often referred as "radiation," thermal radiation is often constrained to the visible and infrared regions. For engineering purposes, it may be stated that thermal radiation is a form of electromagnetic radiation which varies on the nature of a surface and its temperature. Radiation waves may travel in unusual patterns compared to conduction

text: heat flow

text: . Radiation allows waves to travel from a heated body through a cold nonabsorbing or partially absorbing medium and reach a warmer body again. This is the case of the radiation waves that travel from the sun to the earth.

text: Planet Cb was first announced by the European Southern Observatory's HARPS group on 19 October 2009. The announcement was made together with 29 other planets, while Cc was first mentioned by the same group in a pre-print made public on 21 November 2011. Announcement of a refereed journal report came on 2 February 2012 by researchers at the University of Göttingen/Carnegie Institution for Science. In this announcement, GJ 667 Cc was described as one of the best candidates yet found to harbor liquid water, and thus, potentially, support life on its surface. A detailed orbital analysis and refined orbital parameters for Gliese 667 Cc were presented. Based on GJ 667 C's bolometric luminosity, GJ 667 Cc would receive 90% of the light Earth does, however much of that electromagnetic radiation would be in the invisible infrared light part of the spectrum. Based on black body temperature calculation, GJ 667 Cc should absorb more overall electromagnetic radiation, making it warmer (277.4 K) and placing it slightly closer to the "hot" edge of the habitable zone than Earth (254.3 K).

text: Planet Cb was first announced by the

text: European Southern Observatory's

text: HARPS

text: group on 19 October 2009. The announcement was made together with 29 other planets, while Cc was first mentioned by the same group in a pre-print made public on 21 November 2011. Announcement of a refereed journal report came on 2 February 2012 by researchers at the

text: University of Göttingen

text: Carnegie Institution for Science

text: . In this announcement, GJ 667 Cc was described as one of the

entity_name: List of potentially habitable exoplanets

text: best candidates

text: yet found to harbor liquid water, and thus, potentially, support life on its surface. A detailed orbital analysis and refined orbital parameters for Gliese 667 Cc were presented. Based on GJ 667 C's bolometric luminosity, GJ 667 Cc would receive 90% of the

text: light

text: Earth does, however much of that

text: electromagnetic radiation

text: would be in the invisible infrared light part of the spectrum. Based on black body temperature calculation, GJ 667 Cc should absorb more overall electromagnetic radiation, making it warmer (277.4 K) and placing it slightly closer to the "hot" edge of the

text: habitable zone

text: than Earth (254.3 K).

text: In astronomy, interferometry is used to combine signals from two or more telescopes to obtain measurements with higher resolution than could be obtained with either telescopes individually.  This technique is the basis for astronomical interferometer arrays, which can make measurements of very small astronomical objects if the telescopes are spread out over a wide area. If a large number of telescopes are used a picture can be produced which has resolution similar to a single telescope with the diameter of the combined spread of telescopes. These include radio telescope arrays such as VLA, VLBI, SMA, LOFAR and SKA, and more recently  astronomical optical interferometer arrays such as COAST, NPOI and IOTA, resulting in the highest resolution optical images ever achieved in astronomy. The VLT Interferometer is expected to produce its first images using aperture synthesis soon, followed by other interferometers such as the CHARA array and the Magdalena Ridge Observatory Interferometer which may consist of up to 10 optical telescopes. If outrigger telescopes are built at the Keck Interferometer, it will also become capable of interferometric imaging.

text: In

text: astronomy

text: interferometry

text: is used to combine signals from two or more

text: telescope

text: s to obtain measurements with higher resolution than could be obtained with either telescopes individually.  This technique is the basis for astronomical interferometer arrays, which can make measurements of very small astronomical objects if the telescopes are spread out over a wide area. If a large number of telescopes are used a picture can be produced which has

text: resolution

text: similar to a single telescope with the diameter of the combined spread of

text: telescopes

text: . These include

text: radio telescope

text: arrays such as

text: VLA

text: VLBI

text: SMA

text: LOFAR

text: and

text: SKA

text: , and more recently

text: astronomical optical interferometer arrays

text: such as

text: COAST

text: NPOI

text: and

text: IOTA

text: , resulting in the highest resolution optical images ever achieved in astronomy. The

text: VLT Interferometer

text: is expected to produce its first images using

text: aperture synthesis

text: soon, followed by other interferometers such as the

text: CHARA array

text: and the

text: Magdalena Ridge Observatory Interferometer

text: which may consist of up to 10 optical telescopes. If outrigger telescopes are built at the

text: Keck Interferometer

text: , it will also become capable of interferometric imaging.

text: These telescopes will take advantage of the low background and the long Antarctic nights to provide high-accuracy photometric time series for finding extrasolar planets, and to observe wide fields in the infra-red to look for new supernovae.

text: These telescopes will take advantage of the low background and the long Antarctic nights to provide high-accuracy photometric time series for finding

text: extrasolar planets

text: , and to observe wide fields in the infra-red to look for new

text: supernovae

text: The desire for a large infrared space telescope traces back decades; in the United State's the  Shuttle Infrared Telescope Facility was planned while the Space Shuttle was in development and the potential for infrared astronomy was acknowledged at that time. Compared to ground telescopes, space observatories were free from atmospheric absorption of infrared light: it would be a whole "new sky" for astronomers.

text: JWST's primary mirror is a 6.5-meter-diameter gold-coated beryllium reflector with a collecting area of 25 m.  This is too large for existing launch vehicles, so the mirror is composed of 18 hexagonal segments, which will unfold after the telescope is launched. Image plane wavefront sensing through phase retrieval will be used to position the mirror segments in the correct location using very precise micro-motors.  Subsequent to this initial configuration they will only need occasional updates every few days to retain optimal focus. This is unlike terrestrial telescopes like the Keck which continually adjust their mirror segments using active optics to overcome the effects of gravitational and wind loading, and is made possible because of the lack of environmental disturbances of a telescope in space.

text: JWST's

text: primary mirror

text: is a 6.5-meter-diameter gold-coated

text: beryllium

text: reflector with a collecting area of 25 m.  This is too large for existing launch vehicles, so the mirror is composed of 18

text: hexagon

text: al segments, which will unfold after the telescope is launched. Image plane

entity_section: Wavefront sensor and reconstruction techniques

text: wavefront sensing

text: through

text: phase retrieval

text: will be used to position the

text: mirror segment

text: s in the correct location using very precise micro-motors.  Subsequent to this initial configuration they will only need occasional updates every few days to retain optimal focus. This is unlike terrestrial telescopes like the

text: Keck

text: which continually adjust their mirror segments using

text: active optics

text: to overcome the effects of gravitational and wind loading, and is made possible because of the lack of environmental disturbances of a telescope in space.

text: The C. Donald Shane telescope is a 120-inch (3.0-meter) reflecting telescope located at the Lick Observatory in San Jose, California. It was named after astronomer C. Donald Shane in 1978, who led the effort to acquire the necessary funds from the California Legislature, and who then oversaw the telescope's construction. It is the largest and most powerful telescope at the Lick Observatory, and was the second-largest telescope in the world when it was commissioned in 1959.

text: The C. Donald Shane telescope is a 120-inch (3.0-meter)

text: reflecting telescope

text: located at the

text: Lick Observatory

text: in

text: San Jose

text: California

text: . It was named after astronomer

text: C. Donald Shane

text: in 1978, who led the effort to acquire the necessary funds from the

text: California Legislature

text: , and who then oversaw the telescope's construction. It is the largest and most powerful telescope at the Lick Observatory, and was the second-largest telescope in the world when it was commissioned in 1959.

text: Created by VisionCare Ophthalmic Technologies in conjunction with the CentraSight Treatment Program, the telescope is about the size of a pea and is implanted behind the iris of one eye. Images are projected onto healthy areas of the central retina, outside the degenerated macula, and is enlarged to reduce the effect the blind spot has on central vision. 2.2x or 2.7x magnification strengths make it possible to see or discern the central vision object of interest while the other eye is used for peripheral vision because the eye that has the implant will have limited peripheral vision as a side effect. Unlike a telescope which would be hand-held, the implant moves with the eye which is the main advantage. Patients using the device may however still need glasses for optimal vision and for close work. Before surgery, patients should first try out a hand-held telescope to see if they would benefit from image enlargement. One of the main drawbacks is that it cannot be used for patients who have had cataract surgery as the intraocular lens would obstruct insertion of the telescope. It also requires a large incision in the cornea to insert.

text: Created by VisionCare Ophthalmic Technologies in conjunction with the CentraSight Treatment Program, the telescope is about the size of a pea and is implanted behind the

text: iris

text: of one eye. Images are projected onto healthy areas of the central retina, outside the degenerated

text: macula

text: , and is enlarged to reduce the effect the blind spot has on central vision. 2.2x or 2.7x magnification strengths make it possible to see or discern the central vision object of interest while the other eye is used for peripheral vision because the eye that has the implant will have limited peripheral vision as a side effect. Unlike a telescope which would be hand-held, the implant moves with the eye which is the main advantage. Patients using the device may however still need glasses for optimal vision and for close work. Before surgery, patients should first try out a hand-held telescope to see if they would benefit from image enlargement. One of the main drawbacks is that it cannot be used for patients who have had

text: cataract surgery

text: as the

text: intraocular lens

text: would obstruct insertion of the telescope. It also requires a large incision in the

text: cornea

text: to insert.

text: The Richard B. Dunn Solar Telescope is a unique vertical-axis solar telescope, located at the National Solar Observatory at Sacramento Peak, New Mexico.  The optical path starts at a heliostat on top of a  tower and continues 193 feet (58.8 m) more underground to the primary mirror.  It then returns to one of six quartz optical windows in the floor of an optical laboratory at ground level.  The optics are evacuated to eliminate distortion due to convection in the telescope that would otherwise be caused by the great heat produced by focusing the light of the sun.

text: The Richard B. Dunn Solar Telescope is a unique vertical-axis

text: solar telescope

text: , located at the

text: National Solar Observatory

text: at

text: Sacramento Peak

text: New Mexico

text: .  The optical path starts at a

text: heliostat

text: on top of a  tower and continues 193 feet (58.8 m) more underground to the primary mirror.  It then returns to one of six quartz optical windows in the floor of an optical laboratory at ground level.  The optics are evacuated to eliminate distortion due to

text: convection

text: in the telescope that would otherwise be caused by the great heat produced by focusing the light of the

text: sun

text: Antarctic Submillimeter Telescope and Remote Observatory, or AST/RO, was a 1.7 meter diameter off-axis telescope for research in astronomy and aeronomy at wavelengths between 0.2 and 2 mm. The instrument operated between 1994 and 2005 at the South Pole with four heterodyne receivers and three acousto-optical spectrometers. It was replaced by the 10-m South Pole Telescope.

text: Antarctic Submillimeter Telescope and Remote Observatory, or AST/RO, was a 1.7 meter diameter off-axis

text: telescope

text: for research in

text: astronomy

text: and

text: aeronomy

text: at

text: wavelength

text: s between 0.2 and 2 mm. The instrument operated between 1994 and 2005 at the

text: South Pole

text: with four

text: heterodyne receiver

text: s and three acousto-optical spectrometers. It was replaced by the 10-m

text: South Pole Telescope

text: The Space Telescope Science Institute (STScI) is the science operations center for the Hubble Space Telescope (HST; in orbit since 1990) and for the James Webb Space Telescope (JWST; scheduled to be launched in 2018). STScI is located on the Johns Hopkins University Homewood Campus in Baltimore, Maryland and was established in 1981 as a community-based science center that is operated for NASA by the Association of Universities for Research in Astronomy (AURA). Today, in addition to performing continuing science operations of HST and preparing for scientific exploration with JWST, STScI manages and operates the Mikulski Archive for Space Telescopes (MAST), the Data Management Center for the Kepler mission and a number of other activities benefiting from its expertise in and infrastructure for supporting the operations of space-based astronomical observatories. Most of the funding for STScI activities comes from contracts with NASA's Goddard Space Flight Center but there are smaller activities funded by NASA's Ames Research Center, NASA’s Jet Propulsion Laboratory, and the European Space Agency (ESA). The staff at STScI consists of scientists (mostly astronomers and astrophysicists), software engineers, data management and telescope operations personnel, education and public outreach experts, and administrative and business support personnel. There are approximately 100 Ph.D. scientists working at STScI, 15 of which are ESA staff who are on assignment to the HST project. The total STScI staff consists of about 450 people.

text: The Space Telescope Science Institute (STScI) is the science operations center for the

text: Hubble Space Telescope

text: (HST; in orbit since 1990) and for the

text: James Webb Space Telescope

text: (JWST; scheduled to be launched in 2018). STScI is located on the

text: Johns Hopkins University

entity_name: Homewood Campus of Johns Hopkins University

text: Homewood Campus

text: in

text: Baltimore

text: Maryland

text: and was established in 1981 as a community-based science center that is operated for

text: NASA

text: by the

text: (AURA). Today, in addition to performing continuing science operations of HST and preparing for scientific exploration with JWST, STScI manages and operates the Mikulski Archive for Space Telescopes (MAST), the Data Management Center for the

text: Kepler mission

text: and a number of other activities benefiting from its expertise in and infrastructure for supporting the operations of space-based astronomical observatories. Most of the funding for STScI activities comes from contracts with NASA's

text: Goddard Space Flight Center

text: but there are smaller activities funded by NASA's

text: Ames Research Center

text: , NASA’s

text: Jet Propulsion Laboratory

text: , and the

text: European Space Agency

text: (ESA). The staff at STScI consists of scientists (mostly astronomers and astrophysicists), software engineers, data management and telescope operations personnel, education and public outreach experts, and administrative and business support personnel. There are approximately 100 Ph.D. scientists working at STScI, 15 of which are ESA staff who are on assignment to the HST project. The total STScI staff consists of about 450 people.

text: Observation and measurement of starlight through telescopes is the basis for many fields of astronomy, including photometry and stellar spectroscopy. Hipparchus did not have a telescope or any instrument that could measure apparent brightness accurately, so he simply made estimates with his eyes. He sorted the stars into six brightness categories, which he called magnitudes. He referred to the brightest stars in his catalog as first-magnitudes stars, which were the brightest stars and those so faint he could barely see them were sixth-magnitude stars.

text: Observation and measurement of starlight through telescopes is the basis for many fields of

text: astronomy

text: , including photometry and stellar spectroscopy. Hipparchus did not have a telescope or any instrument that could measure apparent brightness accurately, so he simply made estimates with his eyes. He sorted the stars into six brightness categories, which he called magnitudes. He referred to the brightest stars in his catalog as first-magnitudes stars, which were the brightest stars and those so faint he could barely see them were sixth-magnitude stars.

text: Another payload on this mission was the Orbiting Retrievable Far and Extreme Ultraviolet Spectrometer (ORFEUS) telescope mounted on the Shuttle Pallet Satellite (SPAS) payload carrier. ORFEUS was designed to provide information on how stars are born and how they die, while studying gaseous interstellar clouds. Also in the cargo bay was the Limited Duration Space Environment Candidate Materials Exposure (LDCE) experiment.

text: Another payload on this mission was the Orbiting Retrievable Far and Extreme Ultraviolet Spectrometer (ORFEUS) telescope mounted on the Shuttle Pallet Satellite (SPAS) payload carrier. ORFEUS was designed to provide information on how

text: star

text: s are born and how they die, while studying gaseous

text: interstellar cloud

text: s. Also in the cargo bay was the Limited Duration Space Environment Candidate Materials Exposure (LDCE) experiment.

text: There are three optical telescopes on the summit of the Sierra San Pedro Mártir at the OAN complex, all with a Ritchey-Chrétien design:

text: There are three optical telescopes on the summit of the

text: Sierra San Pedro Mártir

text: at the OAN complex, all with a

text: Ritchey-Chrétien

text: design:

text: Lawrence recalls 'I remember Sir Patrick Moore visiting my school and leaving such a strong lasting impression that I decided I just had to have a larger telescope. Being a schoolboy at the time, my funds were limited so my next telescope was completely homemade; I even ground the main 8.75" mirror myself!' Mirror grinding is a very labour intensive task, and it took Lawrence a long time to make the mirror. The final instrument was successfully used for a number of years prior to Lawrence leaving home to study astrophysics at University.

text: The guardian of the UK's electromagnetic spectrum is the communications regulator, Ofcom.

text: The guardian of the UK's

text: electromagnetic spectrum

text: is the communications regulator,

text: Ofcom

text: Offices are located on the University of Arizona campus.  NRAO formerly operated the 12 Meter Telescope on Kitt Peak.  NRAO suspended operations at this telescope and funding was rerouted to the Atacama Large Millimeter Array (ALMA) instead.  The Arizona Radio Observatory now operates the 12 Meter Telescope.

text: Offices are located on the

text: University of Arizona

text: campus.  NRAO formerly operated the

text: 12 Meter Telescope

text: on

text: Kitt Peak

text: .  NRAO suspended operations at this telescope and funding was rerouted to the

text: Atacama Large Millimeter Array

text: (ALMA) instead.  The

text: Arizona Radio Observatory

text: now operates the 12 Meter Telescope.

text: John and Phoebe Brashear were active in their church as well. He served as the choir director of Bingham Street Methodist Episcopal Church, and organized the Cantata Society, composed of church choirs from Pittsburgh's South Side.  During the Panama-Pacific Exposition (1915), in which a 20" Warner-Swasey telescope with Brashear optics was displayed, Brashear was named "the State's most distinguished man" by Pennsylvania's Governor Martin Grove Brumbaugh. The telescope is still in use today at Chabot Space and Science Center at Oakland, California.

text: John and Phoebe Brashear were active in their church as well. He served as the choir director of Bingham Street Methodist Episcopal Church, and organized the Cantata Society, composed of church choirs from Pittsburgh's South Side.  During the

text: Panama-Pacific Exposition

text: (1915), in which a 20" Warner-Swasey telescope with Brashear optics was displayed, Brashear was named "the State's most distinguished man" by Pennsylvania's Governor

text: Martin Grove Brumbaugh

text: . The telescope is still in use today at Chabot Space and Science Center at Oakland, California.

text: Many modern telescopes and observatories are located in space to observe astronomical objects in wavelengths of the electromagnetic spectrum that cannot penetrate the Earth's atmosphere (such as ultraviolet radiation, X-rays, and gamma rays) and are thus impossible to observe using ground-based telescopes.Being above the atmosphere, these space observatories can also avoid the effects of atmospheric turbulence that plague ground based telescopes, although new generations of adaptive optics telescopes have since then dramatically improved the situation on the ground. The space high vacuum environment also frees the detectors from the ancestral diurnal cycle due to the atmospheric blue light background of the sky, thereby increasing significantly the observation time.

text: Many modern telescopes and observatories are located in space to observe astronomical objects in

text: wavelength

text: s of the

text: electromagnetic spectrum

text: that cannot penetrate the Earth's atmosphere (such as

text: ultraviolet

text: radiation,

text: X-rays

text: , and

text: gamma rays

text: ) and are thus impossible to observe using ground-based telescopes.Being above the atmosphere, these

text: space observatories

text: can also avoid the effects of

text: atmospheric turbulence

text: that plague ground based telescopes, although new generations of

text: adaptive optic

text: s telescopes have since then dramatically improved the situation on the ground. The space high vacuum environment also frees the detectors from the ancestral

text: diurnal cycle

text: due to the atmospheric blue light background of the sky, thereby increasing significantly the observation time.

text: J-PAS (Javalambre Physics of the accelerating universe Astronomical Survey) is an astronomical facility located in Pico del Buitre in Sierra de Javalambre, near Teruel, in Spain. It is constituted of two telescopes: a 2.5 metre primary mirror telescope (T250) and an 80-centimeter telescope (T80). The T250 will observe the sky in 56 colors with a large field 1.2 Giga-pixel camera, constituted by an array of 14 CCDs. J-PAS will observe more than 8000 square degrees (about 1/5 of the whole sky) during 5/6 years. J-PAS filters cover the entire visible region of the electromagnetic spectrum (3500 Å to 10000 Å).

text: J-PAS (Javalambre Physics of the accelerating universe Astronomical Survey) is an astronomical facility located in Pico del Buitre in

text: Sierra de Javalambre

text: , near

text: Teruel

text: , in

text: Spain

text: . It is constituted of two telescopes: a 2.5

text: metre

text: primary mirror telescope (T250) and an 80-

text: centimeter

text: telescope (T80). The T250 will observe the sky in 56 colors with a large field 1.2 Giga-pixel camera, constituted by an array of 14

text: CCDs

text: . J-PAS will observe more than 8000 square degrees (about 1/5 of the whole sky) during 5/6 years. J-PAS filters cover the entire visible region of the electromagnetic spectrum (3500 Å to 10000 Å).

text: In an electromagnetic wave, both the electric field and magnetic field are oscillating but in different directions; by convention the "polarization" of light refers to the polarization of the electric field. Light which can be approximated as a plane wave in free space or in an isotropic medium propagates as a transverse wave—both the electric and magnetic fields are perpendicular to the wave's direction of travel. The oscillation of these fields may be in a single direction (linear polarization), or the field may rotate at the optical frequency (circular or elliptical polarization). In that case the direction of the fields' rotation, and thus the specified polarization, may be either clockwise or counter clockwise; this is referred to as the wave's chirality or handedness.

text: In an

text: electromagnetic wave

text: , both the

text: electric field

text: and

text: magnetic field

text: are oscillating but in different directions; by convention the "polarization" of light refers to the polarization of the electric field. Light which can be approximated as a

text: plane wave

text: in free space or in an

text: isotropic

text: medium propagates as a

text: transverse wave

text: —both the electric and magnetic fields are perpendicular to the wave's direction of travel. The oscillation of these fields may be in a single direction (

text: linear polarization

text: ), or the field may rotate at the optical frequency (

text: circular

text: or

text: elliptical polarization

text: ). In that case the direction of the fields' rotation, and thus the specified polarization, may be either clockwise or counter clockwise; this is referred to as the wave's

text: chirality

text: or handedness.

text: The radio telescope was declared a  National Engineering Landmark by Engineers Australia.

text: The radio telescope was declared a

entity_section: Engineering Heritage Recognition Program

text: National Engineering Landmark

text: by

text: Engineers Australia

text: Notropis telescopus (telescope shiner) is a species of ray-finned fish in the genus Notropis. Notropis telescopus is primarily found in a small range of waters located in the Southeastern Region of the United States. There is very little published record of the research and management involving the telescope shiner. The following research will provide information on this species that can be helpful toward monitoring efforts of Notropis telescopus populations.The primary population of telescope shiners occurs throughout drainages of the Tennessee and Cumberland Rivers. This population is distributed throughout Virginia, Kentucky, Tennessee, and Alabama. A second known population occurs in Arkansas and Missouri and is found in the White and Black river systems.The telescope shiner gets its name due to the relatively large eye it possesses compared to other Notropis species. Adult telescopus usually have a length range from 50 to 105 mm. Unlike some other shiners and darters, the telescope shiner is not known for any outstanding coloration. Notropis telescopus occurs in cooler waters such as quick moving streams and small rivers. They can be found in riffle, run, and pool habitats. According to studies the telescope shiner can do better than other similar species when in waters with higher levels of pH, alkalinity, magnesium, and dissolved oxygen. When it comes to feeding, the telescope shiner is classified as an insectivore. Telescope shiners are classified in the spawning guild lithophil. They prefer open rock and gravel to spawn in. Embryos hatch early and stay hidden under the rocks. Notropis species are multiple batch spawners with strong seasonality to gonadal size and condition. The peak of their spawning is usually between April and July.Current monitoring and management is done by government agencies. Most of these surveys are not specific to the telescope shiner, but rather to determine overall biotic integrity of the streams and river systems.

text: Notropis telescopus (telescope shiner) is a species of

text: ray-finned fish

text: in the genus

text: Notropis

text: The Himalayan Chandra Telescope is a 2.01 meters (6.5 feet) diameter optical-infrared telescope named after India-born Nobel laureate Subrahmanyam Chandrasekhar. It contains a modified Ritchey-Chretien system with a primary mirror made of ULE ceramic which is designed to withstand low temperatures it experiences. The telescope was manufactured by Electo-Optical System Technologies Inc. at Tucson, Arizona, USA. The telescope is mounted with 3 science instruments called Himalaya Faint Object Spectrograph (HFOSC), the near-IR imager and the optical CCD imager. The telescope is remotely operated via an INSAT-3B satellite link which allows operation even in sub-zero temperatures in winter.

text: The Himalayan Chandra Telescope is a 2.01 meters (6.5 feet) diameter optical-infrared telescope named after India-born Nobel laureate

text: Subrahmanyam Chandrasekhar

text: . It contains a modified

text: Ritchey-Chretien

text: system with a primary mirror made of ULE ceramic which is designed to withstand low temperatures it experiences. The telescope was manufactured by Electo-Optical System Technologies Inc. at Tucson, Arizona, USA. The telescope is mounted with 3 science instruments called Himalaya Faint Object Spectrograph (HFOSC), the near-IR imager and the optical CCD imager. The telescope is remotely operated via an

text: satellite link which allows operation even in sub-zero temperatures in winter.

text: Strands of Starlight is a novel written by Gael Baudino and published in 1989.  It is the first in the Strands of Starlight tetralogy.  The other novels are Maze of Moonlight, Shroud of Shadow, and Strands of Sunlight.

text: Strands of Starlight is a novel written by

text: Gael Baudino

text: and published in 1989.  It is the first in the

text: Strands of Starlight

text: tetralogy

text: .  The other novels are

text: Maze of Moonlight

text: Shroud of Shadow

text: , and

text: Strands of Sunlight

text: The electromagnetic wave equation is a second-order partial differential equation that describes the propagation of electromagnetic waves through a medium or in a vacuum.  It is a three-dimensional form of the wave equation. The homogeneous form of the equation, written in terms of either the electric field  or the magnetic field , takes the form:

text: The electromagnetic wave equation is a second-order

text: partial differential equation

text: that describes the propagation of

text: electromagnetic wave

text: s through a

text: medium

text: or in a

text: vacuum

text: .  It is a

entity_section: Scalar wave equation in three space dimensions

text: three-dimensional form of the wave equation

text: . The

text: homogeneous

text: form of the equation, written in terms of either the

text: electric field

text: or the

text: magnetic field

text: , takes the form:

text: Mace et al. selected T-type brown dwarf candidates from WISE All-Sky source catalogue and carried out follow up observations using a variety of telescopes. September 11, 2011 WISE J2030+0749 was observed using SpeX at Infrared Telescope Facility (IRTF). The discovery paper was submitted to The Astrophysical Journal Supplement, accepted for publication on 2013 January 15 and published in March, 2013. The total number of announced in Mace et al. (2013) brown dwarfs is 87, all are of T-type.

text: Mace et al. selected T-type brown dwarf candidates from

text: WISE

text: All-Sky source catalogue and carried out follow up observations using a variety of telescopes. September 11, 2011 WISE J2030+0749 was observed using SpeX at

text: Infrared Telescope Facility (IRTF)

text: . The discovery paper was submitted to

text: The Astrophysical Journal Supplement

text: , accepted for publication on 2013 January 15 and published in March, 2013. The total number of announced in Mace et al. (2013) brown dwarfs is 87, all are of T-type.

text: The earliest recorded working telescopes were the refracting telescopes that appeared in the Netherlands in 1608. Their development is credited to three individuals: Hans Lippershey and Zacharias Janssen, who were spectacle makers in Middelburg, and Jacob Metius of Alkmaar. Galileo heard about the Dutch telescope in June 1609, built his own within a month, and improved upon the design in the following year. In the same year, Galileo became the first person to point a telescope skyward in order to make telescopic observations of a celestial object.

text: The earliest recorded working telescopes were the

text: refracting telescope

text: s that appeared in the

text: Netherlands

text: in 1608. Their development is credited to three individuals:

text: Hans Lippershey

text: and

text: Zacharias Janssen

text: , who were spectacle makers in Middelburg, and

text: Jacob Metius

text: of

text: Alkmaar

text: Galileo

text: heard about the Dutch telescope in June 1609, built his own within a month, and improved upon the design in the following year. In the same year, Galileo became the first person to point a telescope skyward in order to make telescopic observations of a celestial object.

text: A tunable metamaterial is a metamaterial with a variable response to an incident electromagnetic wave. This includes remotely controlling how an incident electromagnetic wave (EM wave) interacts with a metamaterial.  This means the capabilitity to determine whether the EM wave is  transmitted, reflected, or absorbed. In general, the lattice structure of the tunable metamaterial is adjustable in real time, making it possible to reconfigure a metamaterial device during operation. It encompasses  developments beyond the bandwidth limitations in left-handed materials by constructing various types of metamaterials. The ongoing research in this domain includes electromagnetic band gap metamaterials (EBG), also known as photonic band gap (PBG), and negative refractive index material (NIM).<ref name=Lapine-structure>"Tunable metamaterials imply the ability to continuously change their properties through an external influence or signal with the intrinsic mechanism of tunability."

text: A tunable metamaterial is a

text: metamaterial

text: with a variable response to an incident

text: electromagnetic

text: wave. This includes remotely controlling how an incident electromagnetic wave (EM wave) interacts with a metamaterial.  This means the capabilitity to determine whether the EM wave is  transmitted, reflected, or absorbed. In general, the lattice structure of the tunable metamaterial is adjustable in real time, making it possible to reconfigure a metamaterial device during operation. It encompasses  developments beyond the

text: bandwidth

text: limitations in

text: left-handed material

text: s by constructing various types of metamaterials. The ongoing research in this domain includes electromagnetic band gap metamaterials (EBG), also known as photonic band gap (PBG), and

text: negative refractive index material

text: (NIM).<ref name=Lapine-structure>"Tunable metamaterials imply the ability to continuously change their properties through an external influence or signal with the intrinsic mechanism of tunability."

text: Sydney Observatory is located on a hill now known as Observatory Hill in the centre of Sydney. The site evolved from a fort built on 'Windmill Hill' in the early 19th century to an astronomical observatory during the nineteenth century. It is now a working museum where evening visitors can observe the stars and planets through a modern 40 cm Schmidt-Cassegrain telescope and a historic 29 cm refractor telescope built in 1874, the oldest telescope in Australia in regular use.

text: Sydney Observatory is located on a hill now known as

text: Observatory Hill

text: in the centre of

text: Sydney

text: . The site evolved from a fort built on 'Windmill Hill' in the early 19th century to an

text: astronomical

text: observatory

text: during the nineteenth century. It is now a working museum where evening visitors can observe the stars and planets through a modern 40 cm

text: Schmidt-Cassegrain telescope

text: and a historic 29 cm

text: refractor telescope

text: built in 1874, the oldest telescope in Australia in regular use.

text: The main telescope at the observatory is the Lovell Telescope, which is the third largest steerable radio telescope in the world. There are three other active telescopes located at the observatory; the Mark II, as well as  and 7 m diameter radio telescopes. Jodrell Bank Observatory is also the base of the Multi-Element Radio Linked Interferometer Network (MERLIN), a National Facility run by the University of Manchester on behalf of the Science and Technology Facilities Council.

text: Lovell Telescope

text: Mark II

text: , as well as  and 7 m diameter radio telescopes. Jodrell Bank Observatory is also the base of the

text: University of Manchester

text: on behalf of the

text: The Microwave Theory and Techniques Society focuses on the theory and applications of radio-frequency (HF, VHF/UHF, microwave, millimeter-wave and terahertz), guided-wave and wireless technologies, as they relate to nanostructures, devices, integrated circuits, multi-circuit assemblies, components, packages, transmission lines, sub-systems, and systems involving the generation, amplification, processing, modulation, control, transmission, reception, detection and demodulation, and effects of electromagnetic energy transport. It also includes the interaction & interface of microwave signals with digital & optical circuitry & interconnecting transmission media. Examples include optical waves in suitably confined structures, as well as the applications of acoustic, magnetic, & plasmonic waves to microwave systems.Radio frequency (RF) is a term that refers to signals and associated currents having characteristics such that, if the current is input to an antenna, an electromagnetic (EM) field is generated suitable for wireless broadcasting and/or communications, radar, etc. These frequencies cover a significant portion of the electromagnetic radiation spectrum, extending from about 9 kHz, the lowest allocated wireless communications frequency (if it were audible it would be within the range of human hearing), to thousands of gigahertz (GHz). The discipline of microwave theory & techniques applies physical and mathematical principles to analyze devices, components and structures that interact with electromagnetic fields and often have dimensions representing a significant fraction of a wavelength, or when in-circuit wave propagation effects need to be considered.The Society's focus shall include scientific, technical, and industrial activities, subject to timely modifications approved by the IEEE Technical Advisory Board. Technical Committee focus areas of interest include microwave and millimeter-wave materials, solid state devices and integrated circuits, filters, passive components and packaging, microwave acoustics and photonics, high power and low noise techniques, frequency conversion, field theory, and computer aided design and measurements. In addition, the Society is involved in terahertz technology, ultra-wide band and microwave systems, and multidisciplinary activities such as RF microelectromechanical (RFMEMS) devices, radio frequency identification devices (RFIDs), digital signal processing, biological effects and medical applications, and business issues.

text: The Stockert Radio Telescope is a historical radio telescope in the Eifel mountain range in Germany, situated 12 km from the Effelsberg 100-m Radio Telescope.

text: The Stockert Radio Telescope is a historical

text: radio telescope

text: in the

text: Eifel

text: mountain range in

text: Germany

text: , situated 12 km from the

text: Effelsberg 100-m Radio Telescope

text: With the addition of the displacement current, Maxwell was able to hypothesize (correctly) that light was a form of electromagnetic wave. See electromagnetic wave equation for a discussion of this important discovery.

text: With the addition of the displacement current, Maxwell was able to hypothesize (correctly) that light was a form of

text: electromagnetic wave

text: . See

text: electromagnetic wave equation

text: for a discussion of this important discovery.

text: In 2008 a study was undertaken of fourteen stars with exoplanets that were originally discovered using the transit method through relatively small telescopes. These systems were re-examined with the  reflector telescope at the Calar Alto Observatory in Spain. This star system, along with two others, was determined to be a previously unknown binary star system. The previously unknown secondary star is a dim magnitude 15 M-type star separated by about 111 AU from the primary, appearing offset from the primary by about one arc second in the images. This discovery resulted in a recalculation of parameters for both the planet and the primary star.

text: In 2008 a study was undertaken of fourteen stars with exoplanets that were originally discovered using the

text: transit method

text: through relatively small telescopes. These systems were re-examined with the

text: reflector telescope

text: at the

text: Calar Alto Observatory

text: in

text: Spain

text: . This star system, along with two others, was determined to be a previously unknown

text: binary star

text: system. The previously unknown secondary star is a dim

text: magnitude

text: M-type

text: star separated by about 111

text: AU

text: from the primary, appearing offset from the primary by about one arc second in the images. This discovery resulted in a recalculation of parameters for both the planet and the primary star.

text: Electromagnetic radiation interacts with matter in different ways across the spectrum. These types of interaction are so different that historically different names have been applied to different parts of the spectrum, as though these were different types of radiation. Thus, although these "different kinds" of electromagnetic radiation form a quantitatively continuous spectrum of frequencies and wavelengths, the spectrum remains divided for practical reasons related to these qualitative interaction differences.

text: The smaller dome on the main building at Lick had originally held the secondhand 12-inch Clark refracting telescope, the first telescope to be used at Lick.  In 1979 it was replaced with the Anna L. Nickel telescope, a 1-meter reflecting telescope.  The telescope is named for Anna L. Nickel, a San Francisco native who donated $50,000, a large portion of her estate, to the Observatory.

text: The smaller dome on the main building at Lick had originally held the secondhand 12-inch Clark

text: refracting telescope

text: , the first telescope to be used at Lick.  In 1979 it was replaced with the Anna L. Nickel telescope, a 1-meter

text: reflecting telescope

text: .  The telescope is named for Anna L. Nickel, a San Francisco native who donated $50,000, a large portion of her estate, to the Observatory.

text: The Advanced Technology Large-Aperture Space Telescope (ATLAST) is an  8 to 16.8-meter (26 to 55-foot) UV-optical-NIR space telescope proposed by Space Telescope Science Institute, the science operations center for the Hubble Space Telescope (HST). If launched, ATLAST would be a replacement and successor for the HST, with the ability to obtain spectroscopic and imaging observations of astronomical objects in the ultraviolet, optical, and infrared wavelengths, but with substantially better resolution than either HST or the planned James Webb Space Telescope (JWST). Like JWST, ATLAST will be launched to the Sun-Earth L Lagrange point.

text: The Advanced Technology Large-Aperture Space Telescope (ATLAST) is an  8 to 16.8-meter (26 to 55-foot) UV-optical-NIR space

text: telescope

text: proposed by

text: Space Telescope Science Institute

text: , the science operations center for the

text: Hubble Space Telescope

text: (HST). If launched, ATLAST would be a replacement and successor for the HST, with the ability to obtain spectroscopic and imaging observations of astronomical objects in the

text: ultraviolet

text: optical

text: , and

text: infrared wavelength

text: s, but with substantially better resolution than either HST or the planned

text: James Webb Space Telescope

text: (JWST). Like JWST, ATLAST will be launched to the

text: Sun

text: Earth

text: L Lagrange point

text: MSSTA and its sister rocket, NIXT, were prototypes for normal incidence EUV imaging telescopes that are in use today, such as the EIT instrument aboard the SOHO spacecraft, and the TRACE spacecraft.  MSSTA flew three times: once in 1991 (NASA Sounding Rocket flight 36.049), once in 1994 (flight 36.091), and once in 2002 (flight 36.194). While Dr. Walker's 1991 telescope was the first in the series to carry the MSSTA moniker, the precursor to the MSSTA, the Stanford/MSFC Rocket Spectroheliograph (NASA Sounding Rocket flight 27.092), which carried two EUV telescopes in 1987, was the first mission to successfully obtain high-resolution, full-disk solar images utilizing normal incidence EUV optics. The MSSTA I flown in 1991 carried 14 telescopes; the MSSTA II flown in 1994 carried 19 telescopes; and the MSSTA III flown in 2002 carried 11 telescopes.

text: MSSTA and its sister rocket,

text: NIXT

text: , were prototypes for normal incidence EUV imaging telescopes that are in use today, such as the

text: EIT instrument

text: aboard the

text: SOHO

text: spacecraft, and the

text: TRACE

text: spacecraft.  MSSTA flew three times: once in 1991 (NASA Sounding Rocket flight 36.049), once in 1994 (flight 36.091), and once in 2002 (flight 36.194). While Dr. Walker's 1991 telescope was the first in the series to carry the MSSTA moniker, the precursor to the MSSTA, the Stanford/MSFC Rocket Spectroheliograph (NASA Sounding Rocket flight 27.092), which carried two EUV telescopes in 1987, was the first mission to successfully obtain high-resolution, full-disk solar images utilizing normal incidence EUV optics. The MSSTA I flown in 1991 carried 14 telescopes; the MSSTA II flown in 1994 carried 19 telescopes; and the MSSTA III flown in 2002 carried 11 telescopes.

text: William Gascoigne was the first who commanded a chief advantage of the form of telescope suggested by Kepler: that a small material object could be placed at the common focal plane of the objective and the eyepiece. This led to his invention of the micrometer, and his application of telescopic sights to precision astronomical instruments. It was not till about the middle of the 17th century that Kepler's telescope came into general use: not so much because of the advantages pointed out by Gascoigne, but because its field of view was much larger than in the Galilean telescope.

text: William Gascoigne

text: was the first who commanded a chief advantage of the form of telescope suggested by Kepler: that a small material object could be placed at the common

text: focal plane

text: of the objective and the eyepiece. This led to his invention of the

text: micrometer

text: , and his application of telescopic sights to precision astronomical instruments. It was not till about the middle of the 17th century that Kepler's telescope came into general use: not so much because of the advantages pointed out by Gascoigne, but because its

text: field of view

text: was much larger than in the

text: Galilean telescope

text: James Clerk Maxwell discovered that he could apply his equations for electromagnetism, which had been previously discovered, along with a slight modification to describe self-propagating waves of oscillating electric and magnetic fields. When the propagation speed of these electromagnetic waves was calculated, the speed of light fell out. It quickly became apparent that visible light, ultraviolet light, and infrared light (phenomena thought previously to be unrelated) were all electromagnetic waves of differing frequency. The wave theory had prevailed—or at least it seemed to.

text: James Clerk Maxwell

text: discovered that he could apply

text: his equations for electromagnetism

text: , which had been previously discovered, along with a slight modification to describe self-propagating waves of oscillating electric and magnetic fields. When the propagation speed of these electromagnetic waves was calculated, the

text: speed of light

text: fell out. It quickly became apparent that visible light, ultraviolet light, and infrared light (phenomena thought previously to be unrelated) were all electromagnetic waves of differing frequency. The wave theory had prevailed—or at least it seemed to.

text: Another example of an infinite-axis telescope is a ball-in-cup mounted telescope, also called a spherical-mounted telescope. The first Newtonian telescope was mounted in this way; the ball was held in place by wrought iron springs. Another type uses a bowling balls as a mount axis. There are modern commercial and amateur mount designs for  Newtonian telescopes that have the "ball" built into the base of the optical tube assembly. These mounts have the advantage of being mechanically simple and allow the observer to rotate the eyepiece to any side of the telescope for easier viewing. Some types have even been adapted for equatorial tracking by motorizing one of the bearing surfaces to turn the ball at the rate of one revolution per day. This rotates the telescope's ball exactly opposite the rotation of the Earth, thus keeping the telescope stationary with respect to the stars.

text: Another example of an infinite-axis telescope is a ball-in-cup mounted telescope, also called a spherical-mounted telescope. The first

text: Newtonian telescope

text: was mounted in this way; the ball was held in place by wrought iron springs. Another type uses a bowling balls as a mount axis. There are modern commercial and

text: amateur

text: mount designs for  Newtonian telescopes that have the "ball" built into the base of the optical tube assembly. These mounts have the advantage of being mechanically simple and allow the observer to rotate the eyepiece to any side of the telescope for easier viewing. Some types have even been adapted for equatorial tracking by motorizing one of the bearing surfaces to turn the ball at the rate of one revolution per day. This rotates the telescope's ball exactly opposite the rotation of the Earth, thus keeping the telescope stationary with respect to the stars.

text: The NASA-funded Space Telescope Science Institute (STScI) in Baltimore named one of the world’s largest astronomy databases after Mikulski (Barbara A. Mikulski Archive for Space Telescopes), as she was a long time champion of the Hubble and James Webb space telescopes.

text: As the use of the telescope for scientific work diminished again, a decision was made to convert it to use for visual observing. Because of the high position of the Cassegrain focus above the observing floor, a system of mirrors and lenses was developed to allow viewing from a position at the bottom of the telescope tube. With the conversion completed in 2014, the 2.5 meter telescope began its new life as the world's largest telescope dedicated to public use. Regularly scheduled observing began with the 2015 observing season.

text: Since the 1960s, robotic spacecraft have been sent to explore Mars from orbit and the surface in extensive detail. In addition, remote sensing of Mars from Earth by ground-based and orbiting telescopes has continued across much of the electromagnetic spectrum. These include infrared observations to determine the composition of the surface, ultraviolet and submillimeter observation of the atmospheric composition, and radio measurements of wind velocities.

text: Since the 1960s, robotic

text: spacecraft

text: have been sent to

text: explore Mars

text: from orbit and the

text: surface

text: in extensive detail. In addition, remote sensing of Mars from Earth by ground-based and orbiting telescopes has continued across much of the

text: electromagnetic spectrum

text: . These include

text: infrared

text: observations to determine the composition of the surface,

text: ultraviolet

text: and

text: submillimeter

text: observation of the atmospheric composition, and

text: radio

text: measurements of wind velocities.

text: The usual Daimler large cruciform chassis had a double wishbone front suspension, with laminated torsion bars, telescopic dampers, and an anti-roll bar, while the rear suspension used leaf springs with telescopic dampers.

text: The usual

text: Daimler

text: large cruciform chassis had a double wishbone front suspension, with laminated torsion bars, telescopic dampers, and an anti-roll bar, while the rear suspension used leaf springs with telescopic dampers.

text: The main mirror of NTT is flexible and its shape is actively adjusted during observations by actuators to preserve the optimal image quality. The secondary mirror position is also actively controlled in three directions. This technology, developed by ESO, known as active optics, is now applied to all major modern telescopes, such as the Very Large Telescope at Cerro Paranal and the future European Extremely Large Telescope. The design of the octagonal enclosure housing the NTT is another technological breakthrough. The telescope dome is relatively small, and is ventilated by a system of flaps that makes air flow smoothly across the mirror, reducing turbulence and leading to sharper images.

text: On 26 June 2014,  was discovered using the Hubble Space Telescope during a preliminary survey to find a suitable Kuiper belt object for the New Horizons probe to flyby. The discovery required the use of the Hubble Space Telescope, because with an apparent magnitude of 26 it is too faint for all but the most powerful telescopes. The Hubble Space Telescope is also capable of very precise astrometry and hence a reliable orbit determination.

text: On 26 June 2014,  was discovered using the

text: Hubble Space Telescope

text: during a preliminary survey to

text: find a suitable Kuiper belt object

text: for the

text: New Horizons

text: probe to flyby. The discovery required the use of the Hubble Space Telescope, because with an

text: apparent magnitude

text: of 26 it is too faint for all but the most powerful telescopes. The Hubble Space Telescope is also capable of very precise

text: astrometry

text: and hence a reliable

text: orbit determination

text: Looking back on the album in a 2011 interview with FACT Magazine, Deacon states: ”I was a very different musician back then trying to figure out how to interact with sound, what could be done with it, where it could go, learning music software for the first time, and discovering many more genres of experimental music than what I was exposed to in my youth on Long Island. It was an exciting time! Since then my aesthetic has shifted, my absurdist mindset subdued and I’ve been exposed to a global audience.”

text: Looking back on the album in a 2011 interview with

text: FACT Magazine

text: , Deacon states: ”I was a very different musician back then trying to figure out how to interact with sound, what could be done with it, where it could go, learning music software for the first time, and discovering many more genres of experimental music than what I was exposed to in my youth on Long Island. It was an exciting time! Since then my aesthetic has shifted, my absurdist mindset subdued and I’ve been exposed to a global audience.”

text: A grow light or plant light is an artificial light source, generally an electric light, designed to stimulate plant growth by emitting an electromagnetic spectrum appropriate for photosynthesis.  Grow lights are used in applications where there is either no naturally occurring light, or where supplemental light is required.  For example, in the winter months when the available hours of daylight may be insufficient for the desired plant growth, lights are used to extend the time the plants receive light. If plants do not receive enough light, they will grow long and spindly.

text: A grow light or plant light is an artificial light source, generally an

text: electric light

text: , designed to stimulate plant growth by emitting an

text: electromagnetic spectrum

text: appropriate for

text: photosynthesis

text: .  Grow lights are used in applications where there is either no naturally occurring light, or where supplemental light is required.  For example, in the winter months when the available hours of daylight may be insufficient for the desired plant growth, lights are used to extend the time the plants receive light. If plants do not receive enough light, they will grow long and spindly.

text: Another cheaper technique, lucky imaging, has had good results on smaller telescopes. This idea dates back to pre-war naked-eye observations of moments of good seeing, which were followed by observations of the planets on cine film after World War II. The technique relies on the fact that every so often the effects of the atmosphere will be negligible, and hence by recording large numbers of images in real-time, a 'lucky' excellent image can be picked out. This happens more often when the number of r0-size patches over the telescope pupil is not too large, and the technique consequently breaks down for very large telescopes. It can nonetheless outperform adaptive optics in some cases and is accessible to amateurs. It does require very much longer observation times than adaptive optics for imaging faint targets, and is limited in its maximum resolution.

text: Another cheaper technique,

text: lucky imaging

text: , has had good results on smaller telescopes. This idea dates back to pre-war naked-eye observations of moments of good seeing, which were followed by observations of the planets on cine film after

text: World War II

text: . The technique relies on the fact that every so often the effects of the atmosphere will be negligible, and hence by recording large numbers of images in real-time, a 'lucky' excellent image can be picked out. This happens more often when the number of r0-size patches over the telescope pupil is not too large, and the technique consequently breaks down for very large telescopes. It can nonetheless outperform adaptive optics in some cases and is accessible to amateurs. It does require very much longer observation times than

text: adaptive optics

text: for imaging faint targets, and is limited in its maximum resolution.

text: Riccioli also used telescopic observations of stars to argue against the Copernican theory. Viewed through the small telescopes of his time, stars appeared as small but distinct disks. These disks were spurious – caused by the diffraction of waves of light entering the telescope. Today they are known as Airy disks, after the nineteenth-century astronomer George Biddell Airy (1801–1892). The real disks of stars are generally too tiny to be seen even with the best of modern telescopes. But during most of the seventeenth century it was thought that these disks seen in a telescope were the actual bodies of stars. In the Copernican theory, the stars had to lie at vast distances from Earth in order to explain why no annual parallax was seen among them. Riccioli and Grimaldi made numerous measurements of star disks using a telescope, providing a detailed description of their procedure so that anyone who wanted could replicate it. Riccioli then calculated the physical sizes that the measured stars would need to have in order for them both to be as far away as was required in the Copernican theory to show no parallax, and to have the sizes seen with the telescope. The result in all cases was that the stars were huge – dwarfing the sun. In some scenarios one single star would exceed the size of the entire universe as estimated by a geocentrist like Tycho Brahe. This problem that the appearance of stars in the telescope posed for the Copernican theory had been noted as early as 1614 by Simon Marius, who said telescopic observations of the disks of stars supported the Tychonic theory. The problem was acknowledged by Copernicans such as Martin van den Hove (1605–1639), who also measured the disks of stars and acknowledged that the issue of vast star sizes might lead people to reject the Copernican theory.

text: Riccioli also used telescopic observations of stars to argue against the Copernican theory. Viewed through the small telescopes of his time, stars appeared as small but distinct disks. These disks were spurious – caused by the diffraction of waves of light entering the telescope. Today they are known as

text: Airy disk

text: s, after the nineteenth-century astronomer

text: George Biddell Airy

text: (1801–1892). The real disks of stars are generally too tiny to be seen even with the best of modern telescopes. But during most of the seventeenth century it was thought that these disks seen in a telescope were the actual bodies of stars. In the Copernican theory, the stars had to lie at vast distances from Earth in order to explain why no annual parallax was seen among them. Riccioli and Grimaldi made numerous measurements of star disks using a telescope, providing a detailed description of their procedure so that anyone who wanted could replicate it. Riccioli then calculated the physical sizes that the measured stars would need to have in order for them both to be as far away as was required in the Copernican theory to show no parallax, and to have the sizes seen with the telescope. The result in all cases was that the stars were huge – dwarfing the sun. In some scenarios one single star would exceed the size of the entire universe as estimated by a geocentrist like Tycho Brahe. This problem that the appearance of stars in the telescope posed for the Copernican theory had been noted as early as 1614 by Simon Marius, who said telescopic observations of the disks of stars supported the Tychonic theory. The problem was acknowledged by Copernicans such as

text: Martin van den Hove

text: (1605–1639), who also measured the disks of stars and acknowledged that the issue of vast star sizes might lead people to reject the Copernican theory.

text: Major Atmospheric Cerenkov Experiment Telescope (MACE) was expected to be set up here by December 2012. The Experiment expects to have a 21 meter collector which can collect gamma rays from space. The effort to establish the facility is led by Bhaba Atomic Research Center in collaboration with Tata Institute of Fundamental Research, Indian Institute of Astrophysics, Bangalore and Saha Institute of Nuclear Physics, Kolkata. The facility is estimated to cost Rs. 400 million. Once completed it will be the only such facility in the eastern hemisphere. As of June 2014 the telescope has been fabricated by the Electronics Corporation of India and is being installed at the IAO.  Once installed, this Telescope will be the second largest gamma ray telescope in the world and the world's largest telescope at the highest altitude.

entity_name: Major Atmospheric Cerenkov Experiment Telescope

text: Major Atmospheric Cerenkov Experiment Telescope

text: (MACE) was expected to be set up here by December 2012. The Experiment expects to have a 21 meter collector which can collect gamma rays from space. The effort to establish the facility is led by Bhaba Atomic Research Center in collaboration with Tata Institute of Fundamental Research,

text: Indian Institute of Astrophysics

text: Bangalore

text: and Saha Institute of Nuclear Physics,

text: Kolkata

text: . The facility is estimated to cost

text: Rs

text: . 400 million. Once completed it will be the only such facility in the

text: eastern hemisphere

text: . As of June 2014 the telescope has been fabricated by the

entity_name: Electronics Corporation of India Limited

text: Electronics Corporation of India

text: and is being installed at the IAO.  Once installed, this Telescope will be the second largest gamma ray telescope in the world and the world's largest telescope at the highest altitude.

text: New physical phenomena appear in consideration of the integral systems which absorb radiation. For example, EPS is based on the regularities of the correlation of physico-chemical properties and integral spectral characteristics for UV or (and) visible regions of the electromagnetic spectrum (so-called law spectrum-properties). Color is also an integral characteristic of a visible spectrum. Therefore, the consequence of this is so-called law color-properties.  All this allow the use of EPS methods for studying individual and complex multicomponent substances.

text: The Springfield Telescope Makers grew out of a class on how to make telescopes that was started by Russell W. Porter in Springfield, Vermont in August 12, 1920. The members of this small group decided to form a club and held their first meeting on December 7, 1923. The Stellafane clubhouse was built in 1924 on a  plot belonging to Porter on the  summit of Breezy Hill outside of town. The original 20 x  clubhouse (with an 11 x  ell added in 1926) included a meeting room, a kitchen, a workshop, and bunkrooms on the second floor. The building incorporated a polar Cassegrain telescope, a transit telescope (no longer functional), a solar telescope, and a sundial, on the south wall. The name Stellafane (originally suggested by Porter at the club's January 1924 meeting) comes from the Latin words stella meaning star, and fane meaning shrine which together means "Shrine to the Stars". Besides the historic Stellafane "pink clubhouse," the site includes Porter's uniquely designed Turret Telescope, a  f/17 Newtonian reflector that was completed in 1931. This telescope consists of an equatorially rotated concrete dome with the telescope mounted on the outside, with the observer on the inside working in heated comfort. Stellafane is still the location where the Springfield Telescope Makers hold most of their meetings.  The clubhouse and the observatory housing Porter's telescope were designated a National Historic Landmark in 1989, in recognition for the club's pioneering role in the popularization of astronomy and the amateur construction of telescopes.

text: The Springfield Telescope Makers grew out of a class on how to make telescopes that was started by

text: Russell W. Porter

text: in Springfield, Vermont in August 12, 1920. The members of this small group decided to form a club and held their first meeting on December 7, 1923. The Stellafane clubhouse was built in 1924 on a  plot belonging to Porter on the  summit of Breezy Hill outside of town. The original 20 x  clubhouse (with an 11 x  ell added in 1926) included a meeting room, a kitchen, a workshop, and bunkrooms on the second floor. The building incorporated a polar

text: Cassegrain telescope

text: , a

text: transit telescope

text: (no longer functional), a

text: solar telescope

text: , and a

text: sundial

text: , on the south wall. The name Stellafane (originally suggested by Porter at the club's January 1924 meeting) comes from the Latin words stella meaning star, and fane meaning shrine which together means "Shrine to the Stars". Besides the historic Stellafane "pink clubhouse," the site includes Porter's uniquely designed Turret Telescope, a  f/17

text: Newtonian reflector

text: that was completed in 1931. This telescope consists of an

text: equatorial

text: ly rotated concrete dome with the telescope mounted on the outside, with the observer on the inside working in heated comfort. Stellafane is still the location where the Springfield Telescope Makers hold most of their meetings.  The clubhouse and the observatory housing Porter's telescope were designated a

text: National Historic Landmark

text: in 1989, in recognition for the club's pioneering role in the popularization of astronomy and the amateur construction of telescopes.

text: Since speculum metal mirror secondaries or diagonal mirrors greatly reduced the light that reached the eyepiece, several reflecting telescope designers tried to do away with them. In 1762 Mikhail Lomonosov presented a reflecting telescope before the Russian Academy of Sciences forum. It had its primary mirror tilted at four degrees to telescope's axis so the image could be viewed via an eyepiece mounted at the front of the telescope tube without the observer's head blocking the incoming light. This innovation was not published until 1827, so this type came to be called the Herschelian telescope after a similar design by William Herschel.

text: Since speculum metal mirror secondaries or diagonal mirrors greatly reduced the light that reached the eyepiece, several reflecting telescope designers tried to do away with them. In 1762

text: Mikhail Lomonosov

text: presented a reflecting telescope before the

text: Russian Academy of Sciences

text: forum. It had its primary mirror tilted at four degrees to telescope's axis so the image could be viewed via an eyepiece mounted at the front of the telescope tube without the observer's head blocking the incoming light. This innovation was not published until 1827, so this type came to be called the Herschelian telescope after a similar design by

text: William Herschel

text: The electromagnetic spectrum is the collective term for all known frequencies and their linked wavelengths of the known photons ( electromagnetic radiation ). The "electromagnetic spectrum" of an object has a different meaning, and is instead the characteristic distribution of electromagnetic radiation emitted or absorbed by that particular object.

text: The electromagnetic spectrum is the collective term for all known frequencies and their linked wavelengths of the known

text: photons

text: electromagnetic radiation

text: ). The "electromagnetic spectrum" of an object has a different meaning, and is instead the characteristic distribution of electromagnetic radiation emitted or absorbed by that particular object.

text: Each design is much larger than previous telescopes. Even with the descale to 39.3 m the E-ELT is significantly larger than both other planned extremely large telescopes. It has the aim of observing the Universe in greater detail than the Hubble Space Telescope by taking images 15 times sharper, although it is designed to be complementary to space telescopes, which typically have very limited observing time available. The E-ELT's 4.2-meter secondary mirror is the same size as the primary mirror on the William Herschel Telescope, the second largest optical telescope in Europe.

text: Each design is much larger than previous telescopes. Even with the descale to 39.3 m the E-ELT is significantly larger than both other planned

text: extremely large telescope

text: s. It has the aim of observing the Universe in greater detail than the

text: Hubble Space Telescope

text: by taking images 15 times sharper, although it is designed to be complementary to space telescopes, which typically have very limited observing time available. The E-ELT's 4.2-meter

text: secondary mirror

text: is the same size as the primary mirror on the

text: William Herschel Telescope

text: , the second largest optical telescope in Europe.

text: Electric fish generate an electrostatic field shaped like a dipole, with field lines describing a curved arc from positive pole to negative. The electric field signals differ from other communicating modes of communication such as sound or optical, which use signals that propagate as waves. While sound waves for acoustic communication or light waves (electromagnetic waves) for visual communications all propagate, electric signals do not (it is different from electromagnetic waves). As an electric field, the signal magnitude decreases in accordance with the inverse square law, which makes the signal sending and formation an energy-costly process.  Electric fish match the impedance of their electric organ to the conductivity of water in order to achieve minimum energy lost, and the final result is electric signals traveling for at most a few meters.  Although electric fish are limited to a short communication range, the signals remain uncorrupted by echo and reverberation, which affects sound and light. Deterioration of waves includes reflection, refraction, absorption, interference, and so on. As a result, the temporal features, which are very important for electric fish signals, remain constant during transmission.

text: Electric fish generate an electrostatic field shaped like a dipole, with field lines describing a curved arc from positive pole to negative. The electric field signals differ from other communicating modes of communication such as sound or optical, which use signals that propagate as waves. While sound waves for acoustic communication or light waves (electromagnetic waves) for visual communications all propagate, electric signals do not (it is different from electromagnetic waves). As an electric field, the signal magnitude decreases in accordance with the inverse square law, which makes the signal sending and formation an energy-costly process.  Electric fish match the

text: impedance

text: of their electric organ to the conductivity of water in order to achieve minimum energy lost, and the final result is electric signals traveling for at most a few meters.  Although electric fish are limited to a short communication range, the signals remain uncorrupted by echo and reverberation, which affects sound and light. Deterioration of waves includes

text: reflection

text: refraction

text: absorption

text: interference

text: , and so on. As a result, the temporal features, which are very important for electric fish signals, remain constant during transmission.

text: There seemed to be no use in waiting by the little door, so she went back to the table, half hoping she might find another key on it, or at any rate a book of rules for shutting people up like telescopes: this time she found a little bottle on it, ("which certainly was not here before," said Alice,) and round the neck of the bottle was a paper label, with the words "DRINK ME" beautifully printed on it in large letters. It was all very well to say "Drink me", but the wise little Alice was not going to do that in a hurry. "No, I'll look first," she said, "and see whether it's marked 'poison' or not"; for she had read several nice little histories about children who had got burnt, and eaten up by wild beasts and other unpleasant things, all because they would not remember the simple rules their friends had taught them: such as, that a red-hot poker will burn you if you hold it too long; and that if you cut your finger very deeply with a knife, it usually bleeds; and she had never forgotten that, if you drink much from a bottle marked "poison", it is almost certain to disagree with you, sooner or later.

text: Recently, the performance of the Penning trap mass spectrometer ISOLTRAP has been considerably enhanced. Major technical improvements were implemented to increase the range of accessible nuclei to those that are produced in minute quantities of only 100 ions/s and to nuclei with half-lives down to ~50 ms as well as to decrease the typical relative uncertainty down to ~1x10. In particular, a linear radiofrequency quadrupole (RFQ) trap and more recently a multi-reflection time-of-flight (MRTOF) mass spectrometer were added to the ISOLTRAP spectrometer. Since the unified atomic mass unit is defined as 1/12 of the mass of C the calibration of the magnetic field with carbon clusters allows absolute mass measurements. For this purpose, a laser-ablation source of carbon-cluster ions is installed at ISOLTRAP.

text: Recently, the performance of the Penning trap mass spectrometer ISOLTRAP has been considerably enhanced. Major technical improvements were implemented to increase the range of accessible nuclei to those that are produced in minute quantities of only 100 ions/s and to nuclei with half-lives down to ~50 ms as well as to decrease the typical relative uncertainty down to ~1x10. In particular, a linear radiofrequency

text: quadrupole

text: (RFQ) trap and more recently a multi-reflection time-of-flight (MRTOF) mass spectrometer were added to the ISOLTRAP spectrometer. Since the unified atomic mass unit is defined as 1/12 of the mass of C the calibration of the magnetic field with carbon clusters allows absolute mass measurements. For this purpose, a laser-ablation source of carbon-cluster ions is installed at ISOLTRAP.

text: List of largest optical telescopes in the 18th century, are listings of what were, for the time period of the 18th century, large optical telescopes. The list includes various refractor and reflector that were active some time between about 1699 to 1801. It is oriented towards astronomy, not terrestrial telescopes (e.g. spyglass).

text: List of largest optical telescopes in the 18th century, are listings of what were, for the time period of the 18th century, large optical telescopes. The list includes various refractor and reflector that were active some time between about 1699 to 1801. It is oriented towards

text: astronomy

text: , not terrestrial telescopes (e.g. spyglass).

text: The James Webb Space Telescope (JWST), previously known as Next Generation Space Telescope (NGST), is a Flagship-class space observatory under construction and scheduled to launch in October 2018. The JWST will offer unprecedented resolution and sensitivity from long-wavelength (orange-red) visible light, through near-infrared to the mid-infrared (0.6 to 27 micrometers). While Hubble has a  mirror, the JWST features a larger and segmented  primary mirror and will be located near the Earth–Sun L point. A large sunshield will keep its mirror and four science instruments below .

text: The James Webb Space Telescope (JWST), previously known as Next Generation Space Telescope (NGST), is a

text: Flagship-class

text: space observatory

text: under construction and scheduled to launch in October 2018. The JWST will offer unprecedented resolution and sensitivity from long-wavelength (orange-red) visible light, through near-infrared to the

text: mid-infrared

text: (0.6 to 27 micrometers). While Hubble has a  mirror, the JWST features a larger and segmented

text: primary mirror

text: and will be located near the Earth–Sun

text: L

text: point. A large

text: sunshield

text: will keep its

text: mirror

text: and four science instruments below .

text: The stadia marks are set a specific distance apart. The distance is chosen so that there is a fixed, integer ratio between the distance observed between the marks and the distance from the telescope to the measuring device observed. This is known as the stadia constant or stadia interval factor. For example, a typical stadia mark pair are set so that the ratio is 100. If one observes a stadia rod, rule or levelling rod with the telescope and sees that the rod spans 0.5m between the marks (the stadia interval), then the distance from the instrument to the rod is:

text: The stadia marks are set a specific distance apart. The distance is chosen so that there is a fixed, integer ratio between the distance observed between the marks and the distance from the telescope to the measuring device observed. This is known as the stadia constant or stadia interval factor. For example, a typical stadia mark pair are set so that the ratio is 100. If one observes a stadia rod, rule or

text: levelling rod

text: with the telescope and sees that the rod spans 0.5m between the marks (the stadia interval), then the distance from the instrument to the rod is:

text: Very-long-baseline interferometry (VLBI) is a type of astronomical interferometry used in radio astronomy. In VLBI a signal from an astronomical radio source, such as a quasar, is collected at multiple radio telescopes on Earth. The distance between the radio telescopes is then calculated using the time difference between the arrivals of the radio signal at different telescopes. This allows observations of an object that are made simultaneously by many radio telescopes to be combined, emulating a telescope with a size equal to the maximum separation between the telescopes.

text: Very-long-baseline interferometry (VLBI) is a type of

text: astronomical interferometry

text: used in

text: radio astronomy

text: . In VLBI a signal from an

text: astronomical radio source

text: , such as a

text: quasar

text: , is collected at multiple radio telescopes on Earth. The distance between the radio telescopes is then calculated using the time difference between the arrivals of the radio signal at different telescopes. This allows observations of an object that are made simultaneously by many radio telescopes to be combined, emulating a telescope with a size equal to the maximum separation between the telescopes.

text: Radio waves are a type of electromagnetic radiation with wavelengths in the electromagnetic spectrum longer than infrared light. Like all other electromagnetic waves, they travel at the speed of light. Naturally occurring radio waves are made by lightning, or by certain astronomical objects. Artificially generated radio waves are used for fixed and mobile radio communication, broadcasting, radar and other navigation systems, satellite communication, computer networks and innumerable other applications. In addition, almost any wire carrying alternating current will radiate some of the energy away as radio waves; these are mostly termed interference. Different frequencies of radio waves have different propagation characteristics in the Earth's atmosphere; long waves may bend at the rate of the curvature of the Earth and may cover a part of the Earth very consistently, shorter waves travel around the world by multiple reflections off the ionosphere and the Earth. Much shorter wavelengths bend or reflect very little and travel along the line of sight.

text: The observatory is equipped with reflecting telescopes ranging from four inches to 20 inches in diameter.  The largest telescope is a one-tenth scale model of the Hale telescope at Mount Palomar.  The smaller telescopes were assembled by the Elmira-Corning Astronomical Society.  Additionally, the observatory maintains an eight-inch Schmidt–Cassegrain telescope and a solar telescope.

text: The observatory is equipped with

text: reflecting telescope

text: s ranging from four inches to 20 inches in diameter.  The largest telescope is a one-tenth scale model of the

text: Hale telescope

text: at

text: Mount Palomar

text: .  The smaller telescopes were assembled by the Elmira-Corning Astronomical Society.  Additionally, the observatory maintains an eight-inch

text: Schmidt–Cassegrain telescope

text: and a

text: solar telescope

text: In 1762, Lomonosov presented an improved design of a reflecting telescope to the Russian Academy of Sciences forum. His telescope had its primary mirror adjusted at an angle of four degrees to the telescope's axis. This made the image focus at the side of the telescope tube, where the observer could view the image with an eyepiece without blocking the image. However, this invention was not published until 1827, so this type of telescope has become associated with a similar design by William Herschel, the Herschelian telescope.

text: In 1762, Lomonosov presented an improved design of a

text: reflecting telescope

text: to the

text: Russian Academy of Sciences

text: forum. His telescope had its

text: primary mirror

text: adjusted at an angle of four degrees to the telescope's axis. This made the image focus at the side of the telescope tube, where the observer could view the image with an

text: eyepiece

text: without blocking the image. However, this invention was not published until 1827, so this type of telescope has become associated with a similar design by

text: William Herschel

text: , the

text: Herschelian telescope

text: When a company requires a break in service of its permatemps, the result is often that those employees regularly cycle between two companies instead of having back-to-back assignments. Other permatemps plan for personal breaks and simply use the time as vacation. In most cases, they are eligible for unemployment insurance as long as they nominally look for work.  This form of permatemping may be attractive to those not wanting a steady, full-time, or year-round position, or not wanting to be committed to one position or one employer.

text: When a company requires a break in service of its permatemps, the result is often that those employees regularly cycle between two companies instead of having back-to-back assignments. Other permatemps plan for personal breaks and simply use the time as vacation. In most cases, they are eligible for

text: unemployment insurance

text: as long as they nominally look for work.  This form of permatemping may be attractive to those not wanting a steady, full-time, or year-round position, or not wanting to be committed to one position or one employer.

