constant lambert

Main Entry: lam·bert
Pronunciation: 'lam-b&rt
Function: noun
: the centimeter-gram-second unit of brightness equal to the brightness of aperfectly diffusing surface that radiates or reflects one lumen per square centimeter
Lamábert /'läm-"bert,/ Johann Heinrich (1728–1777), Germanmathematician, physicist, and philosopher. Largely self-educated, Lambert investigated geometry and astronomy, doing so by means of instruments which he himself designed and built. He also madesignificant contributions to the knowledge of heat and light. In 1760 he demonstrated for the first time how to measure quantitatively the intensity of light. The cgs unit of measurement for lightintensity, the lambert, is named in his honor.

lambert   (lām'bərt)  Pronunciation Key  A unit of luminance in the centimeter-gram-second system, equivalent to the luminance of a perfectly diffusing surface that emits or reflects one lumen per square centimeter. The lambert is named after the Swiss mathematician and physicist Johann Heinrich Lambert (1728-1777).