Electromagnetic Spectrum: visible light, ultraviolet & infrared

Visible light occupies a small band of the electromagnetic spectrum. We can see light from approximately wavelength 700 nm (red light) to 400 nm (violet light). Shorter wavelengths (above violet) are called ultraviolet (even shorter wavelengths include X rays and then gamma rays), whilst longer wavelengths (below red) are called infrared (below infrared lie microwaves, short wave radio, and radio waves). In this graphic, the waves are simplified and arranged as a linear array, whose wavelengths increment by 50 nm.