text: There are three primary types of optical telescope:

text: The designers project further improvements.  These include improved projectile technologies such as environmentally friendly bullets and a change in bullet size in order to increase combat effectiveness, as well as the integration of electronics such as ammunition count readouts, lasers, optical sights, rangefinders, and bullet drop compensation. The Army is pursuing cased telescoped ammunition.  This development is far along, and they say a new LMG could be fielded within two years (2014) with unequivocal support.  The Marine Corps is pursuing caseless ammunition, which is less developed and will take several more years to refine. A compact version is also being developed with a 4-inch shorter barrel and folding, telescoping buttstock. The 5.56 mm LSAT machine gun has been renamed the Cased Telescoped Light Machine Gun (CT LMG).

text: The designers project further improvements.  These include improved projectile technologies such as environmentally friendly bullets and a change in bullet size in order to increase combat effectiveness, as well as the integration of electronics such as ammunition count readouts, lasers, optical sights, rangefinders, and

text: bullet drop compensation

text: . The Army is pursuing

text: cased telescoped ammunition

text: .  This development is far along, and they say a new LMG could be fielded within two years (2014) with unequivocal support.  The Marine Corps is pursuing

text: caseless ammunition

text: , which is less developed and will take several more years to refine. A compact version is also being developed with a 4-inch shorter barrel and folding, telescoping buttstock. The 5.56 mm LSAT machine gun has been renamed the Cased Telescoped Light Machine Gun (CT LMG).

text: It was said that Rev. Father Jesus, in charge of the parish of Gumaca possessed a telescope. Almost every time he looked through his telescope to see whether Moro Vintas were coming. He reached out a focus on the sandy shore of Ilangin, the present sitio of the barrio of Gordon. It came to his mind that an Ermita should be built in that place. So he summoned the leaders of the settlers to congregate and encouraged them to settle at Ilangin in order to make a vesita and build on Ermita.

text: KAT-7 is a radio telescope constructed in the Northern Cape of South Africa. Part of the Karoo Array Telescope project, it is the precursor engineering test bed to the larger MeerKAT telescope, but it has become a science instrument in its own right. The construction was completed in 2011 and commissioned in 2012. It also served as a technology demonstrator for South Africa's bid to host the Square Kilometre Array. KAT-7 is the first Radio telescope to be built with a composite reflector and uses a stirling pump for 75 K cryogenic cooling. The telescope was built to test various system for the MeerKAT array, from the ROACH correlators designed and manufactured in Cape Town, now used by various telescopes internationally, to composite construction techniques.  With the short baselines the telescope is suited to observing diffuse sources, but will begin VLBI observation in 2013.

text: KAT-7 is a

text: radio telescope

text: constructed in the

text: Northern Cape

text: of

text: South Africa

text: . Part of the

text: Karoo

text: Array Telescope project, it is the precursor engineering test bed to the larger

text: MeerKAT

text: telescope, but it has become a science instrument in its own right. The construction was completed in 2011 and commissioned in 2012. It also served as a technology demonstrator for

text: South Africa

text: 's bid to host the

text: Square Kilometre Array

text: . KAT-7 is the first Radio telescope to be built with a composite reflector and uses a

text: stirling pump

text: for 75 K cryogenic cooling. The telescope was built to test various system for the MeerKAT array, from the

text: ROACH

text: correlators

text: designed and manufactured in

text: Cape Town

text: , now used by various telescopes internationally, to composite construction techniques.  With the short baselines the telescope is suited to observing diffuse sources, but will begin

text: VLBI

text: observation in 2013.

text: Aperture of the primary mirror alone can be poor measure of a reflective telescope's significance; for example, the Hubble Space Telescope has only a  primary mirror. In addition, many large or significant telescopes are not optical and/or reflecting. However, many famous optical telescopes have had large apertures on their primary mirror with corresponding good angular resolution and light collecting area, with useful  numbers.

text: Aperture of the primary mirror alone can be poor measure of a reflective telescope's significance; for example, the

text: Hubble Space Telescope

text: has only a  primary mirror. In addition, many large or significant telescopes are not optical and/or reflecting. However, many famous optical telescopes have had large apertures on their primary mirror with corresponding good

text: angular resolution

text: and light collecting area, with useful

text: numbers

text: The Lovell Telescope was used to track both Soviet and American probes aimed at the Moon in the late 1950s and early 1960s. In terms of American space probes, the telescope tracked Pioneer 1 from 11 to 13 November 1958, Pioneer 3 in December 1958, and Pioneer 4 in March 1959. The telescope tracked Pioneer 5 between 11 March and 26 June 1960, and was also used to send commands to the probe, including the one to separate the probe from its carrier rocket and the ones to turn on the more powerful transmitter when the probe was 8 million miles (12.9 million km) away. It also received data from Pioneer 5, and was the only telescope in the world capable of doing so at the time. The last signal was picked up from the probe at a distance of 36.2 million kilometers on the 26 June 1960.

text: The Lovell Telescope was used to track both

text: Soviet

text: and American probes aimed at the

text: Moon

text: in the late 1950s and early 1960s. In terms of American space probes, the telescope tracked

text: Pioneer 1

text: from 11 to 13 November 1958,

text: Pioneer 3

text: in December 1958, and

text: Pioneer 4

text: in March 1959. The telescope tracked

text: Pioneer 5

text: between 11 March and 26 June 1960, and was also used to send commands to the probe, including the one to separate the probe from its carrier rocket and the ones to turn on the more powerful transmitter when the probe was 8 million miles (12.9 million km) away. It also received data from Pioneer 5, and was the only telescope in the world capable of doing so at the time. The last signal was picked up from the probe at a distance of 36.2 million kilometers on the 26 June 1960.

text: The observatory started out with a single 15 cm Cassegrain telescope by Zeiss. Then in August 1969 it was replaced by a 60 cm Cassegrain telescope, mounted in the same 5 m dome of the previous one. Primary focal length is 2400 mm, while focal length at Cassegrain focus is 7500 mm, with a relative aperture of f/12.5. Field of view at Cassegrain focus is 20'. Main instrument also accommodates a smaller 110 mm refractor finder with a focal length of 750 mm and a field of view of 2 degrees. Between 1969 and 1980 it was the biggest telescope on the Balkans to be eclipsed by the 2 m RCC telescope of Rozhen Observatory, which held this title until 2007. The purchase of the telescope was worth 200 000 leva, an enormous value at that time. Both instruments were manufactured by the German Carl Zeiss AG. The connections established with the manufacturer later helped purchase and equip instruments for the Bulgarian National Rozhen Observatory, which also has a twin 60 cm Cassegrain telescope. Currently the 15 cm telescope is used for visitor demonstrations only. In 1994 another catadioptric telescope was added in a separate, smaller dome - a 14-inch (36 cm) Schmidt-Cassegrain model.

text: The observatory started out with a single 15 cm

text: Cassegrain

text: telescope by

text: Zeiss

text: . Then in August 1969 it was replaced by a 60 cm Cassegrain telescope, mounted in the same 5 m dome of the previous one. Primary

text: focal length

text: is 2400 mm, while focal length at Cassegrain focus is 7500 mm, with a

text: relative aperture

text: of f/12.5. Field of view at Cassegrain focus is 20'. Main instrument also accommodates a smaller 110 mm

text: refractor

text: finder with a focal length of 750 mm and a field of view of 2 degrees. Between 1969 and 1980 it was the biggest telescope on the

text: Balkans

text: to be eclipsed by the 2 m RCC telescope of Rozhen Observatory, which held this title until 2007. The purchase of the telescope was worth 200 000

text: leva

text: , an enormous value at that time. Both instruments were manufactured by the German

text: Carl Zeiss AG

text: . The connections established with the manufacturer later helped purchase and equip instruments for the Bulgarian National

text: Rozhen Observatory

text: , which also has a twin 60 cm Cassegrain telescope. Currently the 15 cm telescope is used for visitor demonstrations only. In 1994 another

text: catadioptric

text: telescope was added in a separate, smaller dome - a 14-inch (36 cm)

text: Schmidt-Cassegrain

text: model.

text: Schlieren is the German plural of schliere, which is German for the English word streak. Schlieren are visible streaks produced in a transparent medium as a result of variations in the medium's density leading to variations in refractive index.  Anything that disturbs the atmosphere may be detected (Schlieren Photography) because of the Schlieren effect caused by that atmospheric disturbance.  This type of Measurement and signature intelligence (MASINT) detection falls under the category of Electro-optical MASINT.  A telephoto or telescopic picture of a jet passing between the photographer and a full moon will sometimes show the outline of the aircraft as well as the atmospheric distortions of the exhaust plumes.  This passive principle can be used at all wavelengths of the electromagnetic spectrum.  Passive signature intelligence has captured stealth aircraft in flight by accident, when such aircraft fly between Earth imaging satellites and ground (can be seen in products like Google Earth).  Once a stealth signature has been captured, it may be loaded into a database library for an active and live satellite search at any point in the future.  Ground at past versus ground at present differential comparisons can be made to determine flight paths and altitudes of stealth aircraft.  This disturbance and disturbing influence method has been used for finding ships at sea through wake generation tracking and even in Wilson cloud chambers for particle discovery and tracking. The key principle is that the disturbance is much more visible in area and volume than the disturbing point source and converges attention to the much smaller disturbing source.

text: Schlieren is the German plural of schliere, which is German for the English word streak. Schlieren are visible streaks produced in a transparent medium as a result of variations in the medium's density leading to variations in refractive index.  Anything that disturbs the atmosphere may be detected (

text: Schlieren Photography

text: ) because of the

text: Schlieren effect

text: caused by that

text: atmospheric disturbance

text: .  This type of

text: Measurement and signature intelligence

text: (MASINT) detection falls under the category of

text: Electro-optical MASINT

text: .  A telephoto or telescopic picture of a jet passing between the photographer and a full moon will sometimes show the outline of the aircraft as well as the atmospheric distortions of the exhaust plumes.  This passive principle can be used at all wavelengths of the electromagnetic spectrum.  Passive signature intelligence has captured stealth aircraft in flight by accident, when such aircraft fly between Earth imaging satellites and ground (can be seen in products like

text: Google Earth

text: ).  Once a stealth signature has been captured, it may be loaded into a database library for an active and live satellite search at any point in the future.  Ground at past versus ground at present differential comparisons can be made to determine flight paths and altitudes of stealth aircraft.  This disturbance and disturbing influence method has been used for finding ships at sea through wake generation tracking and even in

text: Wilson cloud chamber

text: s for particle discovery and tracking. The key principle is that the disturbance is much more visible in area and volume than the disturbing point source and converges attention to the much smaller disturbing source.

text: Adam and Jamie look back on their time hosting the show and devise four grand-scale sendoffs.

text: STS-82 Discovery (February 11–21, 1997), the second Hubble Space Telescope (HST) maintenance mission, was launched at night and returned to a night landing at Kennedy Space Center, Florida. During the flight, Dr. Hawley's primary role was to operate the Shuttle's 50-foot robot arm to retrieve and redeploy the HST following completion of upgrades and repairs. Dr. Hawley also operated the robot arm during five space walks in which two teams installed two new spectrometers and eight replacement instruments. They also replaced insulation patches over three compartments containing key data-processing, electronics and scientific-instrument telemetry packages. HST was then redeployed and boosted to a higher orbit. The flight was completed in 149 orbits covering 3.8 million miles in 9 days, 23 hours, 37 minutes.

text: Discovery (February 11–21, 1997), the second

text: Hubble Space Telescope

text: (HST) maintenance mission, was launched at night and returned to a night landing at Kennedy Space Center, Florida. During the flight, Dr. Hawley's primary role was to operate the Shuttle's 50-foot robot arm to retrieve and redeploy the HST following completion of upgrades and repairs. Dr. Hawley also operated the robot arm during five space walks in which two teams installed two new spectrometers and eight replacement instruments. They also replaced insulation patches over three compartments containing key data-processing, electronics and scientific-instrument telemetry packages. HST was then redeployed and boosted to a higher orbit. The flight was completed in 149 orbits covering 3.8 million miles in 9 days, 23 hours, 37 minutes.

text: In 1886-1888 the German physicist Heinrich Hertz conducted his series of experiments that proved the existence of electromagnetic waves (including radio waves), predicted in equations developed in 1862–4 by the Scottish physicist James Clerk Maxwell. In Hertz's 1887 experiment he found that these waves would transmit through different types of materials and also would reflect off metal surfaces in his lab as well as conductors and dielectrics. The nature of these waves being similar to visible light in their ability to be reflected, refracted, and polarized would be shown by Hertz and subsequent experiments by other physicists.

text: In 1886-1888 the German

text: physicist

text: Heinrich Hertz

text: conducted his series of experiments that proved the existence of

text: electromagnetic waves

text: (including

text: radio wave

text: s), predicted in equations developed in 1862–4 by the Scottish physicist

text: James Clerk Maxwell

text: . In Hertz's 1887 experiment he found that these waves would transmit through different types of materials and also would reflect off metal surfaces in his lab as well as

text: conductor

text: s and

text: dielectric

text: s. The nature of these waves being similar to

text: visible light

text: in their ability to be reflected, refracted, and polarized would be shown by Hertz and subsequent experiments by other physicists.

text: The basic design of MROI was completed in 2006. Construction of the facility began in August 2006 with the BCF building, which was completed in 2008. In July 2007, the contract for the design of the ten 1.4 m telescopes was awarded to Advanced Mechanical and Optical Systems S.A. (AMOS) of Belgium.  In 2009 the design of the infrastructure of interferometer arms was completed, as was the design for the telescope enclosures.  In 2010 construction of the arms began.  Also in 2010 the first delay line was installed in the BCF.

text: The basic design of MROI was completed in 2006. Construction of the facility began in August 2006 with the BCF building, which was completed in 2008. In July 2007, the contract for the design of the ten 1.4 m telescopes was awarded to Advanced Mechanical and Optical Systems S.A. (AMOS) of

text: Belgium

text: .  In 2009 the design of the infrastructure of interferometer arms was completed, as was the design for the telescope enclosures.  In 2010 construction of the arms began.  Also in 2010 the first delay line was installed in the BCF.

text: In certain physics applications such as in the computation of bands in a periodic volume, it is often the case that the elements of a matrix will be very complicated functions of frequency and wavenumber, and the matrix will be non-singular for most combinations of frequency and wavenumber, but will also be singular for certain specific combinations. By finding which combinations of frequency and wavenumber drive the determinant of the matrix to zero, the propagation characteristics of the medium may be determined. Relations of this type, between frequency and wavenumber, are known as dispersion relations and some physical systems may admit many different kinds of dispersion relations. An example from electromagnetics is the ordinary waveguide, which may admit numerous dispersion relations, each associated with a unique mode of the waveguide. Each propagation mode of the waveguide is known as an eigenfunction solution (or eigenmode solution) to Maxwell's equations in the waveguide. Free space also admits eigenmode (natural mode) solutions (known more commonly as plane waves), but with the distinction that for any given frequency, free space admits a continuous modal spectrum, whereas waveguides have a discrete mode spectrum.  In this case the dispersion relation is linear, as in section 1.2.

text: In certain physics applications such as in the

text: computation of bands in a periodic volume

text: , it is often the case that the elements of a matrix will be very complicated functions of frequency and wavenumber, and the matrix will be non-singular for most combinations of frequency and wavenumber, but will also be singular for certain specific combinations. By finding which combinations of frequency and wavenumber drive the determinant of the matrix to zero, the propagation characteristics of the medium may be determined. Relations of this type, between frequency and wavenumber, are known as dispersion relations and some physical systems may admit many different kinds of dispersion relations. An example from electromagnetics is the ordinary waveguide, which may admit numerous dispersion relations, each associated with a unique mode of the waveguide. Each propagation mode of the waveguide is known as an

text: eigenfunction

text: solution (or eigenmode solution) to Maxwell's equations in the waveguide. Free space also admits eigenmode (natural mode) solutions (known more commonly as plane waves), but with the distinction that for any given frequency, free space admits a continuous modal spectrum, whereas waveguides have a discrete mode spectrum.  In this case the dispersion relation is linear, as in section 1.2.

text: The SXI aboard GOES 12 is a Wolter Type I (Wolter telescope) grazing incidence X-ray telescope designed to record coronal images in continuous sequence at 1-minute intervals. The Solar X-ray Imager obtains images at multiple wavelengths on the electromagnetic spectrum from 6 to 60 angstrom units (Å).  The imagery obtained by the XSI and XRS on GOES 12 allowed forecasters to see space phenomena such as coronal holes, whose geomagnetic and proton storms impact electrical grid systems on Earth as well as radio communications and satellite communications systems.

text: The SXI aboard GOES 12 is a Wolter Type I (

text: Wolter telescope

text: ) grazing incidence X-ray telescope designed to record

text: corona

text: l images in continuous sequence at 1-minute intervals. The Solar X-ray Imager obtains images at multiple

text: wavelengths

text: on the

text: electromagnetic spectrum

text: from 6 to 60

text: angstrom unit

text: s (Å).  The imagery obtained by the XSI and XRS on GOES 12 allowed forecasters to see space phenomena such as

text: coronal hole

text: s, whose

text: geomagnetic

text: and

text: proton

text: storms impact

text: electrical grid

text: systems on Earth as well as

text: radio communications

text: and satellite communications systems.

text: During this time period, Pearl Jam became known for its intense live performances. Vedder participated in stage diving as well as crowd surfing. Looking back at this time, Vedder said:

text: During this time period, Pearl Jam became known for its intense live performances. Vedder participated in

text: stage diving

text: as well as

text: crowd surfing

text: . Looking back at this time, Vedder said:

text: The original design of WFIRST (Design Reference Mission 1), studied in 2011–2012, featured a  diameter unobstructed three-mirror anastigmat telescope.It contained a single instrument, a visible to near-infrared imager/slitless prism spectrometer. In 2012, another possibility emerged: NASA could use a second-hand National Reconnaissance Office telescope made by Harris Corporation to accomplish a mission like the one planned for WFIRST. NRO offered to donate two telescopes, the same size as the Hubble Space Telescope but with a shorter focal length and hence a wider field of view. This provided important political momentum to the project, even though the telescope represents only a modest fraction of the cost of the mission and the boundary conditions from the NRO design may push the total cost over that of a fresh design. This mission concept, called WFIRST-AFTA (Astrophysics Focused Telescope Assets), was matured by a scientific and technical team; this mission is now the only present NASA plan for the use of the NRO telescopes.The WFIRST baseline design includes a coronagraph to enable the direct imaging of exoplanets.

text: The original design of WFIRST (Design Reference Mission 1), studied in 2011–2012, featured a  diameter unobstructed

text: three-mirror anastigmat

text: telescope.It contained a single instrument, a visible to near-infrared imager/slitless prism spectrometer. In 2012, another possibility emerged: NASA could use a second-hand

text: National Reconnaissance Office

text: telescope made by

text: Harris Corporation

text: to accomplish a mission like the one planned for WFIRST.

entity_name: 2012 National Reconnaissance Office space telescope donation to NASA

text: NRO offered to donate two telescopes

text: , the same size as the

text: Hubble Space Telescope

text: but with a shorter focal length and hence a wider field of view. This provided important political momentum to the project, even though the telescope represents only a modest fraction of the cost of the mission and the boundary conditions from the NRO design may push the total cost over that of a fresh design. This mission concept, called WFIRST-AFTA (Astrophysics Focused Telescope Assets), was matured by a scientific and technical team; this mission is now the only present NASA plan for the use of the NRO telescopes.The WFIRST baseline design includes a

text: coronagraph

text: to enable the

text: direct imaging

text: of

text: exoplanet

text: s.

text: Further concepts for advanced 21st-century space telescopes include the Advanced Technology Large-Aperture Space Telescope, a conceptualized 8- to 16-meter (320- to 640-inch) optical space telescope that if realized could be a more direct successor to HST, with the ability to observe and photograph astronomical objects in the visible, ultraviolet, and infrared wavelengths, with substantially better resolution than Hubble or the Spitzer Space telescope. This effort is being planned for the 2025–2035 time frame.

text: Further concepts for advanced 21st-century space telescopes include the

entity_name: Advanced Technology Large-Aperture Space Telescope

text: Advanced Technology Large-Aperture Space Telescope

text: , a conceptualized 8- to 16-meter (320- to 640-inch) optical space telescope that if realized could be a more direct successor to HST, with the ability to observe and photograph astronomical objects in the visible, ultraviolet, and infrared wavelengths, with substantially better resolution than Hubble or the

text: Spitzer Space telescope

text: . This effort is being planned for the 2025–2035 time frame.

text: Integral field spectroscopy (IFS) has become an important sub-discipline of astronomy with the proliferation of large aperture, high-resolution telescopes where there is a need to study the spectra of extended objects as a function of position, or of clusters of many discrete stars or point sources in a small field.  Such spectroscopic investigations have previously been carried out with long-slit spectrographs in which the spectrum is dispersed perpendicular to the slit, and spatial resolution is obtained in the dimension along the slit.  Then by stepping the position of the slit, the spectrum of points in the imaged field can be obtained, but the process is comparatively slow, and wasteful of potentially restricted telescope time.  Integral field spectrographs are used to speed up such observations by simultaneously obtaining spectra in a two-dimensional field. As the spatial resolution of telescopes in space (and also of ground-based instruments using adaptive optics) has rapidly improved in recent years, the need for such multiplexed instruments has become more and more pressing.

text: Integral field spectroscopy (IFS) has become an important sub-discipline of astronomy with the proliferation of large aperture, high-resolution telescopes where there is a need to study the

text: spectra

text: of extended objects as a function of position, or of clusters of many discrete stars or point sources in a small field.  Such

text: spectroscopic

text: investigations have previously been carried out with

text: long-slit spectrographs

text: in which the spectrum is dispersed perpendicular to the slit, and spatial resolution is obtained in the dimension along the slit.  Then by stepping the position of the slit, the spectrum of points in the imaged field can be obtained, but the process is comparatively slow, and wasteful of potentially restricted telescope time.  Integral field spectrographs are used to speed up such observations by simultaneously obtaining spectra in a two-dimensional field. As the spatial resolution of telescopes in space (and also of ground-based instruments using adaptive optics) has rapidly improved in recent years, the need for such multiplexed instruments has become more and more pressing.

text: In January 2003 an extreme bushfire destroyed the telescopes and buildings at Mount Stromlo - the temperatures were so high that the aluminium dome itself caught fire and melted onto the telescope, shattering the mirror.The fire-ravaged remnants of the telescope were transferred to Museum Victoria, which had previously acquired discarded parts of the original telescope in 1984.

text: In January 2003 an

text: extreme bushfire destroyed the telescopes and buildings

text: at Mount Stromlo - the temperatures were so high that the aluminium dome itself caught fire and melted onto the telescope, shattering the mirror.The fire-ravaged remnants of the telescope were transferred to

text: Museum Victoria

text: , which had previously acquired discarded parts of the original telescope in 1984.

text: Demand characteristicsOther psychologists believe that the telescoping errors that have been reported in studies are not due to a phenomenon of memory, but demand characteristics. Responses to questions about the frequency of behavior can be biased because of demand characteristics. Respondents may provide too much information, rather than too little, because they are trying to provide as much useful information as possible, and therefore over-report the frequency of events. Some researchers perceive this over reporting as telescoping because people are including events beyond the given period, but the over reporting could be due to the demand characteristics of the study.  Demand characteristics can explain the appearance of forward telescoping, but cannot explain backwards telescoping and can not explain the inaccurate recall of dates when respondents are not led to believe that a certain answer is desirable.

text: Relying on more than 150 tools and crew aids, Lee and Smith performed EVAs 1, 3 and 5, with Harbaugh and Tanner performing EVAs 2 and 4. EVA 1 began at 11:34 pm EST, 13 February, and lasted six hours, 42 minutes. One of Hubble's solar arrays was unexpectedly disturbed by a gust of air from Discovery's airlock when it was depressurized, but was not damaged. Lee and Smith removed two scientific instruments from Hubble, the Goddard High Resolution Spectrograph (GHRS) and Faint Object Spectrograph (FOS), and replaced them with the Space Telescope Imaging Spectrograph (STIS) and Near Infrared Camera and Multi-Object Spectrometer (NICMOS), respectively. STIS expected to shed further light on supermassive black holes. NICMOS features more capable infrared detectors and gave astronomers their first clear view of the universe at near infrared wavelengths between 0.8 and 2.5 micrometers.

text: Relying on more than 150 tools and crew aids, Lee and Smith performed EVAs 1, 3 and 5, with Harbaugh and Tanner performing EVAs 2 and 4. EVA 1 began at 11:34 pm EST, 13 February, and lasted six hours, 42 minutes. One of Hubble's solar arrays was unexpectedly disturbed by a gust of air from Discovery's airlock when it was depressurized, but was not damaged. Lee and Smith removed two scientific instruments from Hubble, the

text: Goddard High Resolution Spectrograph

text: (GHRS) and

text: Faint Object Spectrograph

text: (FOS), and replaced them with the

text: Space Telescope Imaging Spectrograph

text: (STIS) and

text: (NICMOS), respectively. STIS expected to shed further light on supermassive black holes. NICMOS features more capable infrared detectors and gave astronomers their first clear view of the universe at near infrared wavelengths between 0.8 and 2.5 micrometers.

text: The Swedish-ESO Submillimetre Telescope (SEST) was a radio telescope of diameter 15 metres located at the La Silla Observatory in Chile. The telescope was built in 1987 as a combined project between ESO and Onsala Space Observatory, with contributions from Finland and Australia. It was then the only large telescope for submillimetre astronomy in the southern hemisphere. It was decommissioned in 2003.

text: The Swedish-ESO Submillimetre Telescope (SEST) was a

text: radio telescope

text: of diameter 15 metres located at the

text: La Silla Observatory

text: in

text: Chile

text: . The telescope was built in 1987 as a combined project between

text: ESO

text: and

text: Onsala Space Observatory

text: , with contributions from Finland and Australia. It was then the only large telescope for

text: submillimetre astronomy

text: in the southern hemisphere. It was decommissioned in 2003.

text: Maxwell's equations predicted an infinite number of frequencies of electromagnetic waves, all traveling at the speed of light. This was the first indication of the existence of the entire electromagnetic spectrum.

text: Maxwell's equations

text: predicted an infinite number of frequencies of

text: electromagnetic waves

text: , all traveling at the speed of light. This was the first indication of the existence of the entire electromagnetic

text: spectrum

text: In the wave equation for the electromagnetic field:

text: In the

text: wave equation

text: for the electromagnetic field:

text: Most astronomical observations are conducted by measuring photons (electromagnetic waves) which originate beyond the sky.  The molecules in the Earth's atmosphere, however, absorb and emit their own light, especially in the visible and near-IR portion of the spectrum, and any ground-based observation is subject to contamination from these telluric (earth-originating) sources.  Water vapor, oxygen, and OH are some of the more important molecules in telluric contamination.  Water contamination was particularly pronounced in the Mount Wilson solar Doppler measurements.

text: Most astronomical observations are conducted by measuring

text: photon

text: s (

text: electromagnetic waves

text: ) which originate beyond the sky.  The molecules in the Earth's atmosphere, however,

text: absorb

text: and

text: emit

text: their own light, especially in the visible and

text: near-IR

text: portion of the

text: spectrum

text: , and any ground-based observation is subject to contamination from these telluric (earth-originating) sources.  Water vapor, oxygen, and OH are some of the more important molecules in telluric contamination.  Water contamination was particularly pronounced in the Mount Wilson solar Doppler measurements.

text: A telescoping stock (alternatively collapsing stock) is a stock on a firearm that telescopes or folds in on itself in order to become more compact. Telescoping stocks are useful for storing a rifle or weapon in a space that it would not normally fit in. The user can either fold in the stock to make the weapon easier to handle, or extend it for better accuracy. Finally, some telescoping stocks, such as those on the M4 carbine, have more than one setting, allowing the stock to be adjusted for different users. In the context of the U.S. Federal Assault Weapons Ban, the National Rifle Association deemed telescoping stocks a "cosmetic feature".

text: A telescoping stock (alternatively collapsing stock) is a

text: stock

text: on a

text: firearm

text: that telescopes or folds in on itself in order to become more compact. Telescoping stocks are useful for storing a

text: rifle

text: or weapon in a space that it would not normally fit in. The user can either fold in the stock to make the weapon easier to handle, or extend it for better accuracy. Finally, some telescoping stocks, such as those on the

text: M4 carbine

text: , have more than one setting, allowing the stock to be adjusted for different users. In the context of the U.S.

text: Federal Assault Weapons Ban

text: , the

text: National Rifle Association

text: deemed telescoping stocks a "cosmetic feature".

text: Article 112 guarantees parties and movements declaring themselves in opposition to the government the right to freely criticize the government and formulate their own alternative policies, and for these purposes they have access to official information and documentation, access to public communications and the electromagnetic spectrum and the right to reply. The 2015 constitutional reform has created seats in elected bodies for runner-up candidates in presidential, gubernatorial and mayoral elections; specifically, the second placed candidate for President, Vice President, governor and mayor shall have the right to hold a seat in the Senate, Chamber of Representatives, departmental assembly and municipal council respectively. This rule will be applicable beginning with the 2018 presidential and congressional elections.

text: Construction on the Schmidt telescope began in 1939 and it was completed in 1948.  It was named the Samuel Oschin telescope in 1986. Before that it was just called the 48-inch Schmidt.

text: Construction on the Schmidt telescope began in 1939 and it was completed in 1948.  It was named the

text: Samuel Oschin

text: telescope in 1986. Before that it was just called the 48-inch Schmidt.

text: Alvan Clark (March 8, 1804 – August 19, 1887), born in Ashfield, Massachusetts, the descendant of a Cape Cod whaling family of English ancestry, was an American astronomer and telescope maker.  He was a portrait painter and engraver (ca.1830s-1850s), and at the age of 40 became involved in telescope making. Using glass blanks made by Chance Brothers of Birmingham and Feil-Mantois of Paris, his firm Alvan Clark & Sons ground lenses for refracting telescopes, including the largest in the world at the time: the  at Dearborn Observatory at the Old University of Chicago (the lens was originally intended for Ole Miss), the two  telescopes at the United States Naval Observatory and McCormick Observatory, the  at Pulkovo Observatory (destroyed in the Siege of Leningrad; only the lens survives), the  telescope at Lick Observatory (still third-largest) and later the  at Yerkes Observatory, which remains the largest successful refracting telescope in the world.  One of Clark's sons, Alvan Graham Clark, discovered the dim companion of Sirius. His other son was George Bassett Clark; both sons were partners in the firm.

text: Alvan Clark (March 8, 1804 – August 19, 1887), born in

text: Ashfield, Massachusetts

text: , the descendant of a Cape Cod whaling family of English ancestry, was an American

text: astronomer

text: and

text: telescope

text: maker.  He was a portrait painter and engraver (ca.1830s-1850s), and at the age of 40 became involved in telescope making. Using glass blanks made by

text: Chance Brothers

text: of Birmingham and

text: Feil-Mantois

text: of Paris, his firm

text: Alvan Clark & Sons

text: ground lenses for

text: refracting telescope

text: s, including the largest in the world at the time: the  at

text: Dearborn Observatory

text: at the

text: Old University of Chicago

text: (the lens was originally intended for

text: Ole Miss

text: ), the two  telescopes at the

text: United States Naval Observatory

text: and

text: McCormick Observatory

text: , the  at

text: Pulkovo Observatory

text: (destroyed in the

text: Siege of Leningrad

text: ; only the lens survives), the  telescope at

text: Lick Observatory

text: (still third-largest) and later the  at

text: Yerkes Observatory

text: , which remains the largest successful refracting telescope in the world.  One of Clark's sons,

text: Alvan Graham Clark

text: , discovered the dim companion of

text: Sirius

text: . His other son was

text: George Bassett Clark

text: ; both sons were partners in the firm.

text: Originally built to observe gamma-ray bursts (GRBs) – deaths of massive stars and births of black holes – simultaneously at multiple wavelengths when only tens of seconds old, PROMPT and its mission have both expanded significantly.  PROMPT, and increasingly all of Skynet’s telescopes, now serve a rapidly growing, state, national, and international user community as a broad-based facility for small-telescope science.

text: Originally built to observe

text: gamma-ray burst

text: s (GRBs) – deaths of massive stars and births of

text: black hole

text: s – simultaneously at multiple wavelengths when only tens of seconds old, PROMPT and its mission have both expanded significantly.  PROMPT, and increasingly all of Skynet’s telescopes, now serve a rapidly growing, state, national, and international user community as a broad-based facility for small-telescope science.

text: The supernova was studied with ultraviolet, optical, and near-infrared photometry as well as optical spectra, using the Magellan telescopes in Chile, the MMT telescope in Arizona, the Gemini and Keck telescopes in Hawaii, and NASA's Swift satellite. Spectroscopically, SN 2008ha was identified as a SN 2002cx-type, a peculiar sub-class of SN Ia. SN 2008ha had a brightness period of only 10 days, which is significantly shorter than that of other SN 2002cx-like objects (~15 days) or normal Ia supernovas (~20 days). From the peak luminosity and the brightness time it was estimated that SN 2008ha generated (3.0 ± 0.9) × 10 M of Ni, had a kinetic energy of 2 × 10 ergs, and ejected 0.15 M of material.

text: The supernova was studied with ultraviolet, optical, and near-infrared

text: photometry

text: as well as optical spectra, using the

text: Magellan telescopes

text: in Chile, the

text: MMT telescope

text: in

text: Arizona

text: , the

text: Gemini

text: and

text: Keck

text: telescopes in Hawaii, and

text: NASA's Swift satellite

text: . Spectroscopically, SN 2008ha was identified as a SN 2002cx-type, a peculiar sub-class of

text: SN Ia

text: . SN 2008ha had a brightness period of only 10 days, which is significantly shorter than that of other SN 2002cx-like objects (~15 days) or normal Ia supernovas (~20 days). From the peak luminosity and the brightness time it was estimated that SN 2008ha generated (3.0 ± 0.9) × 10

text: M

text: of

text: Ni

text: , had a kinetic energy of 2 × 10

text: erg

text: s, and ejected 0.15 M of material.

text: Earphone –Earpiece –Earth's magnetic field –EDIF –EEPROM –Effective antenna gain contour –Effective boresight area –Effective data transfer rate –Effective Earth radius –Effective height –Effective input noise temperature –Effective isotropically radiated power –Effective monopole radiated power –Effective radiated power –Effective transmission rate –Efficiency factor –E-layer –Electric charge –Electric current –Electric field –Electric motor –Electric power transmission –Electric power –Electrical conduction –Electrical conductivity –Electrical connector –Electrical current –Electrical efficiency –Element –Electrical engineering –Electrical generator –Impedance –Insulation –Electrical length –Load –Electrical network –Circuit –Electrical resistance –Electrical room –Electrical signal –Electricity distribution –Electricity –Electrochemical cell –Electrochemistry –Electrode –Electrodynamics –Electrolytic capacitor –Electromagnetic environment –Electromagnetic induction –Electromagnetic interference control –Electromagnetic pulse –Electromagnetic radiation and health –Electromagnetic radiation –Electromagnetic spectrum –Electromagnetic survivability –Electromagnetism –Electrometer –Electron hole –Electron –Electronic amplifier –Electronic color code –Color code –Electronic data processing –Electronic deception –Electronic design automation –Electronic filter –Filter –Electronic imager –Electronic mixer –Electronic musical instrument –Electronic oscillator –Electronic power supply –Electronic switching system –Electronic tagging –Electronic test equipment –Electronic warfare support measures –Electronics –Electro-optic effect –Electro-optic modulator –Electro-optics –Electrostatic discharge –Electrostatics –Emergency Locator Transmitter –Emergency Position-Indicating Radio Beacon –Emitter coupled logic –End distortion –Endurability –Enhanced service –Entropy encoding –Equilibrium length –Equivalent impedance transforms -Equivalent noise resistance –Equivalent pulse code modulation noise –Error burst –Error ratio –Error-correcting code –E-skip –Examples of electrical phenomena –Extremely Low Frequency (ELF) –Eye pattern

text: Earphone

text: Earpiece

text: Earth's magnetic field

text: EDIF

text: EEPROM

text: Effective antenna gain contour

text: Effective boresight area

text: Effective data transfer rate

text: Effective Earth radius

text: Effective height

text: Effective input noise temperature

text: Effective isotropically radiated power

text: Effective monopole radiated power

text: Effective radiated power

text: Effective transmission rate

text: Efficiency factor

text: E-layer

text: Electric charge

text: Electric current

text: Electric field

text: Electric motor

text: Electric power transmission

text: Electric power

text: Electrical conduction

text: Electrical conductivity

text: Electrical connector

text: Electrical current

text: Electrical efficiency

text: Element

text: Electrical engineering

text: Electrical generator

text: Impedance

text: Insulation

text: Electrical length

text: Load

text: Electrical network

text: Circuit

text: Electrical resistance

text: Electrical room

text: Electrical signal

text: Electricity distribution

text: Electricity

text: Electrochemical cell

text: Electrochemistry

text: Electrode

text: Electrodynamics

text: Electrolytic capacitor

text: Electromagnetic environment

text: Electromagnetic induction

text: Electromagnetic interference control

text: Electromagnetic pulse

text: Electromagnetic radiation and health

text: Electromagnetic radiation

text: Electromagnetic spectrum

text: Electromagnetic survivability

text: Electromagnetism

text: Electrometer

text: Electron hole

text: Electron

text: Electronic amplifier

text: Electronic color code

text: Color code

text: Electronic data processing

text: Electronic deception

text: Electronic design automation

text: Electronic filter

text: Filter

text: Electronic imager

text: Electronic mixer

text: Electronic musical instrument

text: Electronic oscillator

text: Electronic power supply

text: Electronic switching system

text: Electronic tagging

text: Electronic test equipment

text: Electronic warfare support measures

text: Electronics

text: Electro-optic effect

text: Electro-optic modulator

text: Electro-optics

text: Electrostatic discharge

text: Electrostatics

entity_name: Emergency position-indicating radiobeacon station

text: Emergency Locator Transmitter

text: Emergency Position-Indicating Radio Beacon

text: Emitter coupled logic

text: End distortion

text: Endurability

text: Enhanced service

text: Entropy encoding

text: Equilibrium length

text: Equivalent impedance transforms

text: Equivalent noise resistance

text: Equivalent pulse code modulation noise

text: Error burst

text: Error ratio

text: Error-correcting code

text: E-skip

text: Examples of electrical phenomena

text: Extremely Low Frequency

text: (ELF) –

text: Eye pattern

text: The HEAO-1 A2 full-sky cosmic X-ray experiment (1977-1979) provided the most comprehensive data (still the most definitive) on the cosmic X-ray background broadband spectrum and large-scale structure, and a much used complete sample of the brightest extragalactic sources;  it posed the challenging "spectral paradox" just now being unraveled with new results on evolution (from deep surveys) and on individual source spectra extending into the gamma-ray band. The SSS (Solid State Spectrometer) at the focus of the HEAO-2 Einstein Observatory (1978-1981) grazing incidence telescope was the first high spectral resolution non-dispersive spectrometer to be used for X-ray astronomy, here for energies up to ~3 keV, limited by the telescope optics.

text: The HEAO-1 A2 full-sky cosmic X-ray experiment (1977-1979) provided the most comprehensive data (still the most definitive) on the cosmic X-ray background broadband spectrum and large-scale structure, and a much used complete sample of the brightest extragalactic sources;  it posed the challenging "spectral paradox" just now being unraveled with new results on evolution (from deep surveys) and on individual source spectra extending into the gamma-ray band. The SSS (Solid State Spectrometer) at the focus of the HEAO-2 Einstein Observatory (1978-1981) grazing incidence telescope was the first high spectral resolution non-dispersive spectrometer to be used for X-ray astronomy, here for energies up to ~3

text: keV

text: , limited by the telescope optics.

text: From the invention of photography in the 19th century, images have been captured using standard optical telescopes including telescope objectives adapted as early portrait lenses. Besides being used in an astronomical role in astrophotography, telescopes are adapted as long-focus lenses in nature photography, surveillance, machine vision and long-focus microscopy.

text: From the invention of photography in the 19th century, images have been captured using standard

text: optical telescope

text: s including telescope

text: objectives

text: adapted as early portrait lenses. Besides being used in an astronomical role in

text: astrophotography

text: , telescopes are adapted as long-focus lenses in nature photography,

text: surveillance

text: machine vision

text: and long-focus microscopy.

text: Typical materials for ATR crystals include germanium, KRS-5 and zinc selenide, while silicon is ideal for use in the Far-IR region of the electromagnetic spectrum. The excellent mechanical properties of diamond make it an ideal material for ATR, particularly when studying very hard solids, but its much higher cost means it is less widely used. The shape of the crystal depends on the type of spectrometer and nature of the sample. With dispersive spectrometers, the crystal is a rectangular slab with chamfered edges, seen in cross-section in the illustrations. Other geometries use prisms, half-spheres, or thin sheets.

text: Typical materials for ATR crystals include

text: germanium

text: and

text: zinc selenide

text: , while

text: silicon

text: is ideal for use in the Far-IR region of the

text: electromagnetic spectrum

text: . The excellent mechanical properties of

text: diamond

text: make it an ideal material for ATR, particularly when studying very hard solids, but its much higher cost means it is less widely used. The shape of the crystal depends on the type of spectrometer and nature of the sample. With

text: dispersive

text: spectrometers, the crystal is a rectangular slab with chamfered edges, seen in cross-section in the illustrations. Other geometries use prisms, half-spheres, or thin sheets.

text: Today the Mauna Kea Science Reserve has 13 observation facilities, each funded by as many as 11 countries. There are nine telescopes working in the visible and infrared spectrum, three in the submillimeter spectrum, and one in the radio spectrum, with mirrors or dishes ranging from . In comparison, the Hubble Space Telescope has a  mirror, similar in size to the UH88, now the second smallest telescope on the mountain.

text: Today the Mauna Kea Science Reserve has 13 observation facilities, each funded by as many as 11 countries. There are nine telescopes working in the visible and infrared spectrum, three in the submillimeter spectrum, and one in the radio spectrum, with mirrors or dishes ranging from . In comparison, the

text: Hubble Space Telescope

text: has a  mirror, similar in size to the UH88, now the second smallest telescope on the mountain.

text: China, Japan, and South Korea are currently entertaining plans to construct a large high-altitude observatory on a ridge 25 km south of Shiquanhe, which was selected after a series of site surveys through Tibet and western China for candidate sites.  Atmospheric conditions from the site's 5050m above sea level have been roughly characterized, initial facilities (including two small domes) have been built, and a 25 cm pathfinder telescope project is in place as of 2012, with 50 and 60 cm telescopes planned for 2013 and 2014 and a 3m telescope in the indefinite future: but the ambitions for the site include the possibilities of megaprojects like a 30m-class competitor to E-ELT and a 10-20m class spectrometer as a sequel to LAMOST.

text: One of the two  telescopes of the MOnitoring NEtwork of Telescopes Project is located at Sutherland, its twin can be found at the McDonald Observatory in Texas. The MONET telescopes are Robotic telescope controllable via the Internet and was constructed by the University of Göttingen. Remote Telescope Markup Language is used to control the telescopes remotely.

text: One of the two  telescopes of the

text: MOnitoring NEtwork of Telescopes

text: Project is located at Sutherland, its twin can be found at the

text: McDonald Observatory

text: in Texas. The MONET telescopes are

text: Robotic telescope

text: controllable via the Internet and was constructed by the

text: University of Göttingen

text: Remote Telescope Markup Language

text: is used to control the telescopes remotely.

text: Gravitational waves can penetrate regions of space that electromagnetic waves cannot. They are able to allow the observation of the merger of black holes and possibly other exotic objects in the distant Universe. Such systems cannot be observed with more traditional means such as optical telescopes or radio telescopes, and so gravitational-wave astronomy gives new insights into the working of the Universe. In particular, gravitational waves could be of interest to cosmologists as they offer a possible way of observing the very early Universe. This is not possible with conventional astronomy, since before recombination the Universe was opaque to electromagnetic radiation. Precise measurements of gravitational waves will also allow scientists to test more thoroughly the general theory of relativity.

text: Gravitational waves can penetrate regions of space that electromagnetic waves cannot. They are able to allow the observation of the merger of black holes and possibly other exotic objects in the distant Universe. Such systems cannot be observed with more traditional means such as

text: optical telescope

text: s or

text: radio telescope

text: s, and so

text: gravitational-wave astronomy

text: gives new insights into the working of the Universe. In particular, gravitational waves could be of interest to cosmologists as they offer a possible way of observing the very early Universe. This is not possible with conventional astronomy, since before

text: recombination

text: the Universe was opaque to electromagnetic radiation. Precise measurements of gravitational waves will also allow scientists to test more thoroughly the general theory of relativity.

text: Following the end of the Galileo mission, astronomers have continued monitoring Io's active volcanoes with adaptive optics imaging from the Keck telescope in Hawaii and the European Southern Observatory in Chile, as well as imaging from the Hubble telescope. These technologies are used to observe the thermal emissions and measure the composition of gases over volcanoes such as Pele and Tvashtar. Imaging from the Keck telescope in February 2001 revealed the most powerful volcanic eruption observed in modern times, either on Io or on Earth, at the volcano Surt. Earth-based telescopes coming online over the next decade, such as the Thirty Meter Telescope at the Mauna Kea Observatory, will provide more-detailed observations of Io's volcanoes, approaching the resolution achieved by Galileo

text: Following the end of the Galileo mission, astronomers have continued monitoring Io's active volcanoes with

text: adaptive optics

text: imaging from the

text: Keck telescope

text: in

text: Hawaii

text: and the

text: European Southern Observatory

text: in

text: Chile

text: , as well as imaging from the

text: Hubble telescope

text: . These technologies are used to observe the thermal emissions and measure the composition of gases over volcanoes such as

text: Pele

text: and

text: Tvashtar

text: . Imaging from the Keck telescope in February 2001 revealed the most powerful volcanic eruption observed in modern times, either on Io or on Earth, at the

text: volcano Surt

text: . Earth-based telescopes coming online over the next decade, such as the

text: Thirty Meter Telescope

text: at the

text: Mauna Kea Observatory

text: , will provide more-detailed observations of Io's volcanoes, approaching the resolution achieved by Galileo

text: How It Began: A Time Traveler’s Guide to the Universe is a non-fiction book by astronomy professor Chris Impey on the origins of everything from the Moon to the universe itself. The finite speed of light and the vastness of space turn modern large telescopes into time machines and astronomers into armchair time travelers. Looking out in space is looking back in time. Each chapter has vignettes that place the reader in increasingly unfamiliar physical situations that are increasingly unfamiliar. How It Began has an associated web site containing source material on each major topic.

text: How It Began: A Time Traveler’s Guide to the Universe is a

text: non-fiction

text: book by

text: astronomy

text: professor

text: Chris Impey

text: on the origins of everything from the

text: Moon

text: to the

text: universe

text: itself. The finite

text: speed of light

text: and the vastness of space turn modern

text: large telescopes

text: into time machines and

text: astronomers

text: into armchair

text: time travel

text: ers. Looking out in space is looking back in time. Each chapter has vignettes that place the reader in increasingly unfamiliar physical situations that are increasingly unfamiliar. How It Began has an associated web site containing source material on each major topic.

text: In early 2007, DFM Engineering began building a new  clear aperture open frame, off-axis Gregorian telescope. The New Solar Telescope (NST) saw first engineering light of the Sun at the Nasmyth focus in December 2008, and observations began in January 2009. The telescope is set on an equatorial mount, which is attached to the existing pier.  The mirror was figured from a 1.7 m blank by the University of Arizona Mirror Lab as a proof-of-concept for the mirrors of the Giant Magellan Telescope. Until the Advanced Technology Solar Telescope is completed, the NST will be the largest clear aperture solar telescope in the world.  It is able to resolve features on the Sun less than 50 km across.  The project was a collaboration between BBSO/NJIT, the University of Hawaii Institute for Astronomy (UH IfA), and the Korea Astronomy and Space Science Institute (KASI).

text: In early 2007,

text: DFM Engineering

text: began building a new  clear aperture open frame, off-axis

text: Gregorian telescope

text: . The New Solar Telescope (NST) saw first engineering light of the Sun at the

text: Nasmyth focus

text: in December 2008, and observations began in January 2009. The telescope is set on an

text: equatorial mount

text: , which is attached to the existing pier.  The mirror was

text: figured

text: from a 1.7 m blank by the

text: University of Arizona

text: Mirror Lab as a proof-of-concept for the mirrors of the

text: Giant Magellan Telescope

text: . Until the

text: Advanced Technology Solar Telescope

text: is completed, the NST will be the largest clear aperture solar telescope in the world.  It is able to resolve features on the Sun less than 50 km across.  The project was a collaboration between BBSO/NJIT, the

text: University of Hawaii

text: Institute for Astronomy (UH IfA), and the

entity_name: Korea Astronomy and Space Science Institute

text: Korea Astronomy and Space Science Institute

text: (KASI).

text: AURA began as a small organization dedicated to ground-based optical astronomy, managing a range of 1- to 4-meter telescopes and providing community advocacy for optical/infrared astronomy.  Over the years, AURA expanded its focus to include Solar Astronomy and the Gemini 8-meter telescopes, going on to partner with other consortia such as WIYN (Wisconsin Indiana Yale & NOAO) and SOAR (Southern Astrophysical Research).  In the 1980s, AURA took on the management of the Space Telescope Science Institute, opening up the ultraviolet, optical, and infrared wavelength bands in space with the Hubble Space Telescope.  AURA is furthering its aims in infrared space astronomy through the James Webb Space Telescope (JWST).

text: AURA began as a small organization dedicated to ground-based optical astronomy, managing a range of 1- to 4-meter telescopes and providing community advocacy for optical/infrared astronomy.  Over the years, AURA expanded its focus to include Solar Astronomy and the Gemini 8-meter telescopes, going on to partner with other consortia such as WIYN (Wisconsin Indiana Yale & NOAO) and SOAR (Southern Astrophysical Research).  In the 1980s, AURA took on the management of the Space Telescope Science Institute, opening up the ultraviolet, optical, and infrared wavelength bands in space with the Hubble Space Telescope.  AURA is furthering its aims in infrared space astronomy through the

text: James Webb Space Telescope

text: (JWST).

text: The first  laser was developed in 1980. This type of laser is likely to be tunable over a wide range of wavelengths (30 nm) in the visible spectrum. This is true even if the absorption phenomena occur on the side of shorter wavelengths and therefore limits the laser action at the red region of the electromagnetic spectrum from light emission. Solid state experiments with  suggest that the gaseous state is more suitable for the development of this type of laser. The measured amplification was correct in the solid state. The liquid state seems like an ideal dye laser although implementation seems complex and costly. Presently, the Cl laser has not been industrially developed. Unlike XeCl, the best chlorine donor is  while no laser action occurs when using HCl.

text: The first  laser was developed in 1980. This type of laser is likely to be tunable over a wide range of wavelengths (30 nm) in the

text: visible spectrum

text: . This is true even if the absorption phenomena occur on the side of shorter wavelengths and therefore limits the laser action at the red region of the

text: electromagnetic spectrum

text: from

text: light emission

text: . Solid state experiments with  suggest that the gaseous state is more suitable for the development of this type of laser. The measured amplification was correct in the solid state. The liquid state seems like an ideal

text: dye laser

text: although implementation seems complex and costly. Presently, the Cl laser has not been industrially developed. Unlike XeCl, the best chlorine donor is

text: while no laser action occurs when using HCl.

text: The electromagnetic spectrum extends from below the low frequencies used for modern radio communication to gamma radiation at the short-wavelength (high-frequency) end, thereby covering wavelengths from thousands of kilometers down to a fraction of the size of an atom.  Visible light lies toward the shorter end, with wavelengths from 400 to 700 nanometres.  The limit for long wavelengths is the size of the universe itself, while it is thought that the short wavelength limit is in the vicinity of the Planck length. Until the middle of the 20th century it was believed by most physicists that this spectrum was infinite and continuous.

text: The electromagnetic spectrum extends from below the low frequencies used for modern

text: radio

text: communication to

text: gamma radiation

text: at the short-

text: wavelength

text: (high-frequency) end, thereby covering wavelengths from thousands of

text: kilometer

text: s down to a

text: fraction

text: of the size of an

text: atom

text: Visible light

text: lies toward the shorter end, with wavelengths from 400 to 700

text: nanometre

text: s.  The limit for long wavelengths is the size of the

text: universe

text: itself, while it is thought that the short wavelength limit is in the vicinity of the

text: Planck length

text: . Until the middle of the 20th century it was believed by most physicists that this spectrum was

text: infinite

text: and

text: continuous

text: An infrared telescope is a telescope that uses infrared light to detect celestial bodies.Infrared light is one of several types of radiation present in the electromagnetic spectrum.

text: An infrared telescope is a telescope that uses

text: infrared

text: light to detect celestial bodies.Infrared light is one of several types of radiation present in the

text: electromagnetic spectrum

text: The Hubble Deep Field South is a composite of several hundred individual images taken using the Hubble Space Telescope's Wide Field and Planetary Camera 2 over 10 days in September and October 1998.  It followed the great success of the original Hubble Deep Field in facilitating the study of extremely distant galaxies in early stages of their evolution.  While the WFPC2 took very deep optical images, nearby fields were simultaneously imaged by the Space Telescope Imaging Spectrograph (STIS) and the Near Infrared Camera and Multi-Object Spectrometer (NICMOS).

text: The Hubble Deep Field South is a composite of several hundred individual images taken using the

text: Hubble Space Telescope

text: 's

text: Wide Field and Planetary Camera 2

text: over 10 days in September and October 1998.  It followed the great success of the original

text: Hubble Deep Field

text: in facilitating the study of extremely distant

text: galaxies

text: in early stages of their

text: evolution

text: .  While the WFPC2 took very deep optical images, nearby fields were simultaneously imaged by the

text: Space Telescope Imaging Spectrograph

text: (STIS) and the

text: (NICMOS).

text: A star diagonal is an angled mirror or prism used in telescopes that allows viewing from a direction that is perpendicular to the usual eyepiece axis. It allows more convenient and comfortable viewing when the telescope is pointed at, or near the zenith (i.e. directly overhead).  Also, the resulting image is right side up, but is reversed from left to right. Star diagonals are available in 1.25" and 2" diameters. The 2" diagonals allow larger longer focal length low power 2 inch barrel eyepieces for a greater field of view. Star diagonals come in all price ranges, from as low as thirty dollars up to hundreds of dollars. However, even an expensive star diagonal will deliver poor performance if it is not in alignment with the optical axis of the telescope. A telescope in perfect collimation will be thrown out of collimation by a misaligned star diagonal and often this misalignment will determine the image quality of the telescope to a larger extent than the surface accuracy of the prism or mirror. Since the mirror or prism of the star diagonal is located nearly at the focal plane of the instrument, surface accuracy of greater that 1/4 wave is more in the line of advertising than any increase in optical performance. A 1/10  wave mirror or prism star diagonal that throws off the collimation of the telescope will perform worse than a 1/2 wave star diagonal that is in proper alignment.

text: A star diagonal is an angled mirror or prism used in

text: telescope

text: s that allows viewing from a direction that is perpendicular to the usual eyepiece axis. It allows more convenient and comfortable viewing when the telescope is pointed at, or near the

text: zenith

text: (i.e. directly overhead).  Also, the resulting image is right side up, but is reversed from left to right. Star diagonals are available in 1.25" and 2" diameters. The 2" diagonals allow larger longer focal length low power 2 inch barrel eyepieces for a greater field of view. Star diagonals come in all price ranges, from as low as thirty dollars up to hundreds of dollars. However, even an expensive star diagonal will deliver poor performance if it is not in alignment with the optical axis of the telescope. A telescope in perfect collimation will be thrown out of collimation by a misaligned star diagonal and often this misalignment will determine the image quality of the telescope to a larger extent than the surface accuracy of the prism or mirror. Since the mirror or prism of the star diagonal is located nearly at the focal plane of the instrument, surface accuracy of greater that 1/4 wave is more in the line of advertising than any increase in optical performance. A 1/10  wave mirror or prism star diagonal that throws off the collimation of the telescope will perform worse than a 1/2 wave star diagonal that is in proper alignment.

text: The Air Force Office of Scientific Research (AFOSR) of the Air Force Research Laboratory (AFRL) operates the Maui Space Surveillance Complex (MSSC), which is part of the Air Force Maui Optical and Supercomputing Site (AMOS).  Located at the MSSC are the  Advanced Electro Optical System Telescope (AEOS), the Maui Space Surveillance System (MSSS), and the Ground-based Electro-Optical Deep Space Surveillance (GEODSS).  The MSSS uses a number of optical assets, including a  telescope, two  telescopes on a common mount, a  beam director/tracker, and a  laser beam director.  The GEODSS uses two  telescopes and one  telescope.

text: The

text: Air Force Office of Scientific Research

text: (AFOSR) of the

text: Air Force Research Laboratory

text: (AFRL) operates the Maui Space Surveillance Complex (MSSC), which is part of the

entity_name: Air Force Maui Optical and Supercomputing observatory

text: Air Force Maui Optical and Supercomputing Site

text: (AMOS).  Located at the MSSC are the

text: Advanced Electro Optical System Telescope

text: (AEOS), the Maui Space Surveillance System (MSSS), and the

entity_section: Ground-based Electro-Optical Deep Space Surveillance

text: Ground-based Electro-Optical Deep Space Surveillance

text: (GEODSS).  The MSSS uses a number of optical assets, including a  telescope, two  telescopes on a common mount, a  beam director/tracker, and a  laser beam director.  The GEODSS uses two  telescopes and one  telescope.

text: Adding further optics to a Nasmyth-style telescope to deliver the light (usually through the declination axis) to a fixed focus point that does not move as the telescope is reoriented gives a coudé focus (from the French word for elbow). The coudé focus gives a narrower field of view than a Nasmyth focus and is used with very heavy instruments that do not need a wide field of view. One such application is high-resolution spectrographs that have large collimating mirrors (ideally with the same diameter as the telescope's primary mirror) and very long focal lengths.  Such instruments could not withstand being moved, and adding mirrors to the light path to divert the light to a fixed position to such an instrument housed on or below the observing floor (and usually built as an unmoving integral part of the observatory building) was the only option.  The 60-inch Hale telescope (1.5 m), Hooker Telescope, 200-inch Hale Telescope, Shane Telescope, and Harlan J. Smith Telescope all were built with coudé foci instrumentation.  The development of echelle spectrometers allowed high-resolution spectroscopy with a much more compact instrument, one which can sometimes be successfully mounted on the Cassegrain focus.  However, since inexpensive and adequately stable computer-controlled alt-az telescope mounts were developed in the 1980s, the Nasmyth design has supplanted the coudé focus for large telescopes.

text: Adding further optics to a Nasmyth-style telescope to deliver the light (usually through the

text: declination

text: axis) to a fixed focus point that does not move as the telescope is reoriented gives a coudé focus (from the French word for elbow). The coudé focus gives a narrower field of view than a Nasmyth focus and is used with very heavy instruments that do not need a wide field of view. One such application is high-resolution

text: spectrograph

text: s that have large collimating mirrors (ideally with the same diameter as the telescope's primary mirror) and very long focal lengths.  Such instruments could not withstand being moved, and adding mirrors to the light path to divert the light to a fixed position to such an instrument housed on or below the observing floor (and usually built as an unmoving integral part of the observatory building) was the only option.  The

text: 60-inch Hale telescope

text: (1.5 m),

text: Hooker Telescope

text: 200-inch Hale Telescope

text: Shane Telescope

text: , and

text: Harlan J. Smith Telescope

text: all were built with coudé foci instrumentation.  The development of

text: echelle

text: spectrometers allowed high-resolution spectroscopy with a much more compact instrument, one which can sometimes be successfully mounted on the Cassegrain focus.  However, since inexpensive and adequately stable computer-controlled alt-az telescope mounts were developed in the 1980s, the Nasmyth design has supplanted the coudé focus for large telescopes.

text: The telescope became operational in October 1957, which was just before the launch of Sputnik 1, the world's first artificial satellite. Only the Soviet hierarchy were aware of Sputnik and it was the Lovell Telescope which tracked the satellite. While the transmissions from Sputnik itself could easily be picked up by a household radio, the Lovell Telescope was the only telescope capable of tracking Sputnik's booster rocket by radar; it first located it just before midnight on 12 October 1957. It also located Sputnik 2's carrier rocket at just after midnight on 16 November 1957. Jodrell Bank continued tracking new artificial satellites in the following years, and also doubled up as a long range ballistic missile radar system, a beneficial trait which helped the telescope gain funding from the British government. The Jodrell Bank Observatory is currently operated by the University of Manchester and was nominated for UNESCO World Heritage Status in 2011.

text: The telescope became operational in October 1957, which was just before the launch of

text: Sputnik 1

text: , the world's first artificial satellite. Only the Soviet hierarchy were aware of Sputnik and it was the Lovell Telescope which tracked the satellite. While the transmissions from Sputnik itself could easily be picked up by a household

text: radio

text: , the Lovell Telescope was the only telescope capable of tracking Sputnik's booster rocket by radar; it first located it just before midnight on 12 October 1957. It also located

text: Sputnik 2

text: 's carrier rocket at just after midnight on 16 November 1957. Jodrell Bank continued tracking new artificial satellites in the following years, and also doubled up as a long range ballistic missile radar system, a beneficial trait which helped the telescope gain funding from the British government. The Jodrell Bank Observatory is currently operated by the University of Manchester and was nominated for UNESCO World Heritage Status in 2011.

text: The Nançay Radioastronomy Facility includes several other operating radio telescopes:

text: Vainu Bappu Observatory (also known as Kavalur Astronomical observatory) is home to the Vainu Bappu Telescope, the largest telescope in Asia. It has a diameter of 2.3 meters and was first used in 1986. Along with the Vainu Bappu telescope, the observatory has two other telescopes.

text: Vainu Bappu Observatory

text: (also known as Kavalur Astronomical observatory) is home to the Vainu Bappu Telescope, the largest telescope in

text: Asia

text: . It has a diameter of 2.3 meters and was first used in 1986. Along with the Vainu Bappu telescope, the observatory has two other telescopes.

text: The Transit Telescope was a  parabolic reflector zenith telescope built at Jodrell Bank in 1947. At the time, it was the largest radio telescope in the world. It consisted of a wire mesh suspended from a ring of  scaffold poles, which focussed radio signals to a focal point  above the ground. The telescope mainly looked directly upwards, but the direction of the beam could be changed by small amounts by tilting the mast to change the position of the focal point. The focal mast was originally going to be wood, but this was changed to a steel mast before construction was complete. The telescope was replaced by the fully steerable  Lovell Telescope, and the Mark II telescope was subsequently built on the same location.

text: The Transit Telescope was a

text: parabolic reflector

text: zenith telescope

text: built at Jodrell Bank in 1947. At the time, it was the largest

text: radio telescope

text: in the world. It consisted of a wire mesh suspended from a ring of

text: scaffold poles

text: , which focussed radio signals to a

text: focal point

text: above the ground. The telescope mainly looked directly upwards, but the direction of the beam could be changed by small amounts by tilting the mast to change the position of the focal point. The focal mast was originally going to be wood, but this was changed to a steel mast before construction was complete. The telescope was replaced by the fully steerable

text: Lovell Telescope

text: , and the

text: Mark II

text: telescope was subsequently built on the same location.

text: The "Mark I" telescope, now known as the Lovell Telescope, was the largest steerable dish radio telescope in the world,  in diameter, when it was completed in 1957; it is now the third largest, after the Green Bank telescope in West Virginia and the Effelsberg telescope in Germany. Part of the gun turret mechanisms from the battleships HMS Revenge and HMS Royal Sovereign were reused in the motor system for the telescope. The telescope became operational in mid-1957, just in time for the launch of Sputnik 1, the world's first artificial satellite. The telescope was the only one in the world able to track Sputnik's booster rocket by radar; first locating it just before midnight on 12 October 1957.

text: The "Mark I" telescope, now known as the

text: Lovell Telescope

text: , was the largest steerable dish radio telescope in the world,  in diameter, when it was completed in 1957; it is now the third largest, after the

text: Green Bank

text: telescope in

text: West Virginia

text: and the

text: Effelsberg

text: telescope in Germany. Part of the gun turret mechanisms from the battleships

text: HMS Revenge

text: and

text: HMS Royal Sovereign

text: were reused in the motor system for the telescope. The telescope became operational in mid-1957, just in time for the launch of

text: Sputnik 1

text: , the world's first artificial satellite. The telescope was the only one in the world able to track Sputnik's

text: booster rocket

text: by radar; first locating it just before midnight on 12 October 1957.

text: Maksutov's most well known contribution in the field of optics was made in 1941, when he invented the Maksutov telescope. Like the Schmidt telescope, the Maksutov corrects for spherical aberration by placing a corrector lens in front of the primary mirror. However, where the Schmidt uses an aspheric corrector at the entrance pupil, Maksutov's telescope uses a deeply curved full diameter negative meniscus lens (a "meniscus corrector shell"). He published the design in 1944 in a paper entitled "Новые катадиоптрические менисковые системы" [New catadioptric meniscus systems]. This method was adopted not only by his own laboratory for many of the most important observatories in the Soviet Union, but also internationally. Several commercial telescope-making companies produce Maksutovs, including Celestron, Meade, and Questar.

text: Maksutov's most well known contribution in the field of optics was made in 1941, when he invented the

text: Maksutov telescope

text: . Like the

text: Schmidt telescope

text: , the Maksutov corrects for

text: spherical aberration

text: by placing a corrector lens in front of the primary mirror. However, where the Schmidt uses an

text: aspheric

text: corrector at the entrance pupil, Maksutov's telescope uses a deeply curved full diameter negative

text: meniscus lens

text: (a "

text: meniscus corrector shell

text: "). He published the design in 1944 in a paper entitled "Новые катадиоптрические менисковые системы" [New catadioptric meniscus systems]. This method was adopted not only by his own laboratory for many of the most important observatories in the Soviet Union, but also internationally. Several commercial telescope-making companies produce Maksutovs, including

text: Celestron

text: Meade

text: , and

text: Questar

text: With courses now officially on the books, Chant started looking for a proper telescope. Previously the university had hosted the Toronto Magnetic and Meteorological Observatory, which had been run by the Meteorological Office of the Ministry of Marine and Fisheries. The observatory had contained the high-quality  Cooke Refractor, but the Observatory was now surrounded by new university buildings, rendering it useless for astronomy. The Meteorological Office had already decided to abandon the site and turn the building over to the university, but they were taking the telescope with them to their new location on Bloor Street. Even if the university had been able to secure time on the instrument, which was highly likely, it was at this time quite a small instrument in comparison to those being built around the world.

text: With courses now officially on the books, Chant started looking for a proper telescope. Previously the university had hosted the

entity_name: Toronto Magnetic and Meteorological Observatory

text: Toronto Magnetic and Meteorological Observatory

text: , which had been run by the Meteorological Office of the

text: Ministry of Marine and Fisheries

text: . The observatory had contained the high-quality  Cooke Refractor, but the Observatory was now surrounded by new university buildings, rendering it useless for astronomy. The Meteorological Office had already decided to abandon the site and turn the building over to the university, but they were taking the telescope with them to their new location on

text: Bloor Street

text: . Even if the university had been able to secure time on the instrument, which was highly likely, it was at this time quite a small instrument in comparison to those being built around the world.

text: Space Telescope Institute - Baltimore - Maryland - (USA)

text: Krupp Steel Works was also contracted in the mid-1960s to construct the Effelsberg 100-m Radio Telescope, which, from 1972 to 2000 was the largest fully steerable radio telescope in the world.

text: Krupp Steel Works was also contracted in the mid-1960s to construct the

text: Effelsberg 100-m Radio Telescope

text: , which, from 1972 to 2000 was the largest fully steerable

text: radio telescope

text: in the world.

text: His book Theory of Electromagnetic Wave Propagation is a recognized classic on electromagnetic theory.

text: This list of space telescopes (astronomical space observatories) is grouped by major frequency ranges: gamma ray, x-ray, ultraviolet, visible, infrared, microwave and radio. Telescopes that work in multiple frequency bands are included in all of the appropriate sections. Space telescopes that collect particles, such as cosmic ray nuclei and/or electrons, as well as instruments that aim to detect gravitational waves, are also listed. Missions with specific targets within the Solar System (e.g. our Sun and its planets), are excluded; see List of Solar System probes for these, and List of Earth observation satellites for missions targeting our planet.

