emitting medium
1Light-emitting diode — LED redirects here. For other uses, see LED (disambiguation). Light emitting diode Red, pure green and blue LEDs of the 5mm diffused type Type Passive, optoelectronic Working principle Electr …
2Interstellar medium — Interstellar redirects here. For other uses, see Interstellar (disambiguation). The distribution of ionized hydrogen (known by astronomers as H II from old spectroscopic terminology) in the parts of the Galactic interstellar medium visible… …
3warm-hot intergalactic medium — noun the relatively hot (warmer than warm, but cooler than hot) intergalactic medium found within a filament of galaxies (galaxy filament), wall of galaxies (galaxy wall), sheet of galaxies (galaxy sheet) or galaxy hypercluster (hypercluster,… …
4Ammonia — For other uses, see Ammonia (disambiguation). Ammonia …
5electromagnetic radiation — Physics. radiation consisting of electromagnetic waves, including radio waves, infrared, visible light, ultraviolet, x rays, and gamma rays. [1950 55] * * * Energy propagated through free space or through a material medium in the form of… …
6Laser — For other uses, see Laser (disambiguation). United States Air Force laser experiment …
7X-ray astronomy — X rays start at 0.008 nm and extend across the electromagnetic spectrum to 8 nm, over which the Earth s atmosphere is opaque. X ray astronomy is an observational branch of astronomy which deals with the study of X ray observation and detection… …
8cosmos — /koz meuhs, mohs/, n., pl. cosmos, cosmoses for 2, 4. 1. the world or universe regarded as an orderly, harmonious system. 2. a complete, orderly, harmonious system. 3. order; harmony. 4. any composite plant of the genus Cosmos, of tropical… …
9laser — /lay zeuhr/, n. Physics. a device that produces a nearly parallel, nearly monochromatic, and coherent beam of light by exciting atoms to a higher energy level and causing them to radiate their energy in phase. Also called optical maser. [1955 60; …
10light — light1 lightful, adj. lightfully, adv. /luyt/, n., adj., lighter, lightest, v., lighted or lit, lighting. n. 1. something that makes things visible or affords illumination: All colors depend on light. 2. Physics …
