Copyright © Philip M. Parker, INSEAD. Terms of Use.
Definition: Reflector |
ReflectorNoun1. Device that reflects radiation. 2. Optical telescope consisting of a large concave mirror that produces an image that is magnified by the eyepiece. Source: WordNet 1.7.1 Copyright © 2001 by Princeton University. All rights reserved. |
Date "reflector" was first used in popular English literature: sometime before 1838. (references) |
| Domain | Definition |
Aerospace | 1. In general, any object that reflects incident energy; usually it is a device designed for specific reflection characteristics. See retroreflector, corner reflector, parabolic reflector, radar reflector. 2. In an antenna, a parasitic element located in a direction other than the general direction of the major lobe of radiation. 3. A material of high scattering cross section that surrounds a reactor core to reduce the escape of neutrons, many of which are reflected back into the core.4. A repeller. (references) |
Electrical Engineering | A conductive surface or conductive assembly which acts as a practically continuous surface, whose dimension is large compared to the wavelength, used to reinforce or divert the incident radiation in desired directions. Source: European Union. (references) |
| The secondary radiator or an array of secondary radiators or a reflecting surface placed behind a primary radiator or an array of primary radiators or a feed, in order to increase forward and reduce backward radiation from the aerial. Source: European Union. (references) | |
| An electrode held at a negative potential with respect to a resonator for the purpose of returning to this resonator the electron beam which issued from it. Source: European Union. (references) | |
| The device used to alter the spatial distribution of the luminous flux from a source and depending essentially on the phenomenon of reflection. Source: European Union. (references) | |
| One of the many concentrator-devices or just a flat reflecting body placed in front of the collector. Source: European Union. (references) | |
Energy | A layer of material immediately surrounding a reactor core that scatters back (or reflects) into the core many neutrons that would otherwise escape. The returned neutrons can then cause more fissions and improve the neutron economy of the reactor. Common reflector materials are graphite, beryllium, water, and natural uranium. (references) |
Medicine | A device which throws back rays of light or heat or waves of sound ; one or more conducting surfaces so shaped as to reflect the energy from and to modify the radiation pattern of a primary radiator or array. Source: European Union. (references) |
Nuclear Energy & Physics | A material or a body of material which reflects incident radiation. In nuclear reactor technology, this term is usually restricted to designate a part of a reactor placed adjacent to the core for the purpose of returning some of the escaping neutrons back into the core by scattering collisions. Source: European Union. (references) |
Source: compiled by the editor from various references; see credits. | |
(From Wikipedia, the free Encyclopedia)
A reflecting telescope (reflector) is an optical telescope which uses mirrors, rather than lenses, to reflect light. Newton designed the first reflector; in order to solve problems, such as chromatic aberration, which occur with refracting telescopes. The traditional two-mirrored reflector is known as a Newtonian reflector.While still used in amateur astronomy, professionals now tend to use prime focus, Cassegrain focus, and coudé focus designs. On Earth (by 2001), there were at least 49 reflectors with primary mirrors having diameters of 2m+.
Technical Difficulties
Reflecting telescopes do not have as many technical issues, as do the refracting telescopes; however, they are also more expensive. In addition, reflectors which have spherical mirrors (rather than parabolic mirrors) tend to suffer from spherical aberrations. These aberrations can be corrected with a Schmidt corrector plate; however, corrected non-parabolic reflectors still lack the magnification-power of parabolic reflectors.
Notable Reflectors
- W.M. Keck telescopes (Hawaii)
The Prime Focus
In a prime focus design, the astronomer sits inside the telescope, at the focal point of the reflected light.The Cassegrain Focus
Designs with a Cassegrain focus have a hole drilled through the primary mirror and a mirror, placed where the astronomer would sit in a prime focus telescope, refleces light through the hole.The Coudé Focus
In a coudé design, the design is similar to the Cassegrain except no hold is drilled in the primary mirror; instead, a third mirror reflects the light to the side.
