Meaning of word telescope

From Wikipedia, the free encyclopedia

A telescope is a device used to observe distant objects by their emission, absorption, or reflection of electromagnetic radiation.^[1] Originally meaning only an optical instrument using lenses, curved mirrors, or a combination of both to observe distant objects, 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.

The first known practical telescopes were refracting telescopes with glass lenses and were invented in the Netherlands at the beginning of the 17th century. They were used for both terrestrial applications and astronomy.

The reflecting telescope, which uses mirrors to collect and focus light, was invented within a few decades of the first refracting telescope.

In the 20th century, many new types of telescopes were invented, including radio telescopes in the 1930s and infrared telescopes in the 1960s.

Etymology[edit]

The word telescope was coined in 1611 by the Greek mathematician Giovanni Demisiani for one of Galileo Galilei’s instruments presented at a banquet at the Accademia dei Lincei.^[2][3] In the Starry Messenger, Galileo had used the Latin term perspicillum. The root of the word is from the Ancient Greek τῆλε, romanized tele ‘far’ and σκοπεῖν, skopein ‘to look or see’; τηλεσκόπος, teleskopos ‘far-seeing’.^[4]

History[edit]

The earliest existing record of a telescope was a 1608 patent submitted to the government in the Netherlands by Middelburg spectacle maker Hans Lipperhey for a refracting telescope.^[5] The actual inventor is unknown but word of it spread through Europe. Galileo heard about it and, in 1609, built his own version, and made his telescopic observations of celestial objects.^[6][7]

The idea that the objective, or light-gathering element, could be a mirror instead of a lens was being investigated soon after the invention of the refracting telescope.^[8] The potential advantages of using parabolic mirrors—reduction of spherical aberration and no chromatic aberration—led to many proposed designs and several attempts to build reflecting telescopes.^[9] In 1668, Isaac Newton built the first practical reflecting telescope, of a design which now bears his name, the Newtonian reflector.^[10]

The invention of the achromatic lens in 1733 partially corrected color aberrations present in the simple lens^[11] and enabled the construction of shorter, more functional refracting telescopes.^{[citation needed]} Reflecting telescopes, though not limited by the color problems seen in refractors, were hampered by the use of fast tarnishing speculum metal mirrors employed during the 18th and early 19th century—a problem alleviated by the introduction of silver coated glass mirrors in 1857, and aluminized mirrors in 1932.^[12] The maximum physical size limit for refracting telescopes is about 1 meter (39 inches), dictating that the vast majority of large optical researching telescopes built since the turn of the 20th century have been reflectors. The largest reflecting telescopes currently have objectives larger than 10 meters (33 feet), and work is underway on several 30-40m designs.^[13]

The 20th century also saw the development of telescopes that worked in a wide range of wavelengths from radio to gamma-rays. The first purpose-built radio telescope went into operation in 1937. Since then, a large variety of complex astronomical instruments have been developed.

In space[edit]

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.^[14] 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 issues such as clouds, astronomical seeing and light pollution.^[15]

The disadvantages of launching a space telescope include cost, size, maintainability and upgradability.^[16]

By electromagnetic spectrum[edit]

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.

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.^[17] 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).^[18]

With photons of the shorter wavelengths, with the higher frequencies, glancing-incident optics, rather than fully reflecting optics are used. Telescopes such as TRACE and SOHO use special mirrors to reflect extreme ultraviolet, producing higher resolution and brighter images than are otherwise possible. A larger aperture does not just mean that more light is collected, it also enables a finer angular resolution.

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.

Radio and submilimeter[edit]

Radio telescopes are directional radio antennas that typically employ a large dish to collect radio waves. The dishes are sometimes constructed of a conductive wire mesh whose openings are smaller than the wavelength being observed.

Unlike an optical telescope, which produces a magnified image of the patch of sky being observed, a traditional radio telescope dish contains a single receiver and records a single time-varying signal characteristic of the observed region; this signal may be sampled at various frequencies. In some newer radio telescope designs, a single dish contains an array of several receivers; this is known as a focal-plane array.

By collecting and correlating signals simultaneously received by several dishes, high-resolution images can be computed. Such multi-dish arrays are known as astronomical interferometers and the technique is called aperture synthesis. The ‘virtual’ apertures of these arrays are similar in size to the distance between the telescopes. As of 2005, the record array size is many times the diameter of the Earth – using 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.^[19]

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 has the advantage of being able to pass through the atmosphere and interstellar gas and dust clouds.

