The scale of light can be described by numbers called the frequency and as the numbers get higher, the light goes from red to blue to ultraviolet. We can't see ultraviolet light, but it can affect photographic plates. It's still… — Richard P. Feynman Copy Share Image
“surprisingly dramatic glow some minerals gave off when illuminated with ultraviolet light, or “black light.” In daylight, for instance, the mineral fluorite is a drab, chalky color; in a dark room under UV light, though, fluorite glows a brilliant blue;… — William M. Bass Copy Share Image
