Radiation is often linked with nuclear power: either through nuclear power stations or nuclear bombs. The particular light given out by a nuclear bomb is gamma-rays, which can be very dangerous to humans.

Not all electromagnetic radiation is dangerous. Here is a complete list of different types. The diagram represents how the wavelength changes from one end of the electromagnetic spectrum to the other.

How many examples of gadgets involving each of these can you find?

All the different types of radiation listed above have the same speed, simply called `the speed of light'. Nothing can travel faster than the speed of light, except in Red Dwarf.

However they have different wavelengths and frequencies. X-rays have very short wavelengths, whereas radio waves have very long wavelengths.

Light has energy. X-rays have a large energy, that makes them dangerous. Radio waves, on the other hand, have very little energy and are very safe. Indeed there are many radio waves passing through you at this very moment!