Waves Light is an electrical disturbance in space, a bit like ripples in a pond or sound waves. Unlike sound, light can travel through a vacuum. The wavelength is related to another wave property called the frequency. The frequency is the number of vibrations of a wave per second. Waves of different wavelength have different color .
White light is a mixture of waves from all the different visible light wavelengths.
A prism splits different wavelength waves into a spectrum. There are around 50 wavelengths of light across the thickness of a single sheet of saran wrap. We call them electromagnetic waves, and the range of their combined radiation is called the electromagnetic spectrum . Radio waves have the longest wavelengths, over 1000 meters long. When you tune a radio, you are actually selecting radio waves of different wavelengths.