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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...

Lucifer

(Encyclopedia)Lucifer lo͞oˈsĭfər [key] [Lat.,=light-bearing], in Christian tradition a name for Satan. In the Vulgate, Lucifer served as a translation of the Hebrew epithet meaning “Day Star,” a name associ...

Edison, Thomas Alva

(Encyclopedia)Edison, Thomas Alva, 1847–1931, American inventor, b. Milan, Ohio. A genius in the practical application of scientific principles, Edison was one of the greatest and most productive inventors of his...

ray, in physics

(Encyclopedia)ray, in physics, term denoting the straight line along which light or other form of radiation is propagated from its source. It generally refers to the line of propagation of waves but is also applied...

quasar

(Encyclopedia)quasar kwāˈsär [key], one of a class of blue celestial objects having the appearance of stars when viewed through a telescope and currently believed to be the most distant and most luminous objects...

Doppler effect

(Encyclopedia)Doppler effect, change in the wavelength (or frequency) of energy in the form of waves, e.g., sound or light, as a result of motion of either the source or the receiver of the waves; the effect is nam...

nimbus, in art

(Encyclopedia)nimbus nĭmˈbəs [key], in art, the luminous disk or circle or other indication of light around the head of a sacred personage. It was used in Buddhist and other Asian art and by the early Greeks and...

Beer's law

(Encyclopedia)Beer's law [for August Beer], physical law stating that the quantity of light absorbed by a substance dissolved in a nonabsorbing solvent is directly proportional to the concentration of the substance...

spectroheliograph

(Encyclopedia)spectroheliograph, device for photographing the surface of the sun in a single wavelength of light, usually one corresponding to a chief element contained in the sun, e.g., hydrogen or calcium; the re...

Granit, Ragnar

(Encyclopedia)Granit, Ragnar, 1900–1991, Swedish physiologist, M.D., Univ. of Helsinki, 1927. A professor at the Univ. of Helsinki from 1927, he joined the faculty of the Karolinska Institute, Sweden, in 1940. Gr...