15 résultats pour "mirror"
- Daily Mirror, The - médias & information.
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Telescope - astronomy.
Observatory). In some telescopes designed in the 1990s, the mirror’s weight has been dramatically reduced by sandwiching a honeycomb pattern of glass ribs between a thin, butrigid, concave mirror and a flat back plate. Engineers have even developed meniscus mirrors—mirrors that are too thin to support their own weight. An adjustableframework supports the meniscus mirror, and servomechanical actuators, controlled by computer, continually adjust the shape of the mirror as it tracks celestial tar...
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Optics
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INTRODUCTION
Mirage
Mirages appear because differences in air temperature cause light rays from an object to take different paths to a viewer's
eye.
Refraction of Light by DiamondsThe brilliance of diamonds is due to their high refractive index, a measure of how strongly a transparent material bendslight rays. The skill of the gem-cutter lies in angling the facets of the stone so that each light ray entering it is reflectedmany times before it emerges again.Spencer Grant/Photo Researchers, Inc. The amount of light reflected depends on the ratio of the refractive indexes for the two media. The plane of incidence contains the incident ray and...
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Analyse chanson Mirrors
SHORT ANALYSIS AND WHY DID I CHOOSE IT: This song was written by Justin Randall Timberlake . He is an American pop musician, composer, presenter and actor. He is also very famous and known all around the world for his songs and the song I just read. The song Mirrors was written in honor of Justin Timberlake’s grandparents for their celebration of 63 years of marriage, and that is why the music video is very special to him. The song is about loved ones being a reflection of one and other, t...
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Observatory - astronomy.
Ultraviolet radiation, X rays, and gamma rays have shorter wavelengths than visible light has. These types of radiation tell astronomers about the hottest and mostviolent phenomena in the universe. Earth’s atmosphere blocks most of this radiation, so astronomers must send their observatories above the atmosphere aboardballoons, rockets, or satellites. Ultraviolet telescopes are much like visible light telescopes, but X-ray telescopes must have special nested cylindrical mirrors to prevent Xrays...
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Astronomy - astronomy.
Telescopes may use either lenses or mirrors to gather visible light, permitting direct observation or photographic recording of distant objects. Those that use lenses arecalled refracting telescopes, since they use the property of refraction, or bending, of light ( see Optics: Reflection and Refraction ). The largest refracting telescope is the 40-in (1-m) telescope at the Yerkes Observatory in Williams Bay, Wisconsin, founded in the late 19th century. Lenses bend different colors of light by d...
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X-Ray Astronomy - astronomy.
Some neutron stars have weaker magnetic fields that allow incoming material to settle onto the entire surface of the neutron star. Eventually, so much material buildsup that the surface layer becomes dense enough to set off a vast thermonuclear explosion, called an outburst. The explosion heats gas to produce X rays. Such aneutron star—called an X-ray burster—can increase its X-ray production by a million times during an outburst. The X-ray glow fades over time, and the binary systementers a lon...
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Organic Chemistry - chemistry.
B Alkenes and Alkynes Isomeric with the cyclanes, or cycloalkanes as they are sometimes called, is the family of alkenes, also represented by the general formula C nH2n. This family of hydrocarbons is characterized by one or more double bonds between carbon atoms. Propene and cyclopropane, for example, are isomers, as are 1,3-dimethylcyclohexane and 3,4-dimethyl-2-hexene. (The location of the double bond is indicated by the 2-hexene part of the name.) Double bonds may also occur incyclic compou...
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Metalwork
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INTRODUCTION
Metalwork, in the fine arts, objects of artistic, decorative, and utilitarian value made of one or more kinds of metal--from precious to base--fashioned by either casting,
hammering, or joining or a combination of these techniques.
Early Bronze DiskThis disk with the head of Acheloos, an Etruscan river god, was made of bronze, an alloy of copper and tin, sometime inthe early 5th century bc. It comes from the necropolis of Monte Quaglieri in Tarquinia. Alloys are made by smelting twodifferent metals together.Scala/Art Resource, NY Knowledge of smelting ultimately led to knowledge of mixing different ores together in the smelting process to produce simple alloys. This followed an intermediateperiod, about 3000 BC, when comp...
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Television.
A charge-coupled device (CCD) can be much smaller than a camera tube and is much more durable. As a result, cameras with CCDs are more compact and portablethan those using a camera tube. The image they create is less vulnerable to distortion and is therefore clearer. In a CCD, the light from a scene strikes an array ofphotodiodes arranged on a silicon chip. Photodiodes are devices that conduct electricity when they are struck by light; they send this electricity to tiny capacitors. Thecapacitors...
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A suggestion of romance
beast feels for Belle grows stronger every day and every night, he would ask her to marry him only to be refused each time. Belle, dreaming of a prince she is persuaded is kept as a prisonner in this castle, always answer him that she only love the Beast as a friend. After several month, Belle eventually become home sick and asks the Beast if he could let her see her family. He allowed her if she would return after one week and give her a mirror where she could see the Beast at any time she wan...
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Article de presse: Diana, du mariage de "conte de fées" aux révélations qui ébranlèrent Buckingham
d'embrasser longuement sur la bouche un officier du régiment des dragons à la sortie d'une soirée. S'effondrant en larmes, elle sefait remettre la pellicule. " Je me suis fait avoir par son charme. Quand je lui ai donné la bobine, comme par enchantement, elle acessé de pleurer ", se souvient le paparazzi. Malgré le parfum de scandale qui flotte subrepticement dans son sillage, les braves gens continuent de l'aimer et de la respecter.Ils lui savent gré d'être moins distante qu'Elizabeth II, m...
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WHAT THE?
the living one.Sometimes Ithink itwould beweird ifthere wereaskyscraper thatmoved upand down whileitselevator stayed inplace. Soifyou wanted togo tothe ninety-fifth floor,you'd justpress the95button andtheninety-fifth floor would cometoyou. Also, thatcould beextremely useful,because ifyou're onthe ninety-fifth floor,andaplane hits below you,thebuilding couldtakeyoutothe ground, andeveryone couldbesafe, even ifyou leftyour birdseed shirtat home thatday. I've only been inalimousine twiceever.Thefi...
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Poetry
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INTRODUCTION
Phyllis McGinley
American poet and author Phyllis McGinley composed light, witty verse, much of which deals with family life.
repetition of certain lines and the rhyming of certain lines. The Provençal sestina features a set of six words that end lines (end-words), repeated in a dizzyingly complexpattern. The range of effects created by the poetic line varies tremendously depending on its length, its patterns of repetition, and whether the sentence stops at the end of theline (end-stopped) or carries over the end of the line (enjambed). Many of the earliest examples of Old English poetry feature an accentual line with...
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History of Astronomy - astronomy.
Egypt, the Sun was directly overhead at noon. On the same date and time in Alexandria, Egypt, the Sun was about 7 degrees south of zenith. With simple geometryand knowledge of the distance between the two cities, he estimated the circumference of the Earth to be 250,000 stadia. (The stadium was a unit of length, derivedfrom the length of the racetrack in an ancient Greek stadium. We have an approximate idea of how big an ancient Greek stadium was, and based on that approximationEratosthenes was...