I love science…

Fluorescent bulbs are made up of a glass tube that is filled with a low-pressure inert gas and a small amount of mercury, have a phosphor coating on the inside, and have an electrode on each end. When a large enough voltage is applied across the electrodes, the gas begins to conduct, which allows an electric current to flow from one electrode to the other. This current causes collisions between gas molecules and the mercury, which creates UV energy that is then converted to visible light by the phosphor coating on the tube.

via Make: Online : Ask MAKE: Why do flourescent lights buzz?.

Go read the whole article. It really is fascinating how we’ve put our knowledge of the noble gases to use in our technologies. It’s even more fascinating that we can study these things and realize how amazing it is that we can create light by heating up an inert gas element!