Columbia Encyclopedia

Search results

500 results found

Raman effect

(Encyclopedia)Raman effect räˈmən [key], appearance of additional lines in the spectrum of monochromatic light that has been scattered by a transparent material medium. The effect was discovered by C. V. Raman i...

Emirates of the South, Federation of the

(Encyclopedia)Emirates of the South, Federation of the: see South Arabia, Federation of. ...

Federation of the Emirates of the South

(Encyclopedia)Federation of the Emirates of the South: see South Arabia, Federation of. ...

Boudin, Eugène Louis

(Encyclopedia)Boudin, Eugène Louis özhĕnˈ lwē bo͞odăNˈ [key], 1824–98, French painter. He began painting at 25 in Paris. His best-known paintings are beach scenes of Brittany, Normandy, and the Netherland...

airglow

(Encyclopedia)airglow, faint diffuse illumination of the sky originating in the upper atmosphere. Although it occurs at all times of day throughout the upper atmosphere, it is most typically visible to an observer ...

color

(Encyclopedia)color, effect produced on the eye and its associated nerves by light waves of different wavelength or frequency. Light transmitted from an object to the eye stimulates the different color cones of the...

laser

(Encyclopedia)CE5 Ordinary light sources produce incoherent light, while a laser produces a beam of coherent light. laser [acronym for light amplification by stimulated emission of radiation], device for the cr...

night blindness

(Encyclopedia)night blindness, inability to see normally in subdued light. It is usually a result of vitamin A deficiency. The rod cells, one of two light-sensitive areas of the retina of the eye, are impaired in t...

albedo

(Encyclopedia)albedo ălbēˈdō [key], reflectivity of the surface of a planet, moon, asteroid, or other celestial body that does not shine by its own light. Albedo is measured as the fraction of incident light th...

photoelectric effect

(Encyclopedia)photoelectric effect, emission of electrons by substances, especially metals, when light falls on their surfaces. The effect was discovered by H. R. Hertz in 1887. The failure of the classical theory ...