text: This list of space telescopes (

text: astronomical

text: space observatories

text: ) is grouped by major

text: frequency range

text: s:

text: gamma ray

text: x-ray

text: ultraviolet

text: visible

text: infrared

text: microwave

text: and

text: radio

text: . Telescopes that work in multiple frequency bands are included in all of the appropriate sections. Space telescopes that collect particles, such as

text: cosmic ray

text: nuclei and/or electrons, as well as instruments that aim to detect

text: gravitational waves

text: , are also listed. Missions with specific targets within the

text: Solar System

text: (e.g. our

text: Sun

text: and its

text: planet

text: s), are excluded; see

text: List of Solar System probes

text: for these, and

text: List of Earth observation satellites

text: for missions targeting

text: our planet

text: In the Earth's atmosphere, water vapor absorbs many wavelengths of IR energy, while others are not absorbed. Those sections of the Electromagnetic spectrum that it does not absorb, are like windows in the atmosphere, allowing electromagnetic energy to flow freely in and out of the system. Like a window, that allows light to enter and leave.  Originally discovered by John Tyndall, most of the infrared coming from the Universe is blocked, absorbed by water vapor (and other greenhouse gases)in the Earth's atmosphere. Those wavelength ranges that can partially reach the surface, are coming through what is called 'water vapor windows'.   These windows are how Astronomers can view the Universe with IR telescopes, called Infrared astronomy. These windows also allow orbiting satellites to measure the IR energy leaving the planet, the SSTs and other important matters.  See Electromagnetic_absorption_by_water

text: In the Earth's atmosphere,

text: water vapor

text: absorbs many wavelengths of IR energy, while others are not absorbed. Those sections of the

text: Electromagnetic spectrum

text: that it does not absorb, are like windows in the atmosphere, allowing electromagnetic energy to flow freely in and out of the system. Like a window, that allows light to enter and leave.  Originally discovered by

text: John Tyndall

text: , most of the

text: infrared

text: coming from the Universe is blocked, absorbed by water vapor (and other

text: greenhouse gases

text: )in the Earth's atmosphere. Those wavelength ranges that can partially reach the surface, are coming through what is called 'water vapor windows'.   These windows are how Astronomers can view the Universe with IR telescopes, called

text: Infrared astronomy

text: . These windows also allow orbiting satellites to measure the IR energy leaving the planet, the SSTs and other important matters.  See

text: Radio waves are a type of electromagnetic radiation with wavelengths in the electromagnetic spectrum longer than infrared light. Like all other electromagnetic waves, they travel at the speed of light. Naturally occurring radio waves are made by lightning, or by astronomical objects. Artificially generated radio waves are used for fixed and mobile radio communication, broadcasting, radar and other navigation systems, satellite communication, computer networks and innumerable other applications. Different frequencies of radio waves have different propagation characteristics in the Earth's atmosphere; long waves may cover a part of the Earth very consistently, shorter waves can reflect off the ionosphere and travel around the world, and much shorter wavelengths bend or reflect very little and travel on a line of sight.

text: The telescoping effect is pertinent for behaviors such as smoking and alcohol usage, especially when they are early onset behaviors.  Studies of the telescoping effect have examined the reported age of onset of smoking, alcohol, and drug use.  Forward telescoping has been found in reported age of initial use of cigarettes and in reported age of beginning daily smoking.  Therefore, people may be misclassified as having late onset of drug use, when in reality, they had early onset.  Forward telescoping of risky behaviors can be problematic in monitoring patients for issues associated with early onset drug use because if they are misclassified, they may not be correctly monitored.  The same effect of forward telescoping is found for marijuana, alcohol, and hard drug usage. The implications of forward telescoping on these behaviors are similar to those of smoking.

text: The telescoping effect is pertinent for behaviors such as smoking and alcohol usage, especially when they are early onset behaviors.  Studies of the telescoping effect have examined the reported age of onset of

text: smoking

text: alcohol

text: , and drug use.  Forward telescoping has been found in reported age of initial use of cigarettes and in reported age of beginning daily smoking.  Therefore, people may be misclassified as having late onset of drug use, when in reality, they had early onset.  Forward telescoping of risky behaviors can be problematic in monitoring patients for issues associated with early onset drug use because if they are misclassified, they may not be correctly monitored.  The same effect of forward telescoping is found for

text: marijuana

text: , alcohol, and hard drug usage. The implications of forward telescoping on these behaviors are similar to those of smoking.

text: Recent telescope projects include the Hamburg Robotic Telescope HRT of the Hamburger Sternwarte (Hamburg Observatory) completed in 2005, the MONET telescopes installed at McDonald Observatory in Texas, and the South African Astronomical Observatory in South Africa.  STELLA and RoboTel telescopes erected at Izana Observatory in Tenerife and at Potsdam, Germany, and IRIS Infrared telescope to be installed at Cerro Armazones Observatory in Chile. All telescopes are designed for remote and robotic operation.

text: Recent telescope projects include the

text: Hamburg Robotic Telescope

text: HRT of the Hamburger Sternwarte (

text: Hamburg Observatory

text: ) completed in 2005, the

text: MONET telescope

text: s installed at

text: McDonald Observatory

text: in

text: Texas

text: , and the

text: South African Astronomical Observatory

text: in

text: South Africa

text: STELLA

text: and

text: RoboTel

text: telescopes erected at

text: Izana Observatory

text: in

text: Tenerife

text: and at

text: Potsdam

text: Germany

text: , and

text: IRIS

text: Infrared

text: telescope to be installed at

text: Cerro Armazones Observatory

text: in

text: Chile

text: . All telescopes are designed for

text: remote

text: and robotic operation.

text: A next generation of infrared space telescopes began when NASA's Wide-field Infrared Survey Explorer launched on 14 December 2009 aboard a Delta II rocket from Vandenberg Air Force Base. Known as WISE, the telescope provided results hundreds of times more sensitive than IRAS at the shorter wavelengths; it also had an extended mission dubbed NEOWISE beginning in October 2010 after its coolant supply ran out.

text: A next generation of infrared space telescopes began when NASA's

text: Wide-field Infrared Survey Explorer

text: launched on 14 December 2009 aboard a

text: Delta II

text: rocket from

text: Vandenberg Air Force Base

text: . Known as WISE, the telescope provided results hundreds of times more sensitive than IRAS at the shorter wavelengths; it also had an extended mission dubbed

text: NEOWISE

text: beginning in October 2010 after its coolant supply ran out.

text: Second, there is an issue regarding the propagation of electromagnetic waves. For example, in free space, where

text: Second, there is an issue regarding the propagation of electromagnetic waves. For example, in

text: free space

text: , where

text: Wireless telegraphy came to mean Morse code transmitted by radio waves (electromagnetic waves), initially called "Hertzian waves", discovered by Heinrich Hertz in 1886.  The first practical wireless telegraphy transmitters and receivers were developed by Guglielmo Marconi beginning in 1895.  By 1910 communication by Hertzian waves was universally referred to as "radio", and the term wireless telegraphy has been largely replaced by the more modern term "radiotelegraphy".  The transmission of speech (radiotelephony) began to displace wireless telegraphy by the 1920s for many applications, making possible radio broadcasting. Wireless telegraphy continued to be used for private point-to-point business, governmental, and military communication, such as telegrams and diplomatic communications, and evolved into radioteletype networks.  Continuous wave (CW) radiotelegraphy is regulated by the International Telecommunication Union (ITU) as emission type A1A.

text: Wireless telegraphy came to mean

text: Morse code

text: transmitted by

text: radio wave

text: s (

text: electromagnetic wave

text: s), initially called "

text: Hertzian waves

text: ", discovered by

text: Heinrich Hertz

text: in 1886.  The first practical wireless telegraphy transmitters and receivers were developed by

text: Guglielmo Marconi

text: beginning in 1895.  By 1910 communication by Hertzian waves was universally referred to as "

text: radio

text: ", and the term wireless telegraphy has been largely replaced by the more modern term "radiotelegraphy".  The transmission of speech (

text: radiotelephony

text: ) began to displace wireless telegraphy by the 1920s for many applications, making possible radio

text: broadcasting

text: . Wireless telegraphy continued to be used for private

text: point-to-point

text: business, governmental, and military communication, such as

text: telegram

text: s and

text: diplomatic communications

text: , and evolved into

text: radioteletype

text: networks.

text: Continuous wave

text: (CW) radiotelegraphy is regulated by the

text: International Telecommunication Union

text: (ITU) as emission type A1A.

text: STScI manages the selection of the Hubble Fellowship Program. Since 1990, Hubble Fellowships support outstanding postdoctoral scientists whose research is broadly related to the scientific mission of the Hubble Space Telescope. In 2009 it was combined with the Spitzer Fellowship that since 2002 had been associated with the Spitzer telescope and science program. It now supports fellows undertaking research associated with all missions within the Cosmic Origins theme: the Herschel Space Observatory, Hubble Space Telescope (HST), James Webb Space Telescope (JWST), Stratospheric Observatory for Infrared Astronomy (SOFIA), and the Spitzer Space Telescope. The research may be theoretical, observational, or instrumental. Each year, since HST’s launch in 1990, 8 to 12 fellowships are awarded; from 2009 it hovers about 16. STScI also sponsors a summer student intern program that allows talented undergraduate students from around the world to work with the Institute’s scientific staff, providing these students with hands-on experience in state-of-the-art astronomical research. STScI’s full-time scientific staff conducts original research spanning a broad range of astrophysics including investigations of the solar system, exoplanet detection and characterization, star formation, galaxy evolution, and cosmology. STScI hosts an annual scientific symposium held each spring as well as several smaller scientific workshops. The employment of an active scientific staff at STScI helps to ensure that HST, and eventually JWST, perform at peak capability.

text: STScI manages the selection of the Hubble Fellowship Program. Since 1990, Hubble Fellowships support outstanding postdoctoral scientists whose research is broadly related to the scientific mission of the Hubble Space Telescope. In 2009 it was combined with the Spitzer Fellowship that since 2002 had been associated with the

text: Spitzer telescope

text: and science program. It now supports fellows undertaking research associated with all missions within the Cosmic Origins theme: the

text: Herschel Space Observatory

text: , Hubble Space Telescope (HST),

text: James Webb Space Telescope

text: (JWST),

text: (SOFIA), and the Spitzer Space Telescope. The research may be theoretical, observational, or instrumental. Each year, since HST’s launch in 1990, 8 to 12 fellowships are awarded; from 2009 it hovers about 16. STScI also sponsors a summer student intern program that allows talented undergraduate students from around the world to work with the Institute’s scientific staff, providing these students with hands-on experience in state-of-the-art astronomical research. STScI’s full-time scientific staff conducts original research spanning a broad range of astrophysics including investigations of the

text: solar system

text: exoplanet

text: detection and characterization,

text: star formation

text: galaxy

text: evolution, and

text: cosmology

text: . STScI hosts an annual scientific symposium held each spring as well as several smaller scientific workshops. The employment of an active scientific staff at STScI helps to ensure that HST, and eventually JWST, perform at peak capability.

text: A vast amount of scientific issues in observational astronomy and cosmology can be addressed using a medium class telescope such as INO 3.4m telescope. At the same time, as it is designed for a wavelength interval limited to between 325 and 2500 nm, INO340 is an excellent tool for collaborative programs joining other, major, similar size and/or larger telescopes as well as with space-based telescopes optimized to work at similar or different, not least very different, wavelength ranges.

text: Deutsch enrolled at MIT, where he excelled at mathematics and physics.  He received his BS degree in 1937, after two years of study.  In 1939, he married Suzanne Zeitlin, a native Bostonian who had just graduated from Simmons College with a master's degree in Social Work.  They had two children, L. Peter Deutsch and Nicholas Deutsch.  Martin earned his Ph.D. in Physics in 1941, under Robley D. Evans leading to a thesis entitled: A Study of Nuclear Radiations by Means of a Magnetic Lens Beta Ray Spectrometer.

text: Deutsch enrolled at MIT, where he excelled at mathematics and physics.  He received his BS degree in 1937, after two years of study.  In 1939, he married Suzanne Zeitlin, a native Bostonian who had just graduated from

text: Simmons College

text: with a master's degree in

text: Social Work

text: .  They had two children,

text: L. Peter Deutsch

text: and Nicholas Deutsch.  Martin earned his Ph.D. in Physics in 1941, under Robley D. Evans leading to a thesis entitled: A Study of Nuclear Radiations by Means of a Magnetic Lens Beta Ray Spectrometer.

text: Nicholson received his Ph.D. from Caltech in 1979. Nicholson's research centers on two main areas: Orbital dynamics in planetary ring systems and infrared observational studies of planets, their satellites, and their rings. His work has included studies of the ring systems of Saturn, Uranus, and Neptune via Voyager observations and ground-based stellar occultations; Earth-based observations with the 5-meter Hale telescope at Palomar Observatory of several small moons of Jupiter and Saturn discovered by the Voyager spacecraft; dynamical investigations of the planetary system around the pulsar PSR 1257 + 12, and of the rotational evolution of natural satellites; and studies of the zodiacal dust bands discovered by the Infrared Astronomical Satellite in 1983. Together with colleagues in Canada and at Harvard, he has been involved in the discovery of numerous outer satellites of Uranus, Saturn and Neptune. Nicholson is a member of the Visual Infrared Mapping Spectrometer science team on the NASA/ESA Cassini–Huygens mission to Saturn, and was the leader of a team of Cornell and Caltech astronomers studying the impact of Comet Shoemaker-Levy 9 into Jupiter in July 1994 using the Hale Telescope. He has served on the Committees on Planetary and Lunar Exploration and on Astronomy and Astrophysics of the National Research Council, time assignment committees for the Kuiper Airborne Observatory and Hubble Space Telescope, and scientific advisory committees for Arecibo and IPAC. He has coauthored review articles on planetary ring dynamics and on the Uranian and Neptunian ring systems.

text: Nicholson received his Ph.D. from

text: Caltech

text: in 1979. Nicholson's research centers on two main areas: Orbital dynamics in planetary ring systems and

text: infrared observational

text: studies of planets, their satellites, and their rings. His work has included studies of the

text: ring systems

text: of Saturn, Uranus, and

text: Neptune

text: via

text: Voyager

text: observations and ground-based stellar occultations; Earth-based observations with the 5-meter

text: Hale telescope

text: at

text: Palomar Observatory

text: of several small moons of

text: Jupiter

text: and Saturn discovered by the Voyager spacecraft; dynamical investigations of the planetary system around the pulsar

text: PSR 1257 + 12

text: , and of the rotational evolution of natural satellites; and studies of the

text: zodiacal dust

text: bands discovered by the

text: Infrared Astronomical Satellite

text: in 1983. Together with colleagues in Canada and at Harvard, he has been involved in the discovery of numerous outer satellites of

text: Uranus

text: Saturn

text: and

text: Neptune

text: . Nicholson is a member of the Visual Infrared Mapping Spectrometer science team on the NASA/ESA

text: Cassini–Huygens

text: mission to Saturn, and was the leader of a team of Cornell and Caltech astronomers studying the impact of

text: Comet Shoemaker-Levy 9

text: into Jupiter in July 1994 using the Hale Telescope. He has served on the Committees on Planetary and Lunar Exploration and on Astronomy and Astrophysics of the

entity_name: National Research Council (United States)

text: National Research Council

text: , time assignment committees for the

text: Kuiper Airborne Observatory

text: and

text: Hubble Space Telescope

text: , and scientific advisory committees for

text: Arecibo

text: and

text: IPAC

text: . He has coauthored review articles on planetary ring dynamics and on the Uranian and Neptunian ring systems.

text: With the development of fast Internet in the last part of the 20th century along with advances in computer controlled telescope mounts and CCD cameras 'Remote Telescope' astronomy is now a viable means for amateur astronomers not aligned with major telescope facilities to partake in research and deep sky imaging. This enables anyone to control a telescope a large distance away in a dark location. The observers can image through the telescopes using CCD cameras. The digital data collected by the telescope is then transmitted and displayed to the user by means of the Internet. An example of a digital remote telescope operation for public use via the Internet is the The Bareket Observatory, and there are telescope farms in New Mexico, Australia and Atacama in Chile.

text: With the development of fast Internet in the last part of the 20th century along with advances in computer controlled telescope mounts and CCD cameras 'Remote Telescope' astronomy is now a viable means for amateur astronomers not aligned with major telescope facilities to partake in research and deep sky imaging. This enables anyone to control a telescope a large distance away in a dark location. The observers can image through the telescopes using CCD cameras. The digital data collected by the telescope is then transmitted and displayed to the user by means of the Internet. An example of a digital remote telescope operation for public use via the Internet is the

text: The Bareket Observatory

text: , and there are telescope farms in

text: New Mexico

text: Australia

text: and

text: Atacama

text: in Chile.

text: An optical telescope gathers and focuses light mainly from the visible part of the electromagnetic spectrum (although some work in the infrared and ultraviolet). Optical telescopes increase the apparent angular size of distant objects as well as their apparent brightness. In order for the image to be observed, photographed, studied, and sent to a computer, telescopes work by employing one or more curved optical elements, usually made from glass lenses and/or mirrors, to gather light and other electromagnetic radiation to bring that light or radiation to a focal point. Optical telescopes are used for astronomy and in many non-astronomical instruments, including: theodolites (including transits), spotting scopes, monoculars, binoculars, camera lenses, and spyglasses. There are three main optical types:

text: An optical telescope gathers and

text: focuses

text: light mainly from the visible part of the

text: electromagnetic spectrum

text: (although some work in the

text: infrared

text: and

text: ultraviolet

text: ). Optical telescopes increase the apparent

text: angular size

text: of distant objects as well as their apparent

text: brightness

text: . In order for the image to be observed, photographed, studied, and sent to a computer, telescopes work by employing one or more curved optical elements, usually made from

text: glass

text: lenses

text: and/or

text: mirror

text: s, to gather light and other electromagnetic radiation to bring that light or radiation to a focal point. Optical telescopes are used for

text: astronomy

text: and in many non-astronomical instruments, including:

text: theodolite

text: s (including transits),

text: spotting scope

text: s,

text: monocular

text: s,

text: binoculars

text: camera lens

text: es, and spyglasses. There are three main optical types:

text: The 19th century saw many developments in mathematics, theories, and counter theories on how electrical energy could be transmitted. In 1826 André-Marie Ampère developed Ampère's circuital law showing that electric current produces a magnetic field.  Michael Faraday developed Faraday's law of induction in 1831, describing the electromagnetic force induced in a conductor by a time-varying magnetic flux. The fact that electrical energy could by transmitted at a distance without wires was actually observed by many inventors and experimenters but limited understanding of the phenomenon meant it was usually attributed it to electromagnetic induction. The explanation of these phenomenon would come from the 1860s development of electromagnetism, a theory that unified electricity and magnetism, thought of as two separate forces, with James Clerk Maxwell developing his Maxwell's equations with his prediction of the existence of electromagnetic waves. This was followed on by Heinrich Rudolf Hertz' 1888 proof of the theory, which included the discovery of radio waves.

text: The 19th century saw many developments in mathematics, theories, and counter theories on how electrical energy could be transmitted. In 1826

text: André-Marie Ampère

text: developed

text: Ampère's circuital law

text: showing that electric current produces a magnetic field.

text: Michael Faraday

text: developed

text: Faraday's law of induction

text: in 1831, describing the electromagnetic force induced in a conductor by a time-varying magnetic flux. The fact that electrical energy could by transmitted at a distance without wires was actually observed by many inventors and experimenters but limited understanding of the phenomenon meant it was usually attributed it to

text: electromagnetic induction

text: . The explanation of these phenomenon would come from the 1860s development of

text: electromagnetism

text: , a theory that unified electricity and magnetism, thought of as two separate forces, with

text: James Clerk Maxwell

text: developing his

text: Maxwell's equations

text: with his prediction of the existence of electromagnetic waves. This was followed on by

text: Heinrich Rudolf Hertz

text: ' 1888 proof of the theory, which included the discovery of

text: radio wave

text: s.

text: The National Radio Astronomy Observatory (NRAO) is a Federally Funded Research and Development Center of the United States National Science Foundation operated under cooperative agreement by Associated Universities, Inc for the purpose of radio astronomy.  NRAO designs, builds, and operates its own high sensitivity radio telescopes for use by scientists around the world.

text: The National Radio Astronomy Observatory (NRAO) is a

entity_name: Federally funded research and development centers

text: Federally Funded Research and Development Center

text: of the

text: United States

text: National Science Foundation

text: operated under cooperative agreement by

text: Associated Universities, Inc

text: for the purpose of

text: radio astronomy

text: .  NRAO designs, builds, and operates its own high sensitivity

text: radio telescope

text: s for use by scientists around the world.

text: Spectroscopic methods for observing the absorption of electromagnetic radiation in the visible spectrum were known as early as the 1860s.Scientists had observed that light traveling through a medium would be absorbed at different wavelengths, depending on the matter-composition of the medium involved.  A white light source would emit light at multiple wavelengths over a range of frequencies.  A prism could be used to separate a light source into specific wavelengths. Shining the light through a sample of a material would cause some wavelengths of light to be absorbed, while others would be unaffected and continue to be transmitted.  Wavelengths in the resulting absorption spectrum would differ depending upon the atomic and molecular  composition if the material involved.

text: Spectroscopic methods for observing the

text: absorption

text: of

text: electromagnetic radiation

text: in the

text: visible spectrum

text: were known as early as the 1860s.Scientists had observed that light traveling through a

text: medium

text: would be absorbed at different wavelengths, depending on the matter-composition of the medium involved.  A white light source would emit light at multiple wavelengths over a range of frequencies.  A prism could be used to separate a light source into specific wavelengths. Shining the light through a sample of a material would cause some wavelengths of light to be absorbed, while others would be unaffected and continue to be transmitted.  Wavelengths in the resulting

text: absorption spectrum

text: would differ depending upon the

text: atom

text: ic and

text: molecular

text: composition if the material involved.

text: The Xingjiang Qitai 110m Radio Telescope (QTT) is a planned radio telescope to be built in Qitai County in Xinjiang, China. Upon completion, it will be the world's largest fully steerable single-dish radio telescope. It is intended to operate at 300 MHz to 117 GHz. The construction of the antenna project is under the leadership of the Xinjiang Astronomical Observatory of the Chinese Academy of Sciences.

text: The Xingjiang Qitai 110m Radio Telescope (QTT) is a planned

text: radio telescope

text: to be built in

text: Qitai

text: County in

text: Xinjiang

text: China

text: . Upon completion, it will be the world's largest fully steerable single-dish radio telescope. It is intended to operate at 300 MHz to 117 GHz. The construction of the antenna project is under the leadership of the

text: Xinjiang Astronomical Observatory

text: of the

text: Chinese Academy of Sciences

text: The Robert C. Byrd Green Bank Telescope is the world's largest fully steerable radio telescope. The 100-meter Green Bank Telescope (GBT) is located in a radio quiet zone in Green Bank, West Virginia.

text: The

text: Robert C. Byrd

text: Green Bank Telescope

text: is the world's largest fully steerable radio telescope. The 100-meter Green Bank Telescope (GBT) is located in a radio quiet zone in Green Bank, West Virginia.

text: Beginning in the 1970s, improvements in the stability of radio telescope receivers permitted telescopes from all over the world (and even in Earth orbit) to be combined to perform very-long-baseline interferometry. Instead of physically connecting the antennas, data received at each antenna is paired with timing information, usually from a local atomic clock, and then stored for later analysis on magnetic tape or hard disk. At that later time, the data is correlated with data from other antennas similarly recorded, to produce the resulting image. Using this method it is possible to synthesise an antenna that is effectively the size of the Earth. The large distances between the telescopes enable very high angular resolutions to be achieved, much greater in fact than in any other field of astronomy. At the highest frequencies, synthesised beams less than 1 milliarcsecond are possible.

text: Beginning in the 1970s, improvements in the stability of radio telescope receivers permitted telescopes from all over the world (and even in Earth orbit) to be combined to perform

text: very-long-baseline interferometry

text: . Instead of physically connecting the antennas, data received at each antenna is paired with timing information, usually from a local

text: atomic clock

text: , and then stored for later analysis on magnetic tape or hard disk. At that later time, the data is correlated with data from other antennas similarly recorded, to produce the resulting image. Using this method it is possible to synthesise an antenna that is effectively the size of the Earth. The large distances between the telescopes enable very high angular resolutions to be achieved, much greater in fact than in any other field of astronomy. At the highest frequencies, synthesised beams less than 1

text: milliarcsecond

text: are possible.

text: According to MTV, the initial concept for the music video was to portray Spears on the porch of a beachfront home watching a group of kids having fun, prompting flashbacks about her former boyfriend. The video begins with Spears going to the telescope, and Spears is looking through a telescope, The concept was later changed a man and a dog walk on the beach, portraying the singer as the girl next door, watching her love interest, played by model Chad Cole, from afar. The beach location was kept, and the music video intercuts with scenes of Spears' dancing on the Paradise Cove pier with her dancers dressed all in beach-friendly white attire, then Spears sits near a car. A writer of Rolling Stone noted the video is best known for "purifying the sexy persona Spears introduced in the '... Baby One More Time' video", while describing it as "a virginal Britney in a long, flowing white dress (and other demure outfits) gazes at a clean-cut boy on the beach, then she walks on the balcony with a pink ball, then does some chaste choreography that features her dancers forming a heart while she sings that she only wants to "hold you tight, treat you right." Spears is sitting on a picnic blanket wishing she was there with him. She leaves alone." On February 20, 2012, behind the scenes footage of the music video leaked online.

text: According to

text: MTV

text: , the initial concept for the music video was to portray Spears on the porch of a beachfront home watching a group of kids having fun, prompting flashbacks about her former boyfriend. The video begins with Spears going to the telescope, and Spears is looking through a telescope, The concept was later changed a man and a dog walk on the beach, portraying the singer as the

text: girl next door

text: , watching her love interest, played by model Chad Cole, from afar. The beach location was kept, and the music video intercuts with scenes of Spears' dancing on the Paradise Cove pier with her dancers dressed all in beach-friendly white attire, then Spears sits near a car. A writer of

text: Rolling Stone

text: noted the video is best known for "purifying the sexy persona Spears introduced in the '... Baby One More Time' video", while describing it as "a virginal Britney in a long, flowing white dress (and other demure outfits) gazes at a clean-cut boy on the beach, then she walks on the balcony with a pink ball, then does some chaste choreography that features her dancers forming a heart while she sings that she only wants to "hold you tight, treat you right." Spears is sitting on a picnic blanket wishing she was there with him. She leaves alone." On February 20, 2012, behind the scenes footage of the music video leaked online.

text: We use this inequality and the amortized cost of access to achieve a telescoping sum that is bounded by:

text: The Westerbork Synthesis Radio Telescope (WSRT) is an aperture synthesis interferometer near camp Westerbork, north of the village of Westerbork, Midden-Drenthe, in the northeastern Netherlands. It consists of a linear array of 14 antennas with a diameter of 25 metres arranged on a 2.7 km East-West line.  It has a similar arrangement to other radio telescopes such as the One-Mile Telescope, Australia Telescope Compact Array and the Ryle Telescope. Its Equatorial mount is what sets it apart from most other radio telescopes, most of which have an Altazimuth mount. This makes it specifically useful for specific types of science, like polarized emission research as the detectors maintain a constant orientation on the sky during an observation. Ten of the telescopes are on fixed mountings while the remaining four dishes are movable along two rail tracks. The telescope was completed in 1970 and underwent a major upgrade between 1995-2000.

text: The Westerbork Synthesis Radio Telescope (WSRT) is an

text: aperture synthesis

text: interferometer

text: near

text: camp Westerbork

text: , north of the village of

text: Westerbork

text: Midden-Drenthe

text: , in the northeastern

text: Netherlands

text: . It consists of a linear array of 14

text: antenna

text: s with a diameter of 25 metres arranged on a 2.7 km East-West line.  It has a similar arrangement to other

text: radio telescope

text: s such as the

text: One-Mile Telescope

text: Australia Telescope Compact Array

text: and the

text: Ryle Telescope

text: . Its

text: Equatorial mount

text: is what sets it apart from most other radio telescopes, most of which have an

text: Altazimuth mount

text: . This makes it specifically useful for specific types of science, like polarized emission research as the detectors maintain a constant orientation on the sky during an observation. Ten of the telescopes are on fixed mountings while the remaining four dishes are movable along two

text: rail tracks

text: . The telescope was completed in 1970 and underwent a major upgrade between 1995-2000.

text: A couple of decades ahead of Newton's publication of a particle theory of light, the Dutch Christiaan Huygens [1629–1695] developed the wave theory of light, published in 1690.  By 1804, Thomas Young's double-slit experiment revealed an interference pattern as though light were a wave, and thus Huygens's wave theory of light, as well as Huygens's inference that light waves were vibrations of the luminiferous aether was accepted.  Jean-Augustin Fresnel modeled hypothetical behavior of the aether.  Michael Faraday introduced the theoretical concept of a field—not action at a distance.  Mid-19th century, the Scottish James Clerk Maxwell [1831–1879] reduced electricity and magnetism to Maxwell's electromagnetic field theory, whittled down by others to the four Maxwell's equations.  Initially, optics was found consequent of Maxwell's field.  Later, radiation and then today's known electromagnetic spectrum were found also consequent of this electromagnetic field.

text: A couple of decades ahead of Newton's publication of a particle theory of light, the Dutch

text: Christiaan Huygens

text: [1629–1695] developed the wave theory of light, published in 1690.  By 1804,

text: Thomas Young

text: 's double-slit experiment revealed an interference pattern as though light were a wave, and thus Huygens's wave theory of light, as well as Huygens's inference that light waves were vibrations of the

text: luminiferous aether

text: was accepted.

text: Jean-Augustin Fresnel

text: modeled hypothetical behavior of the aether.

text: Michael Faraday

text: introduced the theoretical concept of a field—not action at a distance.  Mid-19th century, the Scottish

text: James Clerk Maxwell

text: [1831–1879] reduced electricity and magnetism to Maxwell's electromagnetic field theory, whittled down by others to the four

text: Maxwell's equations

text: .  Initially, optics was found consequent of Maxwell's field.  Later, radiation and then today's known

text: electromagnetic spectrum

text: were found also consequent of this electromagnetic field.

text: The Arecibo Observatory is the largest single-unit radio telescope ever constructed and one of the world's most powerful radar-radio telescopes. The observatory's purpose is to support scientific studies. It has attracted several Hollywood directors who have filmed there; most recently GoldenEye and Contact. The radio telescope was used in 1974 to send the Arecibo message to space.

text: The Arecibo Observatory is the largest single-unit radio telescope ever constructed and one of the world's most powerful radar-radio telescopes. The observatory's purpose is to support scientific studies. It has attracted several

text: Hollywood

text: directors who have filmed there; most recently

text: GoldenEye

text: and

text: Contact

text: . The radio telescope was used in 1974 to send the

text: Arecibo message

text: to space.

text: The different m/z separation elements of a hybrid mass spectrometer can be represented by a shorthand notation. The symbol Q represents a quadrupole mass analyzer, q is a radio frequency collision quadrupole, TOF is a time-of-flight mass spectrometer, B is a magnetic sector and E is an electric sector.

text: The different m/z separation elements of a hybrid

text: mass spectrometer

text: can be represented by a shorthand notation. The symbol Q represents a

text: quadrupole mass analyzer

text: , q is a

text: radio frequency

text: collision quadrupole, TOF is a

text: time-of-flight mass spectrometer

text: , B is a magnetic

text: sector

text: and E is an electric sector.

text: The Far Ultraviolet Camera/Spectrograph (UVC) was one of the experiments deployed on the lunar surface by the Apollo 16 astronauts.  It consisted of a telescope and camera that obtained astronomical images and spectra in the far ultraviolet region of the electromagnetic spectrum.

text: The Far Ultraviolet Camera/Spectrograph (UVC) was one of the experiments deployed on the lunar surface by the

text: Apollo 16

text: astronauts

text: .  It consisted of a

text: telescope

text: and

text: camera

text: that obtained astronomical images and spectra in the far

text: ultraviolet

text: region of the

text: electromagnetic spectrum

text: The Baby Boom Galaxy was discovered and characterized in 2008 using a suite of telescopes operating at different wavelengths. NASA's Hubble Space Telescope and Japan's Subaru Telescope, atop Mauna Kea in Hawaii, first spotted the galaxy in visible-light images, where it appeared as an inconspicuous smudge due to its great distance. It wasn't until the Spitzer and the James Clerk Maxwell Telescope, also on Mauna Kea in Hawaii, observed the galaxy at infrared and submillimeter wavelengths, respectively, that the galaxy was formally discovered.

text: The Baby Boom Galaxy was discovered and characterized in 2008 using a suite of

text: telescopes

text: operating at different

text: wavelength

text: s.

text: NASA

text: 's

text: Hubble Space Telescope

text: and Japan's

text: Subaru Telescope

text: , atop

text: Mauna Kea

text: in

text: Hawaii

text: , first spotted the galaxy in

text: visible-light

text: image

text: s, where it appeared as an inconspicuous smudge due to its great distance. It wasn't until the

text: Spitzer

text: and the

text: James Clerk Maxwell Telescope

text: , also on Mauna Kea in Hawaii, observed the galaxy at

text: infrared

text: and

text: submillimeter wavelengths

text: , respectively, that the galaxy was formally discovered.

text: In 1982, even before the launch of XMM-Newton predecessor EXOSAT in 1983, a proposal was generated for a "multi-mirror" X-ray telescope mission. The XMM mission was formally proposed to the ESA Science Programme Committee in 1984 and gained approval from the Agency's Council of Ministers in January 1985. That same year, several working groups were established to determine the feasibility of such a mission, and mission objectives were presented at a workshop in Denmark in June 1985. At this workshop, it was proposed that the spacecraft contain 12 low-energy and 7 high-energy X-ray telescopes. The spacecraft's overall configuration was developed by February 1987, and drew heavily from lessons learned during the EXOSAT mission; the Telescope Working Group had reduced the number of X-ray telescopes to seven standardised units. In June 1988 the European Space Agency approved the mission and issued a call for investigation proposals (an "announcement of opportunity"). Improvements in technology further reduced the number of X-ray telescopes needed to just three.

text: In 1982, even before the launch of XMM-Newton predecessor

text: EXOSAT

text: in 1983, a proposal was generated for a "multi-mirror" X-ray telescope mission. The XMM mission was formally proposed to the ESA Science Programme Committee in 1984 and gained approval from the Agency's Council of Ministers in January 1985. That same year, several

text: working group

text: s were established to determine the feasibility of such a mission, and mission objectives were presented at a

text: workshop

text: in Denmark in June 1985. At this workshop, it was proposed that the spacecraft contain 12 low-energy and 7 high-energy X-ray telescopes. The spacecraft's overall configuration was developed by February 1987, and drew heavily from lessons learned during the EXOSAT mission; the Telescope Working Group had reduced the number of X-ray telescopes to seven standardised units. In June 1988 the European Space Agency approved the mission and issued a call for investigation proposals (an "announcement of opportunity"). Improvements in technology further reduced the number of X-ray telescopes needed to just three.

text: See also List of space telescopes

text: See also

text: List of space telescopes

text: During his career, he constructed more than four hundred telescopes. The largest and most famous of these was a reflecting telescope with a  primary mirror and a 40-foot (12 m) focal length. Because of the poor reflectivity of the speculum mirrors of that day, Herschel eliminated the small diagonal mirror of a standard newtonian reflector from his design and tilted his primary mirror so he could view the formed image directly. This design has come to be called the Herschelian telescope. In 1789, shortly after this instrument was operational, he discovered a new moon of Saturn: Mimas, only 250 miles in diameter. A second moon followed within the first month of observation. The "40-foot telescope" proved very cumbersome, and most of his observations were done with a smaller    reflector. Herschel discovered that unfilled telescope apertures can be used to obtain high angular resolution, something which became the essential basis for interferometric imaging in astronomy (in particular Aperture Masking Interferometry and hypertelescopes).

text: During his career, he constructed more than four hundred telescopes. The largest and most famous of these was a

text: reflecting telescope

text: with a

text: primary mirror

text: and a 40-foot (12 m)

text: focal length

text: . Because of the poor reflectivity of the speculum mirrors of that day, Herschel eliminated the small diagonal mirror of a standard

text: newtonian reflector

text: from his design and tilted his primary mirror so he could view the formed image directly. This design has come to be called the

text: Herschelian telescope

text: . In 1789, shortly after this instrument was operational, he discovered a new

text: moon

text: of

text: Saturn

text: Mimas

text: , only 250 miles in diameter. A second moon followed within the first month of observation. The "40-foot telescope" proved very cumbersome, and most of his observations were done with a smaller    reflector. Herschel discovered that unfilled telescope apertures can be used to obtain high angular resolution, something which became the essential basis for interferometric imaging in astronomy (in particular

text: Aperture Masking Interferometry

text: and

text: hypertelescope

text: s).

text: The observatory has several telescopes located around the main buildings and also international telescopes like the Nordic Optical Telescope are in use. The one meter Dall-Kirkham reflector () is the largest optical telescope in Finland.

text: The observatory has several telescopes located around the main buildings and also international telescopes like the

text: Nordic Optical Telescope

text: are in use. The one meter

text: Dall-Kirkham reflector

text: () is the largest optical telescope in Finland.

text: Follow-up confirmation observations were made by the Keck 1 telescope at the W.M. Keck Observatory in Hawaii, the Hale and Shane telescopes in California, the Harlan J. Smith and Hobby-Eberly telescopes in west Texas, the Nordic Optical Telescope in the Canary Islands, and by telescopes at the WIYN (including MMT) and Whipple observatories in Arizona. The Spitzer Space Telescope was also used. Kepler-11's planetary system became the first discovered extrasolar system with more than three transiting planets, as well as the most compact and flattest system yet discovered, according to NASA. The planets of Kepler-11, including Kepler-11e, were announced jointly at a press conference on February 2, 2011. The findings were published in the journal Nature on February 3.

text: Follow-up confirmation observations were made by the Keck 1 telescope at the

text: W.M. Keck Observatory

text: in Hawaii, the

text: Hale

text: and

text: Shane

text: telescopes in California, the

text: Harlan J. Smith

text: and

text: Hobby-Eberly

text: telescopes in west Texas, the

text: Nordic Optical Telescope

text: in the Canary Islands, and by telescopes at the

text: WIYN

text: (including

text: MMT

text: ) and

text: Whipple

text: observatories in Arizona. The

text: Spitzer Space Telescope

text: was also used. Kepler-11's planetary system became the first discovered extrasolar system with more than three transiting planets, as well as the most compact and flattest system yet discovered, according to NASA. The planets of Kepler-11, including Kepler-11e, were announced jointly at a press conference on February 2, 2011. The findings were published in the journal

text: Nature

text: on February 3.

text: Sairecabur is since 2003 the site of the  diametre Receiver Lab Telescope, a telescope which operates in the terahertz range of the electromagnetic spectrum; ground-based astronomy in this range was long considered to be impossible since the atmosphere absorbs radiation in that frequency range heavily. With an altitude of  the telescope is the highest submillimeter telescope in the world.

text: Sairecabur is since 2003 the site of the  diametre Receiver Lab Telescope, a telescope which operates in the

text: terahertz

text: range of the

text: electromagnetic spectrum

text: ; ground-based astronomy in this range was long considered to be impossible since the atmosphere absorbs radiation in that frequency range heavily. With an altitude of  the telescope is the highest submillimeter telescope in the world.

text: When using interferometry, a complex system of mirrors brings the light from the different telescopes to the astronomical instruments where it is combined and processed. This is technically demanding as the light paths must be kept equal to within 1/1000 mm over distances of a few hundred metres. For the Unit Telescopes, this gives an equivalent mirror diameter of up to , and when combining the auxiliary telescopes, equivalent mirror diameters of up to  can be achieved. This is up to 25 times better than the resolution of a single VLT unit telescope.

text: List of proposed space observatories: examples of past and present space observatory plans, concepts, and proposals. For observatories in orbit, List of space telescopes. Unlike that list, this list includes concept and proposals that were not and in all likelihood will not ever be launched as they may have been cancelled or were only ever proposals.

text: List of proposed space observatories: examples of past and present space observatory plans, concepts, and proposals. For observatories in orbit,

text: List of space telescopes

text: . Unlike that list, this list includes concept and proposals that were not and in all likelihood will not ever be launched as they may have been cancelled or were only ever proposals.

text: A maser (, an acronym for "microwave amplification by stimulated emission of radiation") is a device that produces coherent electromagnetic waves through amplification by stimulated emission. The first maser was built by Charles H. Townes, James P. Gordon, and H. J. Zeiger at Columbia University in 1953.  Townes, Nikolay Basov and Alexander Prokhorov were awarded the 1964 Nobel Prize in Physics for theoretical work leading to the maser.  Masers are used as the timekeeping device in atomic clocks, and as extremely low-noise microwave amplifiers in radio telescopes and deep space spacecraft communication ground stations.

text: A maser (, an acronym for "microwave

text: amplification

text: by stimulated emission of

text: radiation

text: ") is a device that produces

text: coherent

text: electromagnetic waves

text: through amplification by

text: stimulated emission

text: . The first maser was built by

text: Charles H. Townes

text: , James P. Gordon, and H. J. Zeiger at Columbia University in 1953.  Townes,

text: Nikolay Basov

text: and

text: Alexander Prokhorov

text: were awarded the 1964

text: Nobel Prize in Physics

text: for theoretical work leading to the maser.  Masers are used as the timekeeping device in

text: atomic clock

text: s, and as extremely low-noise microwave

text: amplifier

text: s in

text: radio telescope

text: s and deep space

text: spacecraft communication

text: ground stations.

text: Prince Leopold, a skilled astronomer, knew that the question of telescopes was disjointed from the theoretical one, and he was yet perfectly acquainted with Divini's telescopes quality. In fact in 1660 he had viewed Saturn's shadow on its ring with a telescope made by Divini, a result that Huygens would have been looking for a long time yet. So he proposed Huygens to submit his better telescope to a test in Holland, while the same test would be done in Italy to Divini's better telescope.

text: Hubble was designed to accommodate regular servicing and equipment upgrades. Five servicing missions (SM 1, 2, 3A, 3B, and 4) were flown by NASA space shuttles, the first in December 1993 and the last in May 2009. Servicing missions were delicate operations that began with maneuvering to intercept the telescope in orbit and carefully retrieving it with the shuttle's mechanical arm. The necessary work was then carried out in multiple tethered spacewalks over a period of four to five days. After a visual inspection of the telescope, astronauts conducted repairs, replaced failed or degraded components, upgraded equipment, and installed new instruments. Once work was completed, the telescope was redeployed, typically after boosting to a higher orbit to address the orbital decay caused by atmospheric drag.

text: Hubble was designed to accommodate regular servicing and equipment upgrades. Five servicing missions (SM 1, 2, 3A, 3B, and 4) were flown by NASA

text: space shuttle

text: s, the first in December 1993 and the last in May 2009. Servicing missions were delicate operations that began with maneuvering to intercept the telescope in orbit and carefully retrieving it with the shuttle's

text: mechanical arm

text: . The necessary work was then carried out in multiple tethered

text: spacewalk

text: s over a period of four to five days. After a visual inspection of the telescope, astronauts conducted repairs, replaced failed or degraded components, upgraded equipment, and installed new instruments. Once work was completed, the telescope was redeployed, typically after boosting to a higher orbit to address the

text: orbital decay

text: caused by atmospheric

text: drag

text: Even higher limiting magnitudes can be achieved for telescopes above the Earth's atmosphere, such as the Hubble Space Telescope, where the sky brightness due to the atmosphere is not relevant.  For orbital telescopes, the background sky brightness is set by the zodiacal light.  The Hubble telescope can detect objects as faint as 31st magnitude, and the James Webb Space Telescope (operating in the infrared spectrum) is expected to have an absolute magnitude limit of 34th magnitude.

text: Even higher limiting magnitudes can be achieved for telescopes above the Earth's atmosphere, such as the

text: Hubble Space Telescope

text: , where the sky brightness due to the atmosphere is not relevant.  For orbital telescopes, the background sky brightness is set by the

text: zodiacal light

text: .  The Hubble telescope can detect objects as faint as 31st magnitude, and the

text: James Webb Space Telescope

text: (operating in the

text: infrared

text: spectrum) is expected to have an absolute magnitude limit of 34th magnitude.

text: Perhaps because of the intensity of his new relationship, he stopped writing in his Daybooks at this same time. Six months later he wrote one final entry, looking back from April 22:

text: Consider the transmitted electromagnetic waves

text: New tactics were employed when the horse ran for the second time in the Prince of Wales's Stakes at Royal Ascot. Hanagan positioned the colt just behind the leaders in fourth place, but after being slightly hampered in the straight he was never able to reach the leaders and finished fourth behind The Fugue, Magician and Treve. On 5 July, Mukhadram started a 14/1 outsider for the Eclipse Stakes in a field which included The Fugue, Night of Thunder, Kingston Hill, Verrazano, War Command and Trading Leather. Haggas was in confident mood before the race saying that "Mukhadram is a better horse than a year ago - he's much more mature and focussed". Hanagan settled the horse behind the pacemaker Somewhat before taking the lead three furlongs from the finish. He went clear of the field and was never in any danger of defeat, winning by two lengths from Trading Leather, with Somewhat hanging on to take third at odds of 100/1. After the race Hanagan paid tribute to the winner, saying "I know he stays well, I know he gives his all and it’s a massive plus when you’ve got a temperament like that. He lobs down to the post, I could put my kids on him". Haggas commented "He’s not always had the luck, but we have always believed in him... We know at home how good he is, and he’s proved it today". The trainer also indicated that the horse's next target would be the King George VI and Queen Elizabeth Stakes. Some observers, including Channel 4's Jim McGrath, expressed the view that Mukhadram's victory had been partly due to the riders of the more fancied runners misjudging the pace and giving their mounts too much ground to make up in the straight. Mukhadram was then stepped up in distance to one and a half miles for the first time to contest Britain's most prestigious weight-for-age race the King George VI and Queen Elizabeth Stakes at Ascot on 26 July. He started at odds of 12/1 after Hanagan opted to ride the Epsom Oaks winner Taghrooda. Ridden by Dane O'Neill, he tracked the pacemaker Leitir Mor before taking the lead in the straight and engaging in a protracted struggle with the favourite Telescope. He eventually finished third of the eight runners behind Taghrooda and Telescope, beaten three lengths and a short head. After the race Haggas said "He's run his guts out... I'm as proud as punch of my horse... the Juddmonte International Stakes could be next". On 20 August Mukhadram was brought back in distance to face the Derby winner Australia as well as Telescope and the Prix du Jockey Club winner The Grey Gatsby in the International Stakes over ten and a half furlongs at York. He tracked the pacemaker Kingfisher before moving forward to briefly take the lead in the straight, but faded in the closing stages to finish fourth behind Australia, The Grey Gatsby and Telescope, beaten seven and half lengths by the winner.

text: New tactics were employed when the horse ran for the second time in the Prince of Wales's Stakes at Royal Ascot. Hanagan positioned the colt just behind the leaders in fourth place, but after being slightly hampered in the straight he was never able to reach the leaders and finished fourth behind The Fugue,

text: Magician

text: and

text: Treve

text: . On 5 July, Mukhadram started a 14/1 outsider for the Eclipse Stakes in a field which included The Fugue,

text: Night of Thunder

text: Kingston Hill

text: Verrazano

text: War Command

text: and

text: Trading Leather

text: . Haggas was in confident mood before the race saying that "Mukhadram is a better horse than a year ago - he's much more mature and focussed". Hanagan settled the horse behind the

text: pacemaker

text: Somewhat before taking the lead three furlongs from the finish. He went clear of the field and was never in any danger of defeat, winning by two lengths from Trading Leather, with Somewhat hanging on to take third at odds of 100/1. After the race Hanagan paid tribute to the winner, saying "I know he stays well, I know he gives his all and it’s a massive plus when you’ve got a temperament like that. He lobs down to the post, I could put my kids on him". Haggas commented "He’s not always had the luck, but we have always believed in him... We know at home how good he is, and he’s proved it today". The trainer also indicated that the horse's next target would be the King George VI and Queen Elizabeth Stakes. Some observers, including

text: Channel 4

text: 's

text: Jim McGrath

text: , expressed the view that Mukhadram's victory had been partly due to the riders of the more fancied runners misjudging the pace and giving their mounts too much ground to make up in the straight. Mukhadram was then stepped up in distance to one and a half miles for the first time to contest Britain's most prestigious

text: weight-for-age

text: race the

entity_name: King George VI and Queen Elizabeth Stakes

text: King George VI and Queen Elizabeth Stakes

text: at Ascot on 26 July. He started at odds of 12/1 after Hanagan opted to ride the

text: Epsom Oaks

text: winner

text: Taghrooda

text: . Ridden by Dane O'Neill, he tracked the pacemaker Leitir Mor before taking the lead in the straight and engaging in a protracted struggle with the favourite

text: Telescope

text: . He eventually finished third of the eight runners behind Taghrooda and Telescope, beaten three lengths and a short head. After the race Haggas said "He's run his guts out... I'm as proud as punch of my horse... the

text: Juddmonte International Stakes

text: could be next". On 20 August Mukhadram was brought back in distance to face the Derby winner

text: Australia

text: as well as Telescope and the

text: Prix du Jockey Club

text: winner

text: The Grey Gatsby

text: in the

text: International Stakes

text: over ten and a half furlongs at York. He tracked the pacemaker Kingfisher before moving forward to briefly take the lead in the straight, but faded in the closing stages to finish fourth behind Australia, The Grey Gatsby and Telescope, beaten seven and half lengths by the winner.

text: Johnson, who had a strong interest in amateur astronomy, originally created Celestron as the "Astro-Optical" division of Valor Electronics in 1960. Around 1960, Johnson had been looking for a telescope which could be used by his two sons, but found no such child friendly models on the market at the time. Johnson built a new telescope, a 6-inch reflector telescope, by himself, in 1960. Richardson Medal

text: Johnson, who had a strong interest in

text: amateur astronomy

text: , originally created

text: Celestron

text: as the "Astro-Optical" division of Valor Electronics in 1960. Around 1960, Johnson had been looking for a telescope which could be used by his two sons, but found no such child friendly models on the market at the time. Johnson built a new telescope, a 6-inch reflector telescope, by himself, in 1960. Richardson Medal

text: Messier 74 had been observed approximately 200 days before the explosion with the Hubble Space Telescope, and about 300 days before using the Gemini Telescope. Astronomers were able to identify an object in these pre-supernova images that was in the same position as SN 2003gd, and which is believed to be the supernova's  progenitor star. This progenitor star was a red supergiant, consistent with the expectations of existing single-star stellar evolution models. It is the first progenitor of a normal type II-P supernova to have ever been detected.

text: Messier 74

text: had been observed approximately 200 days before the explosion with the

text: Hubble Space Telescope

text: , and about 300 days before using the

text: Gemini Telescope

text: . Astronomers were able to identify an object in these pre-supernova images that was in the same position as SN 2003gd, and which is believed to be the supernova's  progenitor star. This progenitor star was a

text: red supergiant

text: , consistent with the expectations of existing single-star

text: stellar evolution

text: models. It is the first progenitor of a normal type II-P supernova to have ever been detected.

text: Large telescopes are housed in domes, both to protect them from the weather and to stabilize the environmental conditions.  For example, if the temperature is different from one side of the telescope to the other, the shape of the structure changes, due to thermal expansion pushing optical elements out of position. This can affect the image.  For this reason, the domes are usually bright white (titanium dioxide) or unpainted metal.  Domes are often opened around sunset, long before observing can begin, so that air can circulate and bring the entire telescope to the same temperature as the surroundings.  To prevent wind-buffet or other vibrations affecting observations, it is standard practice to mount the telescope on a concrete pier whose foundations are entirely separate from those of the surrounding dome and building.

text: Large telescopes are housed in domes, both to protect them from the weather and to stabilize the environmental conditions.  For example, if the temperature is different from one side of the telescope to the other, the shape of the structure changes, due to

text: thermal expansion

text: pushing optical elements out of position. This can affect the image.  For this reason, the domes are usually bright white (

text: titanium dioxide

text: ) or unpainted metal.  Domes are often opened around sunset, long before observing can begin, so that air can circulate and bring the entire telescope to the same temperature as the surroundings.  To prevent wind-buffet or other vibrations affecting observations, it is standard practice to mount the telescope on a concrete pier whose foundations are entirely separate from those of the surrounding dome and building.

text: Brotherton's specialty is studying supermassive black holes in the centers of galaxies and how they shine when in their active phase. Brotherton's research seeks to improve our understanding of active galactic nuclei and their relationship to host galaxies, and their mutual evolution. His work is primarily observational in nature, the bulk of which rests on optical and infrared spectroscopy. He uses a wide assortment of telescopes/observatories operating across the electromagnetic spectrum including the Chandra X-ray Observatory, XMM-Newton, Far Ultraviolet Spectroscopic Explorer (FUSE), the Hubble Space Telescope, the Infrared Telescope Facility, and the Very Large Array, and optical telescopes including Keck, Lick, and Kitt Peak.  He works both on large samples that enable the phenomenology to be explored for an entire active galactic nuclei population, as well as individual objects of special interest that may reveal important physics because of their extreme nature.

text: Brotherton's specialty is studying

text: supermassive black holes

text: in the centers of galaxies and how they shine when in their active phase. Brotherton's research seeks to improve our understanding of

text: active galactic nuclei

text: and their relationship to host galaxies, and their mutual evolution. His work is primarily observational in nature, the bulk of which rests on

text: optical

text: and

text: infrared

text: spectroscopy

text: . He uses a wide assortment of telescopes/observatories operating across the

text: electromagnetic spectrum

text: including the

text: Chandra X-ray Observatory

text: XMM-Newton

text: Far Ultraviolet Spectroscopic Explorer

text: (FUSE), the

text: Hubble Space Telescope

text: , the

text: Infrared Telescope Facility

text: , and the

text: Very Large Array

text: , and optical telescopes including

text: Keck

text: Lick

text: , and

text: Kitt Peak

text: .  He works both on large samples that enable the

text: phenomenology

text: to be explored for an entire active galactic nuclei population, as well as individual objects of special interest that may reveal important physics because of their extreme nature.

text: Hartness’s interest in optics and astronomy led to his development of a telescope mount with the revolving dome on an equatorial plane. An additional feature of this telescope, which still stands at the former Hartness Mansion, was that the optics of the telescope passed through a lens in the wall of the dome. This allowed the observer to stay warm in winter. (Conventional telescopes were often contained within domes that opened an aperture for the telescope to gain exposure both to the sky and the ambient air.) The success of this patent led to more telescope activities and commissions. With Hartness's encouragement and financial support, Russell W. Porter initiated the Springfield Telescope Makers Club. The club still celebrates their annual Stellafane gathering in Springfield.

text: Hartness’s interest in

text: optics

text: and

text: astronomy

text: led to his development of a

text: telescope mount

text: with the revolving dome on an

text: equatorial plane

text: . An additional feature of this telescope, which still stands at the former Hartness Mansion, was that the optics of the telescope passed through a lens in the wall of the dome. This allowed the observer to stay warm in winter. (Conventional telescopes were often contained within domes that opened an aperture for the telescope to gain exposure both to the sky and the ambient air.) The success of this patent led to more telescope activities and commissions. With Hartness's encouragement and financial support, Russell W. Porter initiated the Springfield Telescope Makers Club. The club still celebrates their annual

text: Stellafane

text: gathering in Springfield.

text: One of the radio telescopes that make up the Jodrell Bank MERLIN (Multi-Element Radio Linked Interferometer Network) radio telescope array is in Knockin. The array links several observing stations that together form a powerful telescope.

text: One of the

text: radio telescope

text: s that make up the

text: Jodrell Bank

text: MERLIN

text: (Multi-Element Radio Linked Interferometer Network) radio telescope array is in Knockin. The array links several observing stations that together form a powerful telescope.

text: Chandra is one of the Great Observatories, along with the Hubble Space Telescope, Compton Gamma Ray Observatory (1991–2000), and the Spitzer Space Telescope. The telescope is named after astrophysicist Subrahmanyan Chandrasekhar.

text: Chandra is one of the

text: Great Observatories

text: , along with the

text: Hubble Space Telescope

text: Compton Gamma Ray Observatory

text: (1991–2000), and the

text: Spitzer Space Telescope

text: . The telescope is named after astrophysicist

text: Subrahmanyan Chandrasekhar

text: The Galilean Nights was a worldwide astronomy event that also ran 2–5 April 2009, as a project to involve both amateur and professional astronomers around the globe, taking to the streets their telescopes and pointing them as Galileo did 400 years ago. The sources of interest were Jupiter and its moons, the Sun, our Moon and many others celestial marvels. The event was scheduled to take place on 22–24 October 2009. Astronomers were to share their knowledge and enthusiasm for space by encouraging as many people as possible to look through a telescope at planetary neighbours.

text: The Galilean Nights was a worldwide astronomy event that also ran 2–5 April 2009, as a project to involve both amateur and professional astronomers around the globe, taking to the streets their telescopes and pointing them as Galileo did 400 years ago. The sources of interest were

text: Jupiter

text: and its moons, the Sun, our Moon and many others celestial marvels. The event was scheduled to take place on 22–24 October 2009. Astronomers were to share their knowledge and enthusiasm for space by encouraging as many people as possible to look through a telescope at planetary neighbours.

text: When an electromagnetic wave is scattered by an object, currents are induced on said object which subsequently re-radiate electromagnetic energy. The structure of the currents (and fields) are unique to the physical dimensions of the scatterer and incident frequency of radiation. From this perspective, a scatterer can be viewed as a parasitic antenna that radiates electromagnetic radiation in the same manner that the original incident wave was radiated.

text: When an

text: electromagnetic wave

text: is scattered by an object, currents are induced on said object which subsequently re-radiate

text: electromagnetic energy

text: . The structure of the currents (and fields) are unique to the physical dimensions of the scatterer and incident

text: frequency

text: of radiation. From this perspective, a scatterer can be viewed as a parasitic

text: antenna

text: that radiates

text: electromagnetic radiation

text: in the same manner that the original incident wave was radiated.

text: In optical instruments such as telescopes, microscopes, or in telescopic sights used on small arms and theodolites, the error occurs when the optics are not precisely focused: the reticle will appear to move with respect to the object focused on if one moves one's head sideways in front of the eyepiece. Some firearm telescopic sights are equipped with a parallax compensation mechanism which basically consists of a movable optical element that enables the optical system to project the picture of objects at varying distances and the reticle crosshairs pictures together in exactly the same optical plane. Telescopic sights may have no parallax compensation because they can perform very acceptably without refinement for parallax with the sight being permanently adjusted for the distance that best suits their intended usage. Typical standard factory parallax adjustment distances for hunting telescopic sights are 100 yd or 100 m to make them suited for hunting shots that rarely exceed 300 yd/m. Some target and military style telescopic sights without parallax compensation may be adjusted to be parallax free at ranges up to 300 yd/m to make them better suited for aiming at longer ranges. Scopes for rimfires, shotguns, and muzzleloaders will have shorter parallax settings, commonly 50 yd/m for rimfire scopes and 100 yd/m for shotguns and muzzleloaders. Scopes for airguns are very often found with adjustable parallax, usually in the form of an adjustable objective, or AO. These may adjust down as far as 3 yards (2.74 m).

text: In optical instruments such as

text: telescope

text: s,

text: microscope

text: s, or in

text: telescopic sight

text: s used on small arms and

text: theodolite

text: s, the error occurs when the optics are not precisely focused: the reticle will appear to move with respect to the object focused on if one moves one's head sideways in front of the eyepiece. Some firearm telescopic sights are equipped with a parallax compensation mechanism which basically consists of a movable optical element that enables the optical system to project the picture of objects at varying distances and the reticle crosshairs pictures together in exactly the same optical plane. Telescopic sights may have no parallax compensation because they can perform very acceptably without refinement for parallax with the sight being permanently adjusted for the distance that best suits their intended usage. Typical standard factory parallax adjustment distances for hunting telescopic sights are 100 yd or 100 m to make them suited for hunting shots that rarely exceed 300 yd/m. Some target and military style telescopic sights without parallax compensation may be adjusted to be parallax free at ranges up to 300 yd/m to make them better suited for aiming at longer ranges. Scopes for

text: rimfires

text: shotgun

text: s, and

text: muzzleloader

text: s will have shorter parallax settings, commonly 50 yd/m for rimfire scopes and 100 yd/m for shotguns and muzzleloaders. Scopes for

text: airgun

text: s are very often found with adjustable parallax, usually in the form of an adjustable objective, or AO. These may adjust down as far as 3 yards (2.74 m).

text: The electromagnetic spectrum is a plot of the field magnitudes (or energies) as a function of wavelength.

text: The

text: electromagnetic spectrum

text: is a plot of the field magnitudes (or energies) as a function of wavelength.

text: The electromagnetic wave equation describes the propagation of electromagnetic waves through a medium or in a vacuum.  The homogeneous form of the equation, written in terms of either the electric field E or the magnetic field B, takes the form:

text: The electromagnetic wave equation describes the propagation of electromagnetic waves through a

text: medium

text: or in a

text: vacuum

text: .  The

text: homogeneous

text: electric field

text: E or the

text: magnetic field

text: B, takes the form:

text: Because of the distance of Neptune from Earth, its angular diameter only ranges from 2.2 to 2.4 arcseconds, the smallest of the Solar System planets. Its small apparent size makes it challenging to study it visually. Most telescopic data was fairly limited until the advent of the Hubble Space Telescope and large ground-based telescopes with adaptive optics (AO).The first scientifically useful observation of Neptune from ground-based telescopes using adaptive optics, was commenced in 1997 from Hawaii. Neptune is currently entering its spring and summer season and has been shown to be heating up, with increased atmospheric activity and brightness as a consequence. Combined with technological advancements, ground-based telescopes with adaptive optics are recording increasingly more detailed images of it. Both Hubble and the adaptive-optics telescopes on Earth has made many new discoveries within the Solar System since the mid-1990s, with a large increase in the number of known satellites and moons around the outer planet, among others. In 2004 and 2005, five new small satellites of Neptune with diameters between 38 and 61 kilometres were discovered.

text: Because of the distance of Neptune from Earth, its

text: angular diameter

text: only ranges from 2.2 to 2.4

text: arcsecond

text: s, the smallest of the Solar System planets. Its small apparent size makes it challenging to study it visually. Most telescopic data was fairly limited until the advent of the

text: Hubble Space Telescope

text: and large ground-based telescopes with

text: adaptive optics

text: (AO).The first scientifically useful observation of Neptune from ground-based telescopes using adaptive optics, was commenced in 1997 from Hawaii. Neptune is currently entering its spring and summer season and has been shown to be heating up, with increased atmospheric activity and brightness as a consequence. Combined with technological advancements, ground-based telescopes with adaptive optics are recording increasingly more detailed images of it. Both Hubble and the adaptive-optics telescopes on Earth has made many new discoveries within the Solar System since the mid-1990s, with a large increase in the number of known satellites and moons around the outer planet, among others. In 2004 and 2005, five new small satellites of Neptune with diameters between 38 and 61 kilometres were discovered.

text: Nello Carrara was born in Florence on 19 February 1900. He graduated from high school in 1917, and after serving in the Army during World War I, entered the Scuola Normale Superiore in Pisa in 1918, where he studied physics. His fellow students included Enrico Fermi and Franco Rasetti. He wrote his doctoral thesis on X-ray diffraction in 1921. After graduation, he worked for the University of Pisa. At the age of 24, he became a professor at the Italian Naval Academy, where he taught hundreds of Italian Marina Militare officers and academic researchers until 1954. While there he was involved with the development of radar, helping to create the first Italian RDT (Radio Detector Rangefinder), the continuous wave EC1  in 1936. He also taught physics at the University of Bari from 1945 to 1946, and the University of Pisa from 1947 to 1950. Carrara founded the Electromagnetic Wave Research Institute in Florence in 1946. He became Professor of Naval Electromagnetic Waves at the Higher Institute of Naples in 1954, and moved to the University of Florence in 1956. In 1975 he became a professor emeritus. He was also Director of the Center of Microwave National Research Council.

text: Nello Carrara was born in

text: Florence

text: on 19 February 1900. He graduated from high school in 1917, and after serving in the Army during

text: World War I

text: , entered the

text: Scuola Normale Superiore

text: in

text: Pisa

text: in 1918, where he studied

text: physics

text: . His fellow students included

text: Enrico Fermi

text: and

text: Franco Rasetti

text: . He wrote his doctoral thesis on

text: X-ray diffraction

text: in 1921. After graduation, he worked for the

text: University of Pisa

text: . At the age of 24, he became a professor at the

text: Italian Naval Academy

text: , where he taught hundreds of Italian

text: Marina Militare

text: officers and academic researchers until 1954. While there he was involved with the development of radar, helping to create the first Italian RDT (Radio Detector Rangefinder), the continuous wave EC1  in 1936. He also taught physics at the

entity_name: Università degli studi di Bari Aldo Moro

text: University of Bari

text: from 1945 to 1946, and the University of Pisa from 1947 to 1950. Carrara founded the Electromagnetic Wave Research Institute in Florence in 1946. He became Professor of Naval Electromagnetic Waves at the Higher Institute of

text: Naples

text: in 1954, and moved to the

text: University of Florence

text: in 1956. In 1975 he became a

text: professor emeritus

text: . He was also Director of the Center of Microwave National Research Council.

text: As a graduate student in 1999, he used a 4-inch telescope to make the first detection of an exoplanet eclipsing (or transiting) its parent star, which yielded the first ever constraint on the composition of a planet outside the Solar system. Charbonneau was a founding member of the Trans-Atlantic Exoplanet Survey, which used a worldwide network of humble automated telescopes to survey hundreds of thousands of stars to detect 5 more exoplanets by this technique. Charbonneau also pioneered the use of space-based observatories to undertake the first studies of the atmospheres of these distant worlds:  In 2001 he used the Hubble Space Telescope to study directly the chemical make-up of the atmosphere enshrouding one of these exoplanets, and in 2005, he led the team that used the Spitzer Space Telescope to make the first direct detection of the light emitted by an exoplanet.  He is currently leading the NSF-funded MEarth Project and is a member of the NASA Kepler Mission Team. Each of these projects aims to detect Earth-like planets that might be suitable abodes for life beyond the Solar system.

text: As a graduate student in 1999, he used a 4-inch telescope to make the first detection of an exoplanet eclipsing (or transiting) its parent star, which yielded the first ever constraint on the composition of a planet outside the Solar system. Charbonneau was a founding member of the

text: Trans-Atlantic Exoplanet Survey

text: , which used a worldwide network of humble automated telescopes to survey hundreds of thousands of stars to detect 5 more exoplanets by this technique. Charbonneau also pioneered the use of space-based observatories to undertake the first studies of the atmospheres of these distant worlds:  In 2001 he used the

text: Hubble Space Telescope

text: to study directly the chemical make-up of the atmosphere enshrouding one of these exoplanets, and in 2005, he led the team that used the

text: Spitzer Space Telescope

text: to make the first direct detection of the light emitted by an exoplanet.  He is currently leading the NSF-funded

text: MEarth Project

text: and is a member of the NASA

text: Kepler Mission

text: Team. Each of these projects aims to detect Earth-like planets that might be suitable abodes for life beyond the Solar system.

text: The third floor houses the academic offices of the Jodrell Bank Centre for Astrophysics, which provides a new base for the research activities in astronomy and astrophysics with the relocation of many staff and students from Jodrell Bank Observatory. The Observatory now forms part of the JBCA and provides leading observational facilities such as the Lovell Telescope and the Multi-Element Radio Linked Interferometer Network (MERLIN). This floor differs in design from the others in that the rooms have windows onto the atrium and glass walls to central corridors in each wing whilst retaining glass walled walkways across the atrium. The astrophysics seminar room is named after Sir Bernard Lovell, founder of Jodrell Bank Observatory. The fourth floor contains a number of labs, an RFI screened room and clean room, all for astrophysics instrumentation construction, such as receivers for the Lovell Telescope and the Planck spacecraft. In January 2008 the Project Design Office for the Square Kilometre Array relocated to Manchester to be hosted by the JBCA, co-ordinating the global efforts in constructing the next generation radio telescope.

text: The third floor houses the academic offices of the

text: Jodrell Bank Centre for Astrophysics

text: , which provides a new base for the research activities in astronomy and astrophysics with the relocation of many staff and students from

text: Jodrell Bank Observatory

text: . The Observatory now forms part of the JBCA and provides leading observational facilities such as the

text: Lovell Telescope

text: and the

text: (MERLIN). This floor differs in design from the others in that the rooms have windows onto the atrium and glass walls to central corridors in each wing whilst retaining glass walled walkways across the atrium. The astrophysics seminar room is named after

text: Sir Bernard Lovell

text: , founder of

text: Jodrell Bank Observatory

text: . The fourth floor contains a number of labs, an RFI screened room and clean room, all for astrophysics instrumentation construction, such as receivers for the

text: Lovell Telescope

text: and the

text: Planck spacecraft

text: . In January 2008 the Project Design Office for the

text: Square Kilometre Array

text: relocated to Manchester to be hosted by the JBCA, co-ordinating the global efforts in constructing the next generation radio telescope.