- The Newtonian has a parabolic primary mirror, and a flat secondary that reflects the focal plane to the side of the top of the telescope tube. It is one of the simplest and least expensive designs for a given size of primary, and is popular with amateurs. Since the light path is unfolded, the tube is quite long and heavy. The parabolic mirror is difficult to produce with accuracy. Some amateurs produce a spherical mirror, and live with the spherical aberration. The spider supporting the secondary mirror often introduce diffractive effects that cause stars to appear to "flare" in four or six directions.
- The Cassegrain has a spherical primary mirror, and a spherical secondary mirror that reflects the light back down through a hole in the primary. This is one of the most attractive designs. The folded optics make the telescope compact. The secondary corrects spherical aberration intruduced by the spherical primary. The secondary mirror introduces a diffraction pattern that seems to create a ring around stars. The spherical mirrors are easy to produce with automatic equipment. On smaller telescopes, and camera lenses, the secondary is often mounted on an optically-flat, optically-clear glass plate that closes the telescope tube. This support eliminates the "star-shaped" diffraction effects caused by a support spider. The closed tube stays clean, and the primary is protected, at some loss of light-gathering power.
- The Maksutov is similar to the Cassegrain. It starts with an optically transparent corrector lens that is a section of a hollow sphere. It has a spherical primary mirror, and a spherical secondary that is often just a mirrored section of the corrector lens. Maksutovs are mechanically simpler than small Cassegrains, have a closed tube and all-spherical optics.
- One very popular luxury telescope design was the Celestron. It ran a "finder" scope and the main scope to the same eyepiece. It had a 10cm Maksutov reflector as the main telescope. The finder was a 2.5 cm refractor. The focal plane of the reflector and refractor were the same (probably the refractor had a factory adjustment). A flat-mirror near the bottom reflected light to the finder's primary, and a movable mirror at the back of the 10-cm cassegrain hole switched the optical path of the large telescope between the eyepiece and the camera attachment on the back. When the camera was engaged, the finder-scope was operational.
- The Ritchey-Chrétien is a specialized Cassegrain reflector with the advantage that it is coma free. This is why almost every professional reflector telescope in the world is of the Ritchey-Chrétien design. It was invented by George Willis Ritchey and Henri Chrétien in the early 1910s.
- The Schmidt-Cassegrain is a classic wide-field telescope. 30 inch Schmidt-cassegrains are used for sky surveys at astronomical observatories and satellite tracking stations. The first optical element is a "schmidt corrector plate." The plate is figured by placing a vacuum on one side, and grinding the exact correction required to fix the spherical correction. The primary mirror is spherical.
- One exception to the supremacy of Ritchey-Chrétien telescopes for professional use are Schmidt cameras. These instruments have a very wide field a sharp focus, about 30 times greater than Ritchey-Chrétien, with the drawbacks that the focus is inaccessible, making them usable only as cameras, and contrary to Cassegrain, they have their physical length is at least twice they focal length. Their optical performance come from the use of a sperical mirror which reintroduce the spherical and field curvature aberrations but avoid all the others. The spherical aberration is overcome by using a corrector lens in front of the telescope at the radius of curvature of the mirror and field curvature are compensated with a film-holder that stretches the film into a mild spherical shape.
Source: adapted by the editor from Wikipedia, the free encyclopedia under a copyleft GNU Free Documentation License (GFDL) from the article "Reflecting telescope."
(From Wikipedia, the free Encyclopedia)
See:
In some British spellings, reflection may appear as reflexion.
- Reflection (mathematics)
- Reflection (optics)
- Reflection (computer science)
Source: adapted by the editor from Wikipedia, the free encyclopedia under a copyleft GNU Free Documentation License (GFDL) from the article "Reflection."
(From Wikipedia, the free Encyclopedia)
A reflector telescope is a telescope, with which the substantial part of the optics consists of reflecting elements. Optical telescopes use highly exact polished concave mirrors as primary mirrors. The shape of the mirrors can be spherical, parabolic or hyperbolic. The surface must be worked on with an accuracy from 100 to 20nm. Mirror sizes to 8.6m were realized.Nearly all large research-grade astronomical telescopes are reflectors. This is due to several reasons:
In radio telescopes metal surfaces, which collect the radio waves in the actual antenna, work as mirrors. These are used as parabolic reflectors. The largest single piece antenna is the Arecibo radio telescope in Puerto Rico.
