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The Epic Interactive Encyclopedia 1998
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Epic Interactive Encyclopedia, The - 1998 Edition (1998)(Epic Marketing).iso
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Holography
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INFOTEXT
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1992-09-02
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975b
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24 lines
Method of producing three-dimensional (3-D)
images by means of laser light. Although the
possibility of holography was suggested as
early as 1947, it could not be demonstrated
until a pure coherent light source, the
laser, became available 1963. Holography uses
a photographic technique (involving the
splitting of a laser beam into two beams) to
produce a picture, or hologram, that contains
3-D information about the object
photographed. Some holograms show meaningless
patterns in ordinary light and produce a 3-D
image only when laser light is projected
through them, but reflection holograms
produce images when ordinary light is
reflected from them (as found on credit
cards). The technique of holography is also
applicable to sound, and bats may navigate by
ultrasonic holography. Holographic techniques
also have applications in storing dental
records, detecting stresses and strains in
construction and in retail goods, and
detecting forged paintings and documents.