text: Metamaterials were introduced about a decade ago, and these expand control of parts of the electromagnetic spectrum; from microwave, to terahertz, to infrared. Theoretically, metamaterials, as a transmission medium, will eventually expand control and direction of electromagnetic fields into the visible spectrum. Hence, a design strategy was introduced in 2006, to show that a metamaterial can be engineered with arbitrarily assigned positive or negative values of permittivity and permeability, which can also be independently varied at will. Then direct control of electromagnetic fields becomes possible, which is relevant to novel and unusual lens design, as well as a component of the scientific theory for cloaking of objects from electromagnetic detection.

text: Metamaterials

text: were introduced about a decade ago, and these expand control of parts of the

text: electromagnetic spectrum

text: ; from

text: microwave

text: , to

text: terahertz

text: , to

text: infrared

text: . Theoretically, metamaterials, as a

text: transmission medium

text: , will eventually expand control and direction of electromagnetic fields into the

text: visible spectrum

text: . Hence, a design strategy was introduced in 2006, to show that a metamaterial can be engineered with arbitrarily assigned positive or negative values of

text: permittivity

text: and

text: permeability

text: , which can also be independently varied at will. Then direct control of electromagnetic fields becomes possible, which is relevant to novel and unusual lens design, as well as a component of the

text: scientific theory

text: for cloaking of objects from electromagnetic detection.

text: In 1928 the modern day descendant of GMT (though slightly less accurate than UTC) was defined by the International Astronomical Union as Universal Time (UT).  Even to the present day, UT is still based on an international telescopic system. Observations at the Greenwich Observatory itself ceased in 1954, though the location is still used as the basis for the coordinate system. Because the rotational period of Earth is not perfectly constant, the duration of a second would vary if calibrated to a telescope-based standard like GMT or UT—in which a second was defined as a fraction of a day or year. The terms "GMT" and "Greenwich Mean Time" are sometimes used informally to refer to UT, however GMT and UTC are not the same thing, and the most accurate description of the most commonly used international time standard is now UTC, and is no longer "GMT".

text: In 1928 the modern day descendant of GMT (though slightly less accurate than UTC) was defined by the

text: International Astronomical Union

text: as

text: Universal Time

text: (UT).  Even to the present day, UT is still based on an international telescopic system. Observations at the Greenwich Observatory itself ceased in 1954, though the location is still used as the basis for the coordinate system. Because the rotational period of Earth is not perfectly constant, the duration of a second would vary if calibrated to a telescope-based standard like GMT or UT—in which a second was defined as a fraction of a day or year. The terms "GMT" and "Greenwich Mean Time" are sometimes used informally to refer to UT, however GMT and UTC are not the same thing, and the most accurate description of the most commonly used international time standard is now UTC, and is no longer "GMT".

text: Cooke studied optics and became interested in making telescopes, the first of which was a refracting telescope with the base of a tumbler shaped to form its lens.  This led to his friends including John Phillips encouraging him to make telescopes and other optical devices commercially.

text: Cooke studied

text: optics

text: and became interested in making

text: telescope

text: s, the first of which was a

text: refracting telescope

text: with the base of a

text: tumbler

text: shaped to form its

text: lens

text: .  This led to his friends including

text: John Phillips

text: encouraging him to make telescopes and other optical devices commercially.

text: Historically, astronomical observatories consisted generally in a building or group of buildings where observations of astronomical objects such as sunspots, planets, asteroids, comets, stars, nebulae, and galaxies in the visible wavelengths of the electromagnetic spectrum were conducted. At first, for millennia, astronomical observations have been made with naked eyes. Then with the discovery of optics, with the help of different types of refractor telescopes and later with reflector telescopes. Their use allowed to dramatically increase both the collecting power and limit of resolution, thus the brightness, level of detail and apparent angular size of distant celestial objects allowing them to be better studied and understood. Following the development of modern physics, new ground based facilities have been constructed to conduct research in the radio and microwave wavelengths of the electromagnetic spectrum, with radio telescopes and dedicated microwave telescopes.

text: Historically,

text: astronomical observatories

text: consisted generally in a building or group of buildings where observations of

text: astronomical

text: objects such as

text: sunspot

text: s,

text: planets

text: asteroids

text: comet

text: s,

text: star

text: s,

text: nebula

text: e, and

text: galaxies

text: in the

text: visible

text: wavelengths of the electromagnetic spectrum were conducted. At first, for millennia, astronomical observations have been made with naked eyes. Then with the discovery of

text: optics

text: , with the help of different types of

text: refractor telescope

text: s and later with

text: reflector telescope

text: s. Their use allowed to dramatically increase both the

text: collecting power

text: and

text: limit of resolution

text: , thus the

text: brightness

text: , level of detail and apparent

text: angular size

text: of distant celestial objects allowing them to be better studied and understood. Following the development of modern

text: physics

text: , new ground based facilities have been constructed to conduct research in the radio and

text: microwave

text: wavelengths of the electromagnetic spectrum, with

text: radio telescope

text: s and dedicated

text: microwave telescope

text: s.

text: OMEGA is a mineralogical mapping spectrometer that has channels to detect visible (0.5-1.0 µm) and infrared (1.0-5.2 µm) wavelengths with a special resolution of 100 m.  Both channels have a telescope, a spectrometer, and an optical device which focuses light. Visible light is focused onto a charge coupled device and infrared is focused to an InSb multi detector. OMEGA was designed to work in collaboration with the other instruments on Mars Express, specifically the Planetary Fourier Spectrometer (PFS).

text: OMEGA is a mineralogical mapping spectrometer that has channels to detect visible (0.5-1.0 µm) and infrared (1.0-5.2 µm) wavelengths with a special resolution of 100 m.  Both channels have a telescope, a spectrometer, and an optical device which focuses light. Visible light is focused onto a charge coupled device and infrared is focused to an

text: InSb

text: multi detector. OMEGA was designed to work in collaboration with the other instruments on Mars Express, specifically the

text: Planetary Fourier Spectrometer

text: (PFS).

text: Top-down proteomics is a method of protein identification that uses an ion trapping mass spectrometer to store an isolated protein ion for mass measurement and tandem mass spectrometry analysis. Top-down proteomics is capable of identifying and quantitating unique proteoforms through the analysis of intact proteins. The name is derived from the similar approach to DNA sequencing. Proteins are typically ionized by electrospray ionization and trapped in a Fourier transform ion cyclotron resonance (Penning trap) or quadrupole ion trap (Paul trap) mass spectrometer. Fragmentation for tandem mass spectrometry is accomplished by electron-capture dissociation or electron-transfer dissociation. Effective fractionation is critical for sample handling before mass-spectrometry-based proteomics. Proteome analysis routinely involves digesting intact proteins followed by inferred protein identification using mass spectrometry. Top-down proteomics interrogates protein structure through measurement of an intact mass followed by direct ion dissociation in the gas phase.

text: Top-down

text: proteomics

text: is a method of

text: protein

text: identification that uses an

text: ion trap

text: ping

text: mass spectrometer

text: to store an isolated protein ion for mass measurement and

text: tandem mass spectrometry

text: analysis. Top-down proteomics is capable of identifying and quantitating unique proteoforms through the analysis of intact proteins. The name is derived from the similar approach to DNA sequencing. Proteins are typically ionized by

text: electrospray ionization

text: and trapped in a

text: Penning trap

text: ) or

text: quadrupole ion trap

text: (Paul trap) mass spectrometer.

text: Fragmentation

text: for tandem mass spectrometry is accomplished by

text: electron-capture dissociation

text: or

text: electron-transfer dissociation

text: . Effective fractionation is critical for sample handling before mass-spectrometry-based proteomics. Proteome analysis routinely involves digesting intact proteins followed by inferred protein identification using mass spectrometry. Top-down proteomics interrogates protein structure through measurement of an intact mass followed by direct ion dissociation in the gas phase.

text: For optical telescopes, most ground-based observatories are located far from major centers of population, to avoid the effects of light pollution. The ideal locations for modern observatories are sites that have dark skies, a large percentage of clear nights per year, dry air, and are at high elevations. At high elevations, the Earth's atmosphere is thinner thereby minimizing the effects of atmospheric turbulence and resulting in better astronomical "seeing". Sites that meet the above criteria for modern observatories include the southwestern United States, Hawaii, Canary Islands, the Andes, and high mountains in Mexico such as Sierra Negra. Major optical observatories include Mauna Kea Observatory and Kitt Peak National Observatory in the USA, Roque de los Muchachos Observatory in Spain, and Paranal Observatory in Chile.

text: For optical telescopes, most ground-based observatories are located far from major centers of population, to avoid the effects of

text: light pollution

text: . The ideal locations for modern observatories are sites that have dark skies, a large percentage of clear nights per year, dry air, and are at high elevations. At high elevations, the

text: Earth's atmosphere

text: is thinner thereby minimizing the effects of

text: atmospheric turbulence

text: and resulting in better astronomical "

text: seeing

text: ". Sites that meet the above criteria for modern observatories include the

text: southwestern United States

text: Hawaii

text: Canary Islands

text: , the

text: Andes

text: , and high mountains in

text: Mexico

text: such as

text: Sierra Negra

text: . Major optical observatories include

text: Mauna Kea Observatory

text: and

text: Kitt Peak National Observatory

text: in the USA,

text: Roque de los Muchachos Observatory

text: in Spain, and

text: Paranal Observatory

text: in

text: Chile

text: Angular size of patch in atmosphere over which electromagnetic waves in the same plane stay parallel.  The patch size inversely affects the Fried Parameter and the resolution of optical telescopes.  Adaptive optical telescopes uses a bright light source to identify the properties of the patch in the line of sight to the object of interest to correct for seeing effects.

text: Other radio telescopes that are being used by RRI scientists for observations are the Ooty Radio Telescope, at Ooty, and Giant Metrewave Radio Telescope (GMRT), near Pune, both set up by the Tata Institute of Fundamental Research (TIFR). RRI also played an active role in building the Mauritius Radio Telescope, a low-frequency radio telescope in Mauritius jointly with the University of Mauritius and IIA.

text: Other radio telescopes that are being used by RRI scientists for observations are the

text: Ooty Radio Telescope

text: , at Ooty, and

text: Giant Metrewave Radio Telescope

text: (GMRT), near Pune, both set up by the

text: Tata Institute of Fundamental Research

text: (TIFR). RRI also played an active role in building the

text: Mauritius Radio Telescope

text: , a low-frequency radio telescope in Mauritius jointly with the

text: University of Mauritius

text: and IIA.

text: Electromagnetic radiation is a transverse wave, meaning that its oscillations are perpendicular to the direction of energy transfer and travel. The electric and magnetic parts of the field stand in a fixed ratio of strengths in order to satisfy the two Maxwell equations that specify how one is produced from the other. These E and B fields are also in phase, with both reaching maxima and minima at the same points in space (see illustrations). A common misconception is that the E and B fields in electromagnetic radiation are out of phase because a change in one produces the other, and this would produce a phase difference between them as sinusoidal functions (as indeed happens in electromagnetic induction, and in the near-field close to antennas). However, in the far-field EM radiation which is described by the two source-free Maxwell curl operator equations, a more correct description is that a time-change in one type of field is proportional to a space-change in the other. These derivatives require that the E and B fields in EMR are in-phase (see math section below).

text: Electromagnetic radiation is a

text: transverse wave

text: , meaning that its oscillations are perpendicular to the direction of energy transfer and travel. The electric and magnetic parts of the field stand in a fixed ratio of strengths in order to satisfy the two

text: Maxwell equations

text: that specify how one is produced from the other. These E and B fields are also in phase, with both reaching maxima and minima at the same points in space (see illustrations). A common misconception is that the E and B fields in electromagnetic radiation are out of phase because a change in one produces the other, and this would produce a phase difference between them as sinusoidal functions (as indeed happens in

text: electromagnetic induction

text: , and in the

text: near-field

text: close to antennas). However, in the far-field EM radiation which is described by the two source-free Maxwell

text: curl operator

text: equations, a more correct description is that a time-change in one type of field is proportional to a space-change in the other. These derivatives require that the E and B fields in EMR are in-phase (see math section below).

text: Speckle masking (or bispectral analysis, as applied to speckle imaging), is a method which involves estimation of the bispectrum or closure phases from each of the short exposures. The "average bispectrum" can then be calculated and then inverted to obtain an image. With a normal telescope aperture, a large number of short exposures must be averaged to remove the effects of the atmosphere. If a non-redundant aperture mask is used the bispectrum can be calculated without any noise contribution from the atmosphere (but still with a photon shot noise error contribution). In this arrangement a ground-based telescope aperture is blocked by astronomers apart from a few holes which allow light through, creating a small optical interferometer with the resolving power of a diffraction-limited telescope rather than being limited by the astronomical seeing.

text: Speckle masking (or

text: bispectral analysis

text: , as applied to

text: speckle imaging

text: ), is a method which involves estimation of the

text: bispectrum

text: or

text: closure phase

text: s from each of the short exposures. The "average bispectrum" can then be calculated and then inverted to obtain an image. With a normal telescope aperture, a large number of short exposures must be averaged to remove the effects of the atmosphere. If a non-redundant

text: aperture mask

text: is used the bispectrum can be calculated without any noise contribution from the atmosphere (but still with a photon

text: shot noise

text: error contribution). In this arrangement a ground-based telescope aperture is blocked by astronomers apart from a few holes which allow light through, creating a small

text: optical interferometer

text: with the resolving power of a diffraction-limited telescope rather than being limited by the

text: astronomical seeing

text: The electromagnetic spectrum extends from below frequencies used for modern radio to gamma radiation at the short-wavelength end, covering wavelengths from thousands of kilometers down to a fraction of the size of an atom. That would be wavelengths from 10 to 10 kilometers. The long wavelength limit is the size of the universe itself, while it is thought that the short wavelength limit is in the vicinity of the Planck length, although in principle the spectrum is infinite and continuous.

text: The electromagnetic spectrum extends from below frequencies used for modern radio to

text: gamma radiation

text: at the short-wavelength end, covering wavelengths from thousands of kilometers down to a fraction of the size of an atom. That would be wavelengths from 10 to 10 kilometers. The long wavelength limit is the size of the universe itself, while it is thought that the short wavelength limit is in the vicinity of the Planck length, although in principle the spectrum is infinite and continuous.

text: Strands of Sunlight is a novel written by Gael Baudino in 1994.  It is the fourth in the Strands of Starlight tetralogy.  The other novels are Strands of Starlight, Maze of Moonlight, and Shroud of Shadow.  Out of the four-book series, this book alone was not released in the UK market because, according to the author, the publishers believed "that British readers won't have any interest in events set in contemporary Denver".

text: Strands of Sunlight is a novel written by

text: Gael Baudino

text: in 1994.  It is the fourth in the

text: Strands of Starlight

text: tetralogy

text: .  The other novels are

text: Strands of Starlight

text: Maze of Moonlight

text: , and

text: Shroud of Shadow

text: .  Out of the four-book series, this book alone was not released in the UK market because, according to the author, the publishers believed "that British readers won't have any interest in events set in contemporary Denver".

text: Before doing some tests with the telescopes, scientists had to prove that the elements used with the optics fiber were reliable (for example, the off-axis parabola, used to inject the beams in the optics fiber). Those tests were partly carried out on the Infrared Optical Telescope Array Observatory.

text: Before doing some tests with the telescopes, scientists had to prove that the elements used with the optics fiber were reliable (for example, the off-axis parabola, used to inject the beams in the optics fiber). Those tests were partly carried out on the

text: Infrared Optical Telescope Array

text: Observatory.

text: The key instrument of nearly all modern observational astronomy is the telescope. This serves the dual purposes of gathering more light so that very faint objects can be observed, and magnifying the image so that small and distant objects can be observed. Optical astronomy requires telescopes that use optical components of great precision. Typical requirements for grinding and polishing a curved mirror, for example, require the surface to be within a fraction of a wavelength of light of a particular conic shape. Many modern "telescopes" actually consist of arrays of telescopes working together to provide higher resolution through aperture synthesis.

text: The key instrument of nearly all modern observational astronomy is the

text: telescope

text: . This serves the dual purposes of gathering more light so that very faint objects can be observed, and magnifying the image so that small and distant objects can be observed. Optical astronomy requires telescopes that use optical components of great precision. Typical requirements for grinding and polishing a curved mirror, for example, require the surface to be within a fraction of a wavelength of light of a particular

text: conic

text: shape. Many modern "telescopes" actually consist of arrays of telescopes working together to provide higher resolution through

text: aperture synthesis

text: The Phoebe Waterman Haas Public Observatory has a main telescope used during the nighttime, as well as a Sun Gun Telescope and other telescopes for observing the sun.

text: The Phoebe Waterman Haas Public Observatory has a main telescope used during the nighttime, as well as a

text: Sun Gun Telescope

text: and other telescopes for observing the sun.

text: Supported by NSF, we have been developing Skynet, which is telescope control and web-based, dynamic queue-scheduling software that we originally developed for PROMPT, but is now capable of controlling many more telescopes and most types of commercially available small-telescope hardware.  This started as a proof of concept effort, to see if we could expand our geographic footprint beyond CTIO without having to pay for additional telescopes.  This experiment has greatly exceeded expectations:  The Skynet Robotic Telescope Network now spans four continents and soon five countries.  Currently, we have ten non-PROMPT telescopes (Australia, California, Illinois, Italy, four in North Carolina, a 40-inch diameter telescope in Wisconsin, and the 20-meter diameter radio telescope in West Virginia) integrated into Skynet, and plan to add at least seven more non-PROMPT telescopes (Canada, Kansas, Illinois, two in North Carolina, including a 32-inch diameter telescope, Virginia, and Wyoming) over the next two years.

text: UV astronomy was impossible before the Space Age, and some of the first space telescopes were UV telescopes designed to observe this previously inaccessible region of the electromagnetic spectrum. One particular success was the second Orbiting Astronomical Observatory, which had a number of 20 cm UV telescopes on board. It was launched in 1968, and took the first UV observations of 1200 objects, mostly stars. The success of OAO-2 motivated astronomers to consider larger missions.

text: UV astronomy was impossible before the

text: Space Age

text: , and some of the first

text: space telescope

text: s were UV telescopes designed to observe this previously inaccessible region of the

text: electromagnetic spectrum

text: . One particular success was the second

text: Orbiting Astronomical Observatory

text: , which had a number of 20 cm UV telescopes on board. It was launched in 1968, and took the first UV observations of 1200 objects, mostly stars. The success of OAO-2 motivated astronomers to consider larger missions.

text: During the period 1850–1900, reflectors suffered from problems with speculum metal mirrors, and a considerable number of "Great Refractors" were built from 60 cm to 1 metre aperture, culminating in the Yerkes Observatory refractor in 1897; however, starting from the early 1900s a series of ever-larger reflectors with glass mirrors were built, including the Mount Wilson 60-inch, the 100-inch (2.5 metre) Hooker Telescope (1917) and the 200-inch (5 metre) Hale telescope (1948); essentially all major research telescopes since 1900 have been reflectors. A number of 4-metre class (160 inch) telescopes were built on superior higher altitude sites including Hawaii and the Chilean desert in the 1975–1985 era. The development of the computer-controlled alt-azimuth mount in the 1970s and active optics in the 1980s enabled a new generation of even larger telescopes, starting with the 10-metre (400 inch) Keck telescopes in 1993/1996, and a number of 8-metre telescopes including the ESO Very Large Telescope, Gemini Observatory and Subaru Telescope.

text: During the period 1850–1900, reflectors suffered from problems with speculum metal mirrors, and a considerable number of "Great Refractors" were built from 60 cm to 1 metre aperture, culminating in the

text: Yerkes Observatory

text: refractor in 1897; however, starting from the early 1900s a series of ever-larger reflectors with glass mirrors were built, including the Mount Wilson 60-inch, the 100-inch (2.5 metre)

text: Hooker Telescope

text: (1917) and the 200-inch (5 metre)

text: Hale telescope

text: (1948); essentially all major research telescopes since 1900 have been reflectors. A number of 4-metre class (160 inch) telescopes were built on superior higher altitude sites including Hawaii and the Chilean desert in the 1975–1985 era. The development of the computer-controlled

text: alt-azimuth mount

text: in the 1970s and

text: active optics

text: in the 1980s enabled a new generation of even larger telescopes, starting with the 10-metre (400 inch)

text: Keck telescopes

text: in 1993/1996, and a number of 8-metre telescopes including the

text: ESO

text: Very Large Telescope

text: Gemini Observatory

text: and

text: Subaru Telescope

text: Space telescopes are not affected by the Earth's atmosphere but are diffraction limited. For example, the Hubble space telescope can reach an angular size of stars down to about 0.1″. Techniques exist for improving seeing on the ground. Adaptive optics, for example, can produce images around 0.05 arcsecond on a 10 m class telescope.

text: Space telescopes are not affected by the Earth's atmosphere but are

text: diffraction limited

text: . For example, the

text: Hubble space telescope

text: can reach an angular size of stars down to about 0.1″. Techniques exist for improving seeing on the ground.

text: Adaptive optics

text: , for example, can produce images around 0.05 arcsecond on a 10 m class telescope.

text: On 9 August 1979, the Department of the Army announced that Fort Irwin had been selected as the site for the National Training Center. With over  for maneuver and ranges, an uncluttered electromagnetic spectrum, airspace restricted to military use, and its isolation from densely populated areas, Fort Irwin was an ideal site for this facility. The National Training Center was officially activated 16 October 1980, and Fort Irwin was transferred from the California Army National Guard back to the Regular Army and returned to active status on 1 July 1981.

text: On 9 August 1979, the Department of the Army announced that Fort Irwin had been selected as the site for the National Training Center. With over  for maneuver and ranges, an uncluttered electromagnetic spectrum, airspace restricted to military use, and its isolation from densely populated areas, Fort Irwin was an ideal site for this facility. The National Training Center was officially activated 16 October 1980, and Fort Irwin was transferred from the

text: California Army National Guard

text: back to the

text: Regular Army

text: and returned to active status on 1 July 1981.

text: An X-ray spectrometer, an X-ray telescope, Cosmic Ray Detector, and a Laser device were also included. The vehicle was powered by batteries which were recharged during the lunar day by a solar cell array mounted on the underside of the lid. During the lunar nights, the lid was closed and a polonium-210 heat source kept the internal components at operating temperature.

text: An

text: X-ray spectrometer

text: , an

text: X-ray telescope

text: , Cosmic Ray Detector, and a

text: Laser

text: device were also included. The vehicle was powered by

text: batteries

text: which were recharged during the lunar day by a

text: solar cell

text: array mounted on the underside of the lid. During the lunar nights, the lid was closed and a

text: polonium

text: -210 heat source kept the internal components at

text: operating temperature

text: Most amateurs work at visible wavelengths, but a small minority experiment with wavelengths outside the visible spectrum. This includes the use of infrared filters on conventional telescopes, and also the use of radio telescopes. The pioneer of amateur radio astronomy was Karl Jansky, who started observing the sky at radio wavelengths in the 1930s. A number of amateur astronomers use either homemade telescopes or use radio telescopes which were originally built for astronomy research but which are now available to amateurs (e.g. the One-Mile Telescope).

text: Most amateurs work at visible wavelengths, but a small minority experiment with wavelengths outside the visible spectrum. This includes the use of infrared filters on conventional telescopes, and also the use of radio telescopes. The pioneer of amateur radio astronomy was

text: Karl Jansky

text: , who started observing the sky at radio wavelengths in the 1930s. A number of amateur astronomers use either homemade telescopes or use radio telescopes which were originally built for astronomy research but which are now available to amateurs (e.g. the

text: One-Mile Telescope

text: The Five hundred meter Aperture Spherical Telescope to be completed in 2016 will be the world's largest radio telescope.

text: The

text: Five hundred meter Aperture Spherical Telescope

text: to be completed in 2016 will be the world's largest

text: radio telescope

text: The history of the Hubble Space Telescope can be traced back as far as 1946, to the astronomer Lyman Spitzer's paper "Astronomical advantages of an extraterrestrial observatory". In it, he discussed the two main advantages that a space-based observatory would have over ground-based telescopes. First, the angular resolution (the smallest separation at which objects can be clearly distinguished) would be limited only by diffraction, rather than by the turbulence in the atmosphere, which causes stars to twinkle, known to astronomers as seeing. At that time ground-based telescopes were limited to resolutions of 0.5–1.0 arcseconds, compared to a theoretical diffraction-limited resolution of about 0.05 arcsec for a telescope with a mirror 2.5 m in diameter. Second, a space-based telescope could observe infrared and ultraviolet light, which are strongly absorbed by the atmosphere.

text: The history of the Hubble Space Telescope can be traced back as far as 1946, to the

text: astronomer

text: Lyman Spitzer

text: 's paper "Astronomical advantages of an extraterrestrial observatory". In it, he discussed the two main advantages that a space-based observatory would have over ground-based telescopes. First, the

text: angular resolution

text: (the smallest separation at which objects can be clearly distinguished) would be limited only by

text: diffraction

text: , rather than by the turbulence in the atmosphere, which causes stars to twinkle, known to astronomers as

text: seeing

text: . At that time ground-based telescopes were limited to resolutions of 0.5–1.0

text: arcsecond

text: s, compared to a theoretical diffraction-limited resolution of about 0.05 arcsec for a telescope with a

text: mirror

text: 2.5 m in diameter. Second, a space-based telescope could observe

text: infrared

text: and

text: ultraviolet

text: light, which are strongly absorbed by the

text: atmosphere

text: The Small and Medium Research Telescope System (SMARTS) is a consortium formed in 2001 after NOAO announced it would no longer support anything smaller than two meters at CTIO.  The member institutions of SMARTS now fund and manage observing time on four telescopes that fit that definition.  Access has also been purchased by individual scientists.  SMARTS contracts with NOAO to maintain the telescopes it controls at CTIO, and NOAO retains the right to 25% of the observing time, and Chilean scientists retain 10%.  SMARTS began managing telescopes in 2003.

text: The length of a hydraulic cylinder is the total of the stroke, the thickness of the piston, the thickness of bottom and head and the length of the connections. Often this length does not fit in the machine. In that case the piston rod is also used as a piston barrel and a second piston rod is used. These kinds of cylinders are called telescopic cylinders. If we call a normal rod cylinder single stage, telescopic cylinders are multi-stage units of two, three, four, five or more stages. In general telescopic cylinders are much more expensive than normal cylinders. Most telescopic cylinders are single acting (push). Double acting telescopic cylinders must be specially designed and manufactured.

text: The length of a hydraulic cylinder is the total of the stroke, the thickness of the piston, the thickness of bottom and head and the length of the connections. Often this length does not fit in the machine. In that case the piston rod is also used as a piston barrel and a second piston rod is used. These kinds of cylinders are called

text: telescopic cylinder

text: s. If we call a normal rod cylinder single stage, telescopic cylinders are multi-stage units of two, three, four, five or more stages. In general telescopic cylinders are much more expensive than normal cylinders. Most telescopic cylinders are single acting (push). Double acting telescopic cylinders must be specially designed and manufactured.

text: The Giant Magellan Telescope (GMT) is a ground-based extremely large telescope under construction, planned for completion in 2025. It will consist of seven 8.4 m (27.6 ft) diameter primary segments, with the resolving power of a 24.5 m (80.4 ft) primary mirror and collecting area equivalent to a 22.0 m (72.2 ft) one, which is about 368 square meters. The telescope is expected to have the resolving power 10 times greater than the Hubble Space Telescope, and will be the largest optical observatory in the world, at the time of its first light. , four mirrors have been cast and the construction of the summit facility has begun.

text: The Giant Magellan Telescope (GMT) is a ground-based

text: extremely large telescope

text: under construction, planned for completion in 2025. It will consist of seven 8.4 m (27.6 ft) diameter primary segments, with the resolving power of a 24.5 m (80.4 ft) primary mirror and collecting area equivalent to a 22.0 m (72.2 ft) one, which is about 368 square meters. The telescope is expected to have the resolving power 10 times greater than the

text: Hubble Space Telescope

text: , and will be the largest optical observatory in the world, at the time of its

text: first light

text: . , four mirrors have been cast and the construction of the summit facility has begun.

text: The British mathematician, optician James Short began experimenting with building telescopes based on Gregory's designs in the 1730s. He first tried making his mirrors out of glass as suggested by Gregory, but he later switched to speculum metal mirrors creating Gregorian telescopes with original designers parabolic and elliptic figures. Short then adopted telescope-making as his profession which he practised first in Edinburgh, and afterward in London. All Short's telescopes were of the Gregorian form. Short died in London in 1768, having made a considerable fortune selling telescopes.

text: The British mathematician, optician

text: James Short

text: began experimenting with building telescopes based on Gregory's designs in the 1730s. He first tried making his mirrors out of glass as suggested by Gregory, but he later switched to speculum metal mirrors creating Gregorian telescopes with original designers

text: parabolic

text: and

text: elliptic

text: figures. Short then adopted telescope-making as his profession which he practised first in Edinburgh, and afterward in London. All Short's telescopes were of the Gregorian form. Short died in London in 1768, having made a considerable fortune selling telescopes.

text: Nobita sees a fish tail, and tells Doraemon he saw a mermaid. They take pictures, and hear a scream. The shadows of a mermaid and a shark appear. Nobita's father tells police he saw a shark swim past the cigarette store. Nobita and Doraemon ask how he could see it without his goggles, and see that the fish are still there but the water is gone. A boy, Dekisugi, looks through his telescope and sees a mermaid and a shark. Nobita looks for the shark, who is behind him. Doraemon throws a frog into the shark's mouth. The shark and other fish return to the ocean, and the mermaid falls onto a tree branch.

text: Existing ground-based telescopes, and various proposed Extremely Large Telescopes, can exceed the HST in terms of sheer light-gathering power and diffraction limit due to larger mirrors, but other factors affect telescopes. In some cases, they may be able to match or beat Hubble in resolution by using adaptive optics. However, AO on large ground-based reflectors will not make Hubble and other space telescopes obsolete. Most AO systems sharpen the view over a very narrow field—Lucky Cam, for example, produces crisp images just 10" to 20" wide, whereas Hubble's cameras are super sharp across a 2½' (150") field. Furthermore, space telescopes can study the universe across the entire electromagnetic spectrum, most of which is blocked by Earth's atmosphere. Finally, the background sky is darker in space than on the ground, because air absorbs solar energy during the day and then releases it at night, producing a faint—but nevertheless discernible—airglow that washes out low-contrast astronomical objects.

text: Existing ground-based telescopes, and various proposed

text: Extremely Large Telescopes

text: , can exceed the HST in terms of sheer light-gathering power and diffraction limit due to larger mirrors, but other factors affect telescopes. In some cases, they may be able to match or beat Hubble in resolution by using adaptive optics. However, AO on large ground-based reflectors will not make Hubble and other space telescopes obsolete. Most AO systems sharpen the view over a very narrow field—

text: Lucky Cam

text: , for example, produces crisp images just 10" to 20" wide, whereas Hubble's cameras are super sharp across a 2½' (150") field. Furthermore, space telescopes can study the universe across the entire electromagnetic spectrum, most of which is blocked by Earth's atmosphere. Finally, the background sky is darker in space than on the ground, because air absorbs solar energy during the day and then releases it at night, producing a faint—but nevertheless discernible—

text: airglow

text: that washes out low-contrast astronomical objects.

text: A space telescope or space observatory is an instrument located in outer space to observe distant planets, galaxies and other astronomical objects. Space telescopes avoid many of the problems of ground-based observatories, such as light pollution and distortion of electromagnetic radiation (scintillation). In addition, ultraviolet frequencies, X-rays and gamma rays are blocked by the Earth's atmosphere, so they can only be observed from space.

text: A space telescope or space observatory is an instrument located in

text: outer space

text: to observe distant

text: planet

text: s,

text: galaxies

text: and other

text: astronomical object

text: s. Space telescopes avoid many of the problems of

text: ground-based observatories

text: , such as

text: light pollution

text: and distortion of

text: electromagnetic radiation

text: scintillation

text: ). In addition,

text: ultraviolet

text: frequencies,

text: X-rays

text: and

text: gamma rays

text: are blocked by the

text: Earth's atmosphere

text: , so they can only be observed from space.

text: Another current AAOmega based survey on the AAT, Galaxy and Mass Assembly (GAMA), is in the process of obtaining optical spectroscopy for ~250000 galaxies in the Local Universe. The AAOmega data will be used in conjunction with observations from satellite observatories (e.g. Herschel Space Observatory) and other telescopes around the world (e.g. the European Southern Observatory's Visible and Infrared Survey Telescope, VISTA) to critically examine the predictions of the Cold Dark Matter standard cosmological model e.g. the relationship between the number density of dark matter halos and their masses and the relationship between the number density of galaxies and their masses as determined through studying their starlight.

text: Another current AAOmega based survey on the AAT, Galaxy and Mass Assembly (GAMA), is in the process of obtaining optical spectroscopy for ~250000 galaxies in the Local Universe. The AAOmega data will be used in conjunction with observations from satellite observatories (e.g.

text: Herschel Space Observatory

text: ) and other telescopes around the world (e.g. the European Southern Observatory's Visible and Infrared Survey Telescope, VISTA) to critically examine the predictions of the Cold Dark Matter standard cosmological model e.g. the relationship between the number density of dark matter halos and their masses and the relationship between the number density of galaxies and their masses as determined through studying their starlight.

text: The centre also has a  parabolic radio telescope.

text: Required follow-up observations were conducted at the Hale and Shane telescopes in California; the W.M. Keck Observatory's Keck I telescope in Hawaii; telescopes at the WIYN, Whipple, and MMT observatories in Arizona; and the Hobby-Eberly and Harlan J. Smith telescopes of west Texas. Additionally, the Spitzer Space Telescope was used. Kepler-11d, along with its five sister planets, were announced to the public on February 2, 2011. Its discovery paper was published in the journal Nature the next day.

text: Required follow-up observations were conducted at the

text: Hale

text: and

text: Shane

text: telescopes in California; the

text: W.M. Keck Observatory

text: 's Keck I telescope in Hawaii; telescopes at the

text: WIYN

text: Whipple

text: , and

text: MMT

text: observatories in Arizona; and the

text: Hobby-Eberly

text: and

text: Harlan J. Smith

text: telescopes of west Texas. Additionally, the

text: Spitzer Space Telescope

text: was used. Kepler-11d, along with its five sister planets, were announced to the public on February 2, 2011. Its discovery paper was published in the journal

text: Nature

text: the next day.

text: Indian amateur astronomers use the platform of CIAA for the use of a range of instruments to study the sky, depending on a combination of their interests and resources. Methods include simply looking at the night sky with the naked eye, using binoculars, using a variety of telescopes of varying power and quality, as well as additional sophisticated equipment, such as cameras, to study the sky in both the visual and non-visual spectrums. Some people focus on amateur telescope making as their primary interest within the hobby of amateur astronomy. Some members are interested in comet hunting, meteorite hunting, or are interested in radio astronomy.

text: Indian amateur astronomers use the platform of CIAA for the use of a range of instruments to study the sky, depending on a combination of their interests and resources. Methods include simply looking at the night sky with the naked eye, using

text: binoculars

text: , using a variety of

text: telescope

text: s of varying power and quality, as well as additional sophisticated equipment, such as cameras, to study the sky in both the visual and non-visual spectrums. Some people focus on amateur telescope making as their primary interest within the hobby of amateur astronomy. Some members are interested in comet hunting, meteorite hunting, or are interested in

text: radio astronomy

text: Telescopic sights provide some tactical disadvantages. Snipers rely on stealth and concealment to get close to their target. A telescopic sight can hinder this because sunlight may reflect from the lens and a sniper raising his head to use a telescopic sight might reveal his position. The famous Finnish sniper Simo Häyhä preferred to use iron sights rather than telescopic sights to present less of a target. Harsh climate can also cause problems for telescopic sights as they are less rugged than iron sights. Many Finnish snipers in WWII used iron sights heavily because telescopic sights did not cope with very cold Finnish winters.

text: Telescopic sights provide some tactical disadvantages. Snipers rely on stealth and concealment to get close to their target. A telescopic sight can hinder this because sunlight may reflect from the lens and a sniper raising his head to use a telescopic sight might reveal his position. The famous

text: Finnish

text: sniper

text: Simo Häyhä

text: preferred to use iron sights rather than telescopic sights to present less of a target. Harsh climate can also cause problems for telescopic sights as they are less rugged than iron sights. Many Finnish snipers in WWII used

text: iron sights

text: heavily because telescopic sights did not cope with very cold Finnish winters.

text: From 1991 until 2007 he served as Director of the Netherlands Foundation for Research in Astronomy (ASTRON), the Netherlands' national astronomical organization. He oversaw Dutch contributions to innovative instrumentation for astronomy around the world and for the future James Webb Space Telescope.  He worked on the Morphs collaboration studying the formation and morphologies of distant galaxies.  Butcher supported the global Square Kilometre Array radio telescope project.  He led the funding efforts and interdisciplinary development of LOFAR, for which he was awarded a knighthood in the Order of the Netherlands Lion. LOFAR is an innovative low-frequency radio telescope that has the potential to look back in time to the early epoch of the Universe just after the Big Bang when the first luminous objects were forming.

text: From 1991 until 2007 he served as Director of the Netherlands Foundation for Research in Astronomy (

text: ASTRON

text: ), the Netherlands' national astronomical organization. He oversaw Dutch contributions to innovative instrumentation for astronomy around the world and for the future

text: James Webb Space Telescope

text: .  He worked on the

text: Morphs collaboration

text: studying the formation and morphologies of distant galaxies.  Butcher supported the global

text: Square Kilometre Array

text: radio telescope project.  He led the funding efforts and interdisciplinary development of

text: LOFAR

text: , for which he was awarded a knighthood in the

text: Order of the Netherlands Lion

text: . LOFAR is an innovative low-frequency radio telescope that has the potential to look back in time to the early epoch of the Universe just after the

text: Big Bang

text: when the first luminous objects were forming.

text: M87 is located near the high declination border of the Virgo, next to the constellation of Coma Berenices. It lies along a line between the stars Epsilon Virginis and Denebola. At an apparent magnitude of 9.59, this galaxy can be readily observed using a small telescope with a  aperture, extending across an angular area of 7.2 × 6.8 arcminutes with a bright, 45 arcsecond core. Viewing the jet is a challenge without the aid of photography. Before 1991, Russian-American astronomer Otto Struve was the only person known to have seen the jet visually, using the  Hooker telescope. In recent years, however, it has been observed in larger amateur telescopes under excellent conditions.

text: M87 is located near the high

text: declination

text: border of the Virgo, next to the constellation of

text: Coma Berenices

text: . It lies along a line between the stars

text: Epsilon Virginis

text: and

text: Denebola

text: . At an

text: apparent magnitude

text: of 9.59, this galaxy can be readily observed using a small telescope with a

text: aperture

text: , extending across an angular area of 7.2 × 6.8

text: arcminute

text: s with a bright, 45

text: arcsecond

text: core. Viewing the jet is a challenge without the aid of photography. Before 1991, Russian-American astronomer

text: Otto Struve

text: was the only person known to have seen the jet visually, using the

text: Hooker telescope

text: . In recent years, however, it has been observed in larger amateur telescopes under excellent conditions.

text: 1888: Heinrich Hertz demonstrates the existence of electromagnetic waves by building an apparatus that produced and detected UHF radio waves (or microwaves in the UHF region). He also found that radio waves could be transmitted through different types of materials and were reflected by others, the key to radar. His experiments explain reflection, refraction, polarization, interference, and velocity of electromagnetic waves.

text: Heinrich Hertz

text: demonstrates the existence of electromagnetic waves by building an apparatus that produced and detected UHF radio waves (or microwaves in the UHF region). He also found that radio waves could be transmitted through different types of materials and were reflected by others, the key to

text: radar

text: . His experiments explain

text: reflection

text: refraction

text: polarization

text: interference

text: , and

text: velocity

text: of electromagnetic waves.

text: MSFC is involved in some of the most advanced space research of our time. Scientist/Astronaut researchers aboard the International Space Station are engaged in hundreds of advanced experiments, most of which could not be conducted except for the zero-gravity environment. The deep-space images from the Hubble Space Telescope and the Chandra X-ray Observatory are made possible in part by the people and facilities at Marshall. The Center was not only responsible for the design, development, and construction of these telescopes, but it is also now home to the only facility in the world for testing large telescope mirrors in a space-simulated environment. Preliminary work has started on a Hubble successor, the James Webb Space Telescope (JWST); this will be the largest primary mirror ever assembled in space. In the future, the facility will likely be used for another successor, the Advanced Technology Large-Aperture Space Telescope (AT-LAST).

text: MSFC is involved in some of the most advanced space research of our time. Scientist/Astronaut researchers aboard the

text: International Space Station

text: are engaged in hundreds of advanced experiments, most of which could not be conducted except for the zero-gravity environment. The deep-space images from the

text: Hubble Space Telescope

text: and the

text: Chandra X-ray Observatory

text: are made possible in part by the people and facilities at Marshall. The Center was not only responsible for the design, development, and construction of these telescopes, but it is also now home to the only facility in the world for testing large telescope mirrors in a space-simulated environment. Preliminary work has started on a Hubble successor, the

text: James Webb Space Telescope

text: (JWST); this will be the largest primary mirror ever assembled in space. In the future, the facility will likely be used for another successor, the

text: (AT-LAST).

text: PROMPT originally consisted of six 16-inch diameter fully automated, or robotic, optical telescopes at Cerro Tololo Inter-American Observatory (CTIO) in Chile.The University of North Carolina at Chapel Hill (UNC-CH) began building “PROMPT” and “Skynet” in 2004, supported primarily by NSF.  Skynet is PROMPT’s control software, as well as sophisticated web-based, dynamic queue-scheduling software.  Skynet has opened PROMPT to tens of thousands of users, and is capable of controlling scores of telescopes simultaneously, including most commercially available small-telescope hardware.  In partnership with other institutions, Skynet has enabled us to grow PROMPT into a network of small, robotic telescopes.  The Skynet Robotic Telescope Network now numbers 19 optical telescopes between 14 and 40 inches in diameter and spans Chile, Australia, the United States, Italy, and soon Canada.

text: PROMPT originally consisted of six 16-inch diameter fully automated, or robotic, optical telescopes at

text: Cerro Tololo Inter-American Observatory

text: (CTIO) in

text: Chile

text: .The

entity_name: University of North Carolina at Chapel Hill

text: University of North Carolina at Chapel Hill

text: (UNC-CH) began building “PROMPT” and “Skynet” in 2004, supported primarily by NSF.  Skynet is PROMPT’s control software, as well as sophisticated web-based, dynamic queue-scheduling software.  Skynet has opened PROMPT to tens of thousands of users, and is capable of controlling scores of telescopes simultaneously, including most commercially available small-telescope hardware.  In partnership with other institutions, Skynet has enabled us to grow PROMPT into a network of small, robotic telescopes.  The Skynet Robotic Telescope Network now numbers 19 optical telescopes between 14 and 40 inches in diameter and spans Chile, Australia, the United States, Italy, and soon Canada.

text: Green joined Cook's first voyage of circumnavigation in 1768, accompanied by a servant. Green was one of two official astronomers appointed by the Royal Society to observe the transit; the other was Cook himself, who was a capable observer in his own right. Green was to receive 200 guineas from the Society for the appointment. (Cook was to receive 100 guineas for his role in making the observations.) The Society provided instruments for the expedition, including two reflector telescopes built by James Short, two clocks and an astronomical quadrant; these were supplemented by a telescope in the possession of Daniel Solander and another provided by the Navy.

text: Green joined

text: Cook's first voyage of circumnavigation

text: in 1768, accompanied by a servant. Green was one of two official astronomers appointed by the Royal Society to observe the transit; the other was Cook himself, who was a capable observer in his own right. Green was to receive 200

text: guineas

text: from the Society for the appointment. (Cook was to receive 100 guineas for his role in making the observations.) The Society provided instruments for the expedition, including two

text: reflector telescopes

text: built by

text: James Short

text: , two clocks and an

text: astronomical quadrant

text: ; these were supplemented by a telescope in the possession of

text: Daniel Solander

text: and another provided by the Navy.

text: ASTRON operates the Westerbork Synthesis Radio Telescope (WSRT), one of the largest radio telescopes in the world. The WSRT and the International LOFAR Telescope (ILT) are dedicated to explore the universe at radio frequencies from 8 GHz down to 10 MHz.

text: ASTRON operates the

text: Westerbork Synthesis Radio Telescope

text: (WSRT), one of the largest radio telescopes in the world. The WSRT and

text: the International LOFAR Telescope (ILT)

text: are dedicated to explore the universe at radio frequencies from 8 GHz down to 10 MHz.

text: List of largest optical telescopes in the 19th century, are listings of what were, for the time period of the 19th century large optical telescopes. See List of largest optical telescopes in the 20th century for the 1900s. The list includes various refractor and reflector that were active some time between about 1799 to 1901.

text: List of largest optical telescopes in the 19th century, are listings of what were, for the time period of the 19th century large optical telescopes. See

entity_name: List of largest optical telescopes in the 20th century

text: List of largest optical telescopes in the 20th century

text: for the 1900s. The list includes various refractor and reflector that were active some time between about 1799 to 1901.

text: The Algonquin 46m radio telescope (ARO) is a radio telescope at the Algonquin Radio Observatory, Canada. This radio telescope is historically famous for taking part in the first successful very long baseline interferometry experiment in the 1960s, where it was experimentally arrayed with the 26-metre Telescope at the Dominion Radio Astrophysical Observatory near Penticton, British Columbia.

text: The Algonquin 46m radio telescope (ARO) is a

text: radio telescope

text: at the

text: Algonquin Radio Observatory

text: , Canada. This radio telescope is historically famous for taking part in the first successful

text: very long baseline interferometry

text: experiment in the 1960s, where it was experimentally arrayed with the 26-metre Telescope at the

entity_name: Dominion Radio Astrophysical Observatory

text: Dominion Radio Astrophysical Observatory

text: near

text: Penticton, British Columbia

text: Observations using the 3.5 m telescope can be carried out remotely by observers using TUI, the Telescope User Interface, via the internet.

text: The success of IRAS lead to interest in the 1985 Infrared Telescope (IRT) mission on the Space Shuttle, and the planned Shuttle Infrared Telescope Facility which eventually transformed into the Space Infrared Telescope Facility, SIRTF, which in turn was developed into the Spitzer Space Telescope, launched in 2009.  The success of early infrared space astronomy led to further missions, such as the Infrared Space Observatory (1990s) and the Hubble Space Telescope NICMOS instrument.

text: The success of IRAS lead to interest in the 1985 Infrared Telescope (IRT) mission on the Space Shuttle, and the planned Shuttle Infrared Telescope Facility which eventually transformed into the Space Infrared Telescope Facility, SIRTF, which in turn was developed into the

text: Spitzer Space Telescope

text: , launched in 2009.  The success of early infrared space astronomy led to further missions, such as the

text: Infrared Space Observatory

text: (1990s) and the

text: Hubble Space Telescope

text: NICMOS

text: instrument.

text: The purpose of the atlas is to display and describe some of the best multiwavelength images of galaxies. The images originate from a variety of telescopes, instruments and detectors, and therefore possess wide ranges of signal-to-noise, angular resolution, sampling or pixel sizes and fields of view. The atlas is a compendium of galaxy images spanning the Gamma ray, X-ray, Ultraviolet, Optical, Infrared, Submillimeter and Radio regions of the electromagnetic spectrum.

text: The purpose of the atlas is to display and describe some of the best multiwavelength images of

text: galaxies

text: . The images originate from a variety of telescopes, instruments and detectors, and therefore possess wide ranges of signal-to-noise, angular resolution, sampling or pixel sizes and fields of view. The atlas is a compendium of galaxy images spanning the Gamma ray, X-ray, Ultraviolet, Optical, Infrared, Submillimeter and Radio regions of the electromagnetic spectrum.

text: As of the early 2000s these truss tube Dobsonians are the largest commercially available telescopes, with three manufacturers offering models in the  to  range (hard tube and other reflector designs typically stop at  due to the size of the tube). As of March 2010, Orion Telescopes & Binoculars offers the largest commercially available truss tube Dobsonian, a 50" aperture model. As these scopes require teams of several people to operate, and require the observer to perch on top of a ladder, the market for these scopes is limited. Telescopes with a  aperture appear to be the most popular size, as they maximize the amount of aperture yet can still be easily be set up by one person. In early 2009 prices can range from $800 for a 12" instrument to $3500 plus for 18" or larger instruments, depending on the quality and features.

text: As of the early 2000s these truss tube Dobsonians are the largest commercially available telescopes, with three manufacturers offering models in the  to  range (hard tube and other reflector designs typically stop at  due to the size of the tube). As of March 2010,

text: Orion Telescopes & Binoculars

text: offers the largest commercially available truss tube Dobsonian, a 50" aperture model. As these scopes require teams of several people to operate, and require the observer to perch on top of a ladder, the market for these scopes is limited. Telescopes with a  aperture appear to be the most popular size, as they maximize the amount of aperture yet can still be easily be set up by one person. In early 2009 prices can range from $800 for a 12" instrument to $3500 plus for 18" or larger instruments, depending on the quality and features.

text: The Gardner-Kvashennaya International Telescope is one of the three most powerful telescopes in the world. The operating budget is 34 million dollars per year. It spent 2 years focused on the planet Altilis-738. Mason and Tony head there to find out about the mysterious death of Senator Hamantaschen. When they got there they found out that the telescope only needed 3 million to operate and they used the rest of the money on prostitutes, drugs and a llama. It turns out the prostitutes worked for The Vampire and the telescope station was mostly destroyed. The telescope was eventually repaired and made operational and Tony's twin sister Toni is going to be working there. Later, Toni tells Tony that she will not be transferred to the station.

text: The Gardner-Kvashennaya International

text: Telescope

text: is one of the three most powerful telescopes in the world. The operating budget is 34 million dollars per year. It spent 2 years focused on the planet Altilis-738. Mason and Tony head there to find out about the mysterious death of Senator Hamantaschen. When they got there they found out that the telescope only needed 3 million to operate and they used the rest of the money on

text: prostitutes

text: drugs

text: and a

text: llama

text: . It turns out the prostitutes worked for The Vampire and the telescope station was mostly destroyed. The telescope was eventually repaired and made operational and Tony's twin sister Toni is going to be working there. Later, Toni tells Tony that she will not be transferred to the station.

text: The Northern Cross Radio Telescope (Croce del Nord in Italian) is one of the largest transit radio telescopes in the world. Observations are focused around 408 MHz (UHF band), corresponding to 73.5 cm wavelength. The older receivers of the telescope function with a 2.5 MHz wide frequency band, while the upgraded parts have a 16 MHz bandwidth. The telescope is steerable only in declination, meaning that it can solely observe objects that are culminating on the local celestial meridian. The telescope is T-shaped and consists of:

text: The Northern Cross Radio Telescope (Croce del Nord in Italian) is one of the largest transit radio telescopes in the world. Observations are focused around 408 MHz (

text: UHF band

text: ), corresponding to 73.5 cm wavelength. The older receivers of the telescope function with a 2.5 MHz wide frequency band, while the upgraded parts have a 16 MHz

text: bandwidth

text: . The telescope is steerable only in declination, meaning that it can solely observe objects that are culminating on the local

text: celestial meridian

text: . The telescope is T-shaped and consists of:

text: Even at the best ground-based observatories, airglow limits the sensitivity of telescopes at visible wavelengths. Partly for this reason, space-based telescopes such as the Hubble Space Telescope can observe much fainter objects than current ground-based telescopes at visible wavelengths.

text: Even at the best ground-based observatories, airglow limits the sensitivity of telescopes at visible wavelengths. Partly for this reason, space-based telescopes such as the

text: Hubble Space Telescope

text: can observe much fainter objects than current ground-based telescopes at visible wavelengths.

text: In 1886, after noticing unusual induced sparking in a Riess spiral, physicist Heinrich Hertz concluded this phenomenon could be used to scientifically verify James Clerk Maxwell's predictions on electromagnetism. Hertz used a tuned spark gap transmitter and a tuned spark gap detector (consisting of a loop of wire connected to a small spark gap) located a few meters away. In a series of UHF experiments, Hertz verified that electromagnetic waves were being produced by the transmitter. When the transmitter sparked, small sparks also appeared across the receiver's spark gap, which could be seen under a microscope.

text: In 1886, after noticing unusual induced sparking in a

text: Riess spiral

text: , physicist

text: Heinrich Hertz

text: concluded this phenomenon could be used to scientifically verify

text: James Clerk Maxwell

text: 's predictions on

text: electromagnetism

text: . Hertz used a tuned spark gap

text: transmitter

text: and a tuned spark gap detector (consisting of a loop of wire connected to a small spark gap) located a few meters away. In a series of

text: UHF

text: experiments, Hertz verified that electromagnetic waves were being produced by the transmitter. When the transmitter sparked, small sparks also appeared across the receiver's spark gap, which could be seen under a microscope.

text: There are one telescope dome and one roll-off shed on the premises, both housing telescopes. RIT owns a 12" Meade telescope, a 16" telescope, and several smaller refracting telescopes. In addition, a two-element radio interferometer based on the SIMPLE design is being constructed and will be used as a teaching instrument to expose students in astronomy labs to observations at other wavelengths.

text: There are one telescope dome and one roll-off shed on the premises, both housing telescopes. RIT owns a 12" Meade telescope, a 16" telescope, and several smaller

text: refracting telescope

text: s. In addition, a two-element radio interferometer based on the SIMPLE design is being constructed and will be used as a teaching instrument to expose students in astronomy labs to observations at other wavelengths.

text: Past spacecraft and instruments that participated in GCN include Array of Low Energy X-ray Imaging Sensors (ALEXIS), BeppoSAX, the Imaging Compton Telescope (COMPTEL) on CGRO, and the X-Ray/Gamma-Ray Spectrometer (XGRS) on NEAR Shoemaker.

text: Past spacecraft and instruments that participated in GCN include

entity_name: Array of Low Energy X-ray Imaging Sensors

text: Array of Low Energy X-ray Imaging Sensors

text: (ALEXIS),

text: BeppoSAX

text: , the Imaging Compton Telescope (COMPTEL) on CGRO, and the X-Ray/Gamma-Ray Spectrometer (XGRS) on

text: NEAR Shoemaker

text: Astronomer Giovanni Domenico Cassini had the wooden Marly Tower, originally built as part of the Machine de Marly to lift water for the reservoirs and fountains at the Gardens of Versailles, moved to the grounds of the Paris Observatory. On this tower he mounted long tubed telescopes and the objectives of aerial telescopes made for him by the Italian optician Giuseppe Campani. In 1684 he used one of his aerial telescopes to find Dione and Tethys, two satellites of Saturn. James Bradley, on December 27, 1722, measured the diameter of Venus with an aerial telescope whose objective had a focal length of 212 ft (65 m). Francesco Bianchini tried to map the surface of that same planet and deduce its rotational period in Rome in 1726 using a 2.6" (66 mm) 100 foot focal length aerial telescope.

text: Astronomer

text: Giovanni Domenico Cassini

text: had the wooden Marly Tower, originally built as part of the

text: Machine de Marly

text: to lift water for the reservoirs and fountains at the

text: Gardens of Versailles

text: , moved to the grounds of the

text: Paris Observatory

text: . On this tower he mounted long tubed telescopes and the objectives of aerial telescopes made for him by the Italian optician

text: Giuseppe Campani

text: . In 1684 he used one of his aerial telescopes to find

text: Dione

text: and

text: Tethys

text: , two satellites of

text: Saturn

text: James Bradley

text: , on December 27, 1722, measured the diameter of

text: Venus

text: with an aerial telescope whose objective had a focal length of 212 ft (65 m).

text: Francesco Bianchini

text: tried to map the surface of that same planet and deduce its rotational period in Rome in 1726 using a 2.6" (66 mm) 100 foot focal length aerial telescope.

text: The prediction that light represented a transmission of energy in wave form through a "luminiferous ether", and the seeming confirmation of that prediction with Helmholtz student Heinrich Hertz's 1888 detection of electromagnetic radiation, was a major triumph for physical theory and raised the possibility that even more fundamental theories based on the field could soon be developed. Experimental confirmation of Maxwell's theory was provided by Hertz, who generated and detected electric waves in 1886 and verified their properties, at the same time foreshadowing their application in radio, television, and other devices. In 1887, Heinrich Hertz discovered the photoelectric effect. Research on the electromagnetic waves began soon after, with many scientists and inventors conducting experiments on their properties. In the mid to late 1890s Guglielmo Marconi developed a radio wave based wireless telegraphy system (see invention of radio).

text: The prediction that light represented a transmission of energy in wave form through a "

text: luminiferous ether

text: ", and the seeming confirmation of that prediction with Helmholtz student

text: Heinrich Hertz

text: 's 1888 detection of

text: electromagnetic radiation

text: , was a major triumph for physical theory and raised the possibility that even more fundamental theories based on the field could soon be developed. Experimental confirmation of Maxwell's theory was provided by Hertz, who generated and detected electric waves in 1886 and verified their properties, at the same time foreshadowing their application in radio, television, and other devices. In 1887, Heinrich Hertz discovered the

text: photoelectric effect

text: . Research on the electromagnetic waves began soon after, with many scientists and inventors conducting experiments on their properties. In the mid to late 1890s

text: Guglielmo Marconi

text: developed a

text: radio wave

text: based

text: wireless telegraphy

text: system (see

text: invention of radio

text: For earlier top telescopes see List of largest optical telescopes historically

text: For earlier top telescopes see

text: List of largest optical telescopes historically

text: Robert A. Woodruff (born September 1943) is an American physicist who is known principally for having designed and worked on a wide variety of instruments for space telescopes. These include Skylab (1967–1970), Apollo-Soyuz (1970s), Galileo(~1980), SIRTF and MIPS (1970s-1990s), and Hubble Space Telescope instruments [1977–present] (GHRS, STIS, COSTAR, ACS, COS, WFC3); JWST (1995–2000), Kepler (mid-1990s), TPF (2001 to present), and Destiny (2003–present).  He has had one or more instruments flying continuously in space since the early 1970s.

text: Robert A. Woodruff (born September 1943) is an American

text: physicist

text: who is known principally for having designed and worked on a wide variety of instruments for space telescopes. These include

text: Skylab

text: (1967–1970), Apollo-Soyuz (1970s), Galileo(~1980),

text: SIRTF

text: and MIPS (1970s-1990s), and

text: Hubble Space Telescope

text: instruments [1977–present] (GHRS, STIS,

entity_name: Corrective Optics Space Telescope Axial Replacement

text: COSTAR

text: , ACS, COS, WFC3);

text: JWST

text: (1995–2000), Kepler (mid-1990s),

text: TPF

text: (2001 to present), and

text: Destiny

text: (2003–present).  He has had one or more instruments flying continuously in space since the early 1970s.

text: Goldman also manufactured the more familiar and more modern "nesting cart" under a license granted by Telescope Carts, Inc.  In 1946, Orla Watson, co-founder of Telescope Carts, Inc. had developed an innovative "nesting" shopping cart that did not require disassembly after each use like Goldman's designs, and allowed for the shopping carts to telescope, or "nest" together by simply shoving the carts together.  Goldman had patented his own "Nest-Kart" over a year later in 1948, so an interference investigation was ordered by Watson of Telescope Carts, Inc. for alleged patent infringement during the same time period.  In a compromise solution, Goldman agreed to relinquish his rights on his existing patent and agreed to pay the sum of $1 for counterfeit damages.  In return, Telescope Cart, Inc. agreed to an exclusive license granted to Goldman's company for the production of the telescoping, or "nesting" cart.  The telescoping, or nesting cart, based on the patent issued to Orla Watson of Telescope Carts, Inc. forms the basis of the shopping cart designs used to the present, and all royalties for the new design were paid to Telescope Carts, Inc. until their patent expired.

text: Goldman also manufactured the more familiar and more modern "nesting cart" under a license granted by Telescope Carts, Inc.  In 1946,

text: Orla Watson

text: , co-founder of Telescope Carts, Inc. had developed an innovative "nesting" shopping cart that did not require disassembly after each use like Goldman's designs, and allowed for the shopping carts to telescope, or "nest" together by simply shoving the carts together.  Goldman had patented his own "Nest-Kart" over a year later in 1948, so an interference investigation was ordered by Watson of Telescope Carts, Inc. for alleged patent infringement during the same time period.  In a compromise solution, Goldman agreed to relinquish his rights on his existing patent and agreed to pay the sum of $1 for counterfeit damages.  In return, Telescope Cart, Inc. agreed to an exclusive license granted to Goldman's company for the production of the telescoping, or "nesting" cart.  The telescoping, or nesting cart, based on the patent issued to

text: Orla Watson

text: of Telescope Carts, Inc. forms the basis of the shopping cart designs used to the present, and all royalties for the new design were paid to Telescope Carts, Inc. until their patent expired.

text: Astronomy research in the 21st century is combined with the work of the physics department at the University of British Columbia. The 22 staff researchers there engage in an active programme of investigation and have access to cutting edge facilities including the CFHT and Gemini telescopes. The Dominion Astrophysical Observatory near Victoria and the two radio telescopes of the Dominion Radio Astrophysical Observatory near Penticton are also used. Furthermore, department members have built several liquid mirror telescopes, the biggest being the 6 metre Large Zenith Telescope near Vancouver.

text: Astronomy research in the 21st century is combined with the work of the physics department at the University of British Columbia. The 22 staff researchers there engage in an active programme of investigation and have access to cutting edge facilities including the CFHT and Gemini telescopes. The Dominion Astrophysical Observatory near Victoria and the two radio telescopes of the Dominion Radio Astrophysical Observatory near Penticton are also used. Furthermore, department members have built several liquid mirror telescopes, the biggest being the 6 metre

text: Large Zenith Telescope

text: near Vancouver.

text: On 31 October 2006, Griffin announced that the Hubble servicing mission was reinstated, scheduled for 2008, and announced the crew that would fly the mission, which included Grunsfeld. Senator Mikulski expressed her delight at the news, stating "The Hubble telescope has been the greatest telescope since Galileo invented the first one. It has gone to look at places in the universe that we didn't know existed before."

text: The Mark II telescope once constructed was also used as an interferometer with the Lovell telescope. This has a baseline of 425 m (1,394 ft) (meaning that it can synthesize a telescope with 425 m diameter), giving it a resolution of around 0.5 arcminutes. This telescope pair has been used to carry out survey work, and to determine the positions of faint radio objects. Also, one of the drivers behind the construction of the Mark III was to use it as an interferometer with the Mark I to carry out a survey of radio sources.

text: The

text: Mark II

text: telescope once constructed was also used as an interferometer with the Lovell telescope. This has a baseline of 425 m (1,394 ft) (meaning that it can synthesize a telescope with 425 m diameter), giving it a resolution of around 0.5

text: arcminutes

text: . This telescope pair has been used to carry out survey work, and to determine the positions of faint radio objects. Also, one of the drivers behind the construction of the

text: Mark III

text: was to use it as an interferometer with the Mark I to carry out a survey of radio sources.

text: The expected travel time of the Hope probe is about 200 days at a speed of up to 40,000 kph on its journey of 60 million kilometres. Upon arrival at Mars, it will study the atmosphere of Mars for two years. Its unique placement in orbit around Mars will provide a new type of data to build "the first truly holistic models" of the Martian atmosphere. The data is expected to provide reasons for the decay of the atmosphere to a level where it is now too thin to allow liquid water to exist. The Hope probe will carry three scientific instruments to study the Martian atmosphere, which include a digital camera for high resolution coloured images, an infrared spectrometer that will examine the temperature patterns, ice, water vapors in the atmosphere, and an ultraviolet spectrometer that will study the upper atmosphere and traces of oxygen and hydrogen further out into space.

text: The expected travel time of the Hope probe is about 200 days at a speed of up to 40,000 kph on its journey of 60 million kilometres. Upon arrival at Mars, it will study the

text: atmosphere of Mars

text: for two years. Its unique placement in orbit around Mars will provide a new type of data to build "the first truly holistic models" of the Martian atmosphere. The data is expected to provide reasons for the decay of the atmosphere to a level where it is now too thin to allow liquid water to exist. The Hope probe will carry three scientific instruments to study the Martian atmosphere, which include a digital camera for high resolution coloured images, an

text: infrared spectrometer

text: that will examine the temperature patterns, ice, water vapors in the atmosphere, and an ultraviolet spectrometer that will study the upper atmosphere and traces of oxygen and hydrogen further out into space.

text: Polarimetry is the measurement and interpretation of the polarization of transverse waves, most notably electromagnetic waves, such as radio or light waves. Typically polarimetry is done on electromagnetic waves that have traveled through or have been reflected, refracted, or diffracted by some material in order to characterize that object.

text: Polarimetry is the measurement and interpretation of the

text: polarization

text: of

text: transverse wave

text: s, most notably

text: electromagnetic wave

text: s, such as radio or light waves. Typically polarimetry is done on electromagnetic waves that have traveled through or have been

text: reflected

text: refracted

text: , or

text: diffracted

text: by some material in order to characterize that object.

text: Influenced by the observations, the orientalist Percival Lowell founded an observatory which had  telescopes. The observatory was used for the exploration of Mars during the last good opportunity in 1894 and the following less favorable oppositions. He published several books on Mars and life on the planet, which had a great influence on the public. The canali were independently found by other astronomers, like Henri Joseph Perrotin and Louis Thollon in Nice, using one of the largest telescopes of that time.

text: Influenced by the observations, the orientalist

text: Percival Lowell

text: founded an

text: observatory

text: which had  telescopes. The observatory was used for the exploration of Mars during the last good opportunity in 1894 and the following less favorable oppositions. He published several books on Mars and life on the planet, which had a great influence on the public. The canali were independently found by other astronomers, like

text: Henri Joseph Perrotin

text: and

text: Louis Thollon

text: in Nice, using one of the largest telescopes of that time.

text: Telescope for Habitable Exoplanets and Interstellar/Intergalactic Astronomy (THEIA) is a NASA-proposed 4-metre optical/ultraviolet space telescope that would succeed the Hubble Space Telescope and complement the infrared-James Webb Space Telescope. THEIA would use a 40-metre occulter to block starlight so as to directly image exoplanets.

text: Telescope for Habitable Exoplanets and Interstellar/Intergalactic Astronomy (THEIA) is a

text: NASA

text: -proposed 4-metre optical/ultraviolet

text: space telescope

text: that would succeed the

text: Hubble Space Telescope

text: and complement the infrared-

text: James Webb Space Telescope

text: . THEIA would use a 40-metre

text: occulter

text: to block starlight so as to directly image

text: exoplanets

text: Electromagnetic radiation had been first linked to electromagnetism in 1845, when Michael Faraday noticed that the polarization of light traveling through a transparent material responded to a magnetic field (see Faraday effect). During the 1860s James Maxwell developed four partial differential equations for the electromagnetic field. Two of these equations predicted the possibility of, and behavior of, waves in the field. Analyzing the speed of these theoretical waves, Maxwell realized that they must travel at a speed that was about the known speed of light. This startling coincidence in value led Maxwell to make the inference that light itself is a type of electromagnetic wave.

text: Electromagnetic radiation had been first linked to electromagnetism in 1845, when

text: Michael Faraday

text: noticed that the polarization of light traveling through a transparent material responded to a

text: magnetic field

text: (see

text: Faraday effect

text: ). During the 1860s

text: James Maxwell

text: developed four partial differential

text: equations

text: for the

text: electromagnetic field

text: . Two of these equations predicted the possibility of, and behavior of, waves in the field. Analyzing the speed of these theoretical waves, Maxwell realized that they must travel at a speed that was about the known

text: speed of light

text: . This startling coincidence in value led Maxwell to make the inference that light itself is a type of electromagnetic wave.

text: Goode is the Director of the NJIT's Center for Solar-Terrestrial Research.  He led a project to build the world’s most capable solar telescope at Big Bear Solar Observatory (BBSO) at Big Bear Lake. The new solar telescope (NST) is a 1.6 meter clear aperture, off-axis telescope featuring the world’s largest solar aperture.

text: Goode is the Director of the NJIT's Center for Solar-Terrestrial Research.  He led a project to build the world’s most capable solar telescope at

text: Big Bear Solar Observatory

text: (BBSO) at

text: Big Bear Lake

text: . The new solar telescope (NST) is a 1.6 meter clear aperture, off-axis telescope featuring the world’s largest solar aperture.

