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lens, in optics
(Encyclopedia)CE5 Lenses lens, device for forming an image of an object by the refraction of light. In its simplest form it is a disk of transparent substance, commonly glass, with its two surfaces curved or wi...Dreyfus Affair
(Encyclopedia)Dreyfus Affair drāˈfəs, drī– [key], the controversy that occurred with the treason conviction (1894) of Capt. Alfred Dreyfus (1859–1935), a French artillery officer and graduate of the French ...vision
(Encyclopedia)CE5 Optic nerve vision, physiological sense of sight by which the form, color, size, movements, and distance of objects are perceived. Defects of vision include astigmatism, color blindness, far...infrared astronomy
(Encyclopedia)infrared astronomy, study of celestial objects by means of the infrared radiation they emit, in the wavelength range from about 1 micrometer to about 1 millimeter. All objects, from trees and building...acting
(Encyclopedia)acting, the representation of a usually fictional character on stage or in films. At its highest levels of accomplishment acting involves the employment of technique and/or an imaginative ...African literature
(Encyclopedia)African literature, literary works of the African continent. African literature consists of a body of work in different languages and various genres, ranging from oral literature to literature written...printing
(Encyclopedia)printing, means of producing reproductions of written material or images in multiple copies. There are four traditional types of printing: relief printing (with which this article is mainly concerned)...radio
(Encyclopedia)CE5 A. AM transmitter B. AM receiver radio, transmission or reception of electromagnetic radiation in the radio frequency range. The term is commonly applied also to the equipment used, especially...telescope
(Encyclopedia)CE5 Mirror arrangements for a reflecting telescope telescope, traditionally, a system of lenses, mirrors, or both, used to gather light from a distant object and form an image of it. Traditional o...Browse by Subject
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