- In a lens the entire volume of material has to be free of imperfection and inhomogeneities, whereas in a mirror, only one surface has to be perfectly polished.
- Light of different colors travels through a medium other than vacuum at different speeds. This causes chromatic aberration.
- There are technical difficulties involved in manufacturing and manipulating large-aperture lenses. One of them is that a lens can only be held by its perimeter. A mirror, on the other hand, can be supported by the whole side opposite to its reflecting face.
According to their geometry one differentiates different kinds of reflector telescopes:
- (classical) Cassegrain telescope
- Maksutov-Cassegrain telescope
- Newtonian telescope
- Ritchey-Chrétien telescope
- Schiefspiegler telescope
- Schmidt-Cassegrain telescope
- Schmidt camera
Source: adapted by the editor from Wikipedia, the free encyclopedia under a copyleft GNU Free Documentation License (GFDL) from the article "Reflector telescope."
Synonym: ReflectorSynonym: reflecting telescope (n). (additional references) |
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Source: compiled by the editor from various references; see credits. | |||
| Thumbnail | Description & Credit | Thumbnail | Description & Credit |
 | A drift buoy with radar reflector for studying surface currents. Credit: Paths Less Taken - NOAA at the Ends of the Earth. |  | Poses by the cockpit of a Grumman F4F "Wildcat" fighter, at Naval Air Station, Alameda, California, 6 February 1943. Note his "Aviation Green" uniform, and the plane's reflector gunsight. Credit: NAVY. |
 | Interior of the dome at Mt. Wilson Observatory. This view shows the 100 in. reflector telescope, a Cassagrain observing platform, etc., as seen from the west. Credit: Library of Congress. |  | Thomas Corwin, full-length portrait, three-quarters to the left, standing by table with tablecloth, backdrop or reflector screen prominent on left. Credit: Library of Congress. |
Source: pictures compiled by the editor from various references; see picture credits. | |||
| Title | Author | Quote |
Les Miserables | Hugo, Victor | The Bel Air was lighted by a reflector. |
Portrait of the Artist as a Young Man | Joyce, James | A lamp with a reflector hung on the japanned wall of the fireplace and by its light his aunt was reading the evening paper that lay on her knees |
Source: compiled by the editor from various references. | ||
| "Reflector" is generally used as a noun (singular) -- approximately 98.91% of the time. "Reflector" is used about 92 times out of a sample of 100 million words spoken or written in English. Its rank is based on over 700,000 words used in the English language. Some parts-of-speech are not covered due to the samples used by the British National Corpus. (note: percents less than one-hundredth of one percent have been omitted) |
| Parts of Speech | Percent | Usage per 100 Million Words | Rank in English |
| Noun (singular) | 98.91% | 91 | 34,491 |
| Noun (proper) | 1.09% | 1 | 339,140 |
| Total | 100.00% | 92 | N/A |
Source: compiled by the editor from several corpora; see credits.
