Electric light

In many homes there is a voltage tester, generally in the form of a screwdriver. In its handle there is, amongst other things, a small neon tube, which you can easily remove. Hold one metal end firmly and rub the other on a piece of hard foam plastic which may be used for insulation. The lamp begins to glow as it is rubbed to and fro, and you can see this particularly clearly in the dark.

Since the plastic is soft, its layers are rubbed against one another by the movement of the lamp and become strongly charged with electricity. The electrons collect on the surface, flow through the core of the tiny lamp, and into the body which begins to glow .

The ancient Greeks had already discovered that amber attracted other substances when it was rubbed. They called the petrified resin ‘electron’. The power, which has caused such fundamental changes in the world since then therefore, gets its name - electricity.