text: The resources of the IPTA are substantial. The EPTA uses large quantities of time on Europe’s five 100-meter class telescopes: the Lovell Telescope at Jodrell Bank, England, the Effelsberg 100-m Radio Telescope in Germany, the Sardinia Radio Telescope in Italy, the Westerbork Synthesis Radio Telescope in the Netherlands, and the Nancay Radio Telescope in France. Together these 5 telescopes make up the Large European Array for Pulsars (LEAP) in which they operate together as a single 300-meter class telescope. NANOGrav uses about 1-day per month of time at the Green Bank 100-m telescope, and 0.5 days per month at the 300-m Arecibo Observatory in Puerto Rico. The PPTA uses several days per month at the 64-meter Parkes Radio Telescope.

text: The resources of the IPTA are substantial. The EPTA uses large quantities of time on Europe’s five 100-meter class telescopes: the

text: Lovell Telescope

text: at Jodrell Bank, England, the

text: Effelsberg 100-m Radio Telescope

text: in Germany, the

text: Sardinia Radio Telescope

text: in Italy, the

text: Westerbork Synthesis Radio Telescope

text: in the Netherlands, and the

text: Nancay Radio Telescope

text: in France. Together these 5 telescopes make up the Large European Array for Pulsars (LEAP) in which they operate together as a single 300-meter class telescope. NANOGrav uses about 1-day per month of time at the Green Bank 100-m telescope, and 0.5 days per month at the 300-m

text: Arecibo Observatory

text: in Puerto Rico. The PPTA uses several days per month at the 64-meter

text: Parkes Radio Telescope

text: Gamma ray astronomy observes astronomical objects at the shortest wavelengths of the electromagnetic spectrum. Gamma rays may be observed directly by satellites such as the Compton Gamma Ray Observatory or by specialized telescopes called atmospheric Cherenkov telescopes. The Cherenkov telescopes do not detect the gamma rays directly but instead detect the flashes of visible light produced when gamma rays are absorbed by the Earth's atmosphere.

text: Gamma ray astronomy observes astronomical objects at the shortest wavelengths of the electromagnetic spectrum. Gamma rays may be observed directly by satellites such as the

text: Compton Gamma Ray Observatory

text: or by specialized telescopes called

text: atmospheric Cherenkov telescope

text: s. The Cherenkov telescopes do not detect the gamma rays directly but instead detect the flashes of visible light produced when gamma rays are absorbed by the Earth's atmosphere.

text: Williams (2013) suggests the need for a variety of methods for observing Io in the future: "Future Io exploration is recommended to include: 1) a Jupiter-orbiting Io Observer spacecraft of either Discovery-class or New Frontiers-class; 2) a space-based UV telescope with diffraction-limited capability; 3) space-based missions that enable long-term monitoring of Io over a variety of time scales (seconds, minutes, hours, days, months, years); and 4) expanded time for Io observation on ground-based 8- to 10-m class telescopes, particularly those with nighttime Adaptive Optics capability."

text: After studying photos for NASA's Apollo program that contained greater detail than any ground based telescope, Gerard Kuiper began seeking an arid site for infrared studies. While he first began looking in Chile, he also made the decision to perform tests in the Hawaiian Islands. Tests on Maui's Haleakalā were promising but the mountain was too low in the inversion layer and often covered by clouds. On the "Big Island" of Hawaii, Mauna Kea is considered the highest island mountain in the world. While the summit is often covered with snow the air itself is extremely dry. Kuiper began looking into the possibility of an observatory on Mauna Kea. After testing, he discovered the low humidity was perfect for infrared signals. He persuaded then Governor, John A. Burns to bulldoze a dirt road to the summit where he built a small telescope on Puu Poliahu, a cinder cone peak. The peak was the second highest on the mountain with the highest peak being holy ground, so Kuiper avoided it. Next, Kuiper tried enlisting NASA to fund a larger facility with a large telescope, housing and other needed structures. NASA, in turn decided to make the project open to competition. Professor of physics, John Jefferies of the University of Hawaii placed a bid on behalf of the university. Jefferies had gained his reputation through observations at Sacramento Peak Observatory. The proposal was for a two-meter telescope to serve both the needs of NASA and the university. While large telescopes are not ordinarily awarded to universities without well established astronomers, Jefferies and UH were awarded the NASA contract infuriating Kuiper who felt that "his mountain" had been "stolen" from "him". Kuiper would abandon his site (the very first telecope on Mauna Kea) over the competition and begin work in Arizona on a different NASA project. After considerable testing by Jefferies' team, the best locations were determined to be near the summit at the top of the cinder cones. Testing also determined Mauna Kea to be superb for nighttime viewing due to many factors including the thin air, constant trade winds and being surrounded by sea. Jefferies would build a 2.24 meter telescope with the State of Hawaii agreeing to build a reliable, all weather roadway to the summit. Building began in 1967 and first light seen in 1970.

text: After studying photos for NASA's

text: Apollo program

text: that contained greater detail than any ground based telescope,

text: Gerard Kuiper

text: began seeking an arid site for infrared studies. While he first began looking in Chile, he also made the decision to perform tests in the Hawaiian Islands. Tests on

text: Maui

text: 's

text: Haleakalā

text: were promising but the mountain was too low in the inversion layer and often covered by clouds. On the "Big Island" of Hawaii, Mauna Kea is considered the highest island mountain in the world. While the summit is often covered with snow the air itself is extremely dry. Kuiper began looking into the possibility of an observatory on Mauna Kea. After testing, he discovered the low humidity was perfect for infrared signals. He persuaded then Governor,

text: John A. Burns

text: to bulldoze a dirt road to the summit where he built a small telescope on Puu Poliahu, a cinder cone peak. The peak was the second highest on the mountain with the highest peak being holy ground, so Kuiper avoided it. Next, Kuiper tried enlisting NASA to fund a larger facility with a large telescope, housing and other needed structures. NASA, in turn decided to make the project open to competition. Professor of physics, John Jefferies of the

text: University of Hawaii

text: placed a bid on behalf of the university. Jefferies had gained his reputation through observations at

text: Sacramento Peak Observatory

text: . The proposal was for a two-meter telescope to serve both the needs of NASA and the university. While large telescopes are not ordinarily awarded to universities without well established astronomers, Jefferies and UH were awarded the NASA contract infuriating Kuiper who felt that "his mountain" had been "stolen" from "him". Kuiper would abandon his site (the very first telecope on Mauna Kea) over the competition and begin work in Arizona on a different NASA project. After considerable testing by Jefferies' team, the best locations were determined to be near the summit at the top of the cinder cones. Testing also determined Mauna Kea to be superb for nighttime viewing due to many factors including the thin air, constant trade winds and being surrounded by sea. Jefferies would build a 2.24 meter telescope with the State of Hawaii agreeing to build a reliable, all weather roadway to the summit. Building began in 1967 and first light seen in 1970.

text: The main reflector at the DDO remained a major instrument into the 1960s, but in the end even the "remote" location Chant had selected was being encroached on by urban sprawl. Although some consideration was given to moving the telescope to a new site, in the end it was decided the funds would be better spent on a smaller instrument in a much better location. This led to the building of a 60 cm instrument at Las Campanas in Chile in 1971, creating the University of Toronto Southern Observatory (UTSO). It was at this location that University of Toronto telescope operator Ian Shelton discovered Supernova 1987A, the first supernova visible to the naked eye in more than 350 years. The UTSO was later closed in 1997 to re-allocate funds to a share of the Gemini Observatory, and the 60 cm telescope was moved to El Leoncito in Argentina, where the University has a 25% share in observation time. While University operations continued at the DDO, international observers used about 50% of observing time there.

text: The main reflector at the DDO remained a major instrument into the 1960s, but in the end even the "remote" location Chant had selected was being encroached on by

text: urban sprawl

text: . Although some consideration was given to moving the telescope to a new site, in the end it was decided the funds would be better spent on a smaller instrument in a much better location. This led to the building of a 60 cm instrument at

text: Las Campanas

text: in

text: Chile

text: in 1971, creating the

entity_name: University of Toronto Southern Observatory

text: University of Toronto Southern Observatory

text: (UTSO). It was at this location that University of Toronto telescope operator

text: Ian Shelton

text: discovered

text: Supernova 1987A

text: , the first supernova visible to the naked eye in more than 350 years. The UTSO was later closed in 1997 to re-allocate funds to a share of the

text: Gemini Observatory

text: , and the 60 cm telescope was moved to El Leoncito in Argentina, where the University has a 25% share in observation time. While University operations continued at the DDO, international observers used about 50% of observing time there.

text: The discovery of Kepler-6 was confirmed by follow-up observations made using the Hobby Eberly and Smith telescopes in Texas; the Keck 1 telescope in Hawaii; the Hale and Shane telescopes in southern California; the WIYN, MMT, and Tillinghast telescopes in Arizona; and the Nordic Optical Telescope in the Canary Islands.

text: The discovery of Kepler-6 was confirmed by follow-up observations made using the

text: Hobby Eberly

text: and

text: Smith

text: telescopes in

text: Texas

text: ; the

text: Keck 1

text: telescope in

text: Hawaii

text: ; the

text: Hale

text: and

text: Shane

text: telescopes in southern

text: California

text: ; the

text: WIYN

text: MMT

text: , and

text: Tillinghast

text: telescopes in

text: Arizona

text: ; and the

text: Nordic Optical Telescope

text: in the

text: Canary Islands

text: The same reason that made this location a good choice also created additional problems, since many of the necessary infrastructures had to be prepared and installed. The Telescope foundations were studied by the Département of Civil Engineering of the Universidade de Aveiro and the city hall of Pampilhosa da Serra offered 120 tons of concrete. A new connection to the electric grid was made taking into account the size of the transformer to avoid noise in the observed frequencies. This was necessary because the wavelength of the emitted radiation is close to size of the transformer. A small meteorologic station was also installed to measure the wind intensity and help prevent against wind damages on the telescope.

text: The same reason that made this location a good choice also created additional problems, since many of the necessary infrastructures had to be prepared and installed. The Telescope foundations were studied by the Département of Civil Engineering of the

text: Universidade de Aveiro

text: and the city hall of Pampilhosa da Serra offered 120 tons of

text: concrete

text: . A new connection to the electric grid was made taking into account the size of the

text: transformer

text: to avoid noise in the observed frequencies. This was necessary because the wavelength of the emitted radiation is close to size of the transformer. A small meteorologic station was also installed to measure the wind intensity and help prevent against wind damages on the telescope.

text: Since achieving first light in 1996, the telescope has been used for a wide variety of studies ranging from the Solar System to stars in our galaxy and studies of other galaxies. The telescope has been used successfully to find planets orbiting around other stars by measuring radial velocities as precisely as 1 m/s. Using the low-resolution spectrograph, the telescope has been used to identify Type Ia supernovae to measure the acceleration of the universe. The telescope has also been used to measure the rotation of individual galaxies. The telescope was upgraded for use in the Hobby–Eberly Telescope Dark Energy Experiment (HETDEX), which will provide the first observations to allow narrowing of the list of possible explanations for dark energy.

text: Since achieving first light in 1996, the telescope has been used for a wide variety of studies ranging from the

text: Solar System

text: to stars in our galaxy and studies of other

text: galaxies

text: . The telescope has been used successfully to find

text: planet

text: s orbiting around other stars by measuring

text: radial velocities

text: as precisely as 1 m/s. Using the low-resolution spectrograph, the telescope has been used to identify

text: Type Ia supernova

text: e to measure the acceleration of the universe. The telescope has also been used to measure the rotation of individual galaxies. The telescope was upgraded for use in the Hobby–Eberly Telescope Dark Energy Experiment (HETDEX), which will provide the first observations to allow narrowing of the list of possible explanations for

text: dark energy

text: One widespread genre is known as Huaigu (). In this type of poem, the poet looks back at some bygone time, place, or persons. This is "one of the perennial themes of Chinese poetry," according to Burton Watson, in which "the poet contemplates the ruins of past glory."

text: SAFARI is the immediate successor to SRON’s molecule hunter HIFI on board the infrared telescope Herschel. The new and unique infrared imaging spectrometer can fully utilize the ultra-sensitive TES detectors in combination with SPICA’s extremely cold mirror to look even deeper into the far-infrared universe than HIFI. SAFARI will search for the first galaxies to determine how they were formed and how they evolve. Nearer by the instrument will be used to study the ice and water vapor in protoplanetary discs – the physical and chemical conditions in these protoplanetary discs ultimately determine the formation of planets.

text: SAFARI is the immediate successor to SRON’s molecule hunter HIFI on board the infrared telescope

text: Herschel

text: . The new and unique infrared imaging spectrometer can fully utilize the ultra-sensitive TES detectors in combination with SPICA’s extremely cold mirror to look even deeper into the far-infrared universe than HIFI. SAFARI will search for the first galaxies to determine how they were formed and how they evolve. Nearer by the instrument will be used to study the ice and water vapor in protoplanetary discs – the physical and chemical conditions in these protoplanetary discs ultimately determine the formation of planets.

text: The most recent published observation of this system for debris disks was in 2006 by the Spitzer telescope, searching for an excess of infra-red light that would indicate scattering of starlight by dust or planetesimals; no infra-red excess was detected.

text: To do almost any scientific work requires that telescopes track objects as they wheel across the visible sky.  In other words, they must smoothly compensate for the rotation of the Earth.  Until the advent of computer controlled drive mechanisms, the standard solution was some form of equatorial mount, and for small telescopes this is still the norm.   However, this is a structurally poor design and becomes more and more cumbersome as the diameter and weight of the telescope increases.  The world's largest equatorial mounted telescope is the 200 inch (5.1 m) Hale Telescope, whereas recent 8–10 m telescopes use the structurally better altazimuth mount, and are actually physically smaller than the Hale, despite the larger mirrors.  As of 2006, there are design projects underway for gigantic alt-az telescopes: the Thirty Metre Telescope , and the 100 m diameter Overwhelmingly Large Telescope.

text: To do almost any scientific work requires that telescopes track objects as they wheel across the visible sky.  In other words, they must smoothly compensate for the rotation of the Earth.  Until the advent of

text: computer

text: controlled drive mechanisms, the standard solution was some form of

text: equatorial mount

text: , and for small telescopes this is still the norm.   However, this is a structurally poor design and becomes more and more cumbersome as the diameter and weight of the telescope increases.  The world's largest equatorial mounted telescope is the 200 inch (5.1 m)

text: Hale Telescope

text: , whereas recent 8–10 m telescopes use the structurally better

text: altazimuth mount

text: , and are actually physically smaller than the Hale, despite the larger mirrors.  As of 2006, there are design projects underway for gigantic alt-az telescopes: the Thirty Metre Telescope , and the 100 m diameter

text: Overwhelmingly Large Telescope

text: IEEE Fellow, Heinrich Hertz Medal (Gold Medal and Monetary Award, IEEE highestrecognition for electromagnetic waves), (He was the first recipient, 1989)

text: IEEE Fellow,

text: Heinrich Hertz Medal

text: (Gold Medal and Monetary Award, IEEE highestrecognition for electromagnetic waves), (He was the first recipient, 1989)

text: The Very Large Telescope (VLT) consists of four 8.2-metre telescopes operating in the visible and infrared. These telescopes, along with four smaller auxiliary telescopes, are also combined to operate as an optical interferometer on certain nights of the year. All of the 8.2-metre telescopes have adaptive optics and a full suite of instruments.

text: The

text: Very Large Telescope

text: (VLT) consists of four 8.2-metre telescopes operating in the

text: visible

text: and

text: infrared

text: . These telescopes, along with four smaller auxiliary telescopes, are also combined to operate as an

text: optical interferometer

text: on certain nights of the year. All of the 8.2-metre telescopes have

text: adaptive optics

text: and a full suite of instruments.

text: A Pennsylvania Department of Transportation (PennDOT) sign on Crosstown Highway identifies the community as the "Village of Starlight." In Pennsylvania, a village is an unincorporated community within a township, but PennDOT identifies most villages with roadside signs, a fact that might reasonably lead those unfamiliar with this practice to believe that these communities are incorporated municipalities administered separately from the townships in which they are located. Since Pennsylvania's villages, including Starlight, are, in fact, not municipalities in their own right, they do not have official boundaries, and the United States Census Bureau does not collect statistics for them (unless, unlike Starlight, they are census-designated places). In spite of this, because of strong local consensus, as well as the fact that many features are named for the villages they are associated with, it is almost always impossible to consistently determine whether a particular feature is in one village or another.

text: A

entity_name: Pennsylvania Department of Transportation

text: Pennsylvania Department of Transportation (PennDOT)

text: sign on Crosstown Highway identifies the community as the "Village of Starlight." In Pennsylvania, a village is an

text: unincorporated community

text: within a

text: township

text: , but PennDOT identifies most villages with roadside signs, a fact that might reasonably lead those unfamiliar with this practice to believe that these communities are

text: incorporated municipalities

text: administered separately from the townships in which they are located. Since Pennsylvania's villages, including Starlight, are, in fact, not municipalities in their own right, they do not have official boundaries, and the

text: United States Census Bureau

text: does not collect statistics for them (unless, unlike Starlight, they are

text: census-designated places

text: ). In spite of this, because of strong local consensus, as well as the fact that many features are named for the villages they are associated with, it is almost always impossible to consistently determine whether a particular feature is in one village or another.

text: The original dish surface of the telescope was more accurate than the Lovell Telescope's at the time it was made, meaning that it was better suited for observations at higher frequencies. As well as operating as a solo instrument, it has been used as an interferometer with the Lovell Telescope, which provides a  baseline. It is commonly used as part of the Multi-Element Radio Linked Interferometer Network (MERLIN), and for Very Long Baseline Interferometry observations.

text: The original dish surface of the telescope was more accurate than the Lovell Telescope's at the time it was made, meaning that it was better suited for observations at higher frequencies. As well as operating as a solo instrument, it has been used as an

text: interferometer

text: with the

text: Lovell Telescope

text: , which provides a  baseline. It is commonly used as part of the

text: (MERLIN), and for

text: Very Long Baseline Interferometry

text: observations.

text: In the film Can't Buy Me Love, Cindy notices Tycho while looking through a telescope on her final "contractual" date with Ronny in the Airplane Graveyard.

text: In the film

text: Can't Buy Me Love

text: , Cindy notices Tycho while looking through a telescope on her final "contractual" date with Ronny in the Airplane Graveyard.

text: Trained as a theorist in stellar dynamics, he gradually expanded his research to include the analysis and interpretation of observations, and also became involved in the development of new instrumentation. In 1995, he initiated a project with R. Bacon and R. Davies to build SAURON, a panoramic integral-field spectrograph for the 4.2-m William Herschel Telescope (WHT). The SAURON collaboration led to follow-up projects studying galactic nuclei with the VLT, to the initiative to move the integral field spectrograph OASIS from the Canada France Hawaii Telescope to the WHT and to equip the WHT with a laser guide-star, to participation in studies for possible integral-field units on the Hubble Space Telescope and JWST, and to participation in the development of MUSE for the VLT.

text: Trained as a theorist in stellar dynamics, he gradually expanded his research to include the analysis and interpretation of observations, and also became involved in the development of new instrumentation. In 1995, he initiated a project with R. Bacon and R. Davies to build SAURON, a panoramic integral-field spectrograph for the 4.2-m

text: William Herschel Telescope

text: (WHT). The SAURON collaboration led to follow-up projects studying galactic nuclei with the VLT, to the initiative to move the integral field spectrograph OASIS from the

text: Canada France Hawaii Telescope

text: to the WHT and to equip the WHT with a laser guide-star, to participation in studies for possible integral-field units on the

text: Hubble Space Telescope

text: and JWST, and to participation in the development of MUSE for the VLT.

text: At its closest approach, the angular size of Mars is 25 arcseconds; this is much too small for the naked eye to resolve. Hence, prior to the invention of the telescope, nothing was known about the planet besides its position on the sky. The Italian scientist Galileo Galilei was the first person known to use a telescope to make astronomical observations. His records indicate that he began observing Mars through a telescope in September 1610. This instrument was too primitive to display any surface detail on the planet, so he set the goal of seeing if Mars exhibited phases of partial darkness similar to Venus or the Moon. Although uncertain of his success, by December he did note that Mars had shrunk in angular size. Polish astronomer Johannes Hevelius succeeded in observing a phase of Mars in 1645.

text: At its closest approach, the

text: angular size

text: of Mars is 25

text: arcsecond

text: s; this is much too small for the

text: naked eye to resolve

text: . Hence, prior to the invention of the

text: telescope

text: , nothing was known about the planet besides its position on the sky. The Italian scientist

text: Galileo Galilei

text: was the first person known to use a telescope to make astronomical observations. His records indicate that he began observing Mars through a telescope in September 1610. This instrument was too primitive to display any surface detail on the planet, so he set the goal of seeing if Mars exhibited

text: phases

text: of partial darkness similar to

text: Venus

text: or the

text: Moon

text: . Although uncertain of his success, by December he did note that Mars had shrunk in angular size. Polish astronomer

text: Johannes Hevelius

text: succeeded in observing a phase of Mars in 1645.

text: His research interests include active galactic nuclei (particularly Seyfert galaxy, Radio galaxy and quasars) and the ways in which large galaxies and their central supermassive black holes have changed and evolved throughout cosmological time. This research has involved the use of a variety of telescopes, including the Hubble Space Telescope, the Very Large Array, MERLIN, the William Herschel Telescope, and the Very Large Telescope.

text: His research interests include

text: active galactic nuclei

text: (particularly

text: Seyfert galaxy

text: Radio galaxy

text: and

text: quasars

text: ) and the ways in which large

text: galaxies

text: and their central

text: supermassive black hole

text: s have changed and evolved throughout

text: cosmological time

text: . This research has involved the use of a variety of telescopes, including the

text: Hubble Space Telescope

text: , the

text: Very Large Array

text: MERLIN

text: , the

text: William Herschel Telescope

text: , and the

text: Very Large Telescope

text: The VLBA radio telescopes are located at:

text: Gravitational-wave observations complement observations in the electromagnetic spectrum. These waves also promise to yield information in ways not possible via detection and analysis of electromagnetic waves. Electromagnetic waves can be absorbed and re-radiated in ways that make extracting information about the source difficult. Gravitational waves, however, only interact weakly with matter, meaning that they are not scattered or absorbed. This should allow astronomers to view the center of a supernova, stellar nebulae, and even colliding galactic cores in new ways.

text: Gravitational-wave observations complement observations in the

text: electromagnetic spectrum

text: . These waves also promise to yield information in ways not possible via detection and analysis of electromagnetic waves. Electromagnetic waves can be absorbed and re-radiated in ways that make extracting information about the source difficult. Gravitational waves, however, only interact weakly with matter, meaning that they are not scattered or absorbed. This should allow astronomers to view the center of a supernova, stellar nebulae, and even colliding galactic cores in new ways.

text: Chlorophyll (also chlorophyl) is a term used for several closely related green pigments found in cyanobacteria and the chloroplasts of algae and plants. Its name is derived from the Greek words χλωρός, chloros ("green") and φύλλον, phyllon ("leaf"). Chlorophyll is essential in photosynthesis, allowing plants to absorb energy from light. Chlorophyll absorbs light most strongly in the blue portion of the electromagnetic spectrum, followed by the red portion. Conversely, it is a poor absorber of green and near-green portions of the spectrum, which it reflects, producing the green color of chlorophyll-containing tissues. Chlorophyll molecules are specifically arranged in and around photosystems that are embedded in the thylakoid membranes of chloroplasts. Two types of chlorophyll exist in the photosystems of green plants: chlorophyll a and b. Chlorophyll was first isolated and named by Joseph Bienaimé Caventou and Pierre Joseph Pelletier in 1817.<ref>See:

text: Chlorophyll (also chlorophyl) is a term used for several closely related green

text: pigment

text: s found in

text: cyanobacteria

text: and the

text: chloroplast

text: s of

text: alga

text: e and

text: plant

text: s. Its name is derived from the

text: Greek

text: words χλωρός, chloros ("green") and φύλλον, phyllon ("leaf"). Chlorophyll is essential in

text: photosynthesis

text: , allowing plants to absorb

text: energy

text: from light. Chlorophyll absorbs light most strongly in the

text: blue portion

text: of the

text: electromagnetic spectrum

text: , followed by the red portion. Conversely, it is a poor absorber of green and near-green portions of the spectrum, which it reflects, producing the green color of chlorophyll-containing tissues. Chlorophyll molecules are specifically arranged in and around photosystems that are embedded in the thylakoid membranes of chloroplasts. Two types of chlorophyll exist in the photosystems of green plants: chlorophyll a and b. Chlorophyll was first isolated and named by

text: Joseph Bienaimé Caventou

text: and

text: Pierre Joseph Pelletier

text: in 1817.<ref>See:

text: The vast majority of observations are carried out in visitor mode i.e. with the investigating astronomer physically present at the telescope. A shift to service mode operations (those carried out by observatory staff on behalf of astronomers who do not travel to the telescope) has been considered and rejected on scientific and operational grounds.

text: Bioptics, also known as a bioptic in the singular, and sometimes more formally termed a bioptic telescope, is a term for a pair of vision-enhancement lenses.  They magnify between two and four times, and are used to improve distance vision for those with severely impaired eyesight, especially those with albinism. They can either be a combination of head-mounted eyeglasses (termed the "carrier") and binoculars, or be designed to attach to existing glasses. Some use monoculars which have small telescopes mounted on, in, or behind their regular lenses, so that they can look through either the regular lens or the telescope. Newer designs use smaller lightweight mini telescopes magnifying up to six times, which can be embedded into the spectacle glass and improve aesthetic appearance. The mini telescopic eyeglasses have been shown to be used in the treatment of nystagmus.  In some jurisdictions, those with low vision may be permitted to drive automobiles when using Bioptics.

text: Bioptics, also known as a bioptic in the singular, and sometimes more formally termed a bioptic telescope, is a term for a pair of

text: vision

text: -enhancement

text: lenses

text: .  They magnify between two and four times, and are used to improve distance vision for those with severely impaired eyesight, especially those with

text: albinism

text: . They can either be a combination of head-mounted

text: eyeglasses

text: (termed the "carrier") and

text: binoculars

text: , or be designed to attach to existing glasses. Some use

text: monoculars

text: which have small telescopes mounted on, in, or behind their regular lenses, so that they can look through either the regular lens or the telescope. Newer designs use smaller lightweight mini telescopes magnifying up to six times, which can be embedded into the spectacle glass and improve aesthetic appearance. The mini telescopic eyeglasses have been shown to be used in the treatment of

text: nystagmus

text: .  In some jurisdictions, those with low vision may be permitted to drive automobiles when using Bioptics.

text: interaction much more visible. In UPCs, because the ions are heavily charged, it is possible to have two independent interactions between a single ion pair, such as production of two electron-positron pairs. UPCs are studied with the STARlight simulation code.

text: interaction much more visible. In UPCs, because the ions are heavily charged, it is possible to have two independent interactions between a single ion pair, such as production of two electron-positron pairs. UPCs are studied with the

text: STARlight

text: simulation code.

text: Says Phipps of that moment in time, "I holed up in a tiny room within a friend's warehouse and began knocking out as many different songs as I could. I tried not to look back, just wanting to explore everything I could possibly create. I started to feel like I was becoming a Kafka-esque insomniac musical novelist at one point."

text: A robotic telescope is an astronomical telescope and detector system that makes observations without the intervention of a human.  In astronomical disciplines, a telescope qualifies as robotic if it makes those observations without being operated by a human, even if a human has to initiate the observations at the beginning of the  night, or end them in the morning. It may have software agent(s) using Artificial Intelligence that assist in various ways such as automatic scheduling. A robotic telescope is distinct from a remote telescope, though an instrument can be both robotic and remote.

text: A robotic telescope is an

text: astronomical

text: telescope

text: and detector system that makes

text: observation

text: s without the intervention of a

text: human

text: .  In astronomical disciplines, a telescope qualifies as

text: robot

text: ic if it makes those observations without being operated by a human, even if a human has to initiate the observations at the beginning of the  night, or end them in the morning. It may have

text: software agent

text: (s) using Artificial Intelligence that assist in various ways such as automatic scheduling. A robotic telescope is distinct from a

text: remote telescope

text: , though an instrument can be both robotic and remote.

text: SERENDIP takes advantage of ongoing "mainstream" radio telescope observations as a "piggy-back" or "commensal" program. Rather than having its own observation program, SERENDIP analyzes deep space radio telescope data that it obtains while other astronomers are using the telescope.

text: SERENDIP takes advantage of ongoing "mainstream"

text: radio telescope

text: observations as a "

text: piggy-back

text: " or "

text: commensal

text: " program. Rather than having its own observation program, SERENDIP analyzes

text: deep space

text: astronomer

text: s are using the telescope.

text: The first Curator was J. Grant Bruce F.R.A.S., an instrument-maker from Newport, Fife. This was a part-time post, with a small salary. A full-time caretaker, George Dorward, was also appointed. Hours of opening were fixed, with special arrangements for visiting parties, and for qualified persons at other times. In the winter evenings, Mondays, Wednesdays and Fridays were for the public, with Tuesdays and Thursdays reserved for private booked parties. During the day and throughout the summer, visitors could view the scenery from the balcony, using two four-inch (102 mm)  Turret telescopes by Ross, suitable for terrestrial viewing. These were excellent telescopes, also very suitable for wide-field, low-power astronomical work. Unfortunately these are no longer functioning and only parts of one remain.In the dome, the original telescope given by the Mills Trust was an 18-inch (45 cm.) Newtonian reflector by Grubb Parsons, electrically driven. The dome itself, also built by Grubb, is hand-operated and made of papier-mâché on a framework of steel. The only part of the dome which has had to be replaced over the years is the shutter, where the papier-mâché perished and marine plywood was substituted. The 18-inch telescope was rarely used at full aperture, due to its tendency to be affected by reflections from street lights caused by the open lattice-work tube.One of the problems that restricted the astronomical work of the Observatory during this period was that Balgay Park was enclosed, and the gates were locked at dusk.  Special arrangements had to be made with the Parks Department to have a gatekeeper on duty during the nights when the telescope was in use, and for him to supervise entry and exit of public and cars, and ensure no-one was left in the park after the observatory was locked up.  This meant that all children had to be accompanied by an adult.  For this reason the Council placed the Observatory under the administrative control of the Parks Superintendent, under whom it remained until reorganisation brought a transfer to the Museums Department. The railings were removed during the War, since when the park has had "open access."  During the years 1935 to 1939 there was one staff change - Mr. Dorward retired and was succeeded by Mr. McDonald. Shortly after the outbreak of the Second World War the Observatory was closed for the duration and the staff re-deployed to work of more immediate national importance. After the war, when the Observatory re-opened, the  telescope underwent a radical transformation.

text: The first

text: Curator

text: was J. Grant Bruce F.R.A.S., an instrument-maker from

text: Newport

text: Fife

text: . This was a part-time post, with a small salary. A full-time caretaker, George Dorward, was also appointed. Hours of opening were fixed, with special arrangements for visiting parties, and for qualified persons at other times. In the winter evenings, Mondays, Wednesdays and Fridays were for the public, with Tuesdays and Thursdays reserved for private booked parties. During the day and throughout the summer, visitors could view the scenery from the balcony, using two four-inch (102 mm)  Turret telescopes by Ross, suitable for terrestrial viewing. These were excellent telescopes, also very suitable for wide-field, low-power astronomical work. Unfortunately these are no longer functioning and only parts of one remain.In the dome, the original telescope given by the Mills Trust was an 18-inch (45 cm.)

text: Newtonian reflector

text: by

text: Grubb Parsons

text: , electrically driven. The dome itself, also built by Grubb, is hand-operated and made of

text: papier-mâché

text: on a framework of steel. The only part of the dome which has had to be replaced over the years is the shutter, where the papier-mâché perished and marine plywood was substituted. The 18-inch telescope was rarely used at full aperture, due to its tendency to be affected by reflections from street lights caused by the open lattice-work tube.One of the problems that restricted the astronomical work of the Observatory during this period was that

text: Balgay Park

text: was enclosed, and the gates were locked at dusk.  Special arrangements had to be made with the Parks Department to have a gatekeeper on duty during the nights when the telescope was in use, and for him to supervise entry and exit of public and cars, and ensure no-one was left in the park after the observatory was locked up.  This meant that all children had to be accompanied by an adult.  For this reason the Council placed the Observatory under the administrative control of the Parks Superintendent, under whom it remained until reorganisation brought a transfer to the

text: Museum

text: s Department. The railings were removed during the War, since when the park has had "open access."  During the years 1935 to 1939 there was one staff change - Mr. Dorward retired and was succeeded by Mr. McDonald. Shortly after the outbreak of the

text: Second World War

text: the Observatory was closed for the duration and the staff re-deployed to work of more immediate national importance. After the war, when the Observatory re-opened, the  telescope underwent a radical transformation.

text: The Cerro Chajnantor Atacama Telescope (CCAT) is a proposed  telescope that is intended to reveal the cosmic origins of stars, planets, and galaxies with its submillimeter cameras and spectrometers enabled by the superconducting detector arrays.

text: The Cerro Chajnantor Atacama Telescope (CCAT) is a proposed  telescope that is intended to reveal the cosmic origins of stars, planets, and galaxies with its

text: submillimeter

text: cameras and spectrometers enabled by the

text: superconducting

text: detector arrays.

text: Large (more than  10 m in diameter or length) radio telescopes always bend during operation, due to their enormous weight and the fact that even the strongest materials are not perfectly stiff.  This bending, in the range of a few millimetres, does not affect low frequency operation much, but dramatically reduces the efficiency of the telescope at higher frequencies where the wavelengths are comparable to the distortion.  Typically, the efficiency of a telescope drops appreciably when the deviation from the desired shape is more than 1/10 of the considered wavelength.  An active surface uses numerous small actuators to move the surface panels with respect to the underlying frame, and thus maintain the correct shape.

text: Ohio Wesleyan University owns the Perkins Observatory, which is located south of the city of Delaware. The observatory housed the 69-inch Perkins Telescope, which in 1931—the year of its completion—was the third-largest telescope in the world only after the 100-inch at Mt. Wilson, California, and the 72-inch at Victoria, B.C., Canada. The Perkins Telescope was moved to Arizona's Lowell Observatory in 1961 where it was used by Vera Rubin to study Dark Matter. The Perkins Telescope has since been replaced by The Schottland 32-inch Reflector. The grounds near Perkins also housed Ohio State's radio telescope, known locally as The Big Ear; the Big Ear was disassembled in 1998.

text: Ohio Wesleyan University owns the

text: Perkins Observatory

text: , which is located south of the city of Delaware. The

text: observatory

text: housed the 69-inch Perkins

text: Telescope

text: , which in 1931—the year of its completion—was the third-largest telescope in the world only after the 100-inch at

text: Mt. Wilson, California

text: , and the 72-inch at

text: Victoria, B.C.

text: , Canada. The Perkins Telescope was moved to Arizona's

text: Lowell Observatory

text: in 1961 where it was used by

text: Vera Rubin

text: to study

text: Dark Matter

text: . The Perkins Telescope has since been replaced by The Schottland 32-inch Reflector. The grounds near Perkins also housed

text: Ohio State

text: 's

text: radio telescope

text: , known locally as

text: The Big Ear

text: ; the Big Ear was disassembled in 1998.

text: The observatory instruments include two radio telescopes (32'/10m and 26'/8m diameter), and a range of optical instruments, including one 24" Classical cassegrain telescope, a 14" and 8" Schmidt-Cassegrain telescope, and one 12" Dobsonian telescope.

text: The observatory instruments include two radio telescopes (32'/10m and 26'/8m diameter), and a range of optical instruments, including one 24" Classical

text: cassegrain telescope

text: , a 14" and 8"

text: Schmidt-Cassegrain

text: telescope, and one 12"

text: Dobsonian telescope

text: Cam takes Mitch to the restaurant where they had their first date and Mitch realizes immediately why Cam took him there. Mitch finds an excuse to leave and go back home since if Cam proposes, it will destroy his plans of proposing to Cam and being romantic for the first time. On their way back home, they get a flat tire and as they both kneel to change the tire, they just look at each other, share a smile, and say "yes" at the same time.

text: In the 1990s and 2000s, observations by the Hubble Space Telescope and by ground based telescopes equipped with adaptive optics systems (the Keck telescope and NASA Infrared Telescope Facility, for instance) made it possible for the first time to observe discrete cloud features from Earth. Tracking them has allowed astronomers to re-measure wind speeds on Uranus, known before only from the Voyager 2 observations, and to study the dynamics of the Uranian atmosphere.

text: In the 1990s and 2000s, observations by the

text: Hubble Space Telescope

text: and by ground based telescopes equipped with

text: adaptive optics

text: systems (the

text: Keck telescope

text: and

text: NASA Infrared Telescope Facility

text: , for instance) made it possible for the first time to observe discrete cloud features from Earth. Tracking them has allowed astronomers to re-measure wind speeds on Uranus, known before only from the Voyager 2 observations, and to study the dynamics of the Uranian atmosphere.

text: Paul's idea was to start with a Mersenne beam compressor, which looks like a Cassegrain made from two (confocal) paraboloids, with both the input and output beams collimated.  The compressed input beam is then directed to a spherical tertiary mirror, which results in traditional spherical aberration.  Paul's key insight is that the secondary can then be converted back to a spherical mirror.  One way to look at this is to imagine the tertiary mirror, which suffers from spherical aberration, is replaced by a Schmidt telescope, with a correcting plate at its centre of curvature. If the radii of the secondary and tertiary are of the same magnitude, but opposite sign, and if the centre of curvature of the tertiary is placed directly at the vertex of the secondary mirror, then the Schmidt plate would lie on top of the paraboloid secondary mirror. Therefore the Schmidt plate required to make the tertiary mirror a Schmidt telescope is eliminated by the paraboloid figuring on the convex secondary of the Mersenne system, as each corrects the same magnitude of spherical aberration, but the opposite sign. Also, as the system of Mersenne + Schmidt is the sum of two anastigmats: the Mersenne system is an anastigmat, and so is the Schmidt system, the resultant system is also an anastigmat, as third-order aberrations are purely additive.  In addition the secondary is now easier to fabricate.  This design is also called a Mersenne-Schmidt, since it uses a Mersenne configuration as the corrector for a Schmidt telescope.

text: Paul's idea was to start with a Mersenne beam compressor, which looks like a

text: Cassegrain

text: made from two (confocal)

text: paraboloid

text: Newton's third telescope was built in 1671-1672 by Newton and his "chamber fellow" at Trinity College John Wickins. He reported that Wickins did a better job of figuring the mirror than he had done on his second telescope.  This is the telescope that he had by him when he was writing Opticks.  The telescope appeared some time later in the shop of Heath and Wing instrument makers along with an instrument of Newtons belonging to Edmond Halley.  It is most likely that the telescope had passed to Halley and then to Heath and Wing.  This third telescope had the mirror damaged in 1694 by Newton while trying to clean it.  It is thought that the mirror was later refigured by restorers accounting for its plugged eyepiece hole at an appropriate distance for a 6.25 inch focal length mirror and the new eyepiece position for the current mirror focal length of 8.5 inches.  The current brass eyepiece is not original and was added later.  This telescope was restored by Heath and Wing and presented to the Royal Society in 1766 as the telescope that Newton had made.  At a later date a plaque was added to this telescope with the incorrect inscription claiming that it was his first telescope and made in 1671. This telescope probably includes the original mirrors, reground, part of the original base, the original support bar and possibly the original tube or parts of it.

text: One of the most important tests is gravitational lensing. It has been observed in distant astrophysical sources, but these are poorly controlled and it is uncertain how they constrain general relativity. The most precise tests are analogous to Eddington's 1919 experiment: they measure the deflection of radiation from a distant source by the Sun. The sources that can be most precisely analyzed are distant radio sources. In particular, some quasars are very strong radio sources. The directional resolution of any telescope is in principle limited by diffraction; for radio telescopes this is also the practical limit. An important improvement in obtaining positional high accuracies (from milli-arcsecond to micro-arcsecond) was obtained by combining radio telescopes across Earth. The technique is called very long baseline interferometry (VLBI). With this technique radio observations couple the phase information of the radio signal observed in telescopes separated over large distances. Recently, these telescopes have measured the deflection of radio waves by the Sun to extremely high precision, confirming the amount of deflection predicted by general relativity aspect to the 0.03% level. At this level of precision systematic effects have to be carefully taken into account to determine the precise location of the telescopes on Earth. Some important effects are Earth's nutation, rotation, atmospheric refraction, tectonic displacement and tidal waves. Another important effect is refraction of the radio waves by the solar corona. Fortunately, this effect has a characteristic spectrum, whereas gravitational distortion is independent of wavelength. Thus, careful analysis, using measurements at several frequencies, can subtract this source of error.

text: One of the most important tests is

text: gravitational lensing

text: . It has been observed in distant astrophysical sources, but these are poorly controlled and it is uncertain how they constrain general relativity. The most precise tests are analogous to Eddington's 1919 experiment: they measure the deflection of radiation from a distant source by the Sun. The sources that can be most precisely analyzed are distant

text: radio sources

text: . In particular, some

text: quasar

text: s are very strong radio sources. The directional resolution of any telescope is in principle limited by diffraction; for radio telescopes this is also the practical limit. An important improvement in obtaining positional high accuracies (from milli-arcsecond to micro-arcsecond) was obtained by combining radio telescopes across Earth. The technique is called

text: very long baseline interferometry

text: (VLBI). With this technique radio observations couple the phase information of the radio signal observed in telescopes separated over large distances. Recently, these telescopes have measured the deflection of radio waves by the Sun to extremely high precision, confirming the amount of deflection predicted by general relativity aspect to the 0.03% level. At this level of precision systematic effects have to be carefully taken into account to determine the precise location of the telescopes on Earth. Some important effects are Earth's

text: nutation

text: , rotation, atmospheric refraction, tectonic displacement and tidal waves. Another important effect is refraction of the radio waves by the

text: solar corona

text: . Fortunately, this effect has a characteristic

text: spectrum

text: , whereas gravitational distortion is independent of wavelength. Thus, careful analysis, using measurements at several frequencies, can subtract this source of error.

text: The Centre has its roots in the Radio Astronomy Group of TIFR, set up in the early 1960s under the leadership of Govind Swarup. The group designed and built the Ooty Radio Telescope. In the early 80's an ambitious plan for a new telescope was proposed - the Giant Metrewave Radio Telescope. Since the site chosen for this new telescope was close to Pune, a new home for the group was built in the scenic campus of Pune University. The radio astronomy group morphed into the National Centre for Radio Astrophysics around this time.

text: The Centre has its roots in the

text: Radio Astronomy

text: Group of

text: TIFR

text: , set up in the early 1960s under the leadership of

text: Govind Swarup

text: . The group designed and built the Ooty Radio Telescope. In the early 80's an ambitious plan for a new telescope was proposed - the Giant Metrewave Radio Telescope. Since the site chosen for this new telescope was close to Pune, a new home for the group was built in the scenic campus of Pune University. The radio astronomy group morphed into the National Centre for Radio Astrophysics around this time.

text: The JMI website quotes the cost of the telescope at $159,000. The JMI design is more cost-effective than other telescopes because of its dobsonian mount and optical system. SUNY Oneonta acquired the telescope in 2006 for less than $150,000. After construction of a new dedicated observatory building, the telescope had a "first light" ceremony on May 30, 2009.

text: The JMI website quotes the cost of the telescope at $159,000. The JMI design is more cost-effective than other telescopes because of its

text: dobsonian mount

text: and optical system.

text: SUNY Oneonta

text: acquired the telescope in 2006 for less than $150,000. After construction of a new dedicated observatory building, the telescope had a "first light" ceremony on May 30, 2009.

text: Central to the study of electromagnetic waves is the wave equation.  Starting with Maxwell's equations in an isotropic space, containing no free charge, it can be shown that

text: Central to the study of electromagnetic waves is the

text: wave equation

text: .  Starting with

text: Maxwell's equations

text: in an isotropic space, containing no free charge, it can be shown that

text: The principal telescope at the observatory is a  refracting telescope. the objective lens was made by Alvan Clark and Sons. The telescope, which was finished in 1882, was installed at the Halsted Observatory of Princeton University. The telescope was rebuilt in 1933 by J. W. Fecker Company. The telescope was transferred to the US Naval Observatory in 1964. In 1968, it was offered to the Greenville County School District. The telescope was renovated and an observatory was built through a donation from the Charles E. Daniel Family Foundation. It is the eighth largest refractor telescope in the United States.

text: The principal telescope at the observatory is a

text: refracting telescope

text: . the objective lens was made by

text: Alvan Clark

text: and Sons. The telescope, which was finished in 1882, was installed at the Halsted Observatory of

text: Princeton University

text: . The telescope was rebuilt in 1933 by J. W. Fecker Company. The telescope was transferred to the

text: US Naval Observatory

text: in 1964. In 1968, it was offered to the Greenville County School District. The telescope was renovated and an observatory was built through a donation from the

text: Charles E. Daniel

text: Family Foundation. It is the

entity_name: List of largest optical refracting telescopes

text: eighth largest

text: refractor telescope in the United States.

text: From 2009 until 2011 Dr. Harvey-Smith was Chair of the Australia Telescope National Facility's Telescope Time Assignment Committee. She is a current member of the School of Physics Advisory Committee at the University of New South Wales.

text: . The radiated wave can be considered locally as a plane wave. The intensity of an electromagnetic plane wave is:

text: ANTARES is the name of a neutrino detector residing 2.5 km under the Mediterranean Sea off the coast of Toulon, France. It is designed to be used as a directional neutrino telescope to locate and observe neutrino flux from cosmic origins in the direction of the Southern Hemisphere of the Earth, a complement to the southern hemisphere neutrino detector IceCube that detects neutrinos from the North. The name comes from Astronomy with a Neutrino Telescope and Abyss environmental RESearch project; the acronym also being the name of the prominent star Antares.  Other neutrino telescopes designed for use in the nearby area include the Greek NESTOR telescope and the Italian NEMO telescope, which are both in early design stages.

text: ANTARES is the name of a

text: neutrino detector

text: residing 2.5 km under the

text: Mediterranean Sea

text: off the coast of

text: Toulon

text: France

text: . It is designed to be used as a directional neutrino telescope to locate and observe

text: neutrino

text: flux

text: from cosmic origins in the direction of the

text: Southern Hemisphere

text: of the

text: Earth

text: , a complement to the southern hemisphere neutrino detector

text: IceCube

text: that detects neutrinos from the North. The name comes from Astronomy with a Neutrino Telescope and Abyss environmental RESearch project; the

text: acronym

text: also being the name of the prominent star

text: Antares

text: .  Other neutrino telescopes designed for use in the nearby area include the

text: Greek

text: NESTOR

text: telescope and the

text: Italian

text: NEMO

text: telescope, which are both in early design stages.

text: A turntable ladder (TL) is perhaps the best-known form of special purpose aerial apparatus, and is used to gain access to fires occurring at height using a large telescopic ladder, where conventional ladders carried on conventional appliances might not reach. The name is derived from the fact that the large ladder is mounted on a turntable on the back of a truck chassis, allowing it to pivot around a stable base. To increase its length, the ladder is telescopic. Modern telescopic ladders are either hydraulic or pneumatic. These mechanical features allow the use of ladders which are longer, sturdier, and more stable. They may also have pre-attached hoses or other equipment.

text: A turntable ladder (TL) is perhaps the best-known form of special purpose aerial apparatus, and is used to gain access to fires occurring at height using a large telescopic ladder, where conventional ladders carried on conventional appliances might not reach. The name is derived from the fact that the large ladder is mounted on a turntable on the back of a

text: truck

text: chassis, allowing it to pivot around a stable base. To increase its length, the ladder is

text: telescopic

text: . Modern telescopic ladders are either

text: hydraulic

text: or

text: pneumatic

text: . These mechanical features allow the use of ladders which are longer, sturdier, and more stable. They may also have pre-attached hoses or other equipment.

text: MeerKAT, originally the Karoo Array Telescope, is a radio telescope under construction in the Northern Cape of South Africa. It will be the largest and most sensitive radio telescope in the southern hemisphere until the Square Kilometre Array is completed approximately in 2024. The telescope will be used for research into cosmic magnetism, galactic evolution, the large-scale structure of the cosmos, dark matter and the nature of transient radio sources. It will also serve as a technology demonstrator for South Africa's bid to host the Square Kilometer Array.  As of July 2016, only sixteen 13.5-meter diameter (44.3 feet) dish antennae have been completed and are functioning, and the remainder are planned to be in service by 2017.

text: MeerKAT, originally the Karoo Array Telescope, is a

text: radio telescope

text: under construction in the

text: Northern Cape

text: of South Africa. It will be the largest and most sensitive radio telescope in the southern hemisphere until the

text: Square Kilometre Array

text: is completed approximately in 2024. The telescope will be used for research into cosmic magnetism,

text: galactic evolution

text: , the

text: large-scale structure of the cosmos

text: dark matter

text: and the nature of transient

text: radio sources

text: . It will also serve as a technology demonstrator for South Africa's bid to host the Square Kilometer Array.  As of July 2016, only sixteen 13.5-meter diameter (44.3 feet) dish antennae have been completed and are functioning, and the remainder are planned to be in service by 2017.

text: ), then the direct limit is the union, but in general one must use the mapping telescope. The mapping telescope is a sequence of mapping cylinders, joined end-to-end. The picture of the construction looks like a stack of increasingly large cylinders, like a telescope.

text: Since observing time on large, professional telescopes such as Keck or Hubble is always scarce, the Deep Impact scientists called upon "advanced amateur, student, and professional astronomers" to use small telescopes to make long-term observations of the target comet before and after impact. The purpose of these observations was to look for "volatile outgassing, dust coma development and dust production rates, dust tail development, and jet activity and outbursts." By mid-2007, amateur astronomers had submitted over a thousand CCD images of the comet.

text: Since observing time on large, professional

text: telescopes

text: such as

text: Keck

text: or Hubble is always scarce, the Deep Impact scientists called upon "advanced amateur, student, and professional

text: astronomers

text: " to use small telescopes to make long-term observations of the target comet before and after impact. The purpose of these

text: observations

text: was to look for "volatile outgassing, dust coma development and dust production rates, dust tail development, and jet activity and outbursts." By mid-2007, amateur astronomers had submitted over a thousand

text: CCD

text: images of the comet.

text: A wide variety of radiation sources are employed in order to cover the electromagnetic spectrum. For spectroscopy, it is generally desirable for a source to cover a broad swath of wavelengths in order to measure a broad region of the absorption spectrum. Some sources inherently emit a broad spectrum. Examples of these include globars or other black body sources in the infrared, mercury lamps in the visible and ultraviolet and x-ray tubes. One recently developed, novel source of broad spectrum radiation is synchrotron radiation which covers all of these spectral regions. Other radiation sources generate a narrow spectrum but the emission wavelength can be tuned to cover a spectral range. Examples of these include klystrons in the microwave region and lasers across the infrared, visible and ultraviolet region (though not all lasers have tunable wavelengths).

text: A wide variety of radiation sources are employed in order to cover the electromagnetic spectrum. For spectroscopy, it is generally desirable for a source to cover a broad swath of wavelengths in order to measure a broad region of the absorption spectrum. Some sources inherently emit a broad spectrum. Examples of these include

text: globar

text: s or other

text: black body

text: sources in the infrared,

text: mercury lamp

text: s in the visible and ultraviolet and

text: x-ray tube

text: s. One recently developed, novel source of broad spectrum radiation is

text: synchrotron radiation

text: which covers all of these spectral regions. Other radiation sources generate a narrow spectrum but the emission wavelength can be tuned to cover a spectral range. Examples of these include

text: klystron

text: s in the microwave region and

text: laser

text: s across the infrared, visible and ultraviolet region (though not all lasers have tunable wavelengths).

text: UNIT troops engage the Autons, while the Doctor and the Brigadier pursue the Master into the radio telescope's control cabin. The Doctor convinces the Master that the Nestenes are so utterly different they will not be able to distinguish between him and the humans once they arrive. Together, they use the channel opened for the invasion to force the Nestene energy back into space, causing the Autons to collapse. The Master flees, returning to the coach: yet then he re-emerges, apparently surrendering. When he pulls out a gun Yates shoots him dead, but the Doctor peels back the facemask on the body to reveal it is the hypnotised Farrel, disguised to look like the Master. The real Master escapes in the coach. However, with his dematerialisation circuit in the Doctor's hands, the Master is now trapped on Earth.

text: The 1.2 meter Millimeter-Wave Telescope at the Harvard-Smithsonian Center for Astrophysics and its twin instrument at CTIO in Chile have been studying the distribution and properties of molecular clouds in our Galaxy and its nearest neighbours since the 1970s. The telescope is nicknamed "The Mini" because of its unusually small size. At the time it was built, it was the smallest radio telescope in the world. Together, "The Mini" and its twin in Chile have obtained what is by far the most extensive, uniform, and widely used Galactic survey of interstellar carbon monoxide (CO). "The Mini" is currently in operation from October to May each year.

text: The 1.2 meter Millimeter-Wave Telescope at the

text: Harvard-Smithsonian Center for Astrophysics

text: and its twin instrument at

text: CTIO

text: in

text: Chile

text: have been studying the distribution and properties of molecular clouds in our Galaxy and its nearest neighbours since the 1970s. The telescope is nicknamed "The Mini" because of its unusually small size. At the time it was built, it was the smallest radio telescope in the world. Together, "The Mini" and its twin in Chile have obtained what is by far the most extensive, uniform, and widely used Galactic survey of interstellar carbon monoxide (CO). "The Mini" is currently in operation from October to May each year.

text: In Norden's version of the system, the bombardier first looked up the expected time it would take for the bombs to fall from the current altitude. This time was set into a countdown stopwatch, and the bombardier waited for the target to line up with a set of iron sights at the front of the bombsight. When the target passed through the sights, the timer was started, and the bombardier then rotated the telescope around its vertical axis to track the target as they approached it. This movement was linked to a second sight through a gearing system that caused the second to move twice as fast as the first. The bombardier continued moving the telescope until the timer ran out. The second sight was now at the correct aiming angle, or range angle; the bombardier moved his eyes to look through this second set of sights to time the drop.

text: In Norden's version of the system, the bombardier first looked up the expected time it would take for the bombs to fall from the current altitude. This time was set into a countdown

text: stopwatch

text: , and the bombardier waited for the target to line up with a set of

text: iron sight

text: s at the front of the bombsight. When the target passed through the sights, the timer was started, and the bombardier then rotated the telescope around its vertical axis to track the target as they approached it. This movement was linked to a second sight through a gearing system that caused the second to move twice as fast as the first. The bombardier continued moving the telescope until the timer ran out. The second sight was now at the correct aiming angle, or range angle; the bombardier moved his eyes to look through this second set of sights to time the drop.

text: The National Radio Astronomy Observatory (NRAO), headquartered in Charlottesville, VA, is a Federally Funded Research and Development Center (FFRDC) operated by Associated Universities, Inc. under cooperative agreement with the United States National Science Foundation.  NRAO designs, builds, and operates high sensitivity radio telescopes for use by scientists around the world.

text: The National Radio Astronomy Observatory (NRAO), headquartered in Charlottesville, VA, is a

text: (FFRDC) operated by Associated Universities, Inc. under cooperative agreement with the United States

text: National Science Foundation

text: .  NRAO designs, builds, and operates high sensitivity

text: radio telescopes

text: for use by scientists around the world.

text: Electromagnetic waves are produced whenever charged particles are accelerated, and these waves can subsequently interact with any charged particles. EM waves carry energy, momentum and angular momentum away from their source particle and can impart those quantities to matter with which they interact. Quanta of EM waves are called photons, which are massless, but they are still affected by gravity. Electromagnetic radiation is associated with those EM waves that are free to propagate themselves ("radiate") without the continuing influence of the moving charges that produced them, because they have achieved sufficient distance from those charges. Thus, EMR is sometimes referred to as the far field. In this language, the near field refers to EM fields near the charges and current that directly produced them, specifically, electromagnetic induction and electrostatic induction phenomena.

text: Electromagnetic waves are produced whenever

text: charged particle

text: s are

text: accelerated

text: , and these waves can subsequently interact with any charged particles. EM waves carry

text: energy

text: momentum

text: and

text: angular momentum

text: away from their source particle and can impart those quantities to

text: matter

text: with which they interact.

text: Quanta

text: of EM waves are called

text: photon

text: s, which are

text: massless

text: , but they are still affected by

entity_section: Light deflection and gravitational time delay

text: gravity

text: . Electromagnetic radiation is associated with those EM waves that are free to propagate themselves ("radiate") without the continuing influence of the moving charges that produced them, because they have achieved sufficient distance from those charges. Thus, EMR is sometimes referred to as the

text: far field

text: . In this language, the near field refers to EM fields near the charges and current that directly produced them, specifically,

text: electromagnetic induction

text: and

text: electrostatic induction

text: phenomena.

text: BeppoSAX functioned until 2002 and CGRO (with BATSE) was deorbited in 2000. However, the revolution in the study of gamma-ray bursts motivated the development of a number of additional instruments designed specifically to explore the nature of GRBs, especially in the earliest moments following the explosion. The first such mission, HETE-2, launched in 2000 and functioned until 2006, providing most of the major discoveries during this period. One of the most successful space missions to date, Swift, was launched in 2004 and as of 2016 is still operational. Swift is equipped with a very sensitive gamma ray detector as well as on-board X-ray and optical telescopes, which can be rapidly and automatically slewed to observe afterglow emission following a burst. More recently, the Fermi mission was launched carrying the Gamma-Ray Burst Monitor, which detects bursts at a rate of several hundred per year, some of which are bright enough to be observed at extremely high energies with Fermi's Large Area Telescope. Meanwhile, on the ground, numerous optical telescopes have been built or modified to incorporate robotic control software that responds immediately to signals sent through the Gamma-ray Burst Coordinates Network. This allows the telescopes to rapidly repoint towards a GRB, often within seconds of receiving the signal and while the gamma-ray emission itself is still ongoing.

text: BeppoSAX functioned until 2002 and

text: CGRO

text: (with BATSE) was deorbited in 2000. However, the revolution in the study of gamma-ray bursts motivated the development of a number of additional instruments designed specifically to explore the nature of GRBs, especially in the earliest moments following the explosion. The first such mission,

text: , launched in 2000 and functioned until 2006, providing most of the major discoveries during this period. One of the most successful space missions to date,

text: Swift

text: , was launched in 2004 and as of 2016 is still operational. Swift is equipped with a very sensitive gamma ray detector as well as on-board X-ray and optical telescopes, which can be rapidly and automatically

text: slewed

text: to observe afterglow emission following a burst. More recently, the

text: Fermi

text: mission was launched carrying the

text: Gamma-Ray Burst Monitor

text: , which detects bursts at a rate of several hundred per year, some of which are bright enough to be observed at extremely high energies with Fermi's

text: Large Area Telescope

text: . Meanwhile, on the ground, numerous optical telescopes have been built or modified to incorporate robotic control software that responds immediately to signals sent through the

text: Gamma-ray Burst Coordinates Network

text: . This allows the telescopes to rapidly repoint towards a GRB, often within seconds of receiving the signal and while the gamma-ray emission itself is still ongoing.

text: Including optical observatories, including UV, visible and some optical infrared telescopes, near infrared. Covers from about 1901 to 2001, with some flexibility to accommodate ambiguity in classification. For example, some 2002 telescopes, if it was nearly operation in 2001. 19th century and earlier telescopes that ceased operation are not included, but the list is not complete.

text: Including

text: optical

text: observatories, including UV, visible and some optical infrared telescopes,

text: near infrared

text: . Covers from about 1901 to 2001, with some flexibility to accommodate ambiguity in classification. For example, some 2002 telescopes, if it was nearly operation in 2001. 19th century and earlier telescopes that ceased operation are not included, but the list is not complete.

text: The college Theatre Department offers year-round opportunities for students and community members through its two theatres: Rock Valley College Starlight Theatre and Rock Valley College Studio Theatre. The Starlight Theatre is housed in the award-winning outdoor Bengt Sjostrom Theatre, which features a movable roof. Studio Theatre is housed in a converted barn on the campus, along with Theatre Department offices and costume storage facilities. Plans to relocate them from "the barn" to a new Arts Instructional Center (AIC) with modern amenities has been tabled by the college's Board of Trustees.

text: The college Theatre Department offers year-round opportunities for students and community members through its two theatres:

text: Rock Valley College Starlight Theatre

text: and

text: Rock Valley College Studio Theatre

text: . The Starlight Theatre is housed in the award-winning outdoor

text: Bengt Sjostrom Theatre

text: , which features a movable roof. Studio Theatre is housed in a converted barn on the campus, along with Theatre Department offices and costume storage facilities. Plans to relocate them from "the barn" to a new Arts Instructional Center (AIC) with modern amenities has been tabled by the college's Board of Trustees.

text: The astronomers use observations and data captured by the Spitzer Space Telescope and other telescopes to create a complete picture of the star forming regions within an approximately 1600 lightyear radius centered on the Solar System. These regions are partly or completely clouded by interstellar dust and therefore cannot be observed by telescopes using visible light, like the Hubble Space Telescope.

text: The astronomers use observations and data captured by the

text: Spitzer Space Telescope

text: and other telescopes to create a complete picture of the star forming regions within an approximately 1600

text: lightyear

text: radius centered on the

text: Solar System

text: . These regions are partly or completely clouded by

text: interstellar dust

text: and therefore cannot be observed by telescopes using visible light, like the

text: Hubble Space Telescope

text: Beagle 2 has a robotic arm known as the Payload Adjustable Workbench (PAW), designed to be extended after landing. The arm is 109 cm long when fully extended, and it can reach about 70 cm to the nearest rocks.  The PAW contains a pair of stereo cameras, a microscope (with a 6 micrometre resolution), a Mössbauer spectrometer, an X-ray spectrometer, a drill for collecting rock samples and a spot lamp. Rock samples were to be passed by the PAW into a mass spectrometer and gas chromatograph in the body of the lander - the GAP (Gas Analysis Package), to measure the relative proportions of different isotopes of carbon and methane. Since carbon is thought to be the basis of all life, these readings could have revealed whether the samples contained the remnants of living organisms. Atmospheric methane is another signature of existing life, although geological processes can also be a source.

text: Beagle 2 has a robotic arm known as the Payload Adjustable Workbench (PAW), designed to be extended after landing. The arm is 109 cm long when fully extended, and it can reach about 70 cm to the nearest rocks.  The PAW contains a pair of

text: stereo

text: cameras, a

text: microscope

text: (with a 6

text: micrometre

text: resolution), a

text: Mössbauer spectrometer

text: , an

text: X-ray spectrometer

text: , a drill for collecting rock samples and a spot lamp. Rock samples were to be passed by the PAW into a

text: mass spectrometer

text: and

text: gas chromatograph

text: in the body of the lander - the GAP (Gas Analysis Package), to measure the relative proportions of different

text: isotopes of carbon

text: and

text: methane

text: . Since carbon is thought to be the basis of all life, these readings could have revealed whether the samples contained the remnants of living organisms. Atmospheric methane is another signature of existing life, although geological processes can also be a source.

text: Within a few decades, the reflecting telescope was invented, which used mirrors to collect and focus the light. In the 20th century many new types of telescopes were invented, including radio telescopes in the 1930s and infrared telescopes in the 1960s. The word telescope now refers to a wide range of instruments capable of detecting different regions of the electromagnetic spectrum, and in some cases other types of detectors.

text: Within a few decades, the

text: reflecting telescope

text: was invented, which used mirrors to collect and focus the light. In the 20th century many new types of telescopes were invented, including

text: radio telescopes

text: in the 1930s and

text: infrared telescopes

text: in the 1960s. The word telescope now refers to a wide range of instruments capable of detecting different regions of the

text: electromagnetic spectrum

text: , and in some cases other types of detectors.

text: The Kepler team's scientists conducted follow-up observations to confirm or reject the planetary nature of the detected object. To do so, they used the Keck 1 telescope at the W.M. Keck Observatory in Hawaii; the Shane and Hale telescopes in California; telescopes at the WIYN (including MMT) and Whipple observatories in Arizona; Nordic Optical Telescope in the Canary Islands; the Hobby-Eberly and Harlan J. Smith telescopes in Texas; and NASA's Spitzer Space Telescope. Because Kepler-11g orbits its star at a far greater distance than the inner five planets, fewer transits were observed, and radial velocity (the observation of a Doppler effect) interactions could not be easily discerned. As with the discovery of Kepler-9d, the Kepler team ran the information through numerous models to see if Kepler-11g's light curve could fit the profile of some other object, including an eclipsing binary star in the background that may have contaminated the data. The probability that Kepler-11g is not a planet but instead a false positive was determined to be 0.18%, effectively confirming its existence.

text: The Kepler team's scientists conducted follow-up observations to confirm or reject the planetary nature of the detected object. To do so, they used the Keck 1 telescope at the

text: W.M. Keck Observatory

text: in Hawaii; the

text: Shane

text: and

text: Hale

text: telescopes in California; telescopes at the

text: WIYN

text: (including

text: MMT

text: ) and

text: Whipple

text: observatories in Arizona;

text: Nordic Optical Telescope

text: in the Canary Islands; the

text: Hobby-Eberly

text: and

text: Harlan J. Smith

text: telescopes in Texas; and NASA's

text: Spitzer Space Telescope

text: . Because Kepler-11g orbits its star at a far greater distance than the inner five planets, fewer transits were observed, and

text: radial velocity

text: (the observation of a

text: Doppler effect

text: ) interactions could not be easily discerned. As with the discovery of

text: , the Kepler team ran the information through numerous models to see if Kepler-11g's light curve could fit the profile of some other object, including an

text: eclipsing binary

text: star in the background that may have contaminated the data. The probability that Kepler-11g is not a planet but instead a

text: false positive

text: was determined to be 0.18%, effectively confirming its existence.

text: Paul Kalas and collaborators confirmed the sighting. They had time on the Keck II telescope in Hawaii, and had been planning to observe Fomalhaut b, but they spent some of their time looking at the Jupiter impact. Infrared observation by Keck and the NASA Infrared Telescope Facility (IRTF) at Mauna Kea showed a bright spot where the impact took place, indicating the impact warmed a 190 million square km area of the lower atmosphere at 305 W, 57 S near Jupiter's south pole.

text: Paul Kalas

text: and collaborators confirmed the sighting. They had time on the

text: Keck II

text: telescope in

text: Hawaii

text: , and had been planning to observe

text: Fomalhaut b

text: , but they spent some of their time looking at the Jupiter impact. Infrared observation by Keck and the

text: NASA Infrared Telescope Facility

text: (IRTF) at Mauna Kea showed a bright spot where the impact took place, indicating the impact warmed a 190 million square km area of the lower atmosphere at 305 W, 57 S near Jupiter's south pole.

text: In 1871, Helmholtz moved from Heidelberg to Berlin to become a professor in physics. He became interested in electromagnetism and the Helmholtz equation is named for him.  Although he did not make major contributions to this field, his student Heinrich Rudolf Hertz became famous as the first to demonstrate electromagnetic radiation. Oliver Heaviside criticised Helmholtz's electromagnetic theory because it allowed the existence of longitudinal waves.  Based on work on Maxwell's equations, Heaviside pronounced that longitudinal waves could not exist in a vacuum or a homogeneous medium.  Heaviside did not note, however, that longitudinal electromagnetic waves can exist at a boundary or in an enclosed space.

text: In 1871, Helmholtz moved from Heidelberg to Berlin to become a professor in physics. He became interested in

text: electromagnetism

text: and the

text: Helmholtz equation

text: is named for him.  Although he did not make major contributions to this field, his student

text: Heinrich Rudolf Hertz

text: became famous as the first to demonstrate

text: electromagnetic radiation

text: Oliver Heaviside

text: criticised Helmholtz's electromagnetic theory because it allowed the existence of

text: longitudinal wave

text: s.  Based on work on

text: Maxwell's equations

text: , Heaviside pronounced that longitudinal waves could not exist in a vacuum or a homogeneous medium.  Heaviside did not note, however, that longitudinal electromagnetic waves can exist at a boundary or in an enclosed space.

text: The Bohyeon Mountain Starlight Festival takes place in summer and is centered in the Bohyeon Mountain Observatory, which houses the third-largest telescope in Korea.  In late summer, the Grape Festival takes place, hosting events such as the Miss Grape contest and a grape-eating competition.  Yeongcheon is also well known for its Herbal Medicine Festival, which takes place in October and hosts traditional singing and lots of herbs.

text: The pioneering work of Galileo Galilei in the application of the telescope to astronomical observation met with rejection from influential sceptics. They denied the truth of his most startling reports, such as that there were mountains on the moon and satellites around Jupiter. In particular some prominent philosophers, most  notoriously the highly respected Cesare Cremonini, refused to look through the telescope, arguing in effect that the instrument might have introduced artefacts producing illusions of mountains or satellites invisible to the unencumbered eye. To neglect such possibilities amounted to underdetermination in which argument for optical artefacts could be urged as being of merit equal to arguments for observation of new celestial effects, whether the latter were more parsimonious or not. On a similar principle in modern times a prevalent view is that extraordinary claims demand extraordinary proof.