Some radio telescopes such as the Allen Telescope Array are used by programs such as SETI^[20] and the Arecibo Observatory to search for extraterrestrial life.^[21][22]

Infrared[edit]

Visible light[edit]

An optical telescope gathers and focuses light mainly from the visible part of the electromagnetic spectrum.^[23] Optical telescopes increase the apparent angular size of distant objects as well as their apparent brightness. 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:

• The refracting telescope which uses lenses to form an image.^[24]
• The reflecting telescope which uses an arrangement of mirrors to form an image.^[25]
• The catadioptric telescope which uses mirrors combined with lenses to form an image.

A Fresnel imager is a proposed ultra-lightweight design for a space telescope that uses a Fresnel lens to focus light.^[26][27]

Beyond these basic optical types there are many sub-types of varying optical design classified by the task they perform such as astrographs,^[28] comet seekers^[29] and solar telescopes.^[30]

Ultraviolet[edit]

Most ultraviolet light is absorbed by the Earth’s atmosphere, so observations at these wavelengths must be performed from the upper atmosphere or from space.^[31][32]

X-ray[edit]

X-rays are much harder to collect and focus than electromagnetic radiation of longer wavelengths. X-ray telescopes can use X-ray optics, such as Wolter telescopes composed of ring-shaped ‘glancing’ mirrors made of heavy metals that are able to reflect the rays just a few degrees. The mirrors are usually a section of a rotated parabola and a hyperbola, or ellipse. In 1952, Hans Wolter outlined 3 ways a telescope could be built using only this kind of mirror.^[33][34] Examples of space observatories using this type of telescope are the Einstein Observatory,^[35] ROSAT,^[36] and the Chandra X-ray Observatory.^[37][38] In 2012 the NuSTAR X-ray Telescope was launched which uses Wolter telescope design optics at the end of a long deployable mast to enable photon energies of 79 keV.^[39][40]

Gamma ray[edit]

Higher energy X-ray and gamma ray telescopes refrain from focusing completely and use coded aperture masks: the patterns of the shadow the mask creates can be reconstructed to form an image.

X-ray and Gamma-ray telescopes are usually installed on high-flying balloons^[41][42] or Earth-orbiting satellites since the Earth’s atmosphere is opaque to this part of the electromagnetic spectrum. An example of this type of telescope is the Fermi Gamma-ray Space Telescope which was launched in June 2008.^[43][44]

The detection of very high energy gamma rays, with shorter wavelength and higher frequency than regular gamma rays, requires further specialization. An example of this type of observatory is the ground based telescope VERITAS.^[45][46]

A discovery in 2012 may allow focusing gamma-ray telescopes.^[47] At photon energies greater than 700 keV, the index of refraction starts to increase again.^[47]

Lists of telescopes[edit]

See also[edit]

References[edit]

Further reading[edit]

• Elliott, Robert S. (1966), Electromagnetics, McGraw-Hill
• King, Henry C. (1979). The history of the telescope. H. Spencer Jones. New York: Dover Publications. ISBN 0-486-23893-8. OCLC 6025190.
• Pasachoff, Jay M. (1981). Contemporary astronomy (2nd ed.). Philadelphia: Saunders College Pub. ISBN 0-03-057861-2. OCLC 7734917.
• Rashed, Roshdi; Morelon, Régis (1996), Encyclopedia of the History of Arabic Science, vol. 1 & 3, Routledge, ISBN 978-0-415-12410-2
• Sabra, A.I.; Hogendijk, J.P. (2003). The Enterprise of Science in Islam: New Perspectives. MIT Press. pp. 85–118. ISBN 978-0-262-19482-2.
• Wade, Nicholas J.; Finger, Stanley (2001), «The eye as an optical instrument: from camera obscura to Helmholtz’s perspective», Perception, 30 (10): 1157–1177, doi:10.1068/p3210, PMID 11721819, S2CID 8185797
• Watson, Fred (2007). Stargazer : the life and times of the telescope. Crows Nest, NSW: Allen & Unwin. ISBN 978-1-74176-392-8. OCLC 173996168.

External links[edit]

• Galileo to Gamma Cephei – The History of the Telescope
• The Galileo Project – The Telescope by Al Van Helden
• «The First Telescopes». Part of an exhibit from Cosmic Journey: A History of Scientific Cosmology Archived 9 April 2008 at the Wayback Machine by the American Institute of Physics
• Taylor, Harold Dennis; Gill, David (1911). «Telescope» . Encyclopædia Britannica. Vol. 26 (11th ed.). pp. 557–573.
• Outside the Optical: Other Kinds of Telescopes
• Gray, Meghan; Merrifield, Michael (2009). «Telescope Diameter». Sixty Symbols. Brady Haran for the University of Nottingham.

