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fluorescence

(Encyclopedia)fluorescence flo͝orĕsˈəns [key], luminescence in which light of a visible color is emitted from a substance under stimulation or excitation by light or other forms of electromagnetic radiation or ...

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...

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...

photon

(Encyclopedia)photon fōˈtŏn [key], the particle composing light and other forms of electromagnetic radiation, sometimes called light quantum. The photon has no charge and no mass. About the beginning of the 20th...

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...

Nakamura, Shuji

(Encyclopedia)Nakamura, Shuji, 1954–, Japanese physicist and electronics engineer, grad. Univ. of Tokushima (D.Eng., 1994). Nakamura joined the Nichia Corporation in 1977, and it was there that he began his life-...

tachyon

(Encyclopedia)tachyon tăkˈēŏnˌ [key], hypothetical elementary particle that travels only at speeds exceeding that of light. According to the theory of relativity, the speed of light is the limiting velocity fo...