Colours are all around us. They enrich our world in all aspects of life. Colour is light and light is colour. The sun emits light at different frequencies. It is believed that energy is transmitted in waves. The distance between successive waves is called the wavelength, and the number of oscillations of a wave in one second is called the frequency. These frequencies can be separated by a process called white light splitting. As white light passes through a crystal prism, it refracts and splits into the seven colours of the spectrum. Each colour has its own frequency. The physicist who first proved that white light is a mixture of different colours was Isaac Newton, the discoverer of the law of universal gravitation, who we already know. And it was Newton who used a prism in his experiment.

As a general rule: the longer the wavelength, the lower the frequency. Every colour has a specific frequency and wavelength. Only a small part of the electromagnetic spectrum is visible to the human eye. Violet has the shortest wavelength and red the longest. Behind violet is ultraviolet, which, although invisible to the human eye, can penetrate our body. Ultraviolet is responsible for tanning and has antibacterial properties. The longest wavelength is red. Behind red is infrared, which is invisible to the human eye.