English[edit]

Etymology[edit]

tele- +‎ -scope.
From Latin tēlescopium, from Ancient Greek τηλεσκόπος (tēleskópos, “far-seeing”), from τῆλε (têle, “afar”) + σκοπέω (skopéō, “I look at”).

Coined in 1611 by the Greek mathematician Giovanni Demisiani for one of Galileo Galilei’s instruments presented at a banquet at the Accademia dei Lincei. Doublet of Telescopium.

Pronunciation[edit]

• (UK) IPA^(key): /ˈtɛl.ɪ.skəʊp/
• (US) IPA^(key): /ˈtɛl.əˌskoʊp/
• Hyphenation: tele‧scope

Noun[edit]

telescope (plural telescopes)

1. A monocular optical instrument that magnifies distant objects, especially in astronomy.
2. Any instrument used in astronomy for observing distant objects (such as a radio telescope).
3. (television) A retractable tubular support for lights.

   • 1963, Television Engineering: Report, page 245:

     In some studios the telescopes are fixed to the lighting grid […]

Synonyms[edit]

Derived terms[edit]

Translations[edit]

Verb[edit]

telescope (third-person singular simple present telescopes, present participle telescoping, simple past and past participle telescoped)

1. (transitive, intransitive) To extend or contract in the manner of a telescope.
2. (transitive, intransitive) To slide or pass one within another, after the manner of the sections of a small telescope or spyglass.
3. (intransitive) To come into collision, as railway cars, in such a manner that one runs into another.
4. (transitive, intransitive, mathematics, of a series) To collapse, via cancellation.

See also[edit]

• binoculars
• microscope

References[edit]

• telescope at OneLook Dictionary Search

телескоп, оптическая подзорная труба, складывать, складываться, сжимать

существительное ↓

глагол ↓

Словосочетания

telescope fish — рыба-телескоп  

Примеры с переводом

Примеры, ожидающие перевода

Возможные однокоренные слова

Формы слова

noun
ед. ч.(singular): telescope
мн. ч.(plural): telescopes

• 1
  telescope
  
  

  * * *

  telescope

  n

  • /vt/ выдвигать

  Англо-русский строительный словарь.
  Академик.ру.
  2011.

  Англо-русский словарь строительных терминов > telescope

• 2
  telescope
  
  

  telescope [ˊtelɪskəυp]

  1.

  n

  опти́ческая (подзо́рная) труба́; телеско́п

  3) сжима́ть, сокраща́ть ( into — текст, рассказ

  и т.п.

  )

  Англо-русский словарь Мюллера > telescope

• 3
  telescope
  
  

  Персональный Сократ > telescope

• 4
  telescope
  
  

  telescope compensator

  телескопический компенсатор

  English-Russian aviation dictionary > telescope

• 5
  telescope
  
  

  телескоп

  @telescope with full-sky coverage

  полноповоротный радиотелескоп

  @telescope of intermediate aperture

  телескоп умеренной светосилы

  @telescope of moderate power

  телескоп умеренной светосилы

  @telescope of short focal length

  короткофокусный телескоп

  @aerial telescope

  воздушный телескоп

  @altazimuth telescope

  телескоп на азимутальной установке

  @amauter telescope

  любительский телескоп

  @annalatic telescope

  зрительная труба дальномера

  @aplanatic telescope

  апланатический телескоп

  @astrographic telescope

  астрограф

  @astrometric telescope

  астрометрический телескоп

  @astronomical telescope

  визуальный телескоп

  @asymmetrical(-class) telescope

  телескоп на асимметричной установке

  @auxillary telescope

  вспомогательный телескоп

  @balloon-borne telescope

  телескоп, установленный на воздушном шаре

  @Cassegrain telescope

  телескоп системы Кассегрена

  @catadioptric telescope

  катадиоптрический телескоп

  @catoptic telescope

  зеркальный телескоп, рефлектор

  @chromospheric telescope

  хромосферный телескоп

  @collimating telescope

  коллиматорный телескоп

  @correlation telescope

  радиоинтерферометр

  @cosmic-ray telescope

  телескоп для регистрации космических лучей

  @Coude telescope

  телескоп системы кудэ

  @counter telescope

  телескоп счетчиков

  @dioptric telescope

  рефрактор

  @Doll-Kirkham telescope

  телескоп Дола-Киркхэма

  @

  English-Russian astronomy dictionary > telescope

• 6
  telescope
  
  