text: The pioneering work of

text: Galileo Galilei

text: in the application of the

text: telescope

text: to astronomical observation met with rejection from influential sceptics. They denied the truth of his most startling reports, such as that there were

text: mountains on the moon

text: and

text: satellite

text: s around Jupiter. In particular some prominent philosophers, most  notoriously the highly respected

text: Cesare Cremonini

text: , refused to look through the telescope, arguing in effect that the instrument might have introduced

text: artefacts

text: producing illusions of mountains or satellites invisible to the unencumbered eye. To neglect such possibilities amounted to

text: underdetermination

text: in which argument for optical artefacts could be urged as being of merit equal to arguments for observation of new celestial effects, whether the latter were more parsimonious or not. On a similar principle in modern times a prevalent view is that

text: extraordinary claims demand extraordinary proof

text: The oldest form of astronomy, optical or visible-light astronomy extends from approximately 400 to 700 nm. Positioning an optical telescope in space means that the telescope does not see any atmospheric effects (see astronomical seeing), providing higher resolution images. Optical telescopes are used to look at stars, galaxies, planetary nebulae and protoplanetary disks, amongst many other things.

text: The oldest form of astronomy, optical or visible-light astronomy extends from approximately 400 to 700

text: nm

text: . Positioning an optical telescope in space means that the telescope does not see any atmospheric effects (see

text: astronomical seeing

text: ), providing higher resolution images. Optical telescopes are used to look at

text: star

text: s,

text: galaxies

text: planetary nebula

text: e and

text: protoplanetary disk

text: s, amongst many other things.

text: The Bruny Island Radio Spectrometer was one of the first attempts for a terrestrial radio telescope operating at frequencies lower than 20 MHz, and systems demonstrated in BIRS would eventually be integrated into other radio spectrometers. The Green Bank Solar Radio Burst Spectrometer was designed to use a similar spectrometer and data processing unit to BIRS. The Long Wavelength Array (LWA) was 'inspired by Bill Erickson's historical legacy' and BIRS is considered a predecessor to LWA according to the University of New Mexico.

text: The Bruny Island Radio Spectrometer was one of the first attempts for a terrestrial radio telescope operating at frequencies lower than 20 MHz, and systems demonstrated in BIRS would eventually be integrated into other radio spectrometers. The Green Bank Solar Radio Burst Spectrometer was designed to use a similar spectrometer and data processing unit to BIRS. The

text: Long Wavelength Array

text: (LWA) was 'inspired by Bill Erickson's historical legacy' and BIRS is considered a predecessor to LWA according to the University of New Mexico.

text: The speed calculated for electromagnetic waves, which could be predicted from experiments on charges and currents, exactly matches the speed of light; indeed, light is one form of electromagnetic radiation (as are X-rays, radio waves, and others). Maxwell understood the connection between electromagnetic waves and light in 1861, thereby unifying the theories of electromagnetism and optics.

text: The speed calculated for electromagnetic waves, which could be predicted from experiments on charges and currents, exactly matches the

text: speed of light

text: ; indeed,

text: light

text: is one form of

text: electromagnetic radiation

text: (as are

text: X-ray

text: s,

text: radio wave

text: s, and others). Maxwell understood the connection between electromagnetic waves and light in 1861, thereby unifying the theories of

text: electromagnetism

text: and

text: optics

text: As a young adult, Ikeya lived near Lake Hamana and worked for a piano factory. During his employment there, he made his first discovery in 1963 with an optical telescope he built himself within his low budget. Two years later, he discovered the bright comet C/1965 S1 (Ikeya-Seki).  Ikeya discovered  the periodic comet 153P/Ikeya-Zhang on February 1, 2002 in Mori, Hokkaidō. The asteroid 4037 Ikeya is also named after Ikeya.  On November 13, 2010, Ikeya discovered the P/2010 V1 (Ikeya-Murakami) comet using an optical telescope, rare in an era with access to digital imaging technology.

text: As a young adult, Ikeya lived near

text: Lake Hamana

text: and worked for a piano factory. During his employment there, he made his first discovery in 1963 with an optical telescope he built himself within his low budget. Two years later, he discovered the bright comet

text: C/1965 S1

text: (Ikeya-Seki).  Ikeya discovered  the periodic comet

text: on February 1, 2002 in

text: Mori, Hokkaidō

text: . The

text: asteroid

text: 4037 Ikeya

text: is also named after Ikeya.  On November 13, 2010, Ikeya discovered the

text: P/2010 V1

text: (Ikeya-Murakami) comet using an optical telescope, rare in an era with access to digital imaging technology.

text: Color rendering index is a metric for describing the appearance of a source and whether or not it is considered pleasing. The color rendering index of a given source is a measure of that source's ability to faithfully reproduce colors of an object. Older light sources, like candles or incandescent light bulbs produce spectrums of electromagnetic energy that closely resemble Plankian black bodies; they look much like natural sources. Many modern fluorescent lamps or LED light bulbs have spectrums that do not match those of Plankian blackbodies and are considered unnatural. Therefore, the way that they render the perceived colors of an environment may be also considered unnatural. While these newer sources can still achieve correlated color temperatures and illuminance levels that are within the comfortable region of the Kruithof curve, variability in their color rendering indices may cause these sources to ultimately be displeasing.

text: Color rendering index is a

text: metric

text: for describing the

text: appearance

text: of a source and whether or not it is considered pleasing. The color rendering index of a given source is a measure of that source's ability to faithfully reproduce colors of an object. Older light sources, like

text: candle

text: s or incandescent light bulbs produce spectrums of

text: electromagnetic

text: energy that closely resemble Plankian black bodies; they look much like natural sources. Many modern fluorescent lamps or

text: LED light bulbs

text: have spectrums that do not match those of Plankian blackbodies and are considered unnatural. Therefore, the way that they render the perceived colors of an environment may be also considered unnatural. While these newer sources can still achieve correlated color temperatures and illuminance levels that are within the comfortable region of the Kruithof curve, variability in their color rendering indices may cause these sources to ultimately be displeasing.

text: Astronomers use many radio telescopes to look up at objects such as pulsars in our own Galaxy and at distant radio galaxies up to about half the distance of the observable sphere of our Universe. The use of radio frequencies for communication creates pollution from the point of view of astronomers, at best, creating noise or, at worst, totally blinding the astronomical community for certain types of observations of very faint objects. As more and more frequencies are used for communication, astronomical observations are getting more and more difficult.

text: Astronomers use many

text: radio telescope

text: s to look up at objects such as

text: pulsar

text: s in our own

text: Galaxy

text: and at distant

text: radio galaxies

text: up to about half the distance of the observable sphere of our

text: Universe

text: . The use of radio frequencies for communication creates pollution from the point of view of astronomers, at best, creating noise or, at worst, totally blinding the astronomical community for certain types of observations of very faint objects. As more and more frequencies are used for communication, astronomical observations are getting more and more difficult.

text: On the third day of the mission, Discovery's seven-member crew conducted the first of four spacewalks (also called Extra-vehicular Activities or "EVAs") to remove two older instruments and install two new astronomy instruments, as well as perform other servicing tasks. The two older instruments being replaced were the Goddard High Resolution Spectrograph and the Faint Object Spectrograph, exchanged for the Space Telescope Imaging Spectrograph (STIS) and the Near Infrared Camera and Multi-Object Spectrometer (NICMOS), respectively.

text: On the third day of the mission, Discovery's seven-member crew conducted the first of four spacewalks (also called

text: Extra-vehicular Activities

text: or "EVAs") to remove two older instruments and install two new astronomy instruments, as well as perform other servicing tasks. The two older instruments being replaced were the

text: Goddard High Resolution Spectrograph

text: and the

text: Faint Object Spectrograph

text: , exchanged for the

text: Space Telescope Imaging Spectrograph

text: (STIS) and the

text: (NICMOS), respectively.

text: The '40-inch (1-meter) "Ritchey Telescope" is also an equatorially driven, fork-mounted telescope. The Ritchey is the original Station telescope which was moved from USNO in Washington in 1955. It is also the first R-C telescope ever made from that famous optical prescription, and was coincidentally the last telescope built by George Ritchey himself. The telescope is still in operation after a half century of astronomy at NOFS. It performs key quasar-based reference frame operations, transit detections of exoplanets, Vilnius photometry, M-Dwarf star analysis, dynamical system analysis, reference support to orbiting space object information, horizontal parallax guide support to NPOI, and it performs photometric operations support to astrometric studies (along with its newer siblings). The 40-inch also can carry a number of liquid Nitrogen-cooled cameras, a coronagraph, and a nine-stellar magnitude neutral density spot focal plane array camera, through which star positions are cross-checked before use in fundamental NPOI reference frame astrometry. This telescope is also used to test internally developed optical adaptive optics (AO) systems, using tip-tilt and deformable mirror optics. The Shack-Hartmann AO system allows for corrections of the wavefront's aberrations caused by scintillation (degraded seeing), to higher Zernike polynomials. AO systems at NOFS will migrate to the 1.55m and 1.8m telescopes for future incorporation there.

text: The '40-inch (1-meter) "Ritchey Telescope" is also an equatorially driven, fork-mounted telescope. The Ritchey is the original Station telescope which was moved from USNO in Washington in 1955. It is also the first R-C telescope ever made from that famous optical prescription, and was coincidentally the last telescope built by George Ritchey himself. The telescope is still in operation after a half century of astronomy at NOFS. It performs key

text: quasar

text: -based

text: reference frame

text: operations,

text: transit

text: detections of

text: exoplanet

text: s,

text: Vilnius photometry

text: M-Dwarf star

text: analysis,

text: dynamical system analysis

text: , reference support to

text: orbiting space object information

text: , horizontal parallax guide support to

text: NPOI

text: , and it performs

text: photometric operations

text: support to astrometric studies (along with its newer siblings). The 40-inch also can carry a number of

text: liquid Nitrogen

text: -cooled cameras, a

text: coronagraph

text: , and a nine-

text: stellar magnitude

text: neutral density spot focal plane array camera, through which star positions are cross-checked before use in fundamental NPOI reference frame astrometry. This telescope is also used to test internally developed optical

text: adaptive optics

text: (AO) systems, using

text: tip-tilt

text: and

text: deformable mirror

text: optics. The

text: Shack-Hartmann

text: AO system allows for corrections of the

text: wavefront

text: 's

text: aberrations

text: caused by scintillation (

text: degraded seeing

text: ), to higher

text: Zernike polynomials

text: . AO systems at NOFS will migrate to the 1.55m and 1.8m telescopes for future incorporation there.

text: Two ultraviolet spectrometers were involved in this experiment, one to measure UV absorption, the other to sense UV emissions. The occultation spectrometer scanned Mercury's edge as it passed in front of the Sun, and detected whether solar ultraviolet radiation was absorbed at certain wavelengths, which would indicate the presence of gas particles, and therefore an atmosphere. The airglow spectrometer detected extreme ultraviolet radiation emanating from atoms of gaseous hydrogen, helium, carbon, oxygen, neon, and argon. Unlike the occultation spectrometer, it did not require backlighting from the Sun, and could move along with the rotatable scan platform on the spacecraft. The experiment's most important goal was to ascertain whether Mercury had an atmosphere, but would also gather data at Earth and Venus and study the interstellar background radiation.

text: Two ultraviolet

text: spectrometers

text: were involved in this experiment, one to measure UV absorption, the other to sense UV emissions. The occultation spectrometer scanned Mercury's edge as it passed in front of the Sun, and detected whether solar ultraviolet radiation was absorbed at certain wavelengths, which would indicate the presence of gas particles, and therefore an atmosphere. The

text: airglow

text: spectrometer detected extreme ultraviolet radiation emanating from atoms of gaseous hydrogen, helium, carbon, oxygen, neon, and argon. Unlike the occultation spectrometer, it did not require backlighting from the Sun, and could move along with the rotatable scan platform on the spacecraft. The experiment's most important goal was to ascertain whether Mercury had an atmosphere, but would also gather data at Earth and Venus and study the interstellar background radiation.

text: Shroud of Shadow is a novel written by Gael Baudino in 1994.  It is the third in the Strands of Starlight tetralogy.  The other novels are Strands of Starlight, Maze of Moonlight, and Strands of Sunlight.

text: Shroud of Shadow is a novel written by

text: Gael Baudino

text: in 1994.  It is the third in the

text: Strands of Starlight

text: tetralogy

text: .  The other novels are

text: Strands of Starlight

text: Maze of Moonlight

text: , and

text: Strands of Sunlight

text: The IRAS infrared space telescope detected an excess of infrared radiation from the star, indicating a possible circumstellar disk. Using this data and later observations with the Spitzer Space Telescope, Infrared Space Observatory and the Atacama Pathfinder Experiment implies that the disk is located at 25 Astronomical units and has a thin (0.02 AU), ring-like structure, with the sharp cutoff in the disk suggesting a planet. Additionally, a much longer wavelength suggests the existence of a much wider belt of material, analogous to the Kuiper belt. The hierarchy of this system is somewhat reminiscent of that of Epsilon Eridani, without an inner asteroid belt.

text: The

text: IRAS

text: infrared

text: space

text: telescope

text: detected an

text: excess of infrared radiation

text: from the star, indicating a possible circumstellar disk. Using this data and later observations with the

text: Spitzer Space Telescope

text: Infrared Space Observatory

text: and the

text: Atacama Pathfinder Experiment

text: implies that the disk is located at 25

text: Astronomical unit

text: s and has a thin (0.02 AU), ring-like structure, with the sharp cutoff in the disk suggesting a planet. Additionally, a much longer wavelength suggests the existence of a much wider belt of material, analogous to the

text: Kuiper belt

text: . The hierarchy of this system is somewhat reminiscent of that of

text: Epsilon Eridani

text: , without an inner asteroid belt.

text: Although most mirrors are designed to reflect visible light, surfaces reflecting other forms of electromagnetic radiation are also called "mirrors". The mirrors for other ranges of electromagnetic waves are used inoptics and astronomy. Mirrors for radio waves (sometimes known as reflectors) are important elements of radio telescopes.

text: Although most mirrors are designed to reflect visible light, surfaces reflecting other forms of electromagnetic radiation are also called "mirrors". The mirrors for other ranges of

text: electromagnetic waves

text: are used inoptics and

text: astronomy

text: . Mirrors for radio waves (sometimes known as reflectors) are important elements of

text: radio telescope

text: s.

text: A telescope is an optical instrument that aids in the observation of remote objects by collecting electromagnetic radiation (such as visible light). The first known practical telescopes were invented in the Netherlands at the beginning of the 1600s, by using glass lenses. They found use in both terrestrial applications and astronomy.

text: A telescope is an optical instrument that aids in the observation of remote objects by collecting

text: electromagnetic radiation

text: (such as

text: visible light

text: ). The first known practical telescopes were invented in the

text: Netherlands

text: at the beginning of the 1600s, by using glass lenses. They found use in both terrestrial applications and astronomy.

text: Telescopes that observed the occultation included the Danish National Telescope and the survey telescope TRAPPIST of La Silla Observatory, the PROMPT Telescopes (Cerro Tololo Inter-American Observatory), the Brazilian Southern Astrophysical Research Telescope or SOAR (Cerro Pachón), the 0.45-metre ASH telescope (Cerro Burek), and those of the State University of Ponta Grossa Observatory, the Polo Astronomical Pole Casimiro Montenegro Filho (at the Itaipu Technological Park Foundation, in Foz do Iguaçu), the Universidad Católica Observatory of the Pontifical Catholic University of Chile (Santa Martina) and several at Estación Astrofísica de Bosque Alegre, operated by the National University of Córdoba. Negative detections were recorded by El Catalejo Observatory (Santa Rosa, La Pampa, Argentina), the 20-inch Planewave telescope (part of the Searchlight Observatory Network) at San Pedro de Atacama, Chile and the OALM instrument at Los Molinos Astronomical Observatory in Uruguay. Some of the other participating instruments were those at the National Observatory in Rio de Janeiro, the Valongo Observatory (at the Federal University of Rio de Janeiro), the Oeste do Paraná State University Observatory or Unioeste (in the state of Paraná), the Pico dos Dias Observatory or OPL (in Minas Gerais) and the São Paulo State University (UNESP – Guaratinguetá) in São Paulo,

text: Telescopes that observed the occultation included the Danish National Telescope and the survey telescope

text: TRAPPIST

text: of

text: La Silla Observatory

text: , the

text: PROMPT Telescopes

text: Cerro Tololo Inter-American Observatory

text: ), the Brazilian

text: Southern Astrophysical Research Telescope

text: or SOAR (

text: Cerro Pachón

text: ), the 0.45-metre ASH telescope (

text: Cerro Burek

text: ), and those of the State University of Ponta Grossa Observatory, the Polo Astronomical Pole Casimiro Montenegro Filho (at the Itaipu Technological Park Foundation, in Foz do Iguaçu), the Universidad Católica Observatory of the

text: Pontifical Catholic University of Chile

text: (Santa Martina) and several at Estación Astrofísica de Bosque Alegre, operated by the

text: National University of Córdoba

text: . Negative detections were recorded by El Catalejo Observatory (Santa Rosa, La Pampa, Argentina), the 20-inch Planewave telescope (part of the Searchlight Observatory Network) at San Pedro de Atacama, Chile and the OALM instrument at Los Molinos Astronomical Observatory in Uruguay. Some of the other participating instruments were those at the National Observatory in Rio de Janeiro, the

text: Valongo Observatory

text: (at the Federal University of Rio de Janeiro), the Oeste do Paraná State University Observatory or Unioeste (in the state of Paraná), the

text: Pico dos Dias Observatory

text: or OPL (in Minas Gerais) and the São Paulo State University (UNESP – Guaratinguetá) in São Paulo,

text: The museum gives visitors the chance to take a look back in time to the nineteenth century to see how the people in that century were transported. There are examples of the different types of vehicles there. For example, there are funeral wagons, carts, pleasure vehicles, carts a milkman would have used and a lot more. There are docents who dress up in the Victorian American clothing from that time.  It gives the visitors the feeling that they are going back in time. This museum really gives visitors a chance to look into the life of a person from the 19th century. The Thrasher Carriage Museum was named after James Richard Thrasher. He lived in Midland, Maryland and was born in 1913.  Mr. Thrasher developed a love of horses at a very early age which led him into collecting carriages and participating in various parades just to show off his collection. He died in 1987.Thrasher Carriage Museum

text: Extremely low frequency (ELF) is the ITU designation for electromagnetic radiation (radio waves) with frequencies from 3 to 30 Hz, and corresponding wavelengths of 100,000 to 10,000 kilometers, respectively. In atmospheric science, an alternative definition is usually given, from 3 Hz to 3 kHz. In the related magnetosphere science, the lower frequency electromagnetic oscillations (pulsations occurring below ~3 Hz) are considered to lie in the ULF range, which is thus also defined differently from the ITU radio bands.

text: Extremely low frequency (ELF) is the

text: ITU

text: designation for

text: electromagnetic radiation

text: radio wave

text: s) with

text: frequencies

text: from 3 to 30

text: Hz

text: , and corresponding

text: wavelength

text: s of 100,000 to 10,000 kilometers, respectively. In

text: atmospheric science

text: , an alternative definition is usually given, from 3 Hz to 3 kHz. In the related

text: magnetosphere

text: science, the lower frequency electromagnetic oscillations (pulsations occurring below ~3 Hz) are considered to lie in the

text: ULF

text: range, which is thus also defined differently from the

text: ITU radio bands

text: Exoplanetary Circumstellar Environments and Disk Explorer (EXCEDE) is a proposed space telescope for NASA's Explorer program to observe circumstellar protoplanetary and debris discs and study planet formation around nearby (within 100 parsecs) stars of spectral classes M to B. The spacecraft will use a 70 centimeter diameter telescope-mounted coronagraph called PIAA (Phase Induced Amplitude Apodized Coronagraph) to suppress starlight in order to be able to detect fainter radiation of circumstellar dust. Characterizing constitution of such disks would provide clues for planetary formation (mostly in habitable zones), while already existing exoplanets can be detected through their interaction with dust disk. The project's principal investigator is Dr. Glenn Schneider.

text: Exoplanetary Circumstellar Environments and Disk Explorer (EXCEDE) is a proposed

text: space telescope

text: for

text: NASA

text: 's

text: Explorer program

text: to observe circumstellar

text: protoplanetary

text: and

text: debris disc

text: s and study

text: planet formation

text: around nearby (within 100

text: parsec

text: s)

text: star

text: s of

text: spectral class

text: es M to B. The spacecraft will use a 70 centimeter diameter telescope-mounted

text: coronagraph

text: called PIAA (Phase Induced Amplitude Apodized Coronagraph) to suppress starlight in order to be able to detect fainter radiation of circumstellar dust. Characterizing constitution of such disks would provide clues for planetary formation (mostly in

text: habitable zone

text: s), while already existing

text: exoplanet

text: s can be detected through their interaction with dust disk. The project's principal investigator is

text: Dr. Glenn Schneider

text: With support from ground-based observations done using the submillimeter bolometer cameras on the Atacama Pathfinder Experiment radio telescope (November 29, 2009) and the Mayall (Kitt Peak) and Magellan telescopes (December 4, 2009), it was determined that the patch looks black not because it is an extremely dense pocket of gas, but because it is truly empty. The exact cause of this phenomenon is still being investigated, although it has been hypothesized that narrow jets of gas from some of the young stars in the region punctured the sheet of dust and gas, as well as, powerful radiation from a nearby mature star may have helped to create the hole. Researchers believe this discovery should lead to a better understanding of the entire star forming process.

text: With support from ground-based observations done using the

text: submillimeter

text: bolometer

text: cameras on the

text: Atacama Pathfinder Experiment

text: radio telescope

text: (November 29, 2009) and the

text: Mayall (Kitt Peak)

text: and

text: Magellan

text: telescopes (December 4, 2009), it was determined that the patch looks black not because it is an extremely dense pocket of gas, but because it is truly empty. The exact cause of this phenomenon is still being investigated, although it has been hypothesized that narrow jets of gas from some of the young stars in the region punctured the sheet of dust and gas, as well as, powerful radiation from a nearby mature star may have helped to create the hole. Researchers believe this discovery should lead to a better understanding of the entire star forming process.

text: Synta Technology Corporation was founded in Taoyuan, Taiwan around 1980 by mechanical and optical designer Dazhong Shen, (a/k/a David Shen). In 1992 Synta, along with Canadianinvestors, established the Suzhou Synta Optical Technology Co., Ltd in Suzhou (Jiangsu), China (outside Shanghai) as a manufacturing facility producing telescopes for Celestron and Tasco. In 1999 Synta established the brand Sky-Watcher, with head offices in Richmond, British Columbia, to distributed in Canada and Europe, and in the late 2000s, to the USA market. In 2005 Synta purchased the struggling US based Celestron Corporation, continuing its manufacture of Celestron products and running the US facilities through SW Technology Corporation, Synta's Delaware-based holding company. Synta also distributes under the Acuter name and manufactures products for Orion Telescopes & Binoculars.

text: Synta Technology Corporation was founded in Taoyuan, Taiwan around 1980 by mechanical and optical designer Dazhong Shen, (a/k/a David Shen). In 1992 Synta, along with Canadianinvestors, established the

text: Suzhou Synta Optical Technology Co., Ltd

text: in

text: Suzhou (Jiangsu)

text: , China (outside Shanghai) as a manufacturing facility producing telescopes for

text: Celestron

text: and

text: Tasco

text: . In 1999 Synta established the brand

text: Sky-Watcher

text: , with head offices in

text: Richmond, British Columbia

text: , to distributed in Canada and Europe, and in the late 2000s, to the USA market. In 2005 Synta purchased the struggling US based Celestron Corporation, continuing its manufacture of Celestron products and running the US facilities through SW Technology Corporation, Synta's Delaware-based holding company. Synta also distributes under the Acuter name and manufactures products for

text: Orion Telescopes & Binoculars

text: The Wave Optics Module provides dedicated tools for electromagnetic wave propagation in linear and nonlinear optical media. The module can be used to model high-frequency electromagnetic wave simulations in either frequency- or time-domain in optical structures.

text: The telescope is owned and operated by LCOGT. This telescope and its sister telescope Faulkes Telescope South are used by research and education groups around the globe. The Faulkes Telescope Project is one such group which provides observing time (awarded by LCOGT) for educational projects for UK schools and amateur astronomers.

text: The telescope is owned and operated by

text: LCOGT

text: Faulkes Telescope South

text: are used by research and education groups around the globe. The

text: Faulkes Telescope Project

text: is one such group which provides observing time (awarded by LCOGT) for educational projects for UK schools and amateur astronomers.

text: La Silla also hosts several national and project telescopes not operated by ESO. Among them are the Swiss Euler Telescope, the Danish National Telescope and the REM, TRAPPIST and TAROT telescopes.

text: OBSERVATORY: It is the place where we can see the space with special machine called telescope. It also helps to know the placements, formations and changes occurred in the galaxy.Telescope: It is the device which is used to see the galaxy environment. Asia’s 1st largest telescope is started on May 2, 1982 of size 90 inches is established at ‘Kawali’ in Bangalore. The 2nd largest telescope of size 48 inches is started in the year 1974 at Rangapur in Hyderabad. This Rangapur Observatory was supported by Osmania University. The Village Rangapur is also called as ‘Chukkapurpatnam’.

text: The Yebes Observatory with its RT40m radio telescope is located in Yebes.

text: The

text: Yebes Observatory

text: with its

text: RT40m radio telescope

text: is located in Yebes.

text: Celestron telescopes offer the option to use computerized location of astronomical objects as well as mounts that will aim themselves at any given object, a technology known as GoTo. Most of the computerized models can be connected to an external computer via an RS-232 cable, allowing them to be controlled by a third-party astronomy program or connected to a GPS receiver. GPS receivers are useful for programming the telescope with its precise location and time, which allows the telescope to point more accurately.

text: Celestron telescopes offer the option to use computerized location of astronomical objects as well as mounts that will aim themselves at any given object, a technology known as GoTo. Most of the computerized models can be connected to an external computer via an

text: cable, allowing them to be controlled by a third-party astronomy program or connected to a

text: GPS

text: receiver. GPS receivers are useful for programming the telescope with its precise location and time, which allows the telescope to point more accurately.

text: Total internal reflection is used as a means of focusing waves that cannot effectively be reflected by common means. X-ray telescopes are constructed by creating a converging "tunnel" for the waves. As the waves interact at low angle with the surface of this tunnel they are reflected toward the focus point (or toward another interaction with the tunnel surface, eventually being directed to the detector at the focus). A conventional reflector would be useless as the X-rays would simply pass through the intended reflector.

text: Total internal reflection is used as a means of focusing waves that cannot effectively be reflected by common means.

text: X-ray telescope

text: s are constructed by creating a converging "tunnel" for the waves. As the waves interact at low angle with the surface of this tunnel they are reflected toward the focus point (or toward another interaction with the tunnel surface, eventually being directed to the detector at the focus). A conventional reflector would be useless as the X-rays would simply pass through the intended reflector.

text: Electromagnetic waves behave in this same way, although it is slightly harder to see. Electromagnetic waves are also two-dimensional transverse waves. Ray theory does not describe phenomena such as interference and diffraction, which require wave theory (involving the phase of the wave).You can think of a ray of light, in optics, as an idealized narrow beam of electromagnetic radiation. Rays are used to model the propagation of light through an optical system, by dividing the real light field up into discrete rays that can be computationally propagated through the system by the techniques of ray tracing.             A light ray is a line or curve that is perpendicular to the light's wavefronts (and is therefore collinear with the wave vector). Light rays bend at the interface between two dissimilar media and may be curved in a medium in which the refractive index changes. Geometric optics describes how rays propagate through an optical system.

text: Electromagnetic waves behave in this same way, although it is slightly harder to see. Electromagnetic waves are also two-dimensional transverse waves. Ray theory does not describe phenomena such as interference and diffraction, which require wave theory (involving the phase of the wave).You can think of a

text: ray of light

text: , in

text: optics

text: , as an idealized narrow beam of electromagnetic radiation. Rays are used to model the propagation of

text: light

text: through an optical system, by dividing the real light field up into discrete rays that can be computationally propagated through the system by the techniques of

text: ray tracing

text: .             A light ray is a line or curve that is perpendicular to the light's wavefronts (and is therefore collinear with the wave vector). Light rays bend at the interface between two dissimilar media and may be curved in a medium in which the

text: refractive index

text: changes. Geometric optics describes how rays propagate through an optical system.

text: A study reported in June 2015, using images from the Hubble Space Telescope and the Very Large Telescope taken between 1994 and 2014, shows that the emissions from the clumps of matter making up the rings are fading as the clumps are destroyed by the shock wave. It is predicted the ring will fade away between 2020 and 2030. As the shock wave passes the circumstellar ring it will trace the history of mass loss of the supernova's progenitor and provide useful information for discriminating among various models for the progenitor of SN 1987A.

text: A study reported in June 2015, using images from the Hubble Space Telescope and the

text: Very Large Telescope

text: taken between 1994 and 2014, shows that the emissions from the clumps of matter making up the rings are fading as the clumps are destroyed by the shock wave. It is predicted the ring will fade away between 2020 and 2030. As the shock wave passes the circumstellar ring it will trace the history of mass loss of the supernova's progenitor and provide useful information for discriminating among various models for the progenitor of SN 1987A.

text: In the early 18th century, Jai Singh II of Amber invited European Jesuit astronomers to one of his Yantra Mandir observatories, who had bought back the astronomical tables compiled by Philippe de La Hire in 1702. After examining La Hire's work, Jai Singh concluded that the observational techniques and instruments used in European astronomy were inferior to those used in India at the time - it is uncertain whether he was aware of the Copernican Revolution via the Jesuits. He did, however, employ the use of telescopes. In his Zij-i Muhammad Shahi, he states: "telescopes were constructed in my kingdom and using them a number of observations were carried out".

text: In the early 18th century,

text: Jai Singh II of Amber

text: invited European

text: Jesuit

text: astronomers to one of his

text: Yantra Mandir

text: observatories, who had bought back the astronomical tables compiled by

text: Philippe de La Hire

text: in 1702. After examining La Hire's work, Jai Singh concluded that the observational techniques and instruments used in European astronomy were inferior to those used in India at the time - it is uncertain whether he was aware of the

text: Copernican Revolution

text: via the Jesuits. He did, however, employ the use of

text: telescope

text: s. In his Zij-i Muhammad Shahi, he states: "telescopes were constructed in my kingdom and using them a number of observations were carried out".

text: The electromagnetic spectrum has rigid definitions for "super low frequency", "extremely low frequency", "low frequency" and "medium frequency". Acoustics does not have a similar standard. The terms "low" and "mid" have roughly-defined historical meanings in sonar, because not many frequencies have been used over the decades. However, as more experimental sonars have been introduced, the terms have become muddled.

text: The

text: electromagnetic spectrum

text: has rigid definitions for "super low frequency", "extremely low frequency", "low frequency" and "medium frequency".

text: Acoustics

text: does not have a similar standard. The terms "low" and "mid" have roughly-defined historical meanings in sonar, because not many frequencies have been used over the decades. However, as more experimental sonars have been introduced, the terms have become muddled.

text: Telescopes: Through the Looking Glass presents the technology used to gather information about our Universe. The exhibition shows how these amazing instruments have changed our concepts of the Universe and our place in it. Telescopes: Through the Looking Glass has recently received a new addition that explores the South Pole Telescope. Located at the Amundsen-Scott South Pole Station in Antarctica, this extreme weather instrument was designed to explore light emitted from the Universe billions of years ago.

text: Selected ion monitoring (SIM) is a mass spectrometry scanning mode in which only a limited mass-to-charge ratio range is transmitted/detected by the instrument, as opposed to the full spectrum range. This mode of operation typically results in significantly increased sensitivity. Due to their inherent nature, this technique is most effective—and therefore most common—on quadrupole mass spectrometers and Fourier transform ion cyclotron resonance mass spectrometers.

text: Selected ion monitoring (SIM) is a

text: mass spectrometry

text: scanning mode in which only a limited

text: mass-to-charge ratio

text: range is transmitted/detected by the instrument, as opposed to the full

text: spectrum

text: range. This mode of operation typically results in significantly increased sensitivity. Due to their inherent nature, this technique is most effective—and therefore most common—on

text: quadrupole mass spectrometers

text: and

text: Fourier transform ion cyclotron resonance mass spectrometers

text: Within this organisation he was able to study meteors and asteroids more seriously, and played a central role in the forming of the International Meteor Organisation as the organization formed. Korlević participated in the first International Tunguska Expedition. Motivated by new lines of research raise by this expedition, Korlević set about replacing the Višnjan Observatory's telescope, which had been badly damaged during the Serbian occupation of Croatia and Bosnia. In particular, the telescope was sent to Sarajevo to help the defenders during the Siege of Sarajevo. In 1995 this new telescope produced the first astrometric line, and soon Korlević and his colleagues had discovered previously undiscovered asteroids, a big breakthrough for Croatian astronomy.

text: Within this organisation he was able to study meteors and asteroids more seriously, and played a central role in the forming of the

text: International Meteor Organisation

text: as the organization formed. Korlević participated in the first

text: International Tunguska Expedition

text: . Motivated by new lines of research raise by this expedition, Korlević set about replacing the

text: Višnjan Observatory

text: 's telescope, which had been badly damaged during the

text: Serbia

text: n occupation of

text: Croatia

text: and

text: Bosnia

text: . In particular, the telescope was sent to

text: Sarajevo

text: to help the defenders during the

text: Siege of Sarajevo

text: . In 1995 this new telescope produced the first

text: astrometric line

text: , and soon Korlević and his colleagues had discovered previously undiscovered asteroids, a big breakthrough for Croatian astronomy.

text: Originally a big hit in early 1975 for Jamaican Stanley Beckford under the name The Starlights (or The Starlights featuring Stanley Beckford), he is often not credited due to the lack of copyright in Jamaica at the time.

text: Originally a big hit in early 1975 for Jamaican

text: Stanley Beckford

text: under the name The Starlights (or The Starlights featuring Stanley Beckford), he is often not credited due to the lack of

text: copyright

text: in

text: Jamaica

text: at the time.

text: A radio telescope is a form of directional radio antenna used in radio astronomy. They differ from optical telescopes in that they operate in the radio frequency portion of the electromagnetic spectrum where they can detect and collect data on radio sources. Radio telescopes are typically large parabolic or dish antenna used singularly or in an array. Karl Guthe Jansky started the field of radio astronomy serendipitous in 1932 when his directional antenna found radio static that he later identified as coming from the Milky Way.

text: A radio telescope is a form of directional radio antenna used in

text: radio astronomy

text: . They differ from optical telescopes in that they operate in the radio frequency portion of the electromagnetic spectrum where they can detect and collect data on radio sources. Radio telescopes are typically large parabolic or dish antenna used singularly or in an array.

text: Karl Guthe Jansky

text: started the field of

text: radio astronomy

text: serendipitous in 1932 when his directional antenna found radio static that he later identified as coming from the

text: Milky Way

text: NASA's series of Great Observatories satellites are four large, powerful space-based astronomical telescopes. Each of the four missions was designed to examine a specific wavelength/energy region of the electromagnetic spectrum (gamma rays, X-rays, visible and ultraviolet light, infrared light) using very different technologies.  Dr. Charles Pellerin, NASA's Director, Astrophysics invented and developed the program. The four Great Observatories were launched between 1990 and 2003, and three remain operational as of 2016.

text: NASA

text: 's series of Great Observatories

text: satellite

text: s are four large, powerful space-based astronomical

text: telescope

text: s. Each of the four missions was designed to examine a specific wavelength/energy region of the

text: electromagnetic spectrum

text: (gamma rays, X-rays, visible and ultraviolet light, infrared light) using very different technologies.  Dr. Charles Pellerin, NASA's Director, Astrophysics invented and developed the program. The four Great Observatories were launched between 1990 and 2003, and three remain operational as of 2016.

text: He has worked on Baksan Underground Scintillator Telescope for a long time. He has been the leader of two experiments carried out on Baksan Telescope: observation of upward-going muons and searches for superheavy magnetic monopoles.

text: A radio telescope is a specialized antenna and radio receiver used to receive radio waves from astronomical radio sources in the sky in radio astronomy. Radio telescopes are the main observing instrument used in radio astronomy, which studies the radio frequency portion of the electromagnetic spectrum emitted by astronomical objects, just as optical telescopes are the main observing instrument used in traditional optical astronomy which studies the light wave portion of the spectrum coming from astronomical objects. Radio telescopes are typically large parabolic ("dish") antennas similar to those employed in tracking and communicating with satellites and space probes.  They may be used singly, or linked together electronically in an array.  Unlike optical telescopes, radio telescopes can be used in the daytime as well as at night.  Since astronomical radio sources such as stars, nebulas and galaxies are very far away, the radio waves coming from them are extremely weak, so radio telescopes require very large antennas to collect enough radio energy to study them, and extremely sensitive receiving equipment.  Radio observatories are preferentially located far from major centers of population to avoid electromagnetic interference (EMI) from radio, television, radar, motor vehicles, and other EMI emitting devices.

text: A radio telescope is a specialized

text: antenna

text: and

text: radio receiver

text: used to receive

text: radio wave

text: s from

text: astronomical radio source

text: s in the sky in

text: radio astronomy

text: . Radio telescopes are the main observing instrument used in radio astronomy, which studies the

text: radio frequency

text: portion of the

text: electromagnetic spectrum

text: emitted by astronomical objects, just as

text: optical telescope

text: s are the main observing instrument used in traditional

text: optical astronomy

text: which studies the

text: light wave

text: portion of the spectrum coming from astronomical objects. Radio telescopes are typically large

text: parabolic

text: ("dish") antennas similar to those employed in tracking and communicating with

text: satellite

text: s and space probes.  They may be used singly, or linked together electronically in an array.  Unlike optical telescopes, radio telescopes can be used in the daytime as well as at night.  Since astronomical radio sources such as

text: star

text: s,

text: nebula

text: s and

text: galaxies

text: are very far away, the radio waves coming from them are extremely weak, so radio telescopes require very large antennas to collect enough radio energy to study them, and extremely sensitive receiving equipment.  Radio

text: observatories

text: are preferentially located far from major centers of population to avoid

text: electromagnetic interference

text: (EMI) from radio,

text: television

text: radar

text: , motor vehicles, and other EMI emitting devices.

text: Some telescopes cannot achieve the theoretical surface brightness of 100%, while some telescopes can achieve it using a very small diameter eyepiece. To find what eyepiece is required to get our minimum magnification we can rearrange the magnification formula, where its now the division of the telescopes focal length over the minimum magnification:

text: Some telescopes cannot achieve the theoretical surface brightness of 100%, while some telescopes can achieve it using a very small diameter

text: eyepiece

text: . To find what

text: eyepiece

text: is required to get our

text: minimum magnification

text: we can rearrange the magnification formula, where its now the division of the telescopes focal length over the

text: minimum magnification

text: Many astronomical objects are not only observable in visible light but also emit radiation at radio wavelengths. Besides observing energetic objects such as pulsars and quasars, radio telescopes are able to "image" most astronomical objects such as galaxies, nebulae, and even radio emissions from planets.

text: Many astronomical objects are not only observable in

text: visible light

text: but also emit

text: radiation

text: at

text: radio wavelengths

text: . Besides observing energetic objects such as

text: pulsar

text: s and

text: quasar

text: s, radio telescopes are able to "image" most astronomical objects such as

text: galaxies

text: nebula

text: e, and even radio emissions from

text: planets

text: In classical physics, light is described as a type of electromagnetic wave. The classical behaviour of the electromagnetic field is described by Maxwell's equations, which predict that the speed c with which electromagnetic waves (such as light) propagate through the vacuum is related to the electric constant ε and the magnetic constant μ by the equation

text: In

text: classical physics

text: , light is described as a type of

text: electromagnetic wave

text: . The classical behaviour of the

text: electromagnetic field

text: is described by

text: Maxwell's equations

text: , which predict that the speed c with which electromagnetic waves (such as light) propagate through the vacuum is related to the

text: electric constant

text: ε and the

text: magnetic constant

text: μ by the equation

text: To achieve higher angular resolution, some infrared telescopes are combined to form astronomical interferometers. The effective resolution of an interferometer is set by the distance between the telescopes, rather than the size of the individual telescopes. When used together with adaptive optics, infrared interferometers, such as two 10 meter telescopes at Keck Observatory or the four 8.2 meter telescopes that make up the Very Large Telescope Interferometer, can achieve high angular resolution.

text: To achieve higher

text: angular resolution

text: , some infrared telescopes are combined to form

text: astronomical interferometer

text: s. The effective resolution of an interferometer is set by the distance between the telescopes, rather than the size of the individual telescopes. When used together with

text: adaptive optics

text: , infrared interferometers, such as two 10 meter telescopes at Keck Observatory or the four 8.2 meter telescopes that make up the

text: Very Large Telescope

text: Interferometer, can achieve high angular resolution.

text: The EPTA uses five European telescopes. These are the Westerbork Synthesis Radio Telescope, the Effelsberg Radio Telescope, the Lovell Telescope, the Nançay Radio Telescope and the Sardinia Radio Telescope.

text: The EPTA uses five European telescopes. These are the

text: Westerbork Synthesis Radio Telescope

text: , the

text: Effelsberg Radio Telescope

text: , the

text: Lovell Telescope

text: , the

text: Nançay Radio Telescope

text: and the

text: Sardinia Radio Telescope

text: The Infrared Detector Laboratory built the Near Infrared Camera and Multi-Object Spectrometer (NICMOS) instrument for the Hubble Space Telescope and the Multiband Imaging Photometer (MIPS) instrument for the Spitzer Space Telescope.  For the James Webb Space Telescope, Steward built the Near-Infrared Camera (NIRCam) and helped build the Mid-IR Instrument (MIRI).  Both instruments have been delivered to NASA; launch is expected in 2017 or 2018.

text: The Infrared Detector Laboratory built the

text: (NICMOS) instrument for the

text: Hubble Space Telescope

text: and the Multiband Imaging Photometer (MIPS) instrument for the

text: Spitzer Space Telescope

text: .  For the

text: James Webb Space Telescope

text: , Steward built the Near-Infrared Camera (

text: NIRCam

text: ) and helped build the Mid-IR Instrument (MIRI).  Both instruments have been delivered to

text: NASA

text: ; launch is expected in 2017 or 2018.

text: Today, while most of the original buildings still stand on the site, only two of the original instruments remain. Both were installed in 1874 to observe the transit of Venus. One is an  refracting telescope by Troughton and Simms of London, and the other is a fully restored  Photoheliograph by Dallmeyer of London.  The Photoheliograph is privately owned and on indefinite loan to the Astronomical Society of Victoria. The building which was used by the  astrograph telescope for the "Carte du Ciel" survey now houses a  Newtonian reflector telescope owned by the Astronomical Society of Victoria.

text: Today, while most of the original buildings still stand on the site, only two of the original instruments remain. Both were installed in 1874 to observe the transit of Venus. One is an

text: refracting

text: telescope by Troughton and Simms of London, and the other is a fully restored  Photoheliograph by Dallmeyer of London.  The Photoheliograph is privately owned and on indefinite loan to the

text: Astronomical Society of Victoria

text: . The building which was used by the

text: astrograph

text: telescope for the "Carte du Ciel" survey now houses a

text: Newtonian

text: reflector telescope owned by the Astronomical Society of Victoria.

text: An equatorial room, in astronomical observatories, is the room which contains an equatorial mounted telescope. It is usually referred to in observatory buildings that contain more than one type of instrument: for example buildings with an "equatorial room" containing an equatorial telescope and a "transit room" containing a transit telescope. Equatorial rooms tend to be large circular rooms to accommodate all the range of motion of a long telescope on an equatorial mount and are usually topped with a dome to keep out the weather.

text: An equatorial room, in

text: astronomical observatories

text: , is the room which contains an

text: equatorial mount

text: ed

text: telescope

text: . It is usually referred to in observatory buildings that contain more than one type of instrument: for example buildings with an "equatorial room" containing an equatorial telescope and a "transit room" containing a

text: transit telescope

text: . Equatorial rooms tend to be large circular rooms to accommodate all the range of motion of a long telescope on an equatorial mount and are usually topped with a dome to keep out the weather.

text: The POlarization Emission of Millimeter Activity at the Sun (POEMAS) is a solar patrol system composed of two radio telescopes with superheterodyne circular polarization receivers at 45 and 90 GHz. Since their half power beam width is around 1.4°, they observe the full sun. The acquisition system allows to gather 100 values per second at both frequencies and polarizations, with a sensitivity of around 20 solar flux units (SFU) (1 SFU ≡ 10 Jy). The telescope saw first light in November 2011, and showed excellent performance during two years, when it observed many flares. Since November 2013 is stopped for repairing. The main interest of POEMAS is the observation of solar flares in a frequency range where there are very few detectors and fill the gap between microwaves observed with the Radio Solar Telescope Network (1 to 15.4 GHz) and submillimeter observations of the Solar Submillimeter Telescope (212 and 405 GHz). Moreover, POEMAS is the only current telescope capable of carrying on circular polarization solar flare observations at 90 GHz. (Although, in principle, ALMA band 3 may also observe at 90 GHz with circular polarization).

text: The POlarization Emission of Millimeter Activity at the Sun (POEMAS) is a solar patrol system composed of two radio telescopes with

text: superheterodyne

text: circular polarization

text: receivers at 45 and 90 GHz. Since their

text: half power beam width

text: is around 1.4°, they observe the full sun. The acquisition system allows to gather 100 values per second at both frequencies and polarizations, with a sensitivity of around 20

text: solar flux units (SFU)

text: (1 SFU ≡ 10

text: Jy

text: ). The telescope saw

text: first light

text: in November 2011, and showed excellent performance during two years, when it observed many

text: flares

text: . Since November 2013 is stopped for repairing. The main interest of POEMAS is the observation of

text: solar flare

text: s in a frequency range where there are very few detectors and fill the gap between

text: microwave

text: s observed with the

text: Radio Solar Telescope Network

text: (1 to 15.4 GHz) and submillimeter observations of the

text: Solar Submillimeter Telescope

text: (212 and 405 GHz). Moreover, POEMAS is the only current telescope capable of carrying on circular polarization

text: solar flare

text: observations at 90 GHz. (Although, in principle,

text: ALMA

text: band 3 may also observe at 90 GHz with circular polarization).

text: The Gregorian telescope, described by Scottish astronomer and mathematician James Gregory in his 1663 book Optica Promota, employs a concave secondary mirror that reflects the image back through a hole in the primary mirror. This produces an upright image, useful for terrestrial observations. Some small spotting scopes are still built this way. There are several large modern telescopes that use a Gregorian configuration such as the Vatican Advanced Technology Telescope, the Magellan telescopes, the Large Binocular Telescope, and the Giant Magellan Telescope.

text: The

text: Gregorian telescope

text: , described by

text: Scottish

text: astronomer and mathematician

text: James Gregory

text: in his 1663 book Optica Promota, employs a concave secondary mirror that reflects the image back through a hole in the primary mirror. This produces an upright image, useful for terrestrial observations. Some small

text: spotting scope

text: s are still built this way. There are several large modern telescopes that use a Gregorian configuration such as the

text: Vatican Advanced Technology Telescope

text: , the

text: Magellan telescopes

text: , the

text: Large Binocular Telescope

text: , and the

text: Giant Magellan Telescope

text: Beginning in 1930s, radio telescopes have been built for use in the field of radio astronomy to observe the Universe in the radio portion of the electromagnetic spectrum. Such an instrument, or collection of instruments, with supporting facilities such as control centres, visitor housing, data reduction centers, and/or maintenance facilities are called radio observatories. Radio observatories are similarly located far from major population centers to avoid electromagnetic interference (EMI) from radio, TV, radar, and other EMI emitting devices, but unlike optical observatories, radio observatories can be placed in valleys for further EMI shielding. Some of the world's major radio observatories include the Socorro, in New Mexico, United States, Jodrell Bank in the UK, Arecibo, Puerto Rico, Parkes in New South Wales, Australia and Chajnantor in Chile.

text: Beginning in 1930s,

text: radio telescope

text: s have been built for use in the field of

text: radio astronomy

text: to observe the Universe in the radio portion of the electromagnetic spectrum. Such an instrument, or collection of instruments, with supporting facilities such as control centres, visitor housing, data reduction centers, and/or maintenance facilities are called radio observatories. Radio observatories are similarly located far from major population centers to avoid

text: electromagnetic interference

text: (EMI) from

text: radio

text: TV

text: radar

text: , and other EMI emitting devices, but unlike optical observatories, radio observatories can be placed in

text: valley

text: s for further EMI shielding. Some of the world's major radio observatories include the

text: Socorro

text: , in

text: New Mexico

text: , United States,

text: Jodrell Bank

text: in the

text: UK

text: Arecibo

text: Puerto Rico

text: Parkes

text: in

text: New South Wales

text: , Australia and

text: Chajnantor

text: in

text: Chile

text: This list of the largest optical reflecting telescopes with objective diameters of  or greater is sorted by aperture, which is one limit on the light-gathering power and resolution of a reflecting telescope's optical assembly. The mirrors themselves can be larger than the aperture, and telescopes may use aperture synthesis achieved by interferometry. Telescopes designed to be used as optical astronomical interferometers such as the Keck I and II used together as the Keck Interferometer (up to 85 m) can reach very high resolutions, although at a narrower range of observations. When the two mirrors are on one mount, the combined mirror spacing of the Large Binocular Telescope (22.8 m) allows fuller use of the aperture synthesis.

text: This list of the largest optical reflecting telescopes with

text: objective

text: diameters of  or greater is sorted by

text: aperture

text: , which is one limit on the

text: light-gathering power

text: and resolution of a

text: reflecting telescope

text: 's optical assembly. The mirrors themselves can be larger than the aperture, and telescopes may use

text: aperture synthesis

text: achieved by

text: interferometry

text: . Telescopes designed to be used as optical

text: astronomical interferometer

text: s such as the Keck I and II used together as the

text: Keck Interferometer

text: (up to 85 m) can reach very high resolutions, although at a narrower range of observations. When the two mirrors are on one mount, the combined mirror spacing of the

text: Large Binocular Telescope

text: (22.8 m) allows fuller use of the aperture synthesis.

text: EMBRACE (Electronic MultiBeam Radio Astronomy ConcEpt) is a prototype telescope for the phase 2 of the Square Kilometre Array (SKA) project. It's the first dense phased array for radioastronomy in the GHz frequency range (initially planned for covering the 0.5-1.5 GHz, mid-frequency band of SKA). It is composed of two sites, one at the Nançay radio telescope station in France, and one near the Westerbork Synthesis Radio Telescope antennas in Netherlands.

text: EMBRACE (Electronic MultiBeam Radio Astronomy ConcEpt) is a prototype telescope for the phase 2 of the

text: Square Kilometre Array

text: (SKA) project. It's the first dense phased array for radioastronomy in the GHz frequency range (initially planned for covering the 0.5-1.5 GHz, mid-frequency band of SKA). It is composed of two sites, one at the

text: Nançay radio telescope

text: station in France, and one near the

text: Westerbork Synthesis Radio Telescope

text: antennas in Netherlands.

text: The radio telescope is not in use anymore.

text: The UTs are equipped with a large set of instruments permitting observations to be performed from the near-ultraviolet to the mid-infrared (i.e. a large fraction of the light wavelengths accessible from the surface of the Earth), with the full range of techniques including high-resolution spectroscopy, multi-object spectroscopy, imaging, and high-resolution imaging. In particular, the VLT has several adaptive optics systems, which correct for the effects of atmospheric turbulence, providing images almost as sharp as if the telescope were in space. In the near-infrared, the adaptive optics images of the VLT are up to three times sharper than those of the Hubble Space Telescope, and the spectroscopic resolution is many times better than Hubble. The VLTs are noted for their high level of observing efficiency and automation.

text: The UTs are equipped with a large set of instruments permitting observations to be performed from the near-ultraviolet to the mid-infrared (i.e. a large fraction of the

text: light wavelengths accessible from the surface of the Earth

text: ), with the full range of techniques including high-resolution spectroscopy, multi-object spectroscopy, imaging, and high-resolution imaging. In particular, the VLT has several

text: adaptive optics

text: systems, which correct for the effects of atmospheric turbulence, providing images almost as sharp as if the telescope were in space. In the near-infrared, the adaptive optics images of the VLT are up to three times sharper than those of the

text: Hubble Space Telescope

text: , and the spectroscopic resolution is many times better than Hubble. The VLTs are noted for their high level of observing efficiency and automation.

text: Lin claimed that for three consecutive nights, beginning Sept. 20, his residence was attacked by electromagnetic waves and that he had to flee to a hotel.

text: The optical field is a term used in physics and vector calculus to designate the electric field shown as E in the electromagnetic wave equation which can be derived from Maxwell's Equations.  In electromagnetic theory, the electromagnetic wave propagates such that both the magnetic field oscillation, and the electric field oscillation is perpendicular to the direction of propagation of the wave. As with any wave, the electromagnetic wave transports energy, thus the total energy density is shared between the constituent electric and magnetic fields. Since the electric field is considerably more effective at exerting forces and doing work on charges than the magnetic field, the electric field E is referred to as the optical field.

text: The optical field is a term used in physics and vector calculus to designate the electric field shown as E in the

text: electromagnetic

text: wave equation which can be derived from

text: Maxwell's Equations

text: .  In electromagnetic theory, the electromagnetic wave propagates such that both the magnetic field oscillation, and the electric field oscillation is perpendicular to the direction of propagation of the wave. As with any wave, the electromagnetic wave transports energy, thus the total energy density is shared between the constituent electric and magnetic fields. Since the electric field is considerably more effective at exerting forces and doing work on charges than the magnetic field, the electric field E is referred to as the optical field.

text: The term wave is often intuitively understood as referring to a transport of spatial disturbances that are generally not accompanied by a motion of the medium occupying this space as a whole.  In a wave, the energy of a vibration is moving away from the source in the form of a disturbance within the surrounding medium . However, this motion is problematic for a standing wave (for example, a wave on a string), where energy is moving in both directions equally, or for electromagnetic (e.g., light) waves in a vacuum, where the concept of medium does not apply and interaction with a target is the key to wave detection and practical applications. There are water waves on the ocean surface; gamma waves and light waves emitted by the Sun; microwaves used in microwave ovens and in radar equipment; radio waves broadcast by radio stations; and sound waves generated by radio receivers, telephone handsets and living creatures (as voices), to mention only a few wave phenomena.

text: The term wave is often intuitively understood as referring to a transport of spatial disturbances that are generally not accompanied by a motion of the medium occupying this space as a whole.  In a wave, the

text: energy

text: of a

text: vibration

text: is moving away from the source in the form of a disturbance within the surrounding medium . However, this motion is problematic for a

text: standing wave

text: (for example, a wave on a string), where

text: energy

text: is moving in both directions equally, or for electromagnetic (e.g., light) waves in a

text: vacuum

text: , where the concept of medium does not apply and interaction with a target is the key to wave detection and practical applications. There are

text: water waves

text: on the ocean surface;

text: gamma waves

text: and

text: light waves

text: emitted by the Sun;

text: microwaves

text: used in microwave ovens and in

text: radar

text: equipment;

text: radio waves

text: broadcast by radio stations; and

text: sound waves

text: generated by radio receivers, telephone handsets and living creatures (as voices), to mention only a few wave phenomena.

text: MERIS (MEdium Resolution Imaging Spectrometer) measures the reflectance of the Earth (surface and atmosphere) in the solar spectral range (390 to 1040 nm) and transmits 15 spectral bands back to the ground segment. MERIS was built at the Cannes Mandelieu Space Center.

text: MERIS (MEdium Resolution Imaging

text: Spectrometer

text: ) measures the reflectance of the Earth (surface and atmosphere) in the solar spectral range (390 to 1040

text: nm

text: ) and transmits 15 spectral bands back to the

text: ground segment

text: . MERIS was built at the

text: Cannes Mandelieu Space Center

text: The invention of the telescope in 1608 and the subsequent improvements in optics led to the revolutionary progress of the 17th and 18th centuries. We call this type of telescope a refractor because it deviates the light coming from an object in such a way that its image is reversed ; observation is done through an eyepiece at the end of the tube, which allows magnification of the image. Bequeathed by Mr. Robert A. Naef, the observatory's precious telescope is a Reinfelder & Hertel with a diameter of 162.5 mm and a focal distance of 1435 mm - this allows a magnification of X150.

text: ).A waveguide in circuit theory is described by a transmission line having a length and self-impedance. In other words, the impedance is the resistance of the circuit component (in this case a waveguide) to the propagation of the wave. This description of the waveguide was originally intended for alternating current, but is also suitable for electromagnetic and sound waves, once the wave and material properties (such as pressure, density, dielectric constant) are properly converted into electrical terms (current and impedance for example).

text: ).A waveguide in circuit theory is described by a

text: transmission line

text: having a length and self-impedance. In other words, the impedance is the resistance of the circuit component (in this case a waveguide) to the propagation of the wave. This description of the waveguide was originally intended for alternating current, but is also suitable for electromagnetic and sound waves, once the wave and material properties (such as

text: pressure

text: density

text: dielectric constant

text: ) are properly converted into electrical terms (

text: current

text: and impedance for example).

text: Electromagnetic waves were predicted by the classical laws of electricity and magnetism, known as Maxwell's equations. Inspection of Maxwell's equations without sources (charges or currents) results in nontrivial solutions of changing electric and magnetic fields. Beginning with Maxwell's equations in free space:

text: Electromagnetic waves were predicted by the classical laws of

text: electricity

text: and magnetism, known as

text: Maxwell's equations

text: . Inspection of Maxwell's equations without sources (charges or currents) results in nontrivial solutions of changing electric and magnetic fields. Beginning with Maxwell's equations in

text: free space

text: The ETX started out as a 90 mm (3-1/2") Maksutov Cassegrain telescope (first produced in 1996) and took advantage of high volume mass production and simplified optical and parts construction to open a new market for a cheap alternative to the very expensive Questar 3-1/2 Maksutov Cassegrain The ETX "line" has been expanded to 105 mm, and 125 mm Maksutov Cassegrains and achromatic refracting telescopes in sizes of 60 mm and 70 mm, but these two models were later replaced by an 80 mm model. The line has come to take advantage of "goto" telescope mount technology, making it very popular with amateur astronomers.

text: The ETX started out as a 90 mm (3-1/2") Maksutov Cassegrain telescope (first produced in 1996) and took advantage of high volume

text: mass production

text: and simplified optical and parts construction to open a new market for a cheap alternative to the very expensive

text: Questar 3-1/2 Maksutov Cassegrain

text: The ETX "line" has been expanded to 105 mm, and 125 mm Maksutov Cassegrains and

text: achromatic

text: refracting telescope

text: s in sizes of 60 mm and 70 mm, but these two models were later replaced by an 80 mm model. The line has come to take advantage of "

text: goto

text: telescope mount

text: technology, making it very popular with

text: amateur astronomers

text: Congressionally appropriated in 1961, the 61-inch Kaj Strand Telescope (or 1.55-m Kaj Strand Astrometric Reflector, KSAR) remains largest telescope operated by the U.S. Navy since it saw first light in 1964. This status will change when the NPOI four 1.8-meter telescopes see their own first light in the near future. KSAR rides in the arms of an equatorial fork mount. The telescope is used in both the visible spectrum, and in the near infrared (NIR), the latter using a sub-30-Kelvin, helium-refrigerated, InSb (Indium antimonide) camera, "Astrocam". In 1978, the 1.55-m telescope was used to "discover the moon of dwarf planet Pluto, named 'Charon'". (Pluto itself was discovered in 1930, across town at Lowell Observatory). The Charon discovery led to mass calculations which ultimately revealed how tiny Pluto was, and eventually caused the IAU to reclassify Pluto as a dwarf (not a principle) planet. The 1.55-meter telescope was also used to observe and track NASA's Deep Impact Spacecraft, as it navigated to a successful inter-planetary impact with the celebrated Comet 9p/Tempel, in 2005. This telescope is particularly well-suited to perform stellar parallax studies, narrow-field astrometry supporting space navigation, and has also played a key role in discovering one of the coolest-ever known brown dwarf objects, in 2002. The 61" dome is centrally located on NOFS grounds, with support and office buildings attached to the dome structures. The large vacuum coating chamber facility is also located in this complex. The chamber can provide very accurate coatings and overcoatings of 100 (+/-2) Angstrom thickness (approximately 56 aluminium atoms thick), for small-to-multi-ton optics up to 72-inches (1.82 meters) in diameter, in a vacuum exceeding , using a vertical-optic, 1500-ampere discharge system. A dielectric coating capability has also been demonstrated. Large optics and telescope components can be moved about NOFS using its suite of cranes, lifts, cargo elevators and specialized carts. The main complex also contains a controlled-environment, optical and electronics lab for laser, adaptive optics, optics development, collimation, mechanical, and micro-electronic control systems needed for NOFS and NPOI.

text: Congressionally appropriated in 1961, the 61-inch

text: Kaj Strand

text: Telescope (or 1.55-m

text: Kaj Strand

text: Astrometric Reflector, KSAR) remains largest telescope operated by the U.S. Navy since it saw

text: first light

text: in 1964. This status will change when the NPOI four 1.8-meter telescopes see their own first light in the near future. KSAR rides in the arms of an equatorial fork mount. The telescope is used in both the

text: visible spectrum

text: , and in the

text: near infrared

text: (NIR), the latter using a sub-30-

text: Kelvin

text: , helium-refrigerated, InSb (

text: Indium antimonide

text: ) camera, "Astrocam". In 1978, the 1.55-m telescope was used to "discover the moon of

text: dwarf planet

text: Pluto

text: , named '

text: Charon

text: '". (Pluto itself was discovered in 1930, across town at

text: Lowell Observatory

text: ). The Charon discovery led to mass calculations which ultimately revealed how tiny Pluto was, and eventually caused the

text: IAU

text: to reclassify Pluto as a

text: dwarf (not a principle) planet

text: . The 1.55-meter telescope was also used to observe and track NASA's

text: Deep Impact Spacecraft

text: , as it navigated to a successful inter-planetary impact with the celebrated Comet

text: , in 2005. This telescope is particularly well-suited to perform

text: stellar parallax

text: studies, narrow-field astrometry supporting

text: space navigation

text: , and has also played a key role in discovering one of the coolest-ever known

text: brown dwarf

text: objects, in 2002. The 61" dome is centrally located on NOFS grounds, with support and office buildings attached to the dome structures. The large

text: vacuum coating chamber

text: facility is also located in this complex. The chamber can provide very accurate coatings and overcoatings of 100 (+/-2)

text: Angstrom

text: thickness (approximately 56 aluminium atoms thick), for small-to-multi-ton optics up to 72-inches (1.82 meters) in diameter, in a vacuum exceeding , using a vertical-optic, 1500-ampere discharge system. A

text: dielectric coating

text: capability has also been demonstrated. Large optics and telescope components can be moved about NOFS using its suite of cranes, lifts, cargo elevators and specialized carts. The main complex also contains a controlled-environment, optical and electronics lab for laser, adaptive optics, optics development, collimation, mechanical, and micro-electronic control systems needed for NOFS and NPOI.

text: The Single Aperture Far-Infrared Observatory (SAFIR), a proposed cryogenic space telescope, is tentatively set to launch in 2015 with the hopes of exploring "the formation of the first stars and galaxies" in deep space. The telescope will be more than 1000 times more sensitive than two current telescope spacecrafts, the Spitzer Space Telescope and the Herschel Space Observatory. NASA hopes to use SAFIR to learn about black holes, galaxy formation and evolution and the formation of star systems in the far reaches of space.

text: The Single Aperture Far-Infrared Observatory (

text: SAFIR

text: ), a proposed cryogenic space telescope, is tentatively set to launch in 2015 with the hopes of exploring "the formation of the first stars and galaxies" in deep space. The telescope will be more than 1000 times more sensitive than two current telescope spacecrafts, the

text: Spitzer Space Telescope

text: and the

text: Herschel Space Observatory

text: . NASA hopes to use SAFIR to learn about black holes,

text: galaxy formation and evolution

text: and the formation of

text: star system

text: s in the far reaches of space.

text: For example, consider the electromagnetic wave equation:

text: For example, consider the

text: electromagnetic wave equation

text: In the early 17th century Johannes Kepler expanded on geometric optics in his writings, covering lenses, reflection by flat and curved mirrors, the principles of pinhole cameras, inverse-square law governing the intensity of light, and the optical explanations of astronomical phenomena such as lunar and solar eclipses and astronomical parallax. He was also able to correctly deduce the role of the retina as the actual organ that recorded images, finally being able to scientifically quantify the effects of different types of lenses that spectacle makers had been observing over the previous 300 years. After the invention of the telescope Kepler set out the theoretical basis on how they worked and described an improved version, known as the Keplerian telescope, using two convex lenses to produce higher magnification.

text: In the early 17th century

text: Johannes Kepler

text: expanded on geometric optics in his writings, covering lenses, reflection by flat and curved mirrors, the principles of

text: pinhole camera

text: s, inverse-square law governing the intensity of light, and the optical explanations of astronomical phenomena such as

text: lunar

text: and

text: solar eclipse

text: s and astronomical

text: parallax

text: . He was also able to correctly deduce the role of the

text: retina

text: as the actual organ that recorded images, finally being able to scientifically quantify the effects of different types of lenses that spectacle makers had been observing over the previous 300 years. After the invention of the telescope Kepler set out the theoretical basis on how they worked and described an improved version, known as the

text: Keplerian telescope

text: , using two convex lenses to produce higher magnification.

text: Plasmas can have a wide range of values in both temperature and density; plasma temperatures range from close to absolute zero and to well beyond 10 kelvins (for comparison, tungsten melts at 3700 kelvins), and plasma may contain less than one particle per cubic metre, or be denser than lead. Electron temperature is usually expressed as electronvolt (eV), and 1 eV is equivalent to 11,604 K. Common plasmas temperature and density in fluorescent light tubes and semiconductor manufacturing processes are around several eV and 10per cm. For a wide range of parameters and frequencies, plasma is electrically conductive, and its response to low-frequency electromagnetic waves is similar to that of a metal: a plasma simply reflects incident low-frequency radiation. Low-frequency means it is lower than the characteristic electron plasma frequency. The use of plasmas to control the reflected electromagnetic radiation from an object (Plasma stealth) is feasible at suitable frequency where the conductivity of the plasma allows it to interact strongly with the incoming radio wave, and the wave can either be absorbed and converted into thermal energy, or reflected, or transmitted depending on the relationship between the radio wave frequency and the characteristic plasma frequency. If the frequency of the radio wave is lower than the plasma frequency, it is reflected. if it is higher, it transmit. If these two are equal, then resonance occurs. There are also another mechanism where reflection can be reduced. If the electromagnetic wave passes through the plasma, and is reflected by the metal, and the reflected wave and incoming wave are roughly equal in power, then they may form two phasors. When these two phasors are of opposite phase they can cancel each other out. In order to obtain substantial attenuation of radar signal, the plasma slab needs adequate thickness and density.

text: Plasmas can have a wide range of values in both temperature and density; plasma temperatures range from close to absolute zero and to well beyond 10

text: kelvin

text: Apparent FOV is the observable world observed through an ocular eyepiece without insertion into a telescope. It is limited by the barrel size used in a telescope, generally with modern telescopes that being either 1.25 or 2 inches in diameter. A wider FOV may be used to achieve a more vast observable world given the same magnification compared with a smaller FOV without compromise to magnification. Note that increasing the FOV lowers surface brightness of an observed object, as the gathered light is spread over more area, in relative terms increasing the observing area proportionally lowers surface brightness dimming the observed object. Wide FOV eyepieces work best at low magnifications with large apertures, where the relative size of an object is viewed at higher comparative standards with minimal magnification giving an overall brighter image to begin with.

text: Apparent

text: FOV

text: is the observable world observed through an ocular

text: eyepiece

text: without insertion into a

text: telescope

text: . It is limited by the barrel size used in a telescope, generally with modern telescopes that being either 1.25 or 2 inches in diameter. A wider

text: FOV

text: may be used to achieve a more vast observable world given the same

text: magnification

text: compared with a smaller

text: FOV

text: without compromise to magnification. Note that increasing the

text: FOV

text: lowers

text: surface brightness

text: of an observed object, as the gathered light is spread over more area, in relative terms increasing the observing area proportionally lowers surface brightness dimming the observed object. Wide

text: FOV

text: eyepiece

text: s work best at low magnifications with large

text: apertures

text: , where the relative size of an object is viewed at higher comparative standards with minimal magnification giving an overall brighter image to begin with.

