Luminescence

Luminescence is light emitted by a substance not caused by heat. In contrast, incandescence is light emitted by a substance as a result of heating.

Luminescence can be caused by chemical reactions, electrical energy, subatomic motions, or piezoelectricity (stress on a crystal).   The term 'luminescence' was introduced in 1888 by Eilhard Wiedemann.E. Wiedemann (1888) "Über Fluorescenz und Phosphorescenz, I. Abhandlung" (On fluorescence and phosphorescence, first paper), Annalen der Physik, 34: 446-463. p447 (transl.) "For this second type of light excitation, for which we lack a consistent name, I would like to suggest the name of "luminescence", and call "luminescing" [any] bodies that glow in this way".Valeur, Bernard & Berberan-Santos, Mario N. 2011. A brief history of fluorescence and phosphorescence before the emergence of quantum theory. J. Chem. Educ. 88 (6), pp 731–738 

The dials, hands, scales and signs of aviation and navigational instruments and markings are often coated with luminescent materials in a process known as 'luminising'.

 Some types of luminescence 
Chemiluminescence, the making light from a chemical reaction.
Bioluminescence, emission as a result of biochemical reaction by a living organism
Fluorescence, emission after higher-energy electromagnetic radiation is applied
Phosphorescence, same cause, but emission is delayed, lasting sometimes for hours
Electroluminescence: Light-emitting diodes (LEDs)

 References 

 Related pages 
Luminous paint

Category:Light sources