Re: How does fluoresent light work?

First, let's talk about how regular light bulbs work. Inside each bulb is tungsten filament that is very thin. Electricity is passed through this filament, and the filament gets hot. Visible light is emitted by radiation induced by heat. The bulb usually has an inner coating to diffuse the light before it makes it to our eyes.

Fluorescent lamps are more complicated. What you need for this kind of lamp is a gas (usually mercury), electricity, and a phosphor (the white coating inside the tube). Passing electricity through the lamp generates an electric arc that excites the electrons in the gas. When the gas atoms deexcite, they emit radiation which is the ultraviolet part of the electromagnetic spectrum. We cannot see this radiation; it is the same radiation that causes sunburn and skin cancer. The ultraviolet light excites the molecules in the phosphor, which when they deexcite, give off visible light.