What is light?

Throughout human history, light has been something Man has taken for granted. We know that it comes out of the Sun or a lamp, let us see things, and makes us warm. But what is it?

Light is a form of energy. It consists of photons that move in waves. The size of a wave is measured as its wavelength. Light can move through a vacuum, and its speed can be measured.

The white light that we see it not white at all. It is actually a mixture of all colours. The band of this mixture is known as a spectrum. The different colours in the spectrum have different wavelengths. So, we know many things about light, but it is still difficult to define it exactly!