Expressions using "reflector": antenna with cylindrical parabolic reflector ♦ antenna with paraboloidal reflector ♦ balloon reflector ♦ confusion reflector ♦ corner reflector ♦ dish reflector ♦ game reflector ♦ illuminating surface of a retro reflector ♦ illuminating surface of a signalling lamp other than a retro reflector ♦ newtonian reflector ♦ parabolic reflector ♦ paraboloid reflector ♦ paraboloidal dish reflector ♦ paraboloidal reflector ♦ radio reflector ♦ rear reflector ♦ reflector studs ♦ reflex reflector ♦ rod reflector ♦ specular reflector. Additional references. | |
| Hyphenated Usage | |
Beginning with "reflector": reflector-mirror. | |
Ending with "reflector": dish-reflector, reflex-reflector, retro-reflector. | |
| Source: compiled by the editor from various references; see credits. | |
| The following statistics estimate the number of searches per day across the major English-language search engines as identified by various trade publications. Hyperlinks lead to commercial use of the expression at Amazon.com. |
| Language | Translations for "reflector"; alternative meanings/domain in parentheses. | |
Albanian | reflektor (deflector, reverberator), pasqyrë (digest, glass, looking glass, mirror, review, revue). (various references) | |
Arabic | عاكس الضوء (lampshade), التلسكوب العاكس, العاكسة (reverse), العاكس (reverberator, speculum). (various references) | |
Bulgarian | рефлектор (illuminator, reverberator, speculum), отражателен телескоп, отражател (deflector, mitre), огледален телескоп. (various references) | |
Chinese | 反射器. (various references) | |
Czech | reflektor (headlight, lamp, searchlight), odrazové sklo. (various references) | |
Danish | reflektorspejl (mirror, reflector-mirror), reflektorkikkert (catoptric telescope, reflecting telescope), reflektor (mirror, reflecting telescope, reflector lens, reflector-mirror, reflex reflector, repeller, specular reflector), reflekterende overflade (reflecting surface, reflective coating), reflekterende flade (reflecting surface), refleksanordning (reflector lens, reflex reflector). (various references) | |
Dutch | reflektor (mirror, reflector-mirror), reflector (headlight), reflectoor (reflector lens, reflex reflector), reflectievlak (reflecting surface), reflecterend oppervlak (reflecting surface), spiegeltelescoop (catoptric telescope, reflecting telescope), lampspiegel (mirror, reflector-mirror). (various references) | |
Farsi | جسم منعکس کننده , جسم صیقلی , الت انعکاس , بازتابنده . (various references) | |
Finnish | heijastin (luminous badge). (various references) | |
French | réflecteur (reflective, reverberator), catadioptre (rear reflector, reflector lens, reflex reflector). (various references) | |
German | Spiegel (escutcheon, glass, lapel, level, looking-glass, mirror, mirrors, panel, speculum, tab, type area), Reflektor (catoptric telescope, deer mirror, game reflector, mirror, reflecting telescope, reflector-mirror, repeller, roadside mirror, specular reflector), Scheinwerfer (floodlight, headlamp, headlight, headlights, lamp, projector, reverberator, searchlamp, spotlight). (various references) | |
Greek | κάτοπτρο (glass, lens, speculum), καθρέφτησ, επιφάνεια ανάκλασης (reflecting surface), ανακλώσα επιφάνεια (reflecting surface), ανακλαστικό τηλεσκόπιο (catoptric telescope, reflecting telescope), ανακλαστήρας (baffle, mirror, reflector lens, reflector-mirror, reflex reflector, repeller, retro-reflector, specular reflector), ανακλαστής, αντανακλαστικό κάτοπτρο (mirror, reflector-mirror), αντανακλαστήρας (mirror, reflector-mirror), αντανακλαστήρ. (various references) | |
Hebrew | מחזירור. (various references) | |
Hungarian | prizma (clamp, prism), macskaszem (cat's eyes, pavement reflector). (various references) | |
Indonesian | reflektor, penyorot (commentator, projector, reviewer). (various references) | |
Italian | riflettore (floodlight, reverberator, searchlight, spotlight). (various references) | |
Japanese Kanji | レバレッジ効果 (left, left wing, leverage effect, referee, referee's position, reference, reference book, reference service, reflex camera, repertoire, repertory, repertory system, review, reviewer, revue), 反射鏡 . (various references) | |
Japanese Katakana | レフレクター , は"しゃきょう. (various references) | |
Korean | 반사체. (various references) | |
Pig Latin | eflectorray.(various references) | |