text: After awakening at 8:31 UTC, the crew set to work preparing to release Hubble from the payload bay of Atlantis. Using the shuttle's robotic arm, McArthur grappled Hubble at 10:45 UTC, and lifted it out of the orbiter's payload bay to prepare for the release. Good and Massimino were standing by ready to perform a spacewalk in the event that something went wrong during the telescope's deployment. After working through the checklist to prepare the telescope for release, managers on the ground gave the go to Altman to release Hubble, and at 12:57 UTC, McArthur successfully released the telescope as the vehicles flew over Africa. Performing a small separation burn, Johnson backed the orbiter away from the telescope, and Altman called down to managers on the ground confirming the deployment of Hubble. Commending the crew, Altman said "And Houston, Hubble has been released, it's safely back on its journey of exploration as we begin steps to conclude ours. Not everything went as we planned, but we planned a way to work around everything and with the whole team pulling together... we've been able to do some incredible things. And now Hubble can continue on its own, exploring the cosmos, and bringing it home to us as we head for home in a few days. Thank you." Hubble's new equipment and upgraded systems would be tested for several months prior to resuming operation, but if all tests are successful, operation of the telescope would resume in early September.

text: Husband worked with Bernard Lovell – the founder of the Jodrell Bank Observatory near Holmes Chapel in Cheshire – on the design and construction of the observatory's first large steerable radio telescope, the "250-ft telescope" (now known as the Lovell Telescope). After attempting to adapt military radar equipment to detect cosmic rays shortly after the Second World War, Lovell had realised that a much larger aerial would be required, and constructed a 66-metre diameter dish, limited by being static, before proposing the development of an even larger steerable telescope. The idea posed such formidable engineering challenges that the project had been declared "impossible" by other engineers, but Husband is reported to have concluded at their first meeting in September 1949, "It should be easy—about the same problem as throwing a swing bridge over the Thames at Westminster."

text: Husband worked with

text: Bernard Lovell

text: – the founder of the

text: Jodrell Bank Observatory

text: near

text: Holmes Chapel

text: in

text: Cheshire

text: – on the design and construction of the observatory's first large steerable

text: radio telescope

text: , the "250-ft telescope" (now known as the

text: Lovell Telescope

text: ). After attempting to adapt military

text: radar

text: equipment to detect

text: cosmic ray

text: s shortly after the Second World War, Lovell had realised that a much larger aerial would be required, and constructed a 66-metre diameter dish, limited by being static, before proposing the development of an even larger steerable telescope. The idea posed such formidable engineering challenges that the project had been declared "impossible" by other engineers, but Husband is reported to have concluded at their first meeting in September 1949, "It should be easy—about the same problem as throwing a swing bridge over the Thames at Westminster."

text: Installed on the Salyut 4 were OST-1 (Orbiting Solar Telescope) 25 cm solar telescope with a focal length of 2.5m and spectrograph shortwave diffraction spectrometer for far ultraviolet emissions, designed at the Crimean Astrophysical Observatory, and two X-ray telescopes. One of the X-ray telescopes, often called the Filin telescope, consisted of four gas flow proportional counters, three of which had a total detection surface of 450 cm² in the energy range 2–10 keV, and one of which had an effective surface of 37 cm² for the range 0.2 to 2 keV (32 to 320 aJ). The field of view was limited by a slit collimator to 3 in × 10 in full width at half maximum. The instrumentation also included optical sensors which were mounted on the outside of the station together with the X-ray detectors, and power supply and measurement units which were inside the station. Ground based calibration of the detectors was considered along with in-flight operation in three modes: inertial orientation, orbital orientation, and survey. Data could be collected in 4 energy channels: 2 to 3.1 keV (320 to 497 aJ), 3.1 to 5.9 keV (497 to 945 aJ), 5.9 to 9.6 keV (945 to 1,538 aJ), and 2 to 9.6 keV (320 to 1,538 aJ) in the larger detectors. The smaller detector had discriminator levels set at 0.2 keV (32 aJ), 0.55 keV (88 aJ), and 0.95 keV (152 aJ).

text: Installed on the Salyut 4 were OST-1 (Orbiting Solar Telescope) 25 cm

text: solar telescope

text: with a focal length of 2.5m and spectrograph shortwave diffraction spectrometer for far ultraviolet emissions, designed at the

text: Crimean Astrophysical Observatory

text: , and two

text: X-ray

text: telescopes. One of the X-ray telescopes, often called the Filin telescope, consisted of four gas flow proportional counters, three of which had a total detection surface of 450 cm² in the energy range 2–10

text: keV

text: , and one of which had an effective surface of 37 cm² for the range 0.2 to 2 keV (32 to 320

text: aJ

text: ). The field of view was limited by a

text: slit collimator

text: to 3 in × 10 in

text: full width at half maximum

text: . The instrumentation also included optical sensors which were mounted on the outside of the station together with the X-ray detectors, and power supply and measurement units which were inside the station. Ground based calibration of the detectors was considered along with in-flight operation in three modes: inertial orientation, orbital orientation, and survey. Data could be collected in 4 energy channels: 2 to 3.1 keV (320 to 497 aJ), 3.1 to 5.9 keV (497 to 945 aJ), 5.9 to 9.6 keV (945 to 1,538 aJ), and 2 to 9.6 keV (320 to 1,538 aJ) in the larger detectors. The smaller detector had discriminator levels set at 0.2 keV (32 aJ), 0.55 keV (88 aJ), and 0.95 keV (152 aJ).

text: In 2007 AGILE was launched and in 2008 the Fermi Gamma-ray Space Telescope and although these are Earth orbiters, their instruments provide directional discrimination. The Fermi Space Telescope uses both wide-area burst detectors and a narrow-angle telescope, and will have a limited ability to spin itself to place a GRB within the telescope field. MESSENGER's gamma instrument is now fully operational, and is adding data to the IPN. Due to falling power from its RTG, Ulysses was decommissioned on June 30, 2009.

text: In 2007

text: AGILE

text: was launched and in 2008 the

text: Fermi Gamma-ray Space Telescope

text: and although these are Earth orbiters, their instruments provide directional discrimination. The Fermi Space Telescope uses both wide-area burst detectors and a narrow-angle telescope, and will have a limited ability to spin itself to place a GRB within the telescope field. MESSENGER's gamma instrument is now fully operational, and is adding data to the IPN. Due to falling power from its

text: RTG

text: Ulysses

text: was decommissioned on June 30, 2009.

text: In September and October 2010, after Webb's released research, physicists Chad Orzel and Sean M. Carroll suggested various approaches of how Webb's observations may be wrong. Orzel argues that the study may contain wrong data due to subtle differences in the two telescopes, in which one of the telescopes the data set was slightly high and on the other slightly low, so that they cancel each other out when they overlapped. He finds it suspicious that the sources showing the greatest changes are all observed by one telescope, with the region observed by both telescopes aligning so well with the sources where no effect is observed.  Carroll suggested a totally different approach; he looks at the fine-structure constant as a scalar field and claims that if the telescopes are correct and the fine-structure constant varies smoothly over the universe, then the scalar field must have a very small mass. However, previous research has shown that the mass is not likely to be extremely small. Both of these scientists' early criticisms point to the fact that different techniques are needed to confirm or contradict the results, as Webb, et al., also concluded in their study.

text: In September and October 2010, after Webb's released research, physicists

text: Chad Orzel

text: and

text: Sean M. Carroll

text: suggested various approaches of how Webb's observations may be wrong. Orzel argues that the study may contain wrong data due to subtle differences in the two telescopes, in which one of the telescopes the data set was slightly high and on the other slightly low, so that they cancel each other out when they overlapped. He finds it suspicious that the sources showing the greatest changes are all observed by one telescope, with the region observed by both telescopes aligning so well with the sources where no effect is observed.  Carroll suggested a totally different approach; he looks at the fine-structure constant as a scalar field and claims that if the telescopes are correct and the fine-structure constant varies smoothly over the universe, then the scalar field must have a very small mass. However, previous research has shown that the mass is not likely to be extremely small. Both of these scientists' early criticisms point to the fact that different techniques are needed to confirm or contradict the results, as Webb, et al., also concluded in their study.

text: Astronomers from all over the world regularly use this telescope to observe many different astronomical objects such as HII regions, galaxies, pulsars, supernovae, and Sun and solar winds.

text: Astronomers from all over the world regularly use this telescope to observe many different astronomical objects such as

text: HII regions

text: galaxies

text: pulsars

text: supernovae

text: , and Sun and

text: solar wind

text: s.

text: Orion Optics is a telescope manufacturer in Crewe, England. A family run firm, Orion Optics is the only remaining major manufacturer of telescopes in the UK.

text: Orion Optics is a

text: telescope

text: manufacturer in

text: Crewe

text: England

text: . A family run firm, Orion Optics is the only remaining major manufacturer of telescopes in the UK.

text: A solar telescope is a special purpose telescope used to observe the Sun. Solar telescopes usually detect light with wavelengths in, or not far outside, the visible spectrum. Obsolete names for sun telescopes include heliograph and photoheliograph.

text: A solar telescope is a special purpose

text: telescope

text: used to observe the

text: Sun

text: . Solar telescopes usually detect light with wavelengths in, or not far outside, the

text: visible spectrum

text: . Obsolete names for sun telescopes include heliograph and photoheliograph.

text: Of Looking–Glasses, and Telescopes: Reasons given by Mathematicians for the Mysteries of Vision; that those Reasons are not altogether sufficient.

text: Of Looking–Glasses, and Telescopes: Reasons given by Mathematicians for the Mysteries of Vision; that those Reasons are not altogether

text: sufficient

text: Most widely used in former USSR nations, low intensity (usually 10 mW/cm or less) electromagnetic radiation of extremely high frequency (especially in the range 40 – 70 GHz, which corresponds to wavelength of 7.5 – 4.3 mm) is used in human medicine for the treatment of many types of diseases. This type of therapy is called millimeter wave (MMW) therapy or extremely high frequency (EHF) therapy. More than 10 000 devices are used for millimeter wave therapy worldwide and more than a million people have been treated with millimeter wave therapy during its documented history. Established in 1992, the Russian Journal Millimeter waves in biology and medicine is dedicated to the scientific basis and clinical applications of millimeter wave therapy. More than 50 issues of it have been published.

text: Most widely used in former

text: USSR

text: nations, low

text: intensity

text: (usually 10 mW/cm or less) electromagnetic radiation of extremely high frequency (especially in the range 40 – 70

text: GHz

text: , which corresponds to

text: wavelength

text: of 7.5 – 4.3 mm) is used in human medicine for the treatment of many types of diseases. This type of therapy is called millimeter wave (MMW) therapy or extremely high frequency (EHF) therapy. More than 10 000 devices are used for millimeter wave therapy worldwide and more than a million people have been treated with millimeter wave therapy during its documented history. Established in 1992, the Russian Journal Millimeter waves in biology and medicine is dedicated to the scientific basis and clinical applications of millimeter wave therapy. More than 50 issues of it have been published.

text: Fulton taught school at the Chillicothe school district. He was interested in astronomy and owned two telescopes built for him by Amasa Holcomb. One of these Holcomb telescopes was willed to Chillicothe High School in the middle of the nineteenth century. It still had at least one of the lenses as a remaining part to the telescope until at least 1917. One of these two telescopes owned by Fulton made by Holcomb was the first reflecting telescope manufactured in America, however it is not known if this one was that particular telescope.

text: Fulton taught school at the Chillicothe school district. He was interested in astronomy and owned two telescopes built for him by

text: Amasa Holcomb

text: . One of these Holcomb telescopes was willed to

text: Chillicothe High School

text: in the middle of the nineteenth century. It still had at least one of the lenses as a remaining part to the telescope until at least 1917. One of these two telescopes owned by Fulton made by Holcomb was the first reflecting telescope manufactured in America, however it is not known if this one was that particular telescope.

text: The Faulkes Telescope North, part of the Faulkes Telescope Project, is a  reflecting telescope owned and operated by the Las Cumbres Observatory Global Telescope Network.  It provides remote access to a research-quality telescope primarily to students in the United Kingdom.

text: The

text: Faulkes Telescope North

text: , part of the

text: Faulkes Telescope Project

text: , is a  reflecting telescope owned and operated by the

text: Las Cumbres Observatory Global Telescope Network

text: .  It provides remote access to a research-quality telescope primarily to students in the

text: United Kingdom

text: The proposed satellite would have a dimension of 70 m × 70 m, a mass of about 600 kg, and maneuver by means of an ion drive engine in combination with using the sheet as a light sail. Positioned at a distance of 100,000 km from the telescope, it would block more than 99.998% of the starlight.

text: The proposed satellite would have a dimension of 70 m × 70 m, a mass of about 600 kg, and maneuver by means of an

text: ion drive

text: engine in combination with using the sheet as a light sail. Positioned at a distance of 100,000 km from the telescope, it would block more than 99.998% of the starlight.

text: In 1978, the NASA SETI program had been heavily criticized by Senator William Proxmire, and funding for SETI research was removed from the NASA budget by Congress in 1981; however, funding was restored in 1982, after Carl Sagan talked with Proxmire and convinced him of the program's value.  In 1992, the U.S. government funded an operational SETI program, in the form of the NASA Microwave Observing Program (MOP). MOP was planned as a long-term effort to conduct a general survey of the sky and also carry out targeted searches of 800 specific nearby stars. MOP was to be performed by radio antennas associated with the NASA Deep Space Network, as well as the  radio telescope of the National Radio Astronomy Observatory at Green Bank, West Virginia and the  radio telescope at the Arecibo Observatory in Puerto Rico. The signals were to be analyzed by spectrum analyzers, each with a capacity of 15 million channels. These spectrum analyzers could be grouped together to obtain greater capacity. Those used in the targeted search had a bandwidth of 1 hertz per channel, while those used in the sky survey had a bandwidth of 30 hertz per channel.

text: In 1978, the NASA SETI program had been heavily criticized by Senator

text: William Proxmire

text: , and funding for SETI research was removed from the NASA budget by Congress in 1981; however, funding was restored in 1982, after

text: Carl Sagan

text: talked with Proxmire and convinced him of the program's value.  In 1992, the U.S. government funded an operational SETI program, in the form of the NASA Microwave Observing Program (MOP). MOP was planned as a long-term effort to conduct a general survey of the sky and also carry out targeted searches of 800 specific nearby stars. MOP was to be performed by radio antennas associated with the

text: NASA Deep Space Network

text: , as well as the  radio telescope of the

text: National Radio Astronomy Observatory

text: at Green Bank, West Virginia and the  radio telescope at the

text: Arecibo Observatory

text: in Puerto Rico. The signals were to be analyzed by spectrum analyzers, each with a capacity of 15 million channels. These spectrum analyzers could be grouped together to obtain greater capacity. Those used in the targeted search had a bandwidth of 1 hertz per channel, while those used in the sky survey had a bandwidth of 30 hertz per channel.

text: After the invention of the wide field Schmidt camera in the early 1930s at least four optical designers in early 1940s war-torn Europe came up with the idea of replacing the complicated Schmidt corrector plate with a simpler meniscus lens, including Albert Bouwers, Dmitri Dmitrievich Maksutov, K. Penning, and Dennis Gabor. All of these designs used full aperture correctors (a meniscus corrector shell) to create a wide field telescope with little or no coma or astigmatism. Albert Bouwers built a prototype meniscus telescope in August 1940 and patented it in February 1941. His design had the mirror and meniscus lens with surfaces that had a common radius of curvature, called a "concentric" or "monocentric" telescope. The design had an ultrawide field of view but did not correct chromatic aberration and was only suitable as a monochromatic astronomical camera. Dmitri Maksutov built a prototype for a similar type of meniscus telescope, the Maksutov telescope, in October 1941 and patented it in November of that same year. His design corrected most spherical aberration and also corrected for chromatic aberration by placing a weakly negative shaped meniscus corrector closer to the primary mirror. Dennis Gabor’s 1941 design was a non-monocentric meniscus corrector. War time secrecy kept these designers from knowing about each other's design, making each invention independent.

text: After the invention of the wide field

text: Schmidt camera

text: in the early 1930s at least four optical designers in early 1940s war-torn Europe came up with the idea of replacing the complicated

text: Schmidt corrector plate

text: with a simpler meniscus lens, including

text: Albert Bouwers

text: Dmitri Dmitrievich Maksutov

text: , K. Penning, and

text: Dennis Gabor

text: . All of these designs used full aperture correctors (a meniscus corrector shell) to create a wide field telescope with little or no

text: coma

text: or

text: astigmatism

text: . Albert Bouwers built a prototype

text: meniscus telescope

text: in August 1940 and patented it in February 1941. His design had the mirror and meniscus lens with surfaces that had a common radius of curvature, called a "concentric" or "monocentric" telescope. The design had an ultrawide field of view but did not correct

text: chromatic aberration

text: and was only suitable as a monochromatic astronomical camera. Dmitri Maksutov built a prototype for a similar type of meniscus telescope, the

text: Maksutov telescope

text: , in October 1941 and patented it in November of that same year. His design corrected most spherical aberration and also corrected for chromatic aberration by placing a weakly negative shaped meniscus corrector closer to the primary mirror.

text: Dennis Gabor

text: ’s 1941 design was a non-monocentric meniscus corrector. War time secrecy kept these designers from knowing about each other's design, making each invention independent.

text: The MICAS (Miniature Integrated Camera And Spectrometer) instrument combined visible light imaging with infrared and ultraviolet spectroscopy to determine chemical composition. All channels share a  telescope, which uses a silicon carbide mirror.

text: The MICAS (Miniature Integrated Camera And

text: Spectrometer

text: ) instrument combined visible light imaging with infrared and ultraviolet spectroscopy to determine chemical composition. All channels share a  telescope, which uses a

text: silicon carbide

text: mirror.

text: Light, colors, AM and FM radio, and electronic devices make use of the electromagnetic spectrum. The frequencies of the radio spectrum that are available for use for communication are treated as a public resource and are regulated by national organizations such as the Federal Communications Commission in the USA, or Ofcom in the United Kingdom, or “international as ITU-R”, or European as ETSI. This determines which frequency ranges can be used for what purpose and by whom. In the absence of such control or alternative arrangements such as a privatized electromagnetic spectrum, chaos might result if, for example, airlines did not have specific frequencies to work under and an amateur radio operator were interfering with the pilot's ability to land an aircraft. Wireless communication spans the spectrum from 9 kHz to 300 GHz.

text: Light, colors, AM and FM radio, and electronic devices make use of the

text: electromagnetic spectrum

text: . The frequencies of the

text: radio spectrum

text: that are available for use for communication are treated as a public resource and are regulated by national organizations such as the

text: Federal Communications Commission

text: in the USA, or

text: Ofcom

text: in the United Kingdom, or “international as

text: ITU-R

text: ”, or European as

text: ETSI

text: . This determines which frequency ranges can be used for what purpose and by whom. In the absence of such control or alternative arrangements such as a privatized electromagnetic spectrum, chaos might result if, for example, airlines did not have specific frequencies to work under and an

text: amateur radio

text: operator were interfering with the pilot's ability to land an

text: aircraft

text: . Wireless communication spans the spectrum from 9 kHz to 300 GHz.

text: However, all these advantages do come with a price. Space telescopes are much more expensive to build than ground-based telescopes. Due to their location, space telescopes are also extremely difficult to maintain. The Hubble Space Telescope was serviced by the Space Shuttle while many other space telescopes cannot be serviced at all.

text: However, all these advantages do come with a price. Space telescopes are much more expensive to build than ground-based telescopes. Due to their location, space telescopes are also extremely difficult to maintain. The Hubble Space Telescope was serviced by the

text: Space Shuttle

text: The K band ("kay-ay band") covers the frequencies of 26.5–40 GHz, i.e. wavelengths from slightly over one centimeter down to 7.5 millimeters. The K band is part of the K band of the microwave band of the electromagnetic spectrum. This symbol refers to "K-above": in other words, the band directly above the K-band. The 30/20 GHz band is used in communications satellites, uplink in either the 27.5 GHz and 31 GHz bands, and high-resolution, close-range targeting radars aboard military airplanes. Some frequencies in this radio band are used for vehicle speed detection by law enforcement. Kepler Mission uses this frequency range to downlink the scientific data collected by the space telescope.

text: The K band ("kay-ay band") covers the frequencies of 26.5–40 GHz, i.e. wavelengths from slightly over one centimeter down to 7.5 millimeters. The K band is part of the

text: K band

text: of the

text: microwave

text: band of the

text: electromagnetic spectrum

text: . This symbol refers to "K-above": in other words, the band directly above the K-band. The 30/20 GHz band is used in

text: communications satellite

text: s,

text: uplink

text: in either the 27.5 GHz and 31 GHz bands, and high-resolution, close-range targeting

text: radar

text: s aboard military airplanes. Some frequencies in this radio band are used for vehicle speed detection by law enforcement.

text: Kepler Mission

text: uses this frequency range to downlink the scientific data collected by the space telescope.

text: A discussion of the regions (or bands or types) of the electromagnetic spectrum is given below. Note that there are no precisely defined boundaries between the bands of the electromagnetic spectrum; rather they fade into each other like the bands in a rainbow (which is the sub-spectrum of visible light). Radiation of each frequency and wavelength (or in each band) has a mix of properties of the two regions of the spectrum that bound it. For example, red light resembles infrared radiation in that it can excite and add energy to some chemical bonds and indeed must do so to power the chemical mechanisms responsible for photosynthesis and the working of the visual system.

text: A discussion of the regions (or bands or types) of the electromagnetic spectrum is given below. Note that there are no precisely defined boundaries between the bands of the electromagnetic spectrum; rather they fade into each other like the bands in a rainbow (which is the sub-spectrum of visible light). Radiation of each frequency and wavelength (or in each band) has a mix of properties of the two regions of the spectrum that bound it. For example, red light resembles infrared radiation in that it can excite and add energy to some

text: chemical bond

text: s and indeed must do so to power the chemical mechanisms responsible for

text: photosynthesis

text: and the working of the

text: visual system

text: Given its excellent optical qualities, the telescope has been used primarily for imaging and photometric work, in which it regularly outperforms much larger telescopes located elsewhere. Among the  results from this telescope have been the discovery of MACHOs in the Andromeda Galaxy; the validation of the Stromvil photometric filter system; evidence for how the shape and dimensions of galaxies have changed over the age of the universe; discovery of the first binary 'Vesta chip' asteroid; and the characterization and classification by visible colors of some 100 Trans-Neptunian objects, most of them fainter than magnitude 21.

text: Given its excellent optical qualities, the telescope has been used primarily for imaging and

text: photometric

text: work, in which it regularly outperforms much larger telescopes located elsewhere. Among the  results from this telescope have been the discovery of

text: MACHO

text: s in the

text: Andromeda Galaxy

text: ; the validation of the Stromvil photometric filter system; evidence for how the shape and dimensions of galaxies have changed over the age of the universe; discovery of the first binary 'Vesta chip' asteroid; and the characterization and classification by visible colors of some 100

text: Trans-Neptunian object

text: s, most of them fainter than

text: magnitude

text: During the 1840s and 1850s Robinson was a frequent visitor to the world's most powerful telescope of that era, the so-called Leviathan of Parsonstown telescope, which had been built by Robinson's friend and colleague William Parsons, 3rd Earl of Rosse. Robinson was active with Parsons in interpreting the higher-resolution views of the night sky produced by Parsons' telescope, particularly with regard to the galaxies and nebulae and he published leading-edge research reports on the question. Back at his own observatory in Armagh, Robinson compiled a large catalog of stars and wrote many related reports. In 1862 he was awarded a Royal Medal "for the Armagh catalogue of 5345 stars, deduced from observations made at the Armagh Observatory, from the years 1820 up to 1854; for his papers on the construction of astronomical instruments in the memoirs of the Astronomical Society, and his paper on electromagnets in the Transactions of the Royal Irish Academy".

text: During the 1840s and 1850s Robinson was a frequent visitor to the world's most powerful telescope of that era, the so-called

text: Leviathan of Parsonstown

text: telescope, which had been built by Robinson's friend and colleague

text: William Parsons, 3rd Earl of Rosse

text: . Robinson was active with Parsons in interpreting the higher-resolution views of the night sky produced by Parsons' telescope, particularly with regard to the

text: galaxies

text: and

text: nebulae

text: and he published leading-edge research reports on the question. Back at his own observatory in Armagh, Robinson compiled a large catalog of stars and wrote many related reports. In 1862 he was awarded a

text: Royal Medal

text: "for the Armagh catalogue of 5345 stars, deduced from observations made at the Armagh Observatory, from the years 1820 up to 1854; for his papers on the construction of astronomical instruments in the memoirs of the Astronomical Society, and his paper on electromagnets in the Transactions of the Royal Irish Academy".

text: The design of the telescope had always incorporated servicing missions, and astronomers immediately began to seek potential solutions to the problem that could be applied at the first servicing mission, scheduled for 1993. While Kodak had ground a back-up mirror for Hubble, it would have been impossible to replace the mirror in orbit, and too expensive and time-consuming to bring the telescope back to Earth for a refit. Instead, the fact that the mirror had been ground so precisely to the wrong shape led to the design of new optical components with exactly the same error but in the opposite sense, to be added to the telescope at the servicing mission, effectively acting as "spectacles" to correct the spherical aberration.

text: The design of the telescope had always incorporated servicing missions, and astronomers immediately began to seek potential solutions to the problem that could be applied at the first servicing mission, scheduled for 1993. While Kodak had ground a back-up mirror for Hubble, it would have been impossible to replace the mirror in orbit, and too expensive and time-consuming to bring the telescope back to Earth for a refit. Instead, the fact that the mirror had been ground so precisely to the wrong shape led to the design of new optical components with exactly the same error but in the opposite sense, to be added to the telescope at the servicing mission, effectively acting as "

text: spectacles

text: " to correct the spherical aberration.

text: Cha 110913-773444 was discovered in 2004 by Kevin Luhman and others at Pennsylvania State University using the Spitzer Space Telescope and the Hubble Space Telescope, as well as two Earth-bound telescopes in Chile.

text: Cha 110913-773444 was discovered in 2004 by

text: Kevin Luhman

text: and others at

text: Pennsylvania State University

text: using the

text: Spitzer Space Telescope

text: and the

text: Hubble Space Telescope

text: , as well as two Earth-bound telescopes in

text: Chile

text: A medium size optical telescope is thought to be a step to facilitate research in astronomy and observational cosmology. The geographic location of Iran, 32N 53E, relative dry climate and high altitude mountains, offer suitable locations for optical telescopes to carry out surveys and time critical observations.

text: Most of the full plot is unknown. In the version available today, Holmes (Dawley) tells his nephews about an adventure he had in the woodlands around Slumber Mountain, near the Valley of Dreams.  He finds the cabin belonging to the late hermit Mad Dick, who Holmes's friend Joe once saw carrying a strange telescope-like instrument. That night, Holmes searches the cabin and finds the instrument.  Upon doing so, the ghost of Mad Dick (O'Brien) instructs him to use it to look at the peak of Slumber Mountain.  When he does, he seemingly looks back into the past, seeing a Tyrannosaurus and a Triceratops doing battle.  The Tyrannosaurus proves triumphant, and after killing the Triceratops, somehow breaks the time barrier (unless the instrument does that itself) and begins chasing Holmes.

text: Most of the full plot is unknown. In the version available today, Holmes (Dawley) tells his nephews about an adventure he had in the woodlands around Slumber Mountain, near the Valley of Dreams.  He finds the cabin belonging to the late hermit Mad Dick, who Holmes's friend Joe once saw carrying a strange

text: telescope

text: -like instrument. That night, Holmes searches the cabin and finds the instrument.  Upon doing so, the ghost of Mad Dick (O'Brien) instructs him to use it to look at the peak of Slumber Mountain.  When he does, he seemingly looks back into the past, seeing a

text: Tyrannosaurus

text: and a

text: Triceratops

text: doing battle.  The Tyrannosaurus proves triumphant, and after killing the Triceratops, somehow breaks the time barrier (unless the instrument does that itself) and begins chasing Holmes.

text: Radio waves from space were first detected by engineer Karl Guthe Jansky in 1932 at Bell Telephone Laboratories in Holmdel, New Jersey using an antenna built to study noise in radio receivers.  The first purpose-built radio telescope was a 9-meter parabolic dish constructed by radio amateur Grote Reber in his back yard in Wheaton, Illinois in 1937. The sky survey he did with it is often considered the beginning of the field of radio astronomy.

text: Radio waves from space were first detected by engineer

text: Karl Guthe Jansky

text: in 1932 at

text: Bell Telephone Laboratories

text: in Holmdel, New Jersey using an antenna built to study noise in radio receivers.  The first purpose-built radio telescope was a 9-meter parabolic dish constructed by radio amateur

text: Grote Reber

text: in his back yard in Wheaton, Illinois in 1937. The sky survey he did with it is often considered the beginning of the field of radio astronomy.

text: The CLASS instrument will survey 70% of the sky at millimeter wavelengths, in the microwave portion of the electromagnetic spectrum, from a ground-based observatory with a resolution of about 1° — approximately twice the angular size of the sun and moon as viewed from Earth. The CLASS array will consist of two altazimuth mounts that will allow the telescopes to be pointed to observe different patches of sky. The four CLASS telescopes will observe at a range of frequencies to separate emission from our galaxy from that of the CMB. One telescope will observe at 40 GHz (7.5 mm wavelength); two telescopes will observe at 90 GHz (3.3 mm wavelength); and the fourth telescope will observe in two frequency bands centered at 150 GHz (2 mm wavelength) and 220 GHz (1.4 mm wavelength). Two separate telescopes, observing at different frequencies, are housed on each mount.

text: The CLASS instrument will survey 70% of the sky at millimeter wavelengths, in the microwave portion of the

text: electromagnetic spectrum

text: , from a ground-based observatory with a resolution of about 1° — approximately twice the angular size of the sun and moon as viewed from Earth. The CLASS array will consist of two

text: altazimuth mount

text: s that will allow the telescopes to be pointed to observe different patches of sky. The four CLASS telescopes will observe at a range of frequencies to separate emission from our

text: galaxy

text: from that of the CMB. One telescope will observe at 40 GHz (7.5 mm wavelength); two telescopes will observe at 90 GHz (3.3 mm wavelength); and the fourth telescope will observe in two frequency bands centered at 150 GHz (2 mm wavelength) and 220 GHz (1.4 mm wavelength). Two separate telescopes, observing at different frequencies, are housed on each mount.

text: The Institute houses several telescopes on its site. Although some scientific work is done with the telescopes, they are mostly used for public observing and astronomical societies. The poor weather and light-pollution in Cambridge makes most modern astronomy difficult. The telescopes on the site include:

text: The majority of astrophysical observations are made using the electromagnetic spectrum.

text: The majority of astrophysical observations are made using the

text: electromagnetic spectrum

text: The use of the VLBA can be scheduled dynamically, and its sensitivity can be improved by a factor of five by including other radio telescopes such as the Arecibo radio telescope in Puerto Rico, the Green Bank Telescope in West Virginia, the Very Large Array (VLA) in New Mexico and the Effelsberg radio telescope in Germany. These four additional sites are brought online for as much as 100 hours per four-month trimester. In this configuration, the entire array is known as the High-Sensitivity Array (HSA). These sites, with coordinates, are as follows:

text: The use of the VLBA can be scheduled dynamically, and its sensitivity can be improved by a factor of five by including other radio telescopes such as the

text: Arecibo radio telescope

text: in Puerto Rico, the

text: Green Bank Telescope

text: in West Virginia, the

text: Very Large Array

text: (VLA) in New Mexico and the

text: Effelsberg radio telescope

text: in Germany. These four additional sites are brought online for as much as 100 hours per four-month trimester. In this configuration, the entire array is known as the High-Sensitivity Array (HSA). These sites, with coordinates, are as follows:

text: In addition to its own observations, an important purpose of the telescope is to find an accurate source location.  With its wide field of view, it can take an approximate location (±1°) from a gamma-ray detector and produce a location accurate to 1″ within a minute, for the benefit of follow-on observations by larger telescopes with longer reaction times.

text: The film is based on Kieślowski's Dekalog: Six, with minor changes and expansions to the script. The most significant change is to the ending, which was rewritten at the suggestion of lead actress Grażyna Szapołowska, who wanted the film to have a "fairytale ending". The original version ends with Tomek back at work, recovered from his attempted suicide, and telling Magda that he does not watch her anymore. The film ends with Magda's more developed concern for Tomek mirroring his earlier obsession with her. The film concludes in Tomek's room after his return from hospital. She looks through his telescope into her own apartment and Kieślowski replays an earlier scene of Magda crying in her kitchen, which had led Tomek to reveal his feelings to her, only this time she is joined and comforted by Tomek. Like Kieślowski's other Dekalog films, it features the mysterious angelic Man in White.

text: The film is based on Kieślowski's

text: Dekalog: Six

text: , with minor changes and expansions to the script. The most significant change is to the ending, which was rewritten at the suggestion of lead actress

text: Grażyna Szapołowska

text: , who wanted the film to have a "fairytale ending". The original version ends with Tomek back at work, recovered from his attempted suicide, and telling Magda that he does not watch her anymore. The film ends with Magda's more developed concern for Tomek mirroring his earlier obsession with her. The film concludes in Tomek's room after his return from hospital. She looks through his telescope into her own apartment and Kieślowski replays an earlier scene of Magda crying in her kitchen, which had led Tomek to reveal his feelings to her, only this time she is joined and comforted by Tomek. Like Kieślowski's other Dekalog films, it features the mysterious angelic Man in White.

text: Most optical phenomena can be accounted for using the classical electromagnetic description of light. Complete electromagnetic descriptions of light are, however, often difficult to apply in practice. Practical optics is usually done using simplified models. The most common of these, geometric optics, treats light as a collection of rays that travel in straight lines and bend when they pass through or reflect from surfaces. Physical optics is a more comprehensive model of light, which includes wave effects such as diffraction and interference that cannot be accounted for in geometric optics. Historically, the ray-based model of light was developed first, followed by the wave model of light. Progress in electromagnetic theory in the 19th century led to the discovery that light waves were in fact electromagnetic radiation.

text: Most optical phenomena can be accounted for using the

text: classical electromagnetic

text: description of light. Complete electromagnetic descriptions of light are, however, often difficult to apply in practice. Practical optics is usually done using simplified models. The most common of these,

text: geometric optics

text: , treats light as a collection of

text: ray

text: s that travel in straight lines and bend when they pass through or reflect from surfaces.

text: Physical optics

text: is a more comprehensive model of light, which includes

text: wave

text: effects such as

text: diffraction

text: and

text: interference

text: that cannot be accounted for in geometric optics. Historically, the ray-based model of light was developed first, followed by the wave model of light. Progress in electromagnetic theory in the 19th century led to the discovery that light waves were in fact electromagnetic radiation.

text: For most substances, absorptions in the visible spectrum are usually attributed to excitations of electronic energy states. However, water is a simple 3-atom molecule, HO, and all its electronic absorptions occur in the ultraviolet region of the electromagnetic spectrum and are therefore not responsible for the color of water in the visible region of the spectrum. Nevertheless, the water molecule has three fundamental modes of vibration, including two stretching vibrations of the O-H bonds which occur at v = 3650 cm and v = 3755 cm. Absorption due to these vibrations occurs in the infrared region of the spectrum. The absorption in the visible spectrum is due mainly to the harmonic v + 3v  = 14,318 cm, which is equivalent to a wavelength of 698 nm.

text: For most substances, absorptions in the visible spectrum are usually attributed to excitations of

text: electronic

text: energy states. However, water is a simple 3-atom

text: molecule

text: , HO, and all its electronic absorptions occur in the

text: ultraviolet

text: region of the

text: electromagnetic spectrum

text: and are therefore not responsible for the color of water in the visible region of the spectrum. Nevertheless, the water molecule has three fundamental modes of

text: vibration

text: , including two stretching vibrations of the O-H

text: bond

text: s which occur at v = 3650 cm and v = 3755 cm. Absorption due to these vibrations occurs in the

text: infrared

text: region of the spectrum. The absorption in the visible spectrum is due mainly to the

text: harmonic

text: v + 3v  = 14,318 cm, which is equivalent to a wavelength of 698 nm.

text: Interest in metamaterials is a result of their flexibility when interacting with and controlling electromagnetic radiation such as light. These are optical materials that can function in a manner similar to glass or prisms. However, these materials extend the capability to control the electromagnetic radiation that flows through them. Also the manner of control is different and new. With conventional materials the way to alter them is to add a chemical or material such as traces of lead added to glass. In contrast, it is the spacing and shape of a given metamaterial's components that define its use and the way it controls electromagnetic radiation. Unlike most conventional materials, researchers in this field can physically control electromagnetic radiation by altering the geometry of the material's components. Also, metamaterials have successfully interacted in electromagnetic bands across the spectrum from radio frequencies, to microwave, terahertz, across the infrared spectrum and almost to visible wavelengths.

text: Interest in metamaterials is a result of their flexibility when interacting with and controlling electromagnetic radiation such as light. These are optical materials that can function in a manner similar to glass or prisms. However, these materials extend the capability to control the

text: electromagnetic radiation

text: that flows through them. Also the manner of control is different and new. With conventional materials the way to alter them is to add a chemical or material such as traces of lead added to glass. In contrast, it is the spacing and shape of a given metamaterial's components that define its use and the way it controls electromagnetic radiation. Unlike most conventional materials, researchers in this field can physically control electromagnetic radiation by altering the geometry of the material's components. Also, metamaterials have successfully interacted in electromagnetic bands across the spectrum from

text: radio frequencies

text: , to

text: microwave

text: terahertz

text: , across the

text: infrared

text: spectrum and almost to

text: visible wavelengths

text: Then he moved to design space orbital observatories, both on board automatic probes and manned spacecraft. Ultraviolet telescope Procyon was on board Kosmos 309 in 1969, and X-ray telescope Altair on board Meteor 1-16 in 1974; both were launched from Plesetsk cosmodrome. The highlight was Orion 2 Space Observatory (see Orion 1 and Orion 2 Space Observatories),  with a wide-angle meniscus telescope of the Cassegrain system, operated on board the spacecraft Soyuz 13 in December 1973.  Spectra of thousands of stars to as faint as 13th magnitude were obtained, the first satellite UV spectrogram of a planetary nebula (IC 2149) was obtained, revealing lines of aluminum  and  titanium - elements not previously observed in planetary nebulae, two photon emission from nebulae was detected for the first time. For comparison, the Skylab’s UV telescope which was on the orbit at the same time, could only look at stars down to 7.5th magnitude. Two years earlier, in April, 1971, the first space station Salyut 1 carried into orbit Orion 1 Space Observatory, the first space telescope with an objective prism.

text: Then he moved to design space orbital observatories, both on board automatic probes and manned spacecraft. Ultraviolet telescope Procyon was on board

text: Kosmos

text: 309 in 1969, and X-ray telescope Altair on board

text: Meteor

text: 1-16 in 1974; both were launched from

text: Plesetsk cosmodrome

text: . The highlight was

text: Orion 2 Space Observatory

text: (see

text: Orion 1 and Orion 2 Space Observatories

text: ),  with a wide-angle meniscus telescope of the Cassegrain system, operated on board the spacecraft

text: Soyuz 13

text: in December 1973.  Spectra of thousands of stars to as faint as 13th magnitude were obtained, the first satellite UV spectrogram of a

text: planetary nebula

text: IC 2149

text: ) was obtained, revealing lines of aluminum  and  titanium - elements not previously observed in

text: planetary nebulae

text: two photon emission

text: from nebulae was detected for the first time. For comparison, the

text: Skylab

text: ’s UV telescope which was on the orbit at the same time, could only look at stars down to 7.5th magnitude. Two years earlier, in April, 1971, the first space station

text: Salyut 1

text: carried into orbit

text: Orion 1 Space Observatory

text: , the first space telescope with an objective prism.

text: In 1911, Carnegie became a sympathetic benefactor to George Ellery Hale, who was trying to build the  Hooker Telescope at Mount Wilson, and donated an additional ten million dollars to the Carnegie Institution with the following suggestion to expedite the construction of the telescope: "I hope the work at Mount Wilson will be vigorously pushed, because I am so anxious to hear the expected results from it. I should like to be satisfied before I depart, that we are going to repay to the old land some part of the debt we owe them by revealing more clearly than ever to them the new heavens." The telescope saw first light on November 2, 1917, with Carnegie still alive.

text: In 1911, Carnegie became a sympathetic benefactor to

text: George Ellery Hale

text: , who was trying to build the

text: Hooker Telescope

text: at

text: Mount Wilson

text: , and donated an additional ten million dollars to the

text: Carnegie Institution

text: with the following suggestion to expedite the construction of the telescope: "I hope the work at Mount Wilson will be vigorously pushed, because I am so anxious to hear the expected results from it. I should like to be satisfied before I depart, that we are going to repay to the old land some part of the debt we owe them by revealing more clearly than ever to them the new heavens." The telescope saw

text: first light

text: on November 2, 1917, with Carnegie still alive.

text: The project "A Radio Telescope for Spain" was conceived from a series of National Development Plans for Radio Astronomy undertaken in the mid and late 90s. These plans culminated in a technical meeting in Madrid in the late 90s where the CAY personnel in conjunction with experts from all over Europe carried out an exhaustive study to define the characteristics required by such a telescope in order to participate actively in the international astronomy community. Once the appropriate homology and applications of the telescope had been selected a feasibility study was carried out with the fundamental objective of determining whether or not it was practical to construct such a telescope in Spain and if so how to maximize the participation of Spanish industry in said project. This study was undertaken by INISEL Espacio and finally the contract for the detailed design and construction was awarded to a German company with a long experience of design and maintenance of radio telescope and radar dishes, MAN Technologie.Thus the initial construction work began in 2000 with the pouring of foundations and the placement of the concrete pedestal, built by ACS, that would support the telescope reflectors and associated support structure. The same year saw the production of the azimuth and elevation bearings by Rothe-Erde and FAQ of Germany respectively. 2000 also saw the construction of the steel back-support structure for the telescope by Schwartz-Hautmont Construcciones Metálicas of Spain. The contract for the design of the focal plane optics was awarded to ESTI of the Technical University of Telecommunications in Madrid to couple the Cassegrain focal plane radiation to the receivers.  In 2001 the contract for the manufacturing of the surface panels of the primary and secondary reflectors was awarded to Schwartz-Hautmont and then installation of the servo-motors to BBH of Germany. Finally in 2003 the electrical installation was completed by ELIMCO of Spain.

text: Optical observations have been made with the Hubble Space Telescope and Keck Telescopes.  The system has also been observed at infrared and sub-millimeter wavelengths. This light is emitted directly by dust grains as a result of their internal heat (modified blackbody radiation). The disk cannot be resolved at these wavelengths, so such observations are measurements of the amount of light coming from the entire system. Observations at increasingly longer wavelengths give information about dust particles of larger sizes and at larger distances from the star. These observations have been made with the James Clerk Maxwell Telescope and Spitzer Space Telescope.

text: Optical observations have been made with the

text: Hubble Space Telescope

text: and

text: Keck Telescope

text: s.  The system has also been observed at

text: infrared

text: and sub-millimeter wavelengths. This light is emitted directly by dust grains as a result of their internal heat (modified

text: blackbody

text: radiation). The disk cannot be resolved at these wavelengths, so such observations are measurements of the amount of light coming from the entire system. Observations at increasingly longer wavelengths give information about dust particles of larger sizes and at larger distances from the star. These observations have been made with the

text: James Clerk Maxwell Telescope

text: and

text: Spitzer Space Telescope

text: As the electrons used for HREELS are of low energy they do not only have a very short mean free path length in the sample materials but also under normal atmospheric conditions. Therefore, one has to set up the spectrometer in UHV.The spectrometer is in general a computer simulated design that optimizes the resolution while keeping an acceptable electron flux.

text: The existence of the Earth's galaxy, the Milky Way, as a separate group of stars, was only proved in the 20th century, along with the existence of "external" galaxies. The observed recession of those galaxies led to the discovery of the expansion of the Universe. Theoretical astronomy led to speculations on the existence of objects such as black holes and neutron stars, which have be used to explain such observed phenomena such as quasars, pulsars, blazars, and radio galaxies. Physical cosmology made huge advances during the 20th century, with the model of the Big Bang, which is heavily supported by evidence provided by cosmic microwave background radiation, Hubble's law, and the cosmological abundances of elements. Space telescopes have enabled measurements in parts of the electromagnetic spectrum normally blocked or blurred by the atmosphere. Recently, in February 2016, it was revealed that the LIGO project had detected evidence of gravitational waves, in September 2015.

text: The existence of the Earth's galaxy, the

text: Milky Way

text: , as a separate group of stars, was only proved in the 20th century, along with the existence of "external" galaxies. The observed recession of those galaxies led to the discovery of the expansion of the

text: Universe

text: . Theoretical astronomy led to speculations on the existence of objects such as

text: black hole

text: s and

text: neutron star

text: s, which have be used to explain such observed phenomena such as

text: quasar

text: s,

text: pulsar

text: s,

text: blazar

text: s, and

text: radio galaxies

text: Physical cosmology

text: made huge advances during the 20th century, with the model of the

text: Big Bang

text: , which is heavily supported by evidence provided by

text: cosmic microwave background radiation

text: Hubble's law

text: , and the

text: cosmological abundances of elements

text: Space telescope

text: s have enabled measurements in parts of the electromagnetic spectrum normally blocked or blurred by the atmosphere. Recently, in February 2016, it was revealed that the

text: LIGO

text: project had detected evidence of

text: gravitational waves

text: , in September 2015.

text: Stern has extensive experience in instrument development, with a strong concentration in ultraviolet technologies. Stern is a principal investigator (PI) in NASA's UV sounding rocket program, and was the project scientist on a Shuttle-deployable SPARTAN astronomical satellite. He was the PI of the advanced, miniaturized HIPPS Pluto breadboard camera/IR spectrometer/UV spectrometer payload for the NASA/Pluto-Kuiper Express mission, and he is the PI of the PERSI imager/spectrometer payload on NASA's New Horizon's Pluto mission. Stern is also the PI of the ALI CE UV Spectrometer for the ESA/NASA Rosetta comet orbiter. He was a member of the New Millennium Deep Space 1 (DS1) mission science team, and is a Co-investigator on both the ESA SPICAM Mars UV spectrometer launched on Mars Express, and the Hubble Space Telescope Cosmic Origins Spectrograph (COS) installed in 2009. He is the PI of the SWUIS ultraviolet imager, which has flown two Shuttle missions, and the SWUIS-A airborne astronomical facility. In this capacity, Stern has flown numerous WB-57 and F-18 airborne research astronomy missions. Stern and his colleague, Dr. Daniel Durda, have been flying on the modified F/A-18 Hornet with a sophisticated camera system called the Southwest Ultraviolet Imaging System (SWUIS). They use the camera to search for a hypothetical group of asteroids (Vulcanoids) between the orbit of Mercury and the Sun that are so elusive and hard to see that scientists are not sure they exist.

text: Stern has extensive experience in instrument development, with a strong concentration in ultraviolet technologies. Stern is a principal investigator (PI) in NASA's UV sounding rocket program, and was the project scientist on a Shuttle-deployable

text: SPARTAN

text: astronomical satellite. He was the PI of the advanced, miniaturized HIPPS Pluto breadboard camera/IR spectrometer/UV spectrometer payload for the NASA/Pluto-Kuiper Express mission, and he is the PI of the PERSI imager/spectrometer payload on NASA's New Horizon's Pluto mission. Stern is also the PI of the ALI CE UV Spectrometer for the ESA/NASA

text: Rosetta

text: comet orbiter. He was a member of the

text: New Millennium Deep Space 1

text: (DS1) mission science team, and is a Co-investigator on both the ESA SPICAM Mars UV spectrometer launched on

text: Mars Express

text: , and the Hubble Space Telescope Cosmic Origins Spectrograph (COS) installed in 2009. He is the PI of the SWUIS ultraviolet imager, which has flown two Shuttle missions, and the SWUIS-A airborne astronomical facility. In this capacity, Stern has flown numerous WB-57 and F-18 airborne research astronomy missions. Stern and his colleague, Dr. Daniel Durda, have been flying on the modified F/A-18 Hornet with a sophisticated camera system called the Southwest Ultraviolet Imaging System (SWUIS). They use the camera to search for a hypothetical group of asteroids (

text: Vulcanoid

text: s) between the orbit of

text: Mercury

text: and the

text: Sun

text: that are so elusive and hard to see that scientists are not sure they exist.

text: The robotic telescopes used by the Faulkes Telescope Project are owned and operated by Las Cumbres Observatory Global Telescope Network (LCOGTN). Users must register for an account via FTP and, providing they meet the criteria for an account (as explained on the FTP website), the account details will be emailed out to the registered user. Students and teachers can then go online and book time on the telescope and run their own 29-minute-long real-time observational session on one of the telescopes,  remotely controlling it over the internet.  These telescopes are the largest robotic telescopes in the world available for UK schools to control in real time.

text: The antenna converts the energy in the electromagnetic radio waves to an alternating electric current in the antenna, which is connected to the tuning coil. Since in a crystal radio all the power comes from the antenna, it is important that the antenna collect as much power from the radio wave as possible. The larger an antenna, the more power it can intercept. Antennas of the type commonly used with crystal sets are most effective when their length is close to a multiple of a quarter-wavelength of the radio waves they are receiving. Since the length of the waves used with crystal radios is very long (AM broadcast band waves are 182-566 m or 597–1857 ft. long) the antenna is made as long as possible, from a long wire, in contrast to the whip antennas or ferrite loopstick antennas used in modern radios.

text: The antenna converts the energy in the electromagnetic

text: radio wave

text: s to an

text: alternating

text: electric current

text: in the antenna, which is connected to the tuning coil. Since in a crystal radio all the power comes from the antenna, it is important that the antenna collect as much power from the radio wave as possible. The larger an antenna, the more power it can intercept. Antennas of the type commonly used with crystal sets are most effective when their length is close to a multiple of a quarter-

text: wavelength

text: of the radio waves they are receiving. Since the length of the waves used with crystal radios is very long (

text: AM broadcast

text: band waves are 182-566

text: m

text: or 597–1857 ft. long) the antenna is made as long as possible, from a

text: long wire

text: , in contrast to the

text: whip antenna

text: s or ferrite

text: loopstick antennas

text: used in modern radios.

text: VRTX runs the Hubble Space Telescope.

text: VRTX runs the

text: Hubble Space Telescope

text: These waves are solutions for a scalar wave equation in a homogeneous medium.  For vector wave equations, such as the ones describing electromagnetic radiation or waves in an elastic solid, the solution for a homogeneous medium is similar: the scalar amplitude A is replaced by a constant vector A.  For example, in electromagnetism A is typically the vector for the electric field, magnetic field, or vector potential.  A transverse wave is one in which the amplitude vector is orthogonal to k, which is the case for electromagnetic waves in an isotropic medium.  By contrast, a longitudinal wave is one in which the amplitude vector is parallel to k, such as for acoustic waves in a gas or fluid.

text: These waves are solutions for a

text: scalar

text: wave equation

text: in a homogeneous medium.  For

text: vector

text: wave equations, such as the ones describing

text: electromagnetic radiation

text: or waves in an elastic solid, the solution for a homogeneous medium is similar: the scalar amplitude A is replaced by a constant vector A.  For example, in

text: electromagnetism

text: A is typically the vector for the

text: electric field

text: magnetic field

text: , or

text: vector potential

text: .  A

text: transverse wave

text: is one in which the amplitude vector is

text: orthogonal

text: to k, which is the case for electromagnetic waves in an

text: isotropic

text: medium.  By contrast, a

text: longitudinal wave

text: is one in which the amplitude vector is parallel to k, such as for acoustic waves in a gas or fluid.

text: The Japanese National Institute of Natural Sciences (NINS) is the umbrella agency maintaining a radio astronomy facility on Chichijima.  Since 2004, the National Astronomical Observatory of Japan (NAOJ) has been a division of NINS.  The NINS/NAQJ research is on-going using a VLBI Exploration of Radio Astronomy (VERA) 20m radio telescope. The dual-beam VERA array consists of four coordinated radio telescope stations located at Mizusawa, Iriki, Ishigakijima and Ogasawara.  The combined signals of the four-part array produce a correlated image which is used for deep space study.

text: The Japanese

entity_name: National Institutes of Natural Sciences, Japan

text: National Institute of Natural Sciences

text: (NINS) is the umbrella agency maintaining a radio astronomy facility on Chichijima.  Since 2004, the

entity_name: National Astronomical Observatory of Japan

text: National Astronomical Observatory of Japan

text: NAOJ

text: ) has been a division of NINS.  The NINS/NAQJ research is on-going using a

text: VLBI

text: Exploration of Radio Astronomy (

text: VERA

text: ) 20m radio telescope. The dual-beam VERA array consists of four coordinated radio telescope stations located at

text: Mizusawa

text: Iriki

text: Ishigakijima

text: and Ogasawara.  The combined signals of the four-part array produce a correlated image which is used for deep space study.

text: In 1985, Faber was involved with the construction of the Keck Telescope and building the first wide-field planetary camera for the Hubble Space Telescope.  UC Berkeley physicist Jerry Nelson designed the Keck telescope, but Faber helped to sell the idea of large optical telescopes all over the world.  The Keck telescope is the largest optical telescope in the world, with a 10-meter primary mirror of a novel type that consists of 36 hexagonal segments.

text: In 1985, Faber was involved with the construction of the Keck Telescope and building the first wide-field planetary camera for the

text: Hubble Space Telescope

text: UC Berkeley

text: physicist

text: Jerry Nelson

text: designed the Keck telescope, but Faber helped to sell the idea of large optical telescopes all over the world.  The Keck telescope is the largest optical telescope in the world, with a 10-meter primary mirror of a novel type that consists of 36 hexagonal segments.

text: In the summer of 1937, Reber decided to build his own radio telescope in his back yard in Wheaton. Reber's radio telescope was considerably more advanced than Jansky's, consisting of a parabolic sheet metal dish 9 meters in diameter, focusing to a radio receiver 8 meters above the dish. The entire assembly was mounted on a tilting stand, allowing it to be pointed in various directions, though not turned. The telescope was completed in September 1937.

text: In the summer of 1937, Reber decided to build his own

text: radio telescope

text: in his back yard in

text: Wheaton

text: Reber's radio telescope

text: was considerably more advanced than Jansky's, consisting of a parabolic sheet metal dish 9 meters in diameter, focusing to a radio receiver 8 meters above the dish. The entire assembly was mounted on a tilting stand, allowing it to be pointed in various directions, though not turned. The telescope was completed in September 1937.

text: The Ultra Low Energy Isotope Spectrometer (ULEIS) on the ACE spacecraft is an ultra-high-resolution mass spectrometer that measures particle composition and energy spectra of elements He–Ni with energies from ~45 keV/nucleonto a few MeV/nucleon. ULEIS investigates particles accelerated in solar energetic particle events, interplanetary shocks, and at the solar windtermination shock. By determining energy spectra, mass composition, and their temporal variationsin conjunction with other ACE instruments, ULEIS greatly improves our knowledge of solarabundances, as well as other reservoirs such as the local interstellar medium. ULEIS combines the high sensitivity required to measure low particle fluxes, along with the capability tooperate in the largest solar particle or interplanetary shock events. In addition to detailed informationfor individual ions, ULEIS features a wide range of count rates for different ions and energies that allows accurate determination of particle fluxes and anisotropies over short (few minutes) time scales.

text: The Ultra Low Energy Isotope Spectrometer (ULEIS) on the ACE spacecraft is an ultra-high-resolution mass spectrometer that measures particle composition and energy spectra of elements He–Ni with energies from ~45 keV/nucleonto a few MeV/nucleon. ULEIS investigates particles accelerated in

text: solar energetic particle

text: events, interplanetary shocks, and at the

text: solar wind

text: termination shock. By determining energy spectra, mass composition, and their temporal variationsin conjunction with other ACE instruments, ULEIS greatly improves our knowledge of solarabundances, as well as other reservoirs such as the local

text: interstellar medium

text: . ULEIS combines the high sensitivity required to measure low particle fluxes, along with the capability tooperate in the largest solar particle or interplanetary shock events. In addition to detailed informationfor individual ions, ULEIS features a wide range of count rates for different ions and energies that allows accurate determination of particle fluxes and anisotropies over short (few minutes) time scales.

text: EIT is the first long-duration instrument to use normal incidence multilayer coated optics to image the Sun in  extreme ultraviolet.  This portion of the spectrum is extremely difficult to reflect, as most matter absorbs the light very strongly.  Conventionally these wavelengths have been reflected either using grazing incidence (as in a Wolter telescope for imaging X-rays) or a diffraction grating (as in the jocularly-termed overlappograph flown on Skylab in the mid 1970s).  Modern vacuum deposition technology allows mirrors to be coated with extremely thin layers of nearly any material.  The multilayer mirrors in an EUV telescope are coated with alternate layers of a light "spacer" element (such as silicon) that absorbs EUV light only weakly, and a heavy "scatterer" element (such as molybdenum) that absorbs EUV light very strongly.  Perhaps 100 layers of each type might be placed on the mirror, with a thickness of around 10 nm each.  The layer thickness is tightly controlled, so that at the desired wavelength, reflected photons from each layer interfere constructively.  In this way, reflectivities of up to ~50% can be attained.

text: EIT is the first long-duration instrument to use

text: normal incidence

text: multilayer

text: coated optics

text: to image the

text: Sun

text: in

text: extreme ultraviolet

text: .  This portion of the spectrum is extremely difficult to reflect, as most

text: matter

text: absorbs the light very strongly.  Conventionally these wavelengths have been reflected either using

text: grazing incidence

text: (as in a

text: Wolter telescope

text: for imaging

text: X-rays

text: ) or a

text: diffraction grating

text: (as in the jocularly-termed

text: overlappograph

text: flown on

text: Skylab

text: in the mid 1970s).  Modern

text: vacuum deposition

text: technology allows mirrors to be coated with extremely thin layers of nearly any material.  The multilayer mirrors in an EUV telescope are coated with alternate layers of a light "spacer" element (such as

text: silicon

text: ) that absorbs EUV light only weakly, and a heavy "scatterer" element (such as

text: molybdenum

text: ) that absorbs EUV light very strongly.  Perhaps 100 layers of each type might be placed on the mirror, with a thickness of around 10

text: nm

text: each.  The layer thickness is tightly controlled, so that at the desired wavelength, reflected photons from each layer interfere constructively.  In this way, reflectivities of up to ~50% can be attained.

text: Nine teams competed in what was initially called the Junior competition, but later was known as B Grade.  Starlight B were the premiers, winning gold medals and a cup presented by the publican of the Commonwealth Hotel, Mr. W. Hartigan. The nine teams were Belvideres, Blackstone, Harrisville (late entry), Montes (also known as Silkstone), St Paul’s, Starlights A, Starlights B, Western Suburbs A and Western Suburbs B (withdrew).

text: In 2006 the Zadko telescope, a robotic optical telescope, was installed into the 'Zadko Dome' near the Gravitational Observatory. The Zadko telescope is used for research on a worldwide scale, scanning the sky for potentially hazardous asteroids, and can be accessed remotely via the internet. It is a joint resource for the International Centre for Radio Astronomy Research. It is an equatorial fork-mounted Cassegrain reflector telescope with a primary mirror aperture of 1.007 m and a focal length of 4.0386 m. The telescope's optical design is a hybrid Ritchey–Chrétien.

text: In 2006 the Zadko telescope, a robotic optical telescope, was installed into the 'Zadko Dome' near the Gravitational Observatory. The Zadko telescope is used for research on a worldwide scale, scanning the sky for potentially hazardous asteroids, and can be accessed remotely via the internet. It is a joint resource for the

entity_name: International Centre for Radio Astronomy Research

text: International Centre for Radio Astronomy Research

text: . It is an equatorial fork-mounted

text: Cassegrain reflector

text: telescope with a primary mirror aperture of 1.007 m and a focal length of 4.0386 m. The telescope's optical design is a hybrid

text: Ritchey–Chrétien

text: The technique used by the team to find XO-1b is an innovative method in that it uses a relatively inexpensive telescope to hunt for extrasolar planets. It, however, is limited primarily to planets orbiting close to their parent stars, and only finds planets large enough to cause a measurable depression in starlight.

text: The observatory is home to the  Vainu Bappu Telescope, the largest telescope in Asia.  It has a diameter of 2.3 meters and was first used in 1986.  Along with the Vainu Bappu telescope, the observatory has two other telescopes: A 1 meter Zeiss manufactured and another 75 centimeter cassegrain reflector currently being refurbished.  The observatory also has a Fabry–Pérot interferometer.

text: The observatory is home to the  Vainu Bappu Telescope, the largest telescope in Asia.  It has a diameter of 2.3 meters and was first used in 1986.  Along with the Vainu Bappu telescope, the observatory has two other telescopes: A 1 meter Zeiss manufactured and another 75 centimeter cassegrain reflector currently being refurbished.  The observatory also has a

text: Fabry–Pérot interferometer

text: The 3.6m DOT is currently the largest reflecting telescope in Asia. The telescope intends to fill a large longitudinal gap in the 4m class of telescopes in the Asia region. The telescope features an optical spectrograph, a CCD imager and a near-infrared spectrograph. The telescope is also the first of kind in India that features an active optics system, featuring a wavefront sensor and pneumatic actuators which compensates for small distortions in the shape of the 4.3 tonne mirror due to gravity or atmospheric aberrations.

text: The 3.6m DOT is currently the largest reflecting telescope in Asia. The telescope intends to fill a large longitudinal gap in the 4m class of telescopes in the Asia region. The telescope features an optical spectrograph, a CCD imager and a near-infrared spectrograph. The telescope is also the first of kind in India that features an

text: active optics

text: system, featuring a wavefront sensor and pneumatic actuators which compensates for small distortions in the shape of the 4.3 tonne mirror due to gravity or atmospheric aberrations.

text: Parsons improved the techniques of casting, grinding and polishing large telescope mirrors from speculum metal, and constructed steam-powered grinding machines for parabolic mirrors. His 3 ft (90 cm) mirror of 1839 was cast in smaller pieces, fitted together before grinding and polishing; its 1840 successor was cast in a single piece. In 1842, Parsons cast his first 6 ft (1.8 m) mirror, but it took another five casts, before he had two ground and polished mirrors. Speculum mirrors tarnished rapidly; with two mirrors, one could be used in the telescope while the other was being re-polished. The telescope tube and supporting structure were completed in 1845.

text: Parsons improved the techniques of casting, grinding and polishing large telescope mirrors from

text: speculum metal

text: , and constructed steam-powered grinding machines for parabolic mirrors. His 3 ft (90 cm) mirror of 1839 was cast in smaller pieces, fitted together before grinding and polishing; its 1840 successor was cast in a single piece. In 1842, Parsons cast his first 6 ft (1.8 m) mirror, but it took another five casts, before he had two ground and polished mirrors. Speculum mirrors tarnished rapidly; with two mirrors, one could be used in the telescope while the other was being re-polished. The telescope tube and supporting structure were completed in 1845.

text: The following are lists of devices categorized as types of telescopes or devices associated with telescopes. They are broken into major classifications with many variations due to professional, amateur, and commercial sub-types. Telescopes can be classified by optical design or mechanical design/construction. Telescopes can also be classified by where they are placed, such as space telescopes. One major determining factor is type of light, or particle being observed including devices referred to as "telescopes" that do not form an image or use optics. Some telescopes are classified by the task they perform; for example Solar telescopes are all designs that look at the Sun, Dobsonian telescopes are designed to be low cost and portable, Aerial telescopes overcame the optical shortcomings of 17th century objective lenses, etc.

text: The following are lists of devices categorized as types of telescopes or devices associated with

text: telescope

text: s. They are broken into major classifications with many variations due to professional, amateur, and commercial sub-types. Telescopes can be classified by optical design or mechanical design/construction. Telescopes can also be classified by where they are placed, such as

text: space telescope

text: s. One major determining factor is type of light, or particle being observed including devices referred to as "telescopes" that do not form an image or use optics. Some telescopes are classified by the task they perform; for example

text: Solar telescope

text: s are all designs that look at the

text: Sun

text: Dobsonian telescope

text: s are designed to be low cost and portable,

text: Aerial telescope

text: s overcame the optical shortcomings of 17th century objective lenses, etc.

text: A reflecting telescope (also called a reflector) is an optical telescope which uses a single or combination of curved mirrors that reflect light and form an image. The reflecting telescope was invented in the 17th century as an alternative to the refracting telescope which, at that time, was a design that suffered from severe chromatic aberration. Although reflecting telescopes produce other types of optical aberrations, it is a design that allows for very large diameter objectives. Almost all of the major telescopes used in astronomy research are reflectors. Reflecting telescopes come in many design variations and may employ extra optical elements to improve image quality or place the image in a mechanically advantageous position. Since reflecting telescopes use mirrors, the design is sometimes referred to as a "catoptric" telescope.

text: A reflecting telescope (also called a reflector) is an

text: optical telescope

text: which uses a single or combination of

text: curved mirror

text: s that reflect

text: light

text: and form an

text: image

text: . The reflecting telescope was invented in the 17th century as an alternative to the

text: refracting telescope

text: which, at that time, was a design that suffered from severe

text: chromatic aberration

text: . Although reflecting telescopes produce other types of optical aberrations, it is a design that allows for very large diameter

text: objectives

text: . Almost all of the major telescopes used in

text: astronomy

text: research are reflectors. Reflecting telescopes come in many design variations and may employ extra optical elements to improve image quality or place the image in a mechanically advantageous position. Since reflecting telescopes use

text: mirror

text: s, the design is sometimes referred to as a "

text: catoptric

text: " telescope.

text: Of the moons discovered by the Voyager 2 imaging team, only Puck was discovered early enough that the probe could be programmed to image it in some detail. Images showed that Puck has a shape of a slightly prolate spheroid (ratio between axes is 0.97 ± 0.04). Its surface is heavily cratered and is grey in color. There are three named craters on the surface of Puck, the largest being about 45 km in diameter. Observations with the Hubble Space Telescope and large terrestrial telescopes found water-ice absorption features in the spectrum of Puck.

text: Of the moons discovered by the Voyager 2 imaging team, only Puck was discovered early enough that the probe could be programmed to image it in some detail. Images showed that Puck has a shape of a slightly

text: prolate

text: spheroid

text: (ratio between axes is 0.97 ± 0.04). Its surface is heavily cratered and is grey in color. There are three named

text: crater

text: s on the surface of Puck, the largest being about 45 km in diameter. Observations with the

text: Hubble Space Telescope

text: and large terrestrial telescopes found water-ice absorption features in the spectrum of Puck.

text: Pulsars are rapidly rotating stars. A pulsar emits beams of radio waves that, like lighthouse beams, sweep through the sky as the pulsar rotates. The signal from a pulsar can be detected by radio telescopes as a series of regularly spaced pulses, essentially like the ticks of a clock. Gravitational waves affect the time it takes the pulses to travel from the pulsar to a telescope on Earth. A pulsar timing array uses millisecond pulsars to seek out perturbations due to gravitational waves in measurements of pulse arrival times at a telescope, in other words, to look for deviations in the clock ticks. In particular, pulsar timing arrays can search for a distinct pattern of correlation and anti-correlation between the signals over an array of different pulsars (resulting in the name "pulsar timing array"). Although pulsar pulses travel through space for hundreds or thousands of years to reach us, pulsar timing arrays are sensitive to perturbations in their travel time of much less than a millionth of a second.	Globally there are three active pulsar timing array projects. The North American Nanohertz Gravitational Wave Observatory uses data collected by the Arecibo Radio Telescope and Green Bank Telescope. The Parkes Pulsar Timing Array at the Parkes radio-telescope has been collecting data since March 2005. The European Pulsar Timing Array uses data from the four largest telescopes in Europe: the Lovell Telescope, the Westerbork Synthesis Radio Telescope, the Effelsberg Telescope and the Nancay Radio Telescope. (Upon completion the Sardinia Radio Telescope will be added to the EPTA also.) These three projects have begun collaborating under the title of the International Pulsar Timing Array project.

text: Pulsars are rapidly rotating stars. A pulsar emits beams of radio waves that, like lighthouse beams, sweep through the sky as the pulsar rotates. The signal from a pulsar can be detected by radio telescopes as a series of regularly spaced pulses, essentially like the ticks of a clock. Gravitational waves affect the time it takes the pulses to travel from the pulsar to a telescope on Earth. A

text: pulsar timing array

text: uses

text: millisecond pulsar

text: s to seek out perturbations due to gravitational waves in measurements of pulse arrival times at a telescope, in other words, to look for deviations in the clock ticks. In particular, pulsar timing arrays can search for a distinct pattern of correlation and anti-correlation between the signals over an array of different pulsars (resulting in the name "pulsar timing array"). Although pulsar pulses travel through space for hundreds or thousands of years to reach us, pulsar timing arrays are sensitive to perturbations in their travel time of much less than a millionth of a second.	Globally there are three active pulsar timing array projects. The North American Nanohertz Gravitational Wave Observatory uses data collected by the Arecibo Radio Telescope and

text: Green Bank Telescope

text: . The Parkes Pulsar Timing Array at the

text: Parkes radio-telescope

text: has been collecting data since March 2005. The European Pulsar Timing Array uses data from the four largest telescopes in Europe: the

text: Lovell Telescope

text: , the

text: Westerbork Synthesis Radio Telescope

text: , the

text: Effelsberg Telescope

text: and the

text: Nancay Radio Telescope

text: . (Upon completion the Sardinia Radio Telescope will be added to the EPTA also.) These three projects have begun collaborating under the title of the

text: International Pulsar Timing Array

text: project.

