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reflecting telescope

See under telescope (def 1).
Also called reflector.
Origin of reflecting telescope
First recorded in 1695-1705


[tel-uh-skohp] /ˈtɛl əˌskoʊp/
an optical instrument for making distant objects appear larger and therefore nearer. One of the two principal forms (refracting telescope) consists essentially of an objective lens set into one end of a tube and an adjustable eyepiece or combination of lenses set into the other end of a tube that slides into the first and through which the enlarged object is viewed directly; the other form (reflecting telescope) has a concave mirror that gathers light from the object and focuses it into an adjustable eyepiece or combination of lenses through which the reflection of the object is enlarged and viewed.
Compare radio telescope.
(initial capital letter) Astronomy. the constellation Telescopium.
consisting of parts that fit and slide one within another.
verb (used with object), telescoped, telescoping.
to force together, one into another, or force into something else, in the manner of the sliding tubes of a jointed telescope.
to shorten or condense; compress:
to telescope the events of five hundred years into one history lecture.
verb (used without object), telescoped, telescoping.
to slide together, or into something else, in the manner of the tubes of a jointed telescope.
to be driven one into another, as railroad cars in a collision.
to be or become shortened or condensed.
1610-20; tele-1 + -scope; replacing telescopium (< New Latin; see -ium) and telescopio (< It)
Related forms
nontelescoping, adjective Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2018.
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Examples from the Web for reflecting telescope
Historical Examples
British Dictionary definitions for reflecting telescope

reflecting telescope

a type of telescope in which the initial image is formed by a concave mirror Also called reflector Compare refracting telescope


an optical instrument for making distant objects appear larger and brighter by use of a combination of lenses (refracting telescope) or lenses and curved mirrors (reflecting telescope) See also terrestrial telescope, astronomical telescope, Cassegrain telescope, Galilean telescope, Newtonian telescope
any instrument, such as a radio telescope, for collecting, focusing, and detecting electromagnetic radiation from space
to crush together or be crushed together, as in a collision: the front of the car was telescoped by the impact
to fit together like a set of cylinders that slide into one another, thus allowing extension and shortening
to make or become smaller or shorter: the novel was telescoped into a short play
Word Origin
C17: from Italian telescopio or New Latin telescopium, literally: far-seeing instrument; see tele-, -scope
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
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Word Origin and History for reflecting telescope



"to force together one inside the other" (like the sliding tubes of some telescopes), 1867, from telescope (n.). Related: Telescoped; telescoping.



1640s, from Italian telescopio (used by Galileo, 1611), and Modern Latin telescopium (used by Kepler, 1613), both from Greek teleskopos "far-seeing," from tele- "far" (see tele-) + -skopos "seeing" (see -scope). Said to have been coined by Prince Cesi, founder and head of the Roman Academy of the Lincei (Galileo was a member). Used in English in Latin form from 1619.

Online Etymology Dictionary, © 2010 Douglas Harper
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reflecting telescope in Science
reflecting telescope
See under telescope.

  1. An arrangement of lenses, mirrors, or both that collects visible light, allowing direct observation or photographic recording of distant objects. ◇ A refracting telescope uses lenses to focus light to produce a magnified image. Compound lenses are used to avoid distortions such as spherical and chromatic aberrations. ◇ A reflecting telescope uses mirrors to view celestial objects at high levels of magnification. Most large optical telescopes are reflecting telescopes because very large mirrors, which are necessary to maximize the amount of light received by the telescope, are easier to build than very large lenses.

  2. Any of various devices, such as a radio telescope, used to detect and observe distant objects by collecting radiation other than visible light.

The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
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reflecting telescope in Culture

telescope definition

A device used by astronomers to magnify images or collect more light from distant objects by gathering and concentrating radiation. The most familiar kind of telescope is the optical telescope, which collects radiation in the form of visible light. It may work by reflection, with a bowl-shaped mirror at its base, or by refraction, with a system of lenses. Other kinds of telescopes collect other kinds of radiation; there are radio telescopes (which collect radio waves), x-ray telescopes, and infrared telescopes. Radio and optical telescopes may be situated on the Earth, since the Earth's atmosphere allows light and radio waves through but absorbs radiation from several other regions of the electromagnetic spectrum. X-ray telescopes are placed in space.

The New Dictionary of Cultural Literacy, Third Edition
Copyright © 2005 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
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