  Англо-русский технический словарь > telescope

• 7
  telescope
  
  

  1. n телескоп

  2. n оптическая труба

  3. n оптический прицел

  4. n астр. Телескоп

  5. v выдвигать, раздвигать; складывать

  6. v выдвигаться, раздвигаться; складываться

  7. v сталкиваться, врезаться

  8. v сталкиваться, накладываться друг на друга

  9. v сокращать, ужимать, укладывать в более короткие сроки

  10. v использовать в качестве телескопа

  English-Russian base dictionary > telescope

• 8
  telescope
  
  

  6) выдвигаться; вдвигаться

  •

  Англо-русский словарь технических терминов > telescope

• 9
  telescope
  
  

  English-Russian scientific dictionary > telescope

• 10
  telescope
  
  

  телескоп; оптический прибор; сплющиваться ; выдвигать телескопическую штангу

  Englsh-Russian aviation and space dictionary > telescope

• 11
  telescope
  
  

  English-Russian electronics dictionary > telescope

• 12
  telescope
  
  

  оптическая труба; оптический телескопический прицел; визир

  English-Russian military dictionary > telescope

• 13
  telescope
  
  

  [‘telɪskəup]
  1.

  сущ.

  1)

  to focus a telescope on smth. — настраивать телескоп на что-л.

  
  — reflecting telescope
  — mirror telescope

  б) радиотелескоп

  2.

  гл.

  1)

  а) выдвигать, раздвигать; складывать

  б) выдвигаться, раздвигаться; складываться

  2) врезаться, сталкиваться

  3) сжимать, сокращать; ужимать, укладывать в более короткие сроки

  Англо-русский современный словарь > telescope

• 14
  telescope
  
  

  ˈtelɪskəup
  1. сущ.
  1) телескоп to focus a telescope on ≈ настраивать телескоп на что-л. radio telescope refracting telescope reflecting telescope mirror telescope
  2) оптическая труба
  3) оптический прицел
  4) астр. Телескоп (созвездие)
  2. гл.
  1) выдвигать(ся), раздвигать(ся) ;
  складывать(ся)
  2) врезаться, сталкиваться( о поездах) the trains telescoped ≈ поезда столкнулись
  3) сжимать, сокращать (текст, рассказ и т. п.) ;
  ужимать, укладывать в более короткие сроки to telescope a four-year course into three years ≈ пройти четырехгодичный курс за три года
  4) использовать в качестве телескопа ∙ telescope into
  телескоп — refracting * (телескоп-) рефрактор — reflecting * (телескоп-) рефлектор оптическая труба оптический прицел (T.) (астрономия) Телескоп (созвездие) выдвигать, раздвигать;
  складывать выдвигаться, раздвигаться;
  складываться сталкиваться, врезаться (о поездах) — the trains *d поезда столкнулись сталкиваться, накладываться друг на друга (о теориях, учениях и т. п.) сокращать, ужиать, укладывать в более короткие сроки — to * a four-year course into three years пройти четырехгодичный курс за три года использовать в качестве телескопа

  Большой англо-русский и русско-английский словарь > telescope

• 15
  telescope
  
  

  English-Russian dictionary of telecommunications and their abbreviations > telescope

• 16
  telescope
  
  

  Англо-русский синонимический словарь > telescope

• 17
  telescope
  
  

  English-Russian big polytechnic dictionary > telescope

• 18
  telescope
  
  

  English-Russian big medical dictionary > telescope

• 19
  telescope
  
  

  The English-Russian dictionary general scientific > telescope

• 20
  telescope
  
  

  1. [ʹtelıskəʋp]

  1. телескоп

  2. оптическая труба

  3. оптический прицел

  2. [ʹtelıskəʋp]

  1. 1) выдвигать, раздвигать; складывать

  2) выдвигаться, раздвигаться; складываться

  2. 1) сталкиваться, врезаться ()

  2) сталкиваться, накладываться друг на друга ()

  3. сокращать, ужимать, укладывать в более короткие сроки

  to telescope a four-year course into three years — пройти четырёхгодичный курс за три года

  4. использовать в качестве телескопа

  НБАРС > telescope