Electromagnetic waves, depending on their length, have various properties. The last quite often use in scientific or medical research. Despite power of modern science, electromagnetic waves in the certain range of length are still insufficiently studied.
All atoms are in wild spirits capable to radiate electromagnetic waves. For this purpose they need to pass into the main state in which their internal energy gains the smallest value. Process of similar transition is followed by emission of an electromagnetic wave. Depending on length, it has various properties. There are several types of such radiation.
Visible light
Wavelength is called the shortest distance between a surface of equal phases. Visible light is electromagnetic waves which can be perceived by a human eye. Length of light waves varies from 340 (violet light) up to 760 nanometers (red light). Best of all an eye of the person feels flavovirent area of a range.
Infrared radiation
Everything that surrounds the person, including him, - sources of infrared or thermal radiation (wavelength up to 0.5 mm). Atoms radiate electromagnetic waves in this range at chaotic collision with each other. At each collision their kinetic energy passes into thermal. Atom is excited and radiates waves in the infrared range. From the Sun the Earth's surface is reached by only a small part of infrared radiation. Up to 80% it is absorbed by molecules of air and especially carbon dioxide which causes greenhouse effect.
Ultra-violet radiation
Wavelength of ultra-violet radiation is much less, than infrared. In a range of the Sun there is also an ultra-violet component, but it is blocked by an ozone layer of Earth and does not reach its surface. Such radiation is very harmful to all living organisms. Length of ultra-violet radiation lies in the area from 10 to 740 nanometers. That its small share which reaches the Earth's surface together with visible light, causes suntan in people as protective reaction of skin to effects, harmful to it.
Radio waves
It is possible to transmit information through radio waves up to 1.5 km long. It is used in radio receivers and television. Such big length allows them to bend around the Earth's surface. The shortest radio waves can be reflected from an upper atmosphere and reach the stations located on the opposite side of the globe.
Gamma-rays
Gamma-rays carry to especially rigid ultra-violet radiation. They are formed at explosion of an atomic bomb and also at course of processes on a surface of stars. This radiation is pernicious for living organisms, but the magnetosphere of Earth does not pass them. Photons of gamma-rays have ultrahigh energy.