Lighting a particular area, and falls within a given solid angle. The SI unit for luminance is candela per square metre (cd/m). The CGS unit of luminance is the stilb, which is equal to one candela per square centimetre or 10 kcd/m. The amount of useful light emitted from a source or the luminous flux is measured in lumen (lm). The SI unit of illuminance and luminous emittance, being the luminous power per area, is measured in Lux. It is used in photometry as a measure of the intensity, as perceived by the human eye, of light that hits or passes
Rose is a rose is a rose is a rose Rose is a rose is a rose is a rose The sentence "Rose is a rose is a rose is a rose." was written by Gertrude Stein as part of the 1913 poem "Sacred Emily", which appeared in the 1922 book "Geography and Plays". In that poem, the first "Rose" is the name of a person. Stein later used variations on the sentence in other writings, and "A rose is a rose is a rose" is among her most famous quotations, often interpreted as meaning "things are what they are", a statement of the law of identity, "A is A".