phosphorescence

views updated May 17 2018

phos·pho·res·cence / ˌfäsfəˈresəns/ • n. light emitted by a substance without combustion or perceptible heat: the stones overhead gleamed with phosphorescence. ∎ Physics the emission of radiation in a similar manner to fluorescence but on a longer timescale, so that emission continues after excitation ceases.DERIVATIVES: phos·pho·res·cent adj.

phosphorescence

views updated May 08 2018

phosphorescence The property of some minerals of emitting light during exposure to X-rays, ultraviolet light, or cathode radiation and continuing to do so after the exposure has ceased (if light emission ends when the radiation source is switched off, the property is called ‘fluorescence’). The colour of the emitted light varies with the wavelength of the radiation to which the mineral is exposed, and is thought to be due to the presence of traces of organic material or cations within the atomic structure of the mineral.

phosphorescence

views updated Jun 08 2018

phosphorescence Form of luminescence in which a substance emits light of one wavelength. Unlike fluorescence, it may persist for some time after the initial excitation. In biology, phosphorescence is the production of light by an organism without associated heat, as with a firefly. In warm climates, the sea often appears phosphorescent at night, as a result of the activities of millions of microscopic algae.