text: Contrary to the classical image of an old astronomer peering through a telescope through the dark hours of the night, it is far more common to use a charge-coupled device (CCD) camera to record a long, deep exposure, allowing a more sensitive image to be created because the light is added over time. Before CCDs, photographic plates were a common method of observation. Modern astronomers spend relatively little time at telescopes usually just a few weeks per year. Analysis of observed phenomena, along with making predictions as to the causes of what they observe, takes the majority of observational astronomers' time.

text: Contrary to the classical image of an old astronomer peering through a

text: telescope

text: through the dark hours of the night, it is far more common to use a

text: charge-coupled device

text: (CCD) camera to record a long, deep exposure, allowing a more sensitive image to be created because the

text: light

text: is added over time. Before CCDs,

text: photographic plates

text: were a common method of observation. Modern astronomers spend relatively little time at telescopes usually just a few weeks per year. Analysis of observed phenomena, along with making predictions as to the causes of what they observe, takes the majority of observational astronomers' time.

text: The Space Telescope Science Institute is located on the Homewood Campus and controls, analyzes, and collects data from the Hubble Space Telescope.

text: The

text: Space Telescope Science Institute

text: is located on the Homewood Campus and controls, analyzes, and collects data from the

text: Hubble Space Telescope

text: Electromagnetic transitions in atoms, molecules and condensed matter mainly take place at energies corresponding to the UV and visible part of the spectrum. Core electrons in atoms, and a lot of other phenomena, are observed with different brands of XAS in the X-ray energy range. Electromagnetic transitions in atomic nuclei, as observed in Mössbauer spectroscopy, take place in the gamma ray part of the spectrum. The main factors that cause broadening of the spectral line into an absorption band of a molecular solid are the distributions of vibrational and rotational energies of the molecules in the sample (and also those of their excited states). In solid crystals the shape of absorption bands are determined by the density of states of initial and final states of electronic states or lattice vibrations, called phonons, in the crystal structure. In gas phase spectroscopy, the fine structure afforded by these factors can be discerned, but in solution-state spectroscopy, the differences in molecular micro environments further broaden the structure to give smooth bands. Electronic transition bands of molecules may be from tens to several hundred nanometers in breadth.

text: Electromagnetic transitions

text: in atoms, molecules and condensed matter mainly take place at energies corresponding to the

text: UV

text: and

text: visible

text: part of the spectrum.

text: Core electron

text: s in atoms, and a lot of other phenomena, are observed with different brands of

text: XAS

text: in the

text: X-ray

text: energy range. Electromagnetic transitions in

text: atomic nuclei

text: , as observed in

text: Mössbauer spectroscopy

text: , take place in the

text: gamma ray

text: part of the spectrum. The main factors that cause

text: broadening

text: of the spectral line into an absorption band of a molecular solid are the distributions of vibrational and rotational energies of the molecules in the sample (and also those of their excited states). In solid crystals the shape of absorption bands are determined by the

text: density of states

text: of initial and final states of electronic states or lattice vibrations, called

text: phonon

text: s, in the

text: crystal structure

text: . In gas phase spectroscopy, the

text: fine structure

text: afforded by these factors can be discerned, but in solution-state spectroscopy, the differences in molecular micro environments further broaden the structure to give smooth bands. Electronic transition bands of molecules may be from tens to several hundred nanometers in breadth.

text: Deep wide-field imaging from Subaru/Suprime-Cam is used to identify and measure the positions of candidate globular clusters around each survey galaxy. Several (up to 4) DEIMOS masks are then created which include slits corresponding to the locations of globular clusters, galaxy starlight and random background sky locations in the outer parts of the mask. The DEIMOS spectrograph is centred on wavelengths around the Calcium Triplet lines (~850 nm). After a typical 2 hour exposure per mask, spectra of globular clusters and galaxy starlight is obtained.  Using a technique called SKiMS (Stellar Kinematics from Multiple Slits) it is possible to extract the kinematics (and metallicity) of galaxy starlight out to 3 effective radii. Equivalent data for the globular clusters is obtained out to ~10 effective radii. The DEIMOS instrument has the advantages of being a stable, high throughput, wide-field spectrograph coupled with excellent velocity resolution (~12 km/s) on a 10m telescope. This technique effectively uses DEIMOS as a pseudo wide area integral field unit.

text: Deep wide-field imaging from Subaru/Suprime-Cam is used to identify and measure the positions of candidate globular clusters around each survey galaxy. Several (up to 4) DEIMOS masks are then created which include slits corresponding to the locations of globular clusters, galaxy starlight and random background sky locations in the outer parts of the mask. The DEIMOS spectrograph is centred on wavelengths around the

text: Calcium Triplet lines

text: (~850 nm). After a typical 2 hour exposure per mask, spectra of globular clusters and galaxy starlight is obtained.  Using a technique called SKiMS (Stellar Kinematics from Multiple Slits) it is possible to extract the kinematics (and metallicity) of galaxy starlight out to 3

text: effective radii

text: . Equivalent data for the globular clusters is obtained out to ~10 effective radii. The DEIMOS instrument has the advantages of being a stable, high throughput, wide-field spectrograph coupled with excellent velocity resolution (~12 km/s) on a 10m telescope. This technique effectively uses DEIMOS as a pseudo wide area

text: integral field unit

text: The 2012 National Reconnaissance Office space telescope donation to NASA was the declassification and donation to NASA of two identical space telescopes by the United States National Reconnaissance Office. The donation has been described by scientists as a substantial improvement over NASA's current Hubble Space Telescope. Although the telescopes themselves are being given to NASA at no cost, the space agency must still pay for the cost of instruments and electronics for the telescopes, as well as the launch of the telescopes. Scientists plan to use one of the telescopes as the basis for an improved version of the proposed Wide Field Infrared Survey Telescope (WFIRST).

text: The 2012 National Reconnaissance Office space telescope donation to NASA was the

text: declassification

text: and donation to

text: NASA

text: of two identical

text: space telescope

text: s by the United States

text: National Reconnaissance Office

text: . The donation has been described by scientists as a substantial improvement over NASA's current

text: Hubble Space Telescope

text: . Although the telescopes themselves are being given to NASA at no cost, the space agency must still pay for the cost of instruments and electronics for the telescopes, as well as the launch of the telescopes. Scientists plan to use one of the telescopes as the basis for an improved version of the proposed

text: Wide Field Infrared Survey Telescope

text: (WFIRST).

text: This term describes what can be seen using a telescope, when viewing an object or range the observer may use many different techniques. Understanding what can be viewed and how to view it depends on the field of view. Viewing an object at a size that fits entirely in the field of view is measured using the two telescope properties—focal length and aperture, with the inclusion of an ocular eyepiece with suitable focal length (or diameter). Comparing the observable world and the angular diameter of an object shows how much of the object we see. However, the relationship with the optical system may not result in high surface brightness. Celestial objects are often dim because of their vast distance, and detail may be limited by diffraction or unsuitable optical properties.

text: This term describes what can be seen using a telescope, when viewing an object or range the observer may use many different techniques. Understanding what can be viewed and how to view it depends on the

text: field of view

text: . Viewing an object at a size that fits entirely in the

text: field of view

text: is measured using the two telescope properties—

text: focal length

text: and

text: aperture

text: , with the inclusion of an ocular

text: eyepiece

text: with suitable

text: focal length

text: (or diameter). Comparing the observable world and the

text: angular diameter

text: of an object shows how much of the object we see. However, the relationship with the optical system may not result in high

text: surface brightness

text: . Celestial objects are often dim because of their vast distance, and detail may be limited by

text: diffraction

text: or unsuitable optical properties.

text: Visible-light astronomy encompasses a wide variety of observations via telescopes that are sensitive in the range of visible light (optical telescopes).  It includes imaging, where a picture of some sort is made of the object; photometry, where the amount of light coming from an object is measured, spectroscopy, where the distribution of that light with respect to its wavelength is measured, and polarimetry where the polarisation state of that light is measured.  An example of spectroscopy is the study of spectral lines to understand of what kind of matter light is going through. Visible astronomy also includes looking up at night (skygazing).  Visible-light astronomy is part of optical astronomy, and differs from astronomies based on invisible types of light in the electromagnetic radiation spectrum, such as radio waves, infrared waves, ultraviolet waves, X-ray waves and gamma-ray waves.

text: Visible-light astronomy encompasses a wide variety of

text: observation

text: s via

text: telescope

text: s that are sensitive in the range of

text: visible light

text: optical telescope

text: s).  It includes imaging, where a picture of some sort is made of the object;

text: photometry

text: , where the amount of light coming from an object is measured,

text: spectroscopy

text: , where the distribution of that light with respect to its

text: wavelength

text: is measured, and

text: polarimetry

text: where the

text: polarisation

text: state of that light is measured.  An example of

text: spectroscopy

text: is the study of

text: spectral line

text: s to understand of what kind of

text: matter

text: light is going through. Visible astronomy also includes looking up at night (

text: skygazing

text: ).  Visible-light astronomy is part of optical astronomy, and differs from astronomies based on invisible types of light in the

text: electromagnetic radiation spectrum

text: , such as

text: radio waves

text: infrared waves

text: ultraviolet waves

text: X-ray waves

text: and

text: gamma-ray waves

text: Tholins might have also been detected in the stellar system of an eight-million-year-old star known as HR 4796A using the Near-Infrared Camera and Multi-Object Spectrometer (NICMOS) aboard the Hubble Space Telescope. The HR 4796 system is approximately 220 light years from Earth.

text: Tholins might have also been detected in the stellar system of an eight-million-year-old star known as

text: HR 4796A

text: using the

text: Near-Infrared Camera and Multi-Object Spectrometer (NICMOS)

text: aboard the Hubble Space Telescope. The

text: HR 4796

text: system is approximately 220 light years from Earth.

text: The Mark IV, V and VA telescopes were three proposals that were put forward in the 1960s through to the 1980s to build an even larger radio telescope than the Lovell. The Mark IV would have been a  diameter standalone telescope, built as a national project. The Mark V would have been a  moveable telescope. The original concept of this telescope had it located on a 3/4-mile long railway line adjoining Jodrell Bank, however concerns about the future levels of interference meant that a site in Wales would have been used (the preferred site was near Meifod). Several design proposals were put forward, one by Husband and Co., the other by Freeman Fox, who had designed the Parkes Observatory telescope. The Mark VA followed on from the Mark V, but with a smaller dish of  and a design using prestressed concrete, similar to the Mark II (the previous two designs more closely resembled the Lovell telescope).

text: The Mark IV, V and VA telescopes were three proposals that were put forward in the 1960s through to the 1980s to build an even larger radio telescope than the Lovell. The Mark IV would have been a  diameter standalone telescope, built as a national project. The Mark V would have been a  moveable telescope. The original concept of this telescope had it located on a 3/4-mile long railway line adjoining Jodrell Bank, however concerns about the future levels of interference meant that a site in

text: Wales

text: would have been used (the preferred site was near

text: Meifod

text: ). Several design proposals were put forward, one by Husband and Co., the other by Freeman Fox, who had designed the

text: Parkes Observatory

text: telescope. The Mark VA followed on from the Mark V, but with a smaller dish of  and a design using

text: prestressed concrete

text: , similar to the

text: Mark II

text: (the previous two designs more closely resembled the Lovell telescope).

text: Three extremely large telescopes will be the next generation of segmented mirror telescopes and are planned to be commissioned between 2021 and 2024. The Giant Magellan Telescope, uses very large segments and is either grouped with segmented mirrors telescopes or its own category. Planned for completion in 2021. The Thirty meter telescope is being built at the Mauna Kea Observatories in Hawaii (estimated first-light by 2022). The European Extremely Large Telescope will be the largest of all three, using a total of 798 segments for its primary mirror. Its first-light is expected for 2024.

text: Three

text: extremely large telescope

text: s will be the next generation of segmented mirror telescopes and are planned to be commissioned between 2021 and 2024. The

text: Giant Magellan Telescope

text: , uses very large segments and is either grouped with segmented mirrors telescopes or its own category. Planned for completion in 2021. The

text: Thirty meter telescope

text: is being built at the Mauna Kea Observatories in Hawaii (estimated first-light by 2022). The

text: European Extremely Large Telescope

text: will be the largest of all three, using a total of 798 segments for its primary mirror. Its first-light is expected for 2024.

text: The Very Large Telescope (VLT), the largest telescope on Paranal, is composed of four separate  telescopes. In addition, the four main telescopes can combine their light to make a fifth instrument, the Very Large Telescope Interferometer (VLTI). Four auxiliary telescopes of  each are also part of the VLTI to make it available when the main telescopes are being used for other projects.

text: The

text: Very Large Telescope

text: (VLT), the largest telescope on Paranal, is composed of four separate  telescopes. In addition, the four main telescopes can combine their light to make a fifth instrument, the Very Large Telescope Interferometer (VLTI). Four auxiliary telescopes of  each are also part of the VLTI to make it available when the main telescopes are being used for other projects.

text: In 1636 Marin Mersenne proposed a telescope consisting of a paraboloidal primary mirror and a paraboloidal secondary mirror bouncing the image through a hole in the primary, solving the problem of viewing the image. James Gregory went into further detail in his book Optica Promota (1663), pointing out that a reflecting telescope with a mirror that was shaped like the part of a conic section, would correct spherical aberration as well as the chromatic aberration seen in refractors. The design he came up with bears his name: the "Gregorian telescope"; but according to his own confession, Gregory had no practical skill and he could find no optician capable of realizing his ideas and after some fruitless attempts, was obliged to abandon all hope of bringing his telescope into practical use.

text: In 1636

text: Marin Mersenne

text: proposed a telescope consisting of a paraboloidal primary mirror and a paraboloidal secondary mirror bouncing the image through a hole in the primary, solving the problem of viewing the image.

text: James Gregory

text: went into further detail in his book Optica Promota (1663), pointing out that a reflecting telescope with a mirror that was shaped like the part of a

text: conic section

text: , would correct

text: spherical aberration

text: as well as the chromatic aberration seen in refractors. The design he came up with bears his name: the "

text: Gregorian telescope

text: "; but according to his own confession, Gregory had no practical skill and he could find no optician capable of realizing his ideas and after some fruitless attempts, was obliged to abandon all hope of bringing his telescope into practical use.

text: The idea of a spherical reflecting mirror with a steerable secondary has since been used in optical telescopes, in particular the Hobby–Eberly Telescope and the Southern African Large Telescope.

text: The idea of a spherical reflecting mirror with a steerable secondary has since been used in optical telescopes, in particular the

text: Hobby–Eberly Telescope

text: and the

text: Southern African Large Telescope

text: The astronomical seeing conditions at an observatory can be conveniently described by the parameters r and t. For telescopes with diameters smaller than r, the resolution of long-exposure images is determined primarily by diffraction and the size of the Airy pattern and thus is inversely proportional to the telescope diameter. For telescopes with diameters larger than r, the image resolution is determined primarily by the atmosphere and is independent of telescope diameter, remaining constant at the value given by a telescope of diameter equal to r. r also corresponds to the length-scale over which the turbulence becomes significant (10–20 cm at visible wavelengths at good observatories), and t corresponds to the time-scale over which the changes in the turbulence become significant. r determines the spacing of the actuators needed in an adaptive optics system, and t determines the correction speed required to compensate for the effects of the atmosphere.

text: The astronomical seeing conditions at an observatory can be conveniently described by the parameters r and t. For telescopes with diameters smaller than r, the resolution of long-exposure images is determined primarily by diffraction and the size of the Airy pattern and thus is inversely proportional to the telescope diameter. For telescopes with diameters larger than r, the image resolution is determined primarily by the atmosphere and is independent of telescope diameter, remaining constant at the value given by a telescope of diameter equal to r. r also corresponds to the length-scale over which the turbulence becomes significant (10–20 cm at visible wavelengths at good observatories), and t corresponds to the time-scale over which the changes in the turbulence become significant. r determines the spacing of the actuators needed in an

text: adaptive optics

text: system, and t determines the correction speed required to compensate for the effects of the atmosphere.

text: Sunshield is a component of the James Webb Space Telescope, that acts as large parasol allowing the main mirror and optics and the instruments to passively cool down to at least 50 Kelvin (-370 °F, or -223 °C). It consists of layers of Kapton and is big enough to shade the main mirror and secondary mirror, with only one instrument, the one that observes mid-infrared, needing extra cooling. It has five layers to help stop the conduction of heat, and they layers also have a special coating to emit and reflect heat into space. The first layer is 0.002 inches thick and the rest of the layers are 0.001 inches thick. The kite-shaped sunshield about is 22 meters by 10 meters in size. In operation it will receive about 300 kilowatts of solar radiation, but only pass 23 milliwatts on the other side. It is a V-groove radiator and causes a temperature drop of 300 degrees kelvin/Celsius (570 degrees Fahrenheit) from front to back. The reason why the telescope needs to be cold, is that it needs to be colder than what is looking at. It needs to be that cold to observe heat at those wavelengths, and the Sunshield is a critical part of how the telescope was designed to achieve temperature low-enough for the type of observations it is planning to make. The sunshield membrane is one of the enabling technologies that allowed the design of JWST to be built.

text: Sunshield is a component of the

text: James Webb Space Telescope

text: , that acts as large parasol allowing the main mirror and optics and the instruments to passively cool down to at least 50 Kelvin (-370 °F, or -223 °C). It consists of layers of

text: Kapton

text: and is big enough to shade the main mirror and secondary mirror, with only one instrument, the one that observes mid-infrared, needing extra cooling. It has five layers to help stop the conduction of heat, and they layers also have a special coating to emit and reflect heat into space. The first layer is 0.002 inches thick and the rest of the layers are 0.001 inches thick. The kite-shaped sunshield about is 22 meters by 10 meters in size. In operation it will receive about 300 kilowatts of solar radiation, but only pass 23 milliwatts on the other side. It is a V-groove radiator and causes a temperature drop of 300 degrees kelvin/Celsius (570 degrees Fahrenheit) from front to back. The reason why the telescope needs to be cold, is that it needs to be colder than what is looking at. It needs to be that cold to observe heat at those wavelengths, and the Sunshield is a critical part of how the telescope was designed to achieve temperature low-enough for the type of observations it is planning to make. The sunshield membrane is one of the enabling technologies that allowed the design of JWST to be built.

text: It is likely that a key reason eyes specialize in detecting a specific, narrow range of wavelengths on the electromagnetic spectrum—the visible spectrum—is because the earliest species to develop photosensitivity were aquatic, and only two specific wavelength ranges of electromagnetic radiation, blue and green visible light, can travel through water. This same light-filtering property of water also influenced the photosensitivity of plants.

text: It is likely that a key reason eyes specialize in detecting a specific, narrow range of wavelengths on the

text: electromagnetic spectrum

text: —the

text: visible spectrum

text: —is because the earliest species to develop

text: photosensitivity

text: were aquatic, and only two specific wavelength ranges of

text: electromagnetic radiation

text: , blue and green visible light, can travel through water. This same light-filtering property of water also influenced the photosensitivity of plants.

text: Absorption spectroscopy – Anders Jonas Ångström – Astronomical spectroscopy – Astronomy – Black body – Blazar – Bremsstrahlung – Caesium – Cherenkov radiation – Color – Diffraction – Digital signal processing – Direct-sequence spread spectrum – Dispersion (optics) – Eigenstate – Eigenvalue – Electromagnetic radiation – Electromagnetic spectroscopy – Electromagnetic spectrum – Electromagnetism – Emission line – Emission spectrum – FM broadcasting – Frequency domain – Frequency hopping – Frequency spectrum – Gamma-ray burst – Hamiltonian (quantum mechanics) – History of radio – Hue – Isotope – Light – Optical brightener – Particle in a spherically symmetric potential – Piezoelectricity – Power spectrum – RADAR – Radio frequency – Radio – Radiocommunications Agency – Redshift – SETI – Spectrogram – Spectrometer – Spectroscopy – Spectrum analyzer – Sunyaev–Zel'dovich effect – Supernova – Telecommunication – Timbre – Very high frequency – Visible light – Visible spectrum – White noise

text: Absorption spectroscopy

text: Anders Jonas Ångström

text: Astronomical spectroscopy

text: Astronomy

text: Black body

text: Blazar

text: Bremsstrahlung

text: Caesium

text: Cherenkov radiation

text: Color

text: Diffraction

text: Digital signal processing

text: Direct-sequence spread spectrum

text: Dispersion (optics)

text: Eigenstate

text: Eigenvalue

text: Electromagnetic radiation

text: Electromagnetic spectroscopy

text: Electromagnetic spectrum

text: Electromagnetism

text: Emission line

text: Emission spectrum

text: FM broadcasting

text: Frequency domain

text: Frequency hopping

text: Frequency spectrum

text: Gamma-ray burst

text: Hamiltonian (quantum mechanics)

text: History of radio

text: Hue

text: Isotope

text: Light

text: Optical brightener

entity_name: Particle in a spherically symmetric potential

text: Particle in a spherically symmetric potential

text: Piezoelectricity

text: Power spectrum

text: RADAR

text: Radio frequency

text: Radio

text: Radiocommunications Agency

text: Redshift

text: SETI

text: Spectrogram

text: Spectrometer

text: Spectroscopy

text: Spectrum analyzer

text: Sunyaev–Zel'dovich effect

text: Supernova

text: Telecommunication

text: Timbre

text: Very high frequency

text: Visible light

text: Visible spectrum

text: White noise

text: Advantages of the hard link method are that it is easy to look at snapshots of the system at different times and also easy to remove old snapshots compared to incremental backup methods which save difference information between consecutive backup times. However, a drawback of Back In Time is that it does not allow for compression, and requires file systems that support hard links on the backup location.

text: Even before Jor-El's birth, the El family was renowned across Krypton for its various contributions to Kryptonian society. Ancestors of Jor-El included Val-El, a famous explorer; Sul-El, the inventor of Krypton's first telescope; Tala-El, the author of Krypton's first planetary constitution; Hatu-El, the inventor of Krypton's first electromagnet and first electric motor; and Gam-El, the father of modern Kryptonian architecture.

text: Even before Jor-El's birth, the El family was renowned across Krypton for its various contributions to Kryptonian society. Ancestors of Jor-El included Val-El, a famous

text: explorer

text: ; Sul-El, the inventor of Krypton's first

text: telescope

text: ; Tala-El, the author of Krypton's first planetary

text: constitution

text: ; Hatu-El, the inventor of Krypton's first

text: electromagnet

text: and first electric motor; and Gam-El, the father of modern Kryptonian

text: architecture

text: The Multi-Element Radio Linked Interferometer Network (MERLIN) is an array of radio telescopes spread across England and the Welsh borders. The array is run from Jodrell Bank on behalf of the Science and Technology Facilities Council as a National Facility. The array consists of up to seven radio telescopes and includes the Lovell Telescope, Mark II, Cambridge, Defford, Knockin, Darnhall, and Pickmere (previously known as Tabley). The longest baseline is therefore  and MERLIN can operate at frequencies between 151 MHz and 24 GHz. At a wavelength of 6 cm (5 GHz frequency), MERLIN has a resolution of 50 milliarcseconds which is comparable to that of the HST at optical wavelengths.

text: The Multi-Element Radio Linked

text: Interferometer

text: Network (MERLIN) is an array of

text: radio telescope

text: s spread across England and the

text: Welsh borders

text: . The array is run from Jodrell Bank on behalf of the

text: as a National Facility. The array consists of up to seven

text: radio telescope

text: s and includes the

text: Lovell Telescope

text: Mark II

text: Cambridge

text: Defford

text: Knockin

text: Darnhall

text: , and

text: Pickmere

text: (previously known as

text: Tabley

text: ). The longest baseline is therefore  and MERLIN can operate at

text: frequencies

text: between 151

text: MHz

text: and 24

text: GHz

text: . At a

text: wavelength

text: of 6 cm (5 GHz frequency), MERLIN has a resolution of 50 milli

text: arcsecond

text: s which is comparable to that of the

text: HST

text: at optical wavelengths.

text: Follow-up observations were conducted by the Hale and the C. Donald Shane telescopes in California; MMT, WIYN, and Tillinghast telescopes in Arizona; the Keck I telescope in Hawaii; the Hobby-Eberly and Smith telescopes in Texas; and the Nordic Optical Telescope in the Canary Islands.

text: Follow-up observations were conducted by the

text: Hale

text: and the

text: C. Donald Shane telescope

text: s in California;

text: MMT

text: WIYN

text: , and

text: Tillinghast

text: telescopes in Arizona; the

text: Keck I

text: telescope in Hawaii; the

text: Hobby-Eberly

text: and

text: Smith telescopes

text: in Texas; and the

text: Nordic Optical Telescope

text: in the Canary Islands.

text: These astronomers are users of the world's most sophisticated optical, radio, gamma-ray orbital and ground-based telescopes, including the Hubble, Keck, Parkes and the ATNF telescopes. In Lisa Harvey-Smith's case, she is also Project Scientist responsible for Australia's participation in the design of the world's largest ever radio telescope, the SKA and the commissioning of its precursor, ASKAP.

text: These astronomers are users of the world's most sophisticated optical, radio, gamma-ray orbital and ground-based telescopes, including the

text: Hubble

text: Keck

text: Parkes

text: and the

text: ATNF

text: telescopes. In Lisa Harvey-Smith's case, she is also Project Scientist responsible for Australia's participation in the design of the world's largest ever radio telescope, the SKA and the commissioning of its precursor, ASKAP.

text: The Horizon Ultraviolet Program (HUP) demonstrated the ability to measure the spatial and spectral characteristics of the Earth's horizon in the vacuum ultraviolet wavelength. The sensor was an Ebert-Fastie spectrometer telescope. Francis Leblanc and Robert E. Huffman of the Phillips Laboratory were Principal Investigators.

text: The Horizon Ultraviolet Program (HUP) demonstrated the ability to measure the spatial and spectral characteristics of the Earth's horizon in the vacuum

text: ultraviolet

text: wavelength. The sensor was an Ebert-Fastie

text: spectrometer

text: telescope. Francis Leblanc and

text: Robert E. Huffman

text: of the

text: Phillips Laboratory

text: were Principal Investigators.

text: In a plasma, the dispersion relation for an electromagnetic wave is (

text: In a plasma, the

text: dispersion relation

text: for an

text: electromagnetic wave

text: is (

text: X-ray and Gamma-ray telescopes are usually on Earth-orbiting satellites or high-flying balloons since the Earth's atmosphere is opaque to this part of the electromagnetic spectrum. However, high energy X-rays and gamma-rays do not form an image in the same way as telescopes at visible wavelengths. An example of this type of telescope is the Fermi Gamma-ray Space Telescope.

text: X-ray and Gamma-ray telescopes are usually on Earth-orbiting

text: satellite

text: s or high-flying balloons since the

text: Earth's atmosphere

text: is opaque to this part of the electromagnetic spectrum. However, high energy X-rays and gamma-rays do not form an image in the same way as telescopes at visible wavelengths. An example of this type of telescope is the

text: Fermi Gamma-ray Space Telescope

text: Lois and Superman talk at her apartment, where she reveals that she met a perfect man but because he is committed to the world, does not think a relationship could work and thus leaves him. The android member of the Royal Flush Gang meets with Lex Luthor to discuss the fight; the point of the attack was to see what could harm Superman, and Luthor gets an idea when he hears Superman caring for the people around him and tells the android and the Gang to leave Metropolis. After Superman talks to a polar bear close to the Fortress of Solitude over his problems he returns home giving a huge cake for "Fun Day" where Luthor is giving a presentation and Lois hands Superman a card from Gallo; he asks Superman to pick up a check from the first six months of profits to be sent for pediatric care. He reads that toward the audience but heads out when an explosion occurs at the Casino. Just as Gallo stands naked toward the green glow from the rock; Superman begins to fall, losing his ability to fly, into the crater made from the explosion. Luthor watches his men beat Superman up, but cannot believe what they are using is that effective. Once Gallo closes the door from the rock, Superman becomes healthy again and defeats the men, before passing out. Jimmy comes over and helps him out by taking him to Clark's (to which Clark answers, as it is a robot Superman built). Lois goes to see Jimmy at the hideout but he isn't there and finds Luthor instead, who shows her images that prove Superman can be hurt. Mr. Ogilvy, from the Daily Planet, is a double agent as he reveals to Gallo what the reporters have been doing.

text: Lois and Superman talk at her apartment, where she reveals that she met a perfect man but because he is committed to the world, does not think a relationship could work and thus leaves him. The android member of the Royal Flush Gang meets with

text: Lex Luthor

text: to discuss the fight; the point of the attack was to see what could harm Superman, and Luthor gets an idea when he hears Superman caring for the people around him and tells the android and the Gang to leave Metropolis. After Superman talks to a

text: polar bear

text: close to the

text: Fortress of Solitude

text: over his problems he returns home giving a huge cake for "Fun Day" where Luthor is giving a presentation and Lois hands Superman a card from Gallo; he asks Superman to pick up a check from the first six months of profits to be sent for pediatric care. He reads that toward the audience but heads out when an explosion occurs at the Casino. Just as Gallo stands naked toward the green glow from the rock; Superman begins to fall, losing his ability to fly, into the crater made from the explosion. Luthor watches his men beat Superman up, but cannot believe what they are using is that effective. Once Gallo closes the door from the rock, Superman becomes healthy again and defeats the men, before passing out. Jimmy comes over and helps him out by taking him to Clark's (to which Clark answers, as it is a robot Superman built). Lois goes to see Jimmy at the hideout but he isn't there and finds Luthor instead, who shows her images that prove Superman can be hurt. Mr. Ogilvy, from the

text: Daily Planet

text: , is a double agent as he reveals to Gallo what the reporters have been doing.

text: The apparent need for a propagation medium for such Hertzian waves can be seen by the fact that they consist of perpendicular electric (E) and magnetic (B or H) waves. The E waves consist of undulating dipolar electric fields, and all such dipoles appeared to require separated and opposite electric charges. Electric charge is an inextricable property of matter, so it appeared that some form of matter was required to provide the alternating current that would seem to have to exist at any point along the propagation path of the wave. Propagation of waves in a true vacuum would imply the existence of electric fields without associated electric charge, or of electric charge without associated matter. Albeit compatible with Maxwell's equations, electromagnetic induction of electric fields could not be demonstrated in vacuum, because all methods of detecting electric fields required electrically charged matter.

text: The apparent need for a propagation medium for such

text: Hertzian waves

text: can be seen by the fact that they consist of perpendicular electric (E) and magnetic (B or H) waves. The E waves consist of undulating dipolar electric fields, and all such dipoles appeared to require separated and opposite electric charges. Electric charge is an inextricable property of

text: matter

text: , so it appeared that some form of matter was required to provide the alternating current that would seem to have to exist at any point along the propagation path of the wave. Propagation of waves in a true vacuum would imply the existence of

text: electric field

text: s without associated

text: electric charge

text: , or of electric charge without associated matter. Albeit compatible with Maxwell's equations,

text: electromagnetic induction

text: of electric fields could not be demonstrated in vacuum, because all methods of detecting electric fields required electrically charged matter.

text: In 1956, Nelson married Betty Norman, a night club singer with whom he worked and had the remainder of his three children with.

text: Born at Ruatuna in Hukatere in Kaipara Harbour, New Zealand, where his family ran a farm, Coates took on significant responsibility at a relatively early age because his father suffered from bipolar disorder. He received a basic education at a local school, and his well-educated mother also tutored him. He became an accomplished horseman, although an accident left him with a bad leg for the rest of his life. The large Māori population of the area meant that Coates grew up proficient in the Māori language.  Gossip suggests that before his marriage, Coates had two children by a Māori woman. He allegedly became engaged to Eva Ingall, a teacher, but her father forbade marriage on the grounds that the illness of Coates' father might prove hereditary. Eventually, in 1914, he married Marjorie Grace Coles, by whom he had five daughters.

text: Born at

text: Ruatuna

text: in Hukatere in

text: Kaipara Harbour

text: , New Zealand, where his family ran a farm, Coates took on significant

text: responsibility

text: at a relatively early age because his father suffered from

text: bipolar disorder

text: . He received a basic education at a local school, and his well-educated mother also tutored him. He became an accomplished

text: horseman

text: , although an accident left him with a bad leg for the rest of his life. The large

text: Māori

text: population of the area meant that Coates grew up proficient in the

text: Māori language

text: .  Gossip suggests that before his marriage, Coates had two children by a Māori woman. He allegedly became engaged to Eva Ingall, a teacher, but her father forbade marriage on the grounds that the illness of Coates' father might prove hereditary. Eventually, in 1914, he married Marjorie Grace Coles, by whom he had five daughters.

text: Over an archway on the northern end of the mosque is a final inscription which reads:

text: In May 2016, EVGA released its first gaming laptop called the EVGA SC17, including such features as an IPS 4K display, Nvidia GTX 980M graphics and an Intel i7 6820HK processor.

text: Norman C. Schneider (9 December 1888 – 26 August 1985) was a Canadian politician and businessman.

text: Norman C. Schneider (9 December 1888 – 26 August 1985) was a

text: Canadian

text: politician and businessman.

text: "The Amateur Scientist" traces its pedigree to May 1928, when Albert G. Ingalls began the column as "The Back Yard Astronomer." Ingalls told amateurs how they could get personally involved in astronomy by building professional-quality instruments and carrying out cutting-edge observations. The first sentence in the new column stated: "Here we amateur telescope makers are, more than 3000 of us, gathered together in our own back yard at last."  The name of the column changed several times, to "The Amateur Astronomer", "The Amateur Telescope Maker", and "Telescoptics." Much of the information from these articles was eventually published by Ingalls and Scientific American in the books Amateur Telescope Making. The articles and the books are credited with helping to expand the hobby of amateur telescope making. In April 1952, Ingalls chose to broaden the column's scope to include "how-to's" from all fields of science. When he did, he also changed the department's name to "The Amateur Scientist."

text: "The Amateur Scientist" traces its pedigree to May 1928, when

text: Albert G. Ingalls

text: began the column as "The Back Yard Astronomer." Ingalls told amateurs how they could get personally involved in astronomy by building professional-quality instruments and carrying out cutting-edge observations. The first sentence in the new column stated: "Here we amateur telescope makers are, more than 3000 of us, gathered together in our own back yard at last."  The name of the column changed several times, to "The Amateur Astronomer", "The Amateur Telescope Maker", and "Telescoptics." Much of the information from these articles was eventually published by Ingalls and Scientific American in the books

text: Amateur Telescope Making

text: . The articles and the books are credited with helping to expand the

text: hobby

text: of

text: amateur telescope making

text: . In April 1952, Ingalls chose to broaden the column's scope to include "how-to's" from all fields of science. When he did, he also changed the department's name to "The Amateur Scientist."

text: In late 2002, a novel deformable secondary mirror was added to the telescope. While other adaptive optics designs do their corrections with additional mirrors, minimizing the number of warm surfaces in the light path produces better results in infrared wavelengths. The MMT AO system contributed to the design of the Large Binocular Telescope, which achieved record breaking Strehl ratios with its AO system in 2010.

text: In late 2002, a novel

text: deformable

text: secondary mirror

text: was added to the telescope. While other

text: adaptive optics

text: designs do their corrections with additional mirrors, minimizing the number of warm surfaces in the light path produces better results in

text: infrared

text: wavelengths. The MMT AO system contributed to the design of the

text: Large Binocular Telescope

text: , which achieved record breaking

text: Strehl ratio

text: s with its AO system in 2010.

text: KELT consists of two telescopes, KELT-North in Arizona in the United States, and KELT-South at the SAAO [[South_African_Astronomical_Observatory#Facilities#Telescopes (Sutherland)|observing station]] near Sutherland, South Africa.

text: "You're Only Lonely" is a 1979 single by J. D. Souther from his album of the same name. The single peaked at number seven on the Billboard Hot 100, Souther's only top ten pop hit, and spent five weeks at number one on the Adult Contemporary chart.

text: "You're Only Lonely" is a 1979 single by

text: J. D. Souther

text: from his

text: album of the same name

text: . The single peaked at number seven on the

text: Billboard Hot 100

text: , Souther's only top ten pop hit, and spent five weeks at number one on the

text: Adult Contemporary

text: chart.

text: The Ooty Radio Telescope is located in Muthorai near Ootacamund (Ooty), south India. It is part of the National Centre for Radio Astrophysics (NCRA) of the well known Tata Institute of Fundamental Research (TIFR) which is funded by the Government of India through the Department of atomic energy. The Ooty Radio Telescope (ORT) is a  long and  wide Cylindrical Paraboloid telescope. It operates at a frequency of 326.5 MHz with a maximum bandwidth of 15 MHz at the front-end.

text: The Ooty Radio Telescope is located in Muthorai near

text: Ootacamund

text: (Ooty), south

text: India

text: . It is part of the

text: National Centre for Radio Astrophysics

text: (NCRA) of the well known

text: Tata Institute of Fundamental Research

text: (TIFR) which is funded by the

text: Government of India

text: through the

text: Department of atomic energy

text: . The Ooty Radio Telescope (ORT) is a  long and  wide Cylindrical

text: Paraboloid

text: telescope. It operates at a frequency of 326.5 MHz with a maximum bandwidth of 15 MHz at the front-end.

text: In April 2008, Moore was confirmed to be joining the cast as the courtesan Alexandra.  Interviewed at the 2009 Middle East International Film Festival, Moore described Bunraku as a "big action adventure". "It has tremendous special effects," she enthused.  In May 2008, Harrelson and Perlman were announced to be joining the cast.  Harrelson is set to play The Bartender, one of the protagonists while Perlman was signed to the role of Nicola the Woodcutter, powerful warrior and crime boss, who is the central focus of vengeance for the film's protagonists.  Bunraku marks the first time that Moore and Harrelson have worked together since the 1993 film Indecent Proposal.  When asked in a 2010 interview how he had managed to sign two international stars like Harrelson and Moore onto an experimental film, Moshe explained "They really liked [Moshe's film] Holly and responded immediately to the Bunraku script."

text: In April 2008, Moore was confirmed to be joining the cast as the courtesan Alexandra.  Interviewed at the 2009

text: Middle East International Film Festival

text: , Moore described Bunraku as a "big action adventure". "It has tremendous special effects," she enthused.  In May 2008, Harrelson and Perlman were announced to be joining the cast.  Harrelson is set to play The Bartender, one of the protagonists while Perlman was signed to the role of Nicola the Woodcutter, powerful warrior and crime boss, who is the central focus of vengeance for the film's protagonists.  Bunraku marks the first time that Moore and Harrelson have worked together since the 1993 film

text: Indecent Proposal

text: .  When asked in a 2010 interview how he had managed to sign two international stars like Harrelson and Moore onto an experimental film, Moshe explained "They really liked [Moshe's film] Holly and responded immediately to the Bunraku script."

text: 23) Jozef Cardijn, priest, cardinal and humanitarian. Founder of the Young Christian Workers.

text: Jozef Cardijn

text: , priest, cardinal and humanitarian. Founder of the

text: Young Christian Workers

text: Euchelus eucastus is a species of sea snail, a marine gastropod mollusk in the family Chilodontidae.

text: Euchelus eucastus is a

text: species

text: of

text: sea snail

text: , a

text: marine

text: gastropod

text: mollusk

text: in the

text: family

text: Chilodontidae

text: This pylon was built by Horemheb near the end of his reign and only partly decorated by him. Ramesses I usurped Horemheb's reliefs and inscriptions on the pylon and added his own to them. These were later usurped by Ramesses II. The east (rear) face of the pylon became the west wall of the newly built Great Hypostyle Hall under Seti I who added some honorary images of the late Ramesses I to compensate for having had to erase his father's images there when he built the hall.

text: The geological history of the formation may be traced back some 50 million years, when the uplift of the continental margin in the region created modern landforms. The Herbert River, which previously flowed west, began to cut through the terrain en route to its outflow in the Coral Sea. The gorge produced by this erosive action gradually retreated inland along the Herbert River's course at a rate of  per hundred years. The river's tributaries were eventually left suspended by this action, forming their own gorges.

text: The geological history of the formation may be traced back some 50 million years, when the uplift of the

text: continental margin

text: in the region created modern landforms. The Herbert River, which previously flowed west, began to cut through the terrain en route to its outflow in the

text: Coral Sea

text: . The gorge produced by this

text: erosive

text: action gradually

text: retreated

text: inland along the Herbert River's course at a rate of  per hundred years. The river's tributaries were eventually left suspended by this action, forming their own gorges.

text: Radio waves were first predicted by mathematical work done in 1867 by Scottish mathematical physicist James Clerk Maxwell. Maxwell noticed wavelike properties of light and similarities in electrical and magnetic observations. His mathematical theory, now called Maxwell's equations, described light waves and radio waves as waves of electromagnetism that travel in space, radiated by a charged particle as it undergoes acceleration. In 1887, Heinrich Hertz demonstrated the reality of Maxwell's electromagnetic waves by experimentally generating radio waves in his laboratory, showing that they exhibited the same wave properties as light:  standing waves, refraction, diffraction, and polarization.  Radio waves were first used for communication in the mid 1890s by Guglielmo Marconi, who developed the first practical radio transmitters and receivers.

text: Radio waves were first predicted by mathematical work done in 1867 by Scottish mathematical physicist

text: James Clerk Maxwell

text: . Maxwell noticed wavelike properties of light and similarities in electrical and magnetic observations. His mathematical theory, now called

text: Maxwell's equations

text: , described light waves and radio waves as waves of electromagnetism that travel in space, radiated by a charged particle as it undergoes acceleration. In 1887,

text: Heinrich Hertz

text: demonstrated the reality of Maxwell's electromagnetic waves by experimentally generating radio waves in his laboratory, showing that they exhibited the same wave properties as light:

text: standing wave

text: s,

text: refraction

text: diffraction

text: , and

text: polarization

text: .  Radio waves were first used for communication in the mid 1890s by

text: Guglielmo Marconi

text: , who developed the first practical radio

text: transmitter

text: s and

text: receivers

text: Mas (, ) is a surname of Catalan and Occitan or North German and Dutch origin. It accounts for 0.068% of the population in Spain, with 0.879% found amongst Catalans, and 0.017% in France.

text: Mas (, ) is a

text: surname

text: of

text: Catalan

text: and

text: Occitan

text: or

text: North German

text: and

text: Dutch

text: origin. It accounts for 0.068% of the population in Spain, with 0.879% found amongst Catalans, and 0.017% in France.

text: The name "telescope" covers a wide range of instruments. Most detect electromagnetic radiation, but there are major differences in how astronomers must go about collecting light (electromagnetic radiation) in different frequency bands.

text: The name "telescope" covers a wide range of instruments. Most detect

text: electromagnetic radiation

text: , but there are major differences in how astronomers must go about collecting light (electromagnetic radiation) in different frequency bands.

text: The siege was instigated by Richard II, prince of Capua, who had been exiled from his own capital for seven years (1091–1098) by Lando IV until, reaching his majority, he requested the aid of his great uncle, the count of Sicily, Roger I, and his first cousin once removed, the duke of Apulia, Roger Borsa. The two Rogers came, the former in exchange for the city of Naples and the latter for Richard's recognition of Apulian suzerainty.

text: The siege was instigated by

text: Richard II

text: prince of Capua

text: , who had been exiled from his own capital for seven years (1091–1098) by

text: Lando IV

text: until, reaching his majority, he requested the aid of his great uncle, the

text: count of Sicily

text: Roger I

text: , and his first cousin once removed, the

text: duke of Apulia

text: Roger Borsa

text: . The two Rogers came, the former in exchange for the city of

text: Naples

text: and the latter for Richard's recognition of Apulian suzerainty.

text: was a Japanese mathematician working in algebra and topology.

text: was a Japanese

text: mathematician

text: working in

text: algebra

text: and

text: topology

text: On 30 November 2016 it was announced that Banerjee would take charge of the West Bengal football team for their Santosh Trophy qualifying matches after being selected from a shortlist of other potential head coaches.

text: On 30 November 2016 it was announced that Banerjee would take charge of the

text: West Bengal football team

text: for their

text: Santosh Trophy

text: qualifying matches after being selected from a shortlist of other potential head coaches.

text: Thompson and Hughes bought four stores as partners in the 1960s. During the early 1970s they obtained former A&P, Kroger and Weingarten's stores in Lake Charles, Beaumont, Port Arthur and Orange. In 1983, Bruce Thompson purchased Hughes’ interest in their jointly held corporation.

text: Thompson and Hughes bought four stores as partners in the 1960s. During the early 1970s they obtained former

entity_name: The Great Atlantic & Pacific Tea Company

text: A&P

text: Kroger

text: and

text: Weingarten's

text: stores in

text: Lake Charles

text: Beaumont

text: Port Arthur

text: and

text: Orange

text: . In 1983, Bruce Thompson purchased Hughes’ interest in their jointly held corporation.

text: Japanese Mahjong has a special rule called , which is, if three players claim the same discard in order to win, the hand is drawn. One reason for this is that there are cases in which bars of 1,000 points for declaring rīchi cannot be divided by three. The rule is treated the same as "abortive draws".

text: The international press reported that Madrid would not be defended, and General Franco declared prematurely that the city had been liberated. Radio Lisbon even reported Franco's victorious entry into the city.On 7 November the first troops of Franco's Army of Africa reached the Casa del Campo on the edge of the city.Formation of the Madrid Defense Council was announced that day,The Defense Council was desperately short of men and munitions. However, Franco's forces were over-extended, with only 3,000 men available to push into the city, and Franco was naturally cautious. The first units of the International Brigades reached the city on 8 November 1936 and were immediately thrown into action.As more units came into action the rebel advance was halted. By 23 November a stalemate had been reached, with both sides exhausted.

text: The international press reported that Madrid would not be defended, and General Franco declared prematurely that the city had been liberated. Radio Lisbon even reported Franco's victorious entry into the city.On 7 November the first troops of Franco's Army of Africa reached the Casa del Campo on the edge of the city.Formation of the Madrid Defense Council was announced that day,The Defense Council was desperately short of men and munitions. However, Franco's forces were over-extended, with only 3,000 men available to push into the city, and Franco was naturally cautious. The first units of the

text: International Brigades

text: reached the city on 8 November 1936 and were immediately thrown into action.As more units came into action the rebel advance was halted. By 23 November a stalemate had been reached, with both sides exhausted.

text: Gerard "Gerry" Marsden MBE (born 24 September 1942) is an English musician and television personality, best known for being leader of the British Merseybeat band Gerry and the Pacemakers.

text: Gerard "Gerry" Marsden

text: MBE

text: (born 24 September 1942) is an English musician and

text: television personality

text: , best known for being leader of the British

text: Merseybeat

text: band

text: Gerry and the Pacemakers

text: On November 26, 2015, it was announced that the series was cancelled and won't be renewed for a third season.

text: According to the United States Census Bureau, the CDP has a total area of .  of it is land and  of it (7.72%) is water.

text: According to the

text: United States Census Bureau

text: , the CDP has a total area of .  of it is land and  of it (7.72%) is water.

text: Gloucester County is largely composed of low-lying rivers and coastal plains. The highest elevation in the county is a slight rise along County Route 654 southeast of Cross Keys that reaches approximately  above sea level; the lowest point is at sea level on the Delaware River.

text: Gloucester County is largely composed of low-lying rivers and coastal plains. The highest elevation in the county is a slight rise along County Route 654 southeast of Cross Keys that reaches approximately  above

text: sea level

text: ; the lowest point is at sea level on the

text: Delaware River

text: The transducer is physically designed as a pressure-sensitive optical interferometer according to the Fabry–Pérot principle. The sensor element is produced in silicon using microstructure processes originating from the semiconductor industry. The optical fiber is made of glass and has special coatings. The Samba Preclin transducer is an example of a MOMS (Micro Optic Mechanical System) device.

text: The transducer is physically designed as a pressure-sensitive

text: optical interferometer

text: according to the

text: Fabry–Pérot principle

text: . The sensor element is produced in

text: silicon

text: using

text: microstructure

text: processes originating from the

text: semiconductor

text: industry. The optical fiber is made of glass and has special coatings. The Samba Preclin transducer is an example of a MOMS (Micro Optic Mechanical System) device.

text: Every September from 2008, the Philippa Pearce Memorial Lecture at Homerton College, Cambridge celebrates "excellence in writing for children and to emphasize its continuing vital importance." The lecturers are children's literature authors, scholars or critics, and most of the lectures are published online.

text: Every September from 2008, the Philippa Pearce Memorial Lecture at

text: Homerton College, Cambridge

text: celebrates "excellence in writing for children and to emphasize its continuing vital importance." The lecturers are children's literature authors, scholars or critics, and most of the lectures are published online.

text: According to quantum mechanics, atoms and molecules can only hold certain defined quantities of energy, or exist in specific states. When such quanta of  electromagnetic radiation are emitted or absorbed by an atom or molecule, the energy of the radiation changes the state of the atom or molecule from an initial state to a final state. An absorption band is a range of wavelengths, frequencies or energies in the electromagnetic spectrum which are characteristic of a particular transition from initial to final state in a substance.

text: According to

text: quantum mechanics

text: atom

text: s and

text: molecule

text: s can only hold certain defined quantities of

text: energy

text: , or exist in specific

text: states

text: . When such

text: quanta

text: of

text: electromagnetic radiation

text: are emitted or absorbed by an atom or molecule, the energy of the radiation changes the state of the atom or molecule from an

text: initial state

text: to a

text: final state

text: . An absorption band is a range of

text: wavelength

text: s,

text: frequencies

text: or energies in the

text: electromagnetic spectrum

text: which are characteristic of a particular transition from initial to final state in a substance.

text: The Plaza complex was completed in 1979 .

text: The primary of June 13, 2006, ended with Mike Campbell receiving 47 percent of the vote, Andre Bauer 37%, and Henry Jordan 18%. As Campbell did not win a majority, he faced Bauer in a runoff election on June 27 for the Republican nomination. Bauer won the runoff with slightly over 51 percent of vote. He then narrowly defeated Democrat Robert A. Barber, Jr., a former state representative, attorney and lobbyist in the General Election. Bauer received 543,414 votes (50.08%), while Barber received 540,306 votes (49.79%).

text: The primary of June 13, 2006, ended with Mike Campbell receiving 47 percent of the vote, Andre Bauer 37%, and Henry Jordan 18%. As Campbell did not win a majority, he faced Bauer in a runoff election on June 27 for the Republican nomination. Bauer won the runoff with slightly over 51 percent of vote. He then narrowly defeated Democrat

text: Robert A. Barber, Jr.

text: , a former state representative, attorney and lobbyist in the General Election. Bauer received 543,414 votes (50.08%), while Barber received 540,306 votes (49.79%).

text: Both impetrativa and oblativa auspices could be divided into five classes:ex caelo (thunder,lightning), ex avibus, ex tripudiis (attitude to food and feeding manner of the sacred chickens), ex quadrupedibus (dog, horse, wolf, fox), ex diris (ominous events).

text: Other horses with long losing streaks include Dona Chepa (0 wins out of 125 starts), Ouroene (0 for 124), Gloria Springs (0 for 106, Japan), Thrust (0 for 105, North America) and Quixall Crossett (0 for 103, Britain).

text: Other horses with long losing streaks include Dona Chepa (0 wins out of 125 starts), Ouroene (0 for 124), Gloria Springs (0 for 106, Japan), Thrust (0 for 105, North America) and

text: Quixall Crossett

text: (0 for 103, Britain).

text: Juan Leal was born in 1676 in the city of Teguise, in Lanzarote (Canary Islands, Spain). He was the son of Antonio Goraz and Maria Peres and became a councilor of the municipality of Teguise. He lived in the village of San Bartolomé, on the same island.

text: Juan Leal was born in 1676 in the city of

text: Teguise

text: , in

text: Lanzarote

text: Canary Islands

text: Spain

text: ). He was the son of Antonio Goraz and Maria Peres and became a councilor of the municipality of Teguise. He lived in the village of San Bartolomé, on the same island.

text: DLC Set #1 - Miku Uta, Okawari

text: DLC Set #1 - Miku Uta, Okawari

text: The October Tour was a concert tour by Irish rock band U2 that took place in 1981 and 1982 to support the band's second studio album, October, which was released in October 1981.

text: The October Tour was a

text: concert tour

text: by

text: Irish

text: rock

text: band

text: that took place in 1981 and 1982 to support the band's second studio album,

text: October

text: , which was released in October

text: In 1761, Müller was elected a foreign member of the Royal Swedish Academy of Sciences.  He died, aged 77, in Moscow.

text: In 1761, Müller was elected a foreign member of the

text: Royal Swedish Academy of Sciences

text: .  He died, aged 77, in

text: Moscow

text: Allen was born in Woodford County, Illinois. He joined the 39th Illinois infantry Regiment from Bloomington, Illinois in January 1864, and mustered out with his regiment on December 6, 1865.

text: Allen was born in

text: Woodford County, Illinois

text: . He joined the

entity_name: 39th Illinois Volunteer Infantry Regiment

text: 39th Illinois infantry Regiment

text: from

text: Bloomington, Illinois

text: in January 1864, and mustered out with his regiment on December 6, 1865.

text: George was a member of the Australian Test touring squad in 2010, first being called in as an emergency replacement midway through the 2009-10 tour of New Zealand after a series of injuries to Australian pacemen, then joining the team for the 2010 series against Pakistan in England and the 2010-11 tour of India. He played his only Test in the Second Test against India in Bangalore, taking two wickets.

text: George was a member of the Australian Test touring squad in 2010, first being called in as an emergency replacement midway through the

entity_name: Australian cricket team in New Zealand in 2009–10

text: 2009-10 tour of New Zealand

text: after a series of injuries to Australian pacemen, then joining the team for the

entity_name: Australian cricket team against Pakistan in England in 2010

text: 2010 series against Pakistan in England

text: and the

entity_name: Australian cricket team in India in 2010–11

text: 2010-11 tour of India

text: . He played his only Test in the Second Test against India in Bangalore, taking two wickets.

text: | class="note" | | class="note" | |- class="vcard"| class="fn org" | Knarston| class="adr" |

text: | class="note" | | class="note" | |- class="vcard"| class="fn org" |

text: Knarston

text: | class="adr" |

text: Mullard Radio Astronomy Observatory (MRAO) is home to a number of large aperture synthesis radio telescopes, including the One-Mile Telescope, 5-km Ryle Telescope, and the Arcminute Microkelvin Imager.

text: Mullard Radio Astronomy Observatory (MRAO) is home to a number of large

text: aperture synthesis

text: radio telescope

text: s, including the

text: One-Mile Telescope

text: , 5-km

text: Ryle Telescope

text: , and the

text: Arcminute Microkelvin Imager

text: The solar community was rocked by the launch of Yohkoh (Solar A) from Kagoshima Space Centre in August 1991. It was lost on 14 December 2001 due to battery failure but revolutionised X-ray observations in its decade of operations. Yohkoh (or Sunbeam) orbited the Earth in an elliptical orbit, observing X-ray and γ-ray emissions from solar phenomena such as solar flares. Yohkoh carried four instruments. The Bragg Crystal Spectrometer (BCS), the Wide Band Spectrometer (WBS), the Soft X-Ray Telescope (SXT) and the Hard X-Ray Telescope (HXT) were operated by a consortium of scientists from Japan, the USA and the UK. Of particular interest is the SXT instrument for observing X-ray-emitting coronal loops.

text: The solar community was rocked by the launch of

text: Yohkoh

text: (Solar A) from

text: Kagoshima Space Centre

text: in August 1991. It was lost on 14 December 2001 due to battery failure but revolutionised X-ray observations in its decade of operations. Yohkoh (or Sunbeam) orbited the Earth in an

text: elliptical

text: orbit

text: , observing X-ray and

text: γ-ray

text: emissions from solar phenomena such as solar flares. Yohkoh carried four instruments. The Bragg Crystal Spectrometer (BCS), the Wide Band Spectrometer (WBS), the Soft X-Ray Telescope (

text: SXT

text: ) and the Hard X-Ray Telescope (HXT) were operated by a consortium of scientists from Japan, the USA and the UK. Of particular interest is the

text: SXT

text: instrument for observing X-ray-emitting coronal loops.

text: Turbonilla terminuslevis is a species of sea snail, a marine gastropod mollusk in the family Pyramidellidae, the pyrams and their allies.

text: Turbonilla terminuslevis is a

text: species

text: of

text: sea snail

text: , a

text: marine

text: gastropod

text: mollusk

text: in the

text: family

text: Pyramidellidae

text: , the pyrams and their allies.

text: There were large cost overruns with the telescope's construction, mainly due to the steeply rising cost of steel at the time the telescope was constructed. The original grant for the telescope's construction came jointly from the Nuffield Foundation and the government; this amounted to £335,000. The government increased its share of the funding several times as the cost of the telescope rose; other money came from private donations. The final part of the debt from the construction of the telescope, £50,000, was paid off by Lord Nuffield and the Nuffield Foundation on 25 May 1960 (partly due to the telescope's early, very public role in space probe tracking; see below), and Jodrell Bank observatory was renamed to the Nuffield Radio Astronomy Laboratories. The final total cost for the telescope was £700,000.

text: There were large cost overruns with the telescope's construction, mainly due to the steeply rising cost of steel at the time the telescope was constructed. The original grant for the telescope's construction came jointly from the

text: Nuffield Foundation

text: and the government; this amounted to £335,000. The government increased its share of the funding several times as the cost of the telescope rose; other money came from private donations. The final part of the debt from the construction of the telescope, £50,000, was paid off by

text: Lord Nuffield

text: and the

text: Nuffield Foundation

text: on 25 May 1960 (partly due to the telescope's early, very public role in space probe tracking; see below), and Jodrell Bank observatory was renamed to the Nuffield Radio Astronomy Laboratories. The final total cost for the telescope was £700,000.

text: Brophy was honored as being part of a group of legislators awarded with the “Common Sense in the Courtroom” award for 2012. This award from the Colorado Civil Justice League focuses on stopping lawsuit abuse while maintaining a fair civil justice system.

text: Without having a record deal, Music for Pleasure continued to release records on their own Whirlpool label, the Colin Richardson co-produced single "Disconnection" (1984), the John Porter produced EP Chrome Hit Corrosion (1984) and the album Blacklands (1985). However, following the release of Blacklands the band disbanded.

text: Without having a record deal, Music for Pleasure continued to release records on their own Whirlpool label, the

text: Colin Richardson

text: co-produced single "

text: Disconnection

text: " (1984), the

text: John Porter

text: produced

text: EP

text: Chrome Hit Corrosion

text: (1984) and the album

text: Blacklands

text: (1985). However, following the release of Blacklands the band disbanded.

text: Weeks go by, but then Nelson sees a light in one of the cities.  Over the following days the men see more signs of activity in the city and one day they see a collection of crates lying in a plaza.  To keep a longer watch on the crates Nelson and Jim take their rocketship’s lifeboat to Deimos and set up the spare telescope some distance from their landing site.  Jim goes back to the lifeboat to get the telescope’s other lens and when he doesn’t come back after some time Nelson goes to see what’s taking him so long.  He finds that Jim has been murdered: someone bashed in the back of Jim’s helmet to let the air out of his spacesuit and then sabotaged the lifeboat and its radio.

text: Point Pleasant Borough High School is a four-year comprehensive community public high school located on Laura Herbert Drive in Point Pleasant in Ocean County, New Jersey, United States. The school serves students in ninth through twelfth grades, operating as the lone secondary school of the Point Pleasant School District. The mascot is the panther, and the school colors are black and gold.

text: Point Pleasant Borough High School is a four-year

text: comprehensive

text: community

text: public

entity_name: Secondary education in the United States

text: high school

text: located on Laura Herbert Drive in

text: Point Pleasant

text: in

text: Ocean County

text: New Jersey

text: , United States. The school serves students in

text: ninth

text: through

text: twelfth grade

text: s, operating as the lone secondary school of the

text: Point Pleasant School District

text: . The mascot is the panther, and the school colors are black and gold.

text: In 2002, it was revealed that she had named her album, The Diary; she had confirmed it was inspired by the early 2000s reality show of the same name. Charli briefly explained to MTV in a 2002 interview about the concept of the album:

text: In 2002, it was revealed that she had named her album, The Diary; she had confirmed it was inspired by the

text: early 2000s reality show of the same name

text: . Charli briefly explained to MTV in a 2002 interview about the concept of the album:

text: During the mid-1980s, the station was at the vanguard of the American alternative music scene, under the able leadership of Music Director Sean "The Hag" Hagearty. In 2002, the Fairfield University's worldwide, state-of-the-art radio station opened for business in a brand new three-studio complex in the John A. Barone Campus Center.  WVOF regularly hears from listeners in South America, Europe, the West Coast and Canada.

text: Speed limits vary throughout the road. North of Hemlock Road, the speed limit is  with two lanes. Between Hemlock Road and McArthur Avenue, the speed limit is  on four lanes of traffic. Then, from McArthur Avenue south to Tremblay Road, it increases to . Then from Tremblay Road until Smyth Road, it reaches its highest speed limit of . From there to its end, the limit reduces once more to 50 km/h.

text: Speed limits vary throughout the road. North of

text: Hemlock Road

text: , the speed limit is  with two lanes. Between Hemlock Road and

text: McArthur Avenue

text: , the speed limit is  on four lanes of traffic. Then, from McArthur Avenue south to

text: Tremblay Road

text: , it increases to . Then from Tremblay Road until

text: Smyth Road

text: , it reaches its highest speed limit of . From there to its end, the limit reduces once more to 50 km/h.

text: More recently large-scale mass spectrometry analyses have been used to determine sites of protein phosphorylation. Over the last 4 years, dozens of studies have been published, each identifying thousands of sites, many of which were previously undescribed. Mass spectrometry is ideally suited for such analyses using HCD or ETD fragmentation, as the addition of phosphorylation results in an increase in the mass of the protein and the phosphorylated residue. Advanced, highly accurate mass spectrometers are needed for these studies, limiting the technology to labs with high-end mass spectrometers. However, the analysis of phosphorylated peptides by mass spectrometry is still not as straightforward as for “regular”, unmodified peptides. Recently EThcD has been developed combining electron-transfer and higher-energy collision dissociation. Compared to the usual fragmentation methods, EThcD scheme provides more informative MS/MS spectra for unambiguous phosphosite localization.

text: More recently large-scale mass spectrometry analyses have been used to determine sites of protein phosphorylation. Over the last 4 years, dozens of studies have been published, each identifying thousands of sites, many of which were previously undescribed. Mass spectrometry is ideally suited for such analyses using HCD or

text: ETD

text: fragmentation, as the addition of phosphorylation results in an increase in the mass of the protein and the phosphorylated residue. Advanced, highly accurate mass spectrometers are needed for these studies, limiting the technology to labs with high-end mass spectrometers. However, the analysis of phosphorylated peptides by mass spectrometry is still not as straightforward as for “regular”, unmodified peptides. Recently

text: EThcD

text: has been developed combining electron-transfer and higher-energy collision dissociation. Compared to the usual fragmentation methods,

text: EThcD

text: scheme provides more informative MS/MS spectra for unambiguous phosphosite localization.

text: "Starlight" is booked to play in Star Cafe, a famous cafe known for the variety of music played. There is a rumor that if the owner likes a band's music, they'll do well in Rockin' Pretty. Following their performance, DJ H-Star compliments "Starlight" on their performance and reveals that he is the owner of the cafe. He tells them that although they are lacking skill-wise, they have soul. The next day at the preliminaries, DJ H-Star visits "Starlight" to tell them that they are performing first. Out of the twenty bands, the two who made it to the next round were "The Dreamboats" and "Love Connection". However, runners-up have a second chance at the preliminaries at Melody Mall. Thirty bands have arrived at Melody Mall and "Starlight" was selected as the 15th band to perform. During their waiting period, Reena felt that they just didn't reach their crowd's heart. Mio suggests that they should be more cute, energetic, and have more fun. The band accepts Mio's suggestion and decide to play "Fluttering Heart" and "Happy Sunday".

text: The new prosthesis corresponds to a conventional total prosthesis but the basis contains cavities so that the secondary crowns can be incorporated. The prosthesis is controlled at the terminal position and corrected if needed. The cavities are filled with a self-curing cement and the prosthesis is placed in the terminal position. After the self-curing process, the gold caps are definitely cemented in the prosthesis cavities and the prosthesis can now be detached. Excess cement may be removed and some corrections like polishing or under filling around the secondary crowns may be necessary.The new prosthesis is fitted using a construction of telescope double cone crowns. At the end position, the prosthesis buttons down on the abutments to ensure an adequate hold.

text: The Large Millimetre Telescope (LMT) (, or GTM) was inaugurated in Mexico on 22 November 2006. It is the world's largest single-aperture telescope in its frequency range, built for observing radio waves in the wave lengths from approximately 0.85 to 4 mm. It has an active surface with a diameter of  and  of collecting area.

text: The Large Millimetre Telescope (LMT) (, or GTM) was inaugurated in Mexico on 22 November 2006. It is the world's largest single-aperture

text: telescope

text: in its frequency range, built for observing

text: radio wave

text: s in the

text: wave length

text: s from approximately 0.85 to 4 mm. It has an

text: active surface

text: with a diameter of  and  of collecting area.

text: As preparation for the Rosetta mission, Hubble Space Telescope pictures taken on 12 March 2003 were closely analysed. An overall 3D model was constructed and computer-generated images were created.

text: As preparation for the Rosetta mission,

text: Hubble Space Telescope

text: pictures taken on 12 March 2003 were closely analysed. An overall 3D model was constructed and computer-generated images were created.

text: The forthcoming James Webb Space Telescope will contain both a near-infrared spectrograph (NIRSpec) and a mid-infrared spectrometer (MIRI).

text: The forthcoming

text: James Webb Space Telescope

text: will contain both a near-infrared spectrograph (

text: NIRSpec

text: ) and a mid-infrared spectrometer (MIRI).

text: In 1925 he wrote an essay entitled "The Religious Effect of the Idea of Evolution". He wrote a number of books, including Life after Death "with replies by Sir Arthur Conan Doyle" in 1920. In addition to spiritual works, he co-wrote an astronomy book on double stars (mentioned above) and mathematical books on geometry and conic sections.  He contributed the article "On two fragments of geometrical treatises found in Worcester Cathedral" to the Mathematical Gazette (March 1911, p. 19).

text: In 1925 he wrote an essay entitled "The Religious Effect of the Idea of Evolution". He wrote a number of books, including Life after Death "with replies by Sir

text: Arthur Conan Doyle

text: " in 1920. In addition to spiritual works, he co-wrote an astronomy book on double stars (mentioned above) and mathematical books on

text: geometry

text: and

text: conic section

text: s.  He contributed the article "On two fragments of geometrical treatises found in Worcester Cathedral" to the

text: Mathematical Gazette

text: (March 1911, p. 19).

text: Infrared light can penetrate the cosmic dust clouds, allowing us to peer into regions of star formation and the centers of galaxies. NASA's Spitzer Space Telescope is the largest infrared telescope ever launched into space. The Spitzer Space Telescope (formerly SIRTF, the Space Infrared Telescope Facility) was launched into space by a Delta rocket from Cape Canaveral, Florida on 25 August 2003. During its mission, Spitzer will obtain images and spectra by detecting the infrared energy, or heat, radiated by objects in space between wavelengths of 3 and 180 micrometres. Most of this infrared radiation is blocked by the Earth's atmosphere and cannot be observed from the ground. The findings from the Spitzer already revitalized the studies of cosmic dust. A recent report from a Spitzer team shows some evidence that cosmic dust is formed near a supermassive black hole.

text: Infrared light can penetrate the cosmic dust clouds, allowing us to peer into regions of star formation and the centers of galaxies.

text: NASA

text: 's

text: Spitzer Space Telescope

text: is the largest infrared telescope ever launched into space. The Spitzer Space Telescope (formerly SIRTF, the Space Infrared Telescope Facility) was launched into space by a Delta rocket from Cape Canaveral, Florida on 25 August 2003. During its mission, Spitzer will obtain images and spectra by detecting the infrared energy, or heat, radiated by objects in space between wavelengths of 3 and 180 micrometres. Most of this infrared radiation is blocked by the Earth's atmosphere and cannot be observed from the ground. The findings from the Spitzer already revitalized the studies of cosmic dust. A recent report from a Spitzer team shows some evidence that cosmic dust is formed near a supermassive black hole.