How a Lightbulb Works

In the 1800's, the electric light bulb was invented, the one that illuminates our night. The technology of the basic light bulb has evolved very little from the past. The mechanics of a light bulb are very simple, as long as you understand wire resistance. Let's go into the science of how a light bulb works.

Structure

(Picture from Energy Crysis I own no rights to the diagram.)

There are two small metal rods at the bottom of the bulb, which are connected to the electrical foot contact. Attached to the two rods are two pieces of stiff wire. On top of the wire is something called a filament. This filament is usually made from tungsten, which is a very resistant material. This means that the tungsten has many atoms blocking the path of electrons. When the flow of electrons go through the resistant filament, some of them collide with the atoms. This kicks the electron up to a higher energy level for a fraction of a second. When the electron calms down, it releases a photon of light, which is the light that you see coming from the bulb. The electrons collide all the time, and photons of light are released all the time so that you can have a consistent source of light.