Definition of light
For better understanding, light can be defined as an electromagnetic wave. The human eye can only perceive the electromagnetic waves that are in the so-called visible range. In addition, there are other waves of other frequencies that are not visible to the eye as color. These waves are named to explain what they are used for. The entire electromagnetic spectrum ranges from radio waves, which are among the lowest energy long waves, to X-rays and the gamma rays of atomic nuclei, which are among the most energy-rich. On the contrary, the visible area is only a small part of this spectrum. The value is between about 380 nm (violet) and 780 nm (red).