Fluorescence

phosphor fluorescence

Question: What causes some objects to glow under a black light? Black lights give off  Ultraviolet A light, which is a type of high-energy invisible light (radiation). Photons are packets of light energy. UV light photons have a higher energy than do the photons for visible light. Materials that glow under a black light contain [...]

Fluorescence vs. Photoluminescence

fluorescence energy chart

Fluorescence and Photoluminescence are types of luminescence (cold light) where the energy is supplied by EMR (electromagnetic radiation). EMR from most to least energetic are: gamma rays, x-rays, ultraviolet light, visible light, infrared light, microwaves,  and radio waves. The starting EMR energy source needed to produce visible light must be more energetic than visible light. [...]