Electromagnetic radiation (EM radiation or EMR) refers to the waves (or their quanta, photons) of the electromagnetic field, propagating (radiating) through space-time, carrying electromagnetic radiant energy.[1] The electromagnetic spectrum, or types of radiation, are: radio waves, microwaves, infrared, (visible) light, ultraviolet, X-rays, and gamma rays.[2]


  1. *Purcell and Morin, Harvard University. (2013). Electricity and Magnetism, 820p (3rd ed.). Cambridge University Press, New York. ISBN 978-1-107-01402-2.  p 430: "These waves... require no medium to support their propagation. Traveling electromagnetic waves carry energy, and... the Poynting vector describes the energy flow...;" p 440: ... the electromagnetic wave must have the following properties: 1) The field pattern travels with speed c (speed of light); 2) At every point within the wave... the electric field strength E equals "c" times the magnetic field strength B; 3) The electric field and the magnetic field are perpendicular to one another and to the direction of travel, or propagation."
  2. * Browne, Michael (2013). Physics for Engineering and Science, p427 (2nd ed.). McGraw Hill/Schaum, New York.. ISBN 978-0-07-161399-6. ; p319: "For historical reasons, different portions of the EM spectrum are given different names, although they are all the same kind of thing. Visible light constitutes a narrow range of the spectrum, from wavelengths of about 400-800 nm.... ;p 320 "An electromagnetic wave carries forward momentum... If the radiation is absorbed by a surface, the momentum drops to zero and a force is exerted on the surface... Thus the radiation pressure of an electromagnetic wave is (formula).