- REDIRECT
Luminescence is emission of
light by a substance not resulting from heat; it is thus a form of cold body
radiation. It can be caused by
chemical reactions,
electrical energy, subatomic motions, or
stress on a crystal. This distinguishes luminescence from
incandescence, which is light emitted by a substance as a result of heating. Historically,
radioactivity was thought of as a form of "radio-luminescence", although it is today considered to be separate since it involves more than electromagnetic radiation. 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'.