Portuguese | refletor (baffler, floodlight, headlight, reverberator, tent pole), reflector (mirror, reflector-mirror, repeller, specular reflector), telescópio de reflexão (catoptric telescope, reflecting telescope), telescópio de espelho, superfície reflectora (reflecting surface, reflective coating), som ou calor, espelho (glass, keeking-glass, looking glass, mirror, speculum), capta-focos (reflector lens, reflex reflector), aparelho refletor. (various references) | |
Romanian | retrovizor (driving mirror), reflector (flood-light, reverberator, searchlight, search-light, spotlight). (various references) | |
Russian | рефлектор, отражатель (baffler, deflector, ejector, rejector, reverberator). (various references) | |
Serbo-Croatian | reflektor (floodlight, olivet, searchlight, spotlight), mačje oko. (various references) | |
Spanish | reflector (baffler, dish, floodlight, rejector, searchlight, spotlight). (various references) | |
Swedish | reflektor (specular reflector). (various references) | |
Turkish | reflektör (reverberator), yansıtıcı (reflective, reverberator, specular), projektör (floodlight, floodlight projector, headlight, klieg, projector, reverberator, searchlight), aynalı teleskop, ayna (glass, looking glass, looking-glass, mirror, peeper). (various references) | |
Ukrainian | рефлектор (reverberator, speculum), відбивач (deflector, mirror, rejector, reverberator). (various references) | |
Welsh | adlewyrchydd. (various references) | |
| Source: compiled by the editor from various translation references. | ||
| Language | Period | Translations |
| Latin | 500 BCE-Modern | specula, speculis, speculum. (various references) |
| Source: compiled by the editor from various references. | ||
Derivations | |
Words beginning with "reflector": reflectorize, reflectorized, reflectorizes, reflectorizing, reflectors. (additional references) | |
Words ending with "reflector": retroreflector. (additional references) | |
Words containing "reflector": retroreflectors. (additional references) | |
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"Reflector" is suggested in spellcheckers for the following: refector, reflecter, reflectorr, reflectory, Reflotron, Relekto. (additional references) | |
| Source: compiled by the editor, based on several corpora (additional references). | |
| Words rhyming with "reflector" (pronounced 'Re*flect"or'): Acceptor, Assertor, Assessor, Assistor, Assizor, Attractor, Chantor, Circumventor, Co-assessor, Collector, Compressor, Conductor, Confessor, Conjector, Connector, Consignor, Constrictor, constructor, Contractor, Contradictor, Conveyor, Corrector, Countor, Cruor, Debtor, Decolor, Deflector, Deforceor, Devisor, Duressor, Embraceor, Encolor, Escheator, flexor, grantor, ignitor, inductor, inspector, instructor, INVENTOR, investor, Mainor, Maintainor, manor, mayor, Miscolor, misdemeanor, Nonconductor, Objector, Oppressor. (additional references) |
Scrabble® Enable2K-Verified Anagrams | |
| Words within the letters "c-e-e-f-l-o-r-r-t" | |
-2 letters: crofter, elector, electro, erector, reflect. | |
-3 letters: colter, creole, ferrel, ferret, floret, forcer, lector, lefter, lofter, rector, refect, refelt, reflet, retore, rolfer, telfer, tercel. | |
-4 letters: ceorl, cleft, corer, creel, croft, crore, elect, erect, fetor, fleer, fleet, force, forte, freer, frere, frore, ofter, recto, refel, refer, relet, retro, terce. | |
-5 letters: celt, cere, cero, cete, clef, clot. | |
| Words containing the letters "c-e-e-f-l-o-r-r-t" | |
+1 letter: reflectors. | |
+2 letters: electroform. | |
+3 letters: electroforms, reflectorize. | |
+4 letters: electroformed, ferroelectric, reflectometer, reflectometry, reflectorized, reflectorizes, retroflection. | |
+5 letters: electroforming, ferroelectrics, reflectometers, reflectorizing, retroflections, retroreflector. | |
| Source: compiled by the editor from various references; see credits. SCRABBLE® is a registered trademark. All intellectual property rights in and to the game are owned in the U.S.A and Canada by Hasbro Inc., and throughout the rest of the world by J.W. Spear & Sons Limited of Maidenhead, Berkshire, England, a subsidiary of Mattel Inc. Mattel and Spear are not affiliated with Hasbro. | |
| 1. Definition 2. Synonyms 3. Crosswords 4. Usage: Commercial | 5. Images: Slideshow 6. Images: Photo Album 7. Quotations: Fiction 8. Usage Frequency | 9. Expressions 10. Expressions: Internet 11. Translations: Modern 12. Translations: Ancient | 13. Derivations 14. Rhymes 15. Anagrams 16. Bibliography |
Copyright © Philip M. Parker, INSEAD. Terms of Use.
