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.
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[change | change source]
- 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[change | change source]
- ↑ 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 doi:10.1021/ed100182h