uv-light - blacklight?
uv light and blacklight are not the same. however black light is only a certain range of the wave spectrum of uv light. uv light divides thereby into three ranges:
uv-a: wave band 320-400 nm
uv-b: wave band 290-320 nm
uv-c: wave band 200-290 nm
the uv-a light (the ultraviolet light) also called blacklight is not visible, but with its wave band of 380 - 345 nm near the visibilty for the human eye you can see it bluish glimmering.
why is black light used in the art ( theatre. music etc.) or in discos?
many articles catch under irradiation from uv light to shine - they are fluorescent. fluorescent articles absorb the short-wave light of the black light and emit then later a longer-wave, visible light. one calls this shining under effect of the uv-radiation fluorescence.This fluorescence also raises in the adult human a fascination, that magically touches the soul. not only children's eyes beam with joy.
the uv-b light will be used e.g. in solarien. it is already from the more unpleasant sort: sun fire lets greet!
the uv-c light is very high-energy and dangerous the shortest-wave light and thus for all organisms. with an intact ozone layer this spectrum is filtered.
