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mirage
mirage , atmospheric optical illusion in which an observer sees in the distance a nonexistent body of water or an image, sometimes distorted, of some object or of a complete scene. Examples of mirages are pools of water seen over hot desert sand or over hot pavement; at sea, an inverted image of a ship seen in the heavens or, also at sea, some object that is actually over the horizon but seems to loom up a relatively short distance away. These phenomena can be explained by the facts (1) that light rays undergo refraction, i.e., are bent, in passing from a medium of one density into another of different density and (2) that the boundary between two such media acts as a mirror for rays of light coming in at certain angles (see reflection ). Ordinarily the density of the atmosphere gradually decreases with altitude. Variations in temperature disturb the normal state (the density of warm air is less than that of cold air), producing unusual variations in the density of the atmosphere. The "lake" mirage in the desert is essentially a reflection of the sky. Light rays coming at a grazing angle from the sky just above the horizon are thrown upward by the surface of the area of extremely hot air just above the sand, and the effect to an observer is a shimmering reflecting expanse resembling the surface of a body of water. The inverted image of a ship seen in the heavens at sea is caused by a layer of dense, cool air over the water; this layer bends the rays of light from the ship (below the horizon) in a curved path that arches over the horizon and back to earth. The image formed appears to be that produced by an object somewhere distant in a straight line from the observer and, therefore, at a position in the sky. It is sometimes inverted because in the bending process the light rays coming from the object are changed in relative position. The type of mirage described as looming, in which distant objects appear much nearer than they actually are, is explained in the same way as the image of the ship, except that the image is not inverted; the density variations may also act as a magnifying glass. Mirages can be photographed. The strange phenomenon known as the fata morgana [Ital.,=Morgan le Fay, of the Arthurian legend, the supposed author of the mirage] is a complex mirage especially in evidence at the Strait of Messina; in this mirage images of objects such as ships, houses, or men, often two of the same object with one inverted, are seen suspended in the air over the object itself or on the water. |
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"mirage." The Columbia Encyclopedia, 6th ed.. 2011. Encyclopedia.com. 27 May. 2012 <http://www.encyclopedia.com>. "mirage." The Columbia Encyclopedia, 6th ed.. 2011. Encyclopedia.com. (May 27, 2012). http://www.encyclopedia.com/doc/1E1-mirage.html "mirage." The Columbia Encyclopedia, 6th ed.. 2011. Retrieved May 27, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1E1-mirage.html |
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mirage
mirage, a natural optical illusion caused both at sea and on land by the refraction of light passing through layers of air of different densities. These are usually caused by temperature differences, but can be because the layers of air contain different amounts of water vapour. Particularly in tropical seas, heat hazes often result in the appearance, above the horizon, of islands that normally would be below the horizon and too far away to be in line of sight.
M. V. Angel |
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"mirage." The Oxford Companion to Ships and the Sea. 2006. Encyclopedia.com. 27 May. 2012 <http://www.encyclopedia.com>. "mirage." The Oxford Companion to Ships and the Sea. 2006. Encyclopedia.com. (May 27, 2012). http://www.encyclopedia.com/doc/1O225-mirage.html "mirage." The Oxford Companion to Ships and the Sea. 2006. Retrieved May 27, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O225-mirage.html |
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mirage
mi·rage / məˈräzh/ • n. an optical illusion caused by atmospheric conditions, esp. the appearance of a sheet of water in a desert or on a hot road caused by the refraction of light from the sky by heated air. ∎ something that appears real or possible but is not in fact so: the notion that the public is pro-business is a mirage. |
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"mirage." The Oxford Pocket Dictionary of Current English. 2009. Encyclopedia.com. 27 May. 2012 <http://www.encyclopedia.com>. "mirage." The Oxford Pocket Dictionary of Current English. 2009. Encyclopedia.com. (May 27, 2012). http://www.encyclopedia.com/doc/1O999-mirage.html "mirage." The Oxford Pocket Dictionary of Current English. 2009. Retrieved May 27, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O999-mirage.html |
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mirage
mirage Type of optical illusion sometimes seen near the Earth's surface when light is refracted (bent) as it passes between cool dense air to warmer, less dense air. Mirages are most commonly seen shimmering on hot, dry roads; the shimmer is a refracted image of the sky.
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"mirage." World Encyclopedia. 2005. Encyclopedia.com. 27 May. 2012 <http://www.encyclopedia.com>. "mirage." World Encyclopedia. 2005. Encyclopedia.com. (May 27, 2012). http://www.encyclopedia.com/doc/1O142-mirage.html "mirage." World Encyclopedia. 2005. Retrieved May 27, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O142-mirage.html |
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mirage
mirage An optical effect in which major vertical variation in temperature of the lower atmosphere produces differential refraction of light, resulting, for example, in raised images and in gaps, which may give the appearance of a water surface.
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MICHAEL ALLABY. "mirage." A Dictionary of Ecology. 2004. Encyclopedia.com. 27 May. 2012 <http://www.encyclopedia.com>. MICHAEL ALLABY. "mirage." A Dictionary of Ecology. 2004. Encyclopedia.com. (May 27, 2012). http://www.encyclopedia.com/doc/1O14-mirage.html MICHAEL ALLABY. "mirage." A Dictionary of Ecology. 2004. Retrieved May 27, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O14-mirage.html |
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mirage
mirage Optical effect in which major vertical variation in temperature of the lower atmosphere produces differential refraction of light, resulting for example in raised images and in gaps, which may give the appearance of a water surface.
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AILSA ALLABY and MICHAEL ALLABY. "mirage." A Dictionary of Earth Sciences. 1999. Encyclopedia.com. 27 May. 2012 <http://www.encyclopedia.com>. AILSA ALLABY and MICHAEL ALLABY. "mirage." A Dictionary of Earth Sciences. 1999. Encyclopedia.com. (May 27, 2012). http://www.encyclopedia.com/doc/1O13-mirage.html AILSA ALLABY and MICHAEL ALLABY. "mirage." A Dictionary of Earth Sciences. 1999. Retrieved May 27, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O13-mirage.html |
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mirage
mirage XIX. — F. mirage, f. mirer refl. look at oneself in a mirror — L. mīrāre; see prec., -AGE.
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T. F. HOAD. "mirage." The Concise Oxford Dictionary of English Etymology. 1996. Encyclopedia.com. 27 May. 2012 <http://www.encyclopedia.com>. T. F. HOAD. "mirage." The Concise Oxford Dictionary of English Etymology. 1996. Encyclopedia.com. (May 27, 2012). http://www.encyclopedia.com/doc/1O27-mirage.html T. F. HOAD. "mirage." The Concise Oxford Dictionary of English Etymology. 1996. Retrieved May 27, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O27-mirage.html |
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mirage
mirage •décolletage, découpage, Lesage, maquillage, paysage, plage, potage, vernissage
•triage • persiflage • fuselage • collage
•ménage • badinage
•counter-espionage • mirage
•entourage • corsage • repêchage
•frottage
•montage, photomontage
•cabotage
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"mirage." Oxford Dictionary of Rhymes. 2007. Encyclopedia.com. 27 May. 2012 <http://www.encyclopedia.com>. "mirage." Oxford Dictionary of Rhymes. 2007. Encyclopedia.com. (May 27, 2012). http://www.encyclopedia.com/doc/1O233-mirage.html "mirage." Oxford Dictionary of Rhymes. 2007. Retrieved May 27, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O233-mirage.html |
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