| the entire spectrum, considered as a continuum, of all kinds of electric, magnetic, and visible radiation, from gamma rays having a wavelength of 0.001 angstrom to long waves having a wavelength of more than 1 million km. |
electromagnetic spectrum  (click for larger image in new window) n. The entire range of radiation extending in frequency from approximately 1023 hertz to 0 hertz or, in corresponding wavelengths, from 10-13 centimeter to infinity and including, in order of decreasing frequency, cosmic-ray photons, gamma rays, x-rays, ultraviolet radiation, visible light, infrared radiation, microwaves, and radio waves. |
The family of electromagnetic waves. The electromagnetic spectrum, starting from the waves with the longest wavelengths (and least energy), consists of radio waves, microwaves, infrared radiation, visible light, ultraviolet radiation, x-rays, and gamma radiation. Members of the family differ from one another only in their wavelength, or frequency. For example, the wavelength of blue light is roughly half that of red light, but the waves corresponding to the two colors are otherwise identical.
electromagnetic spectrum
(click for larger image in new window) The entire range of electromagnetic radiation. At one end of the spectrum are gamma rays, which have the shortest wavelengths and high frequencies. At the other end are radio waves, which have the longest wavelengths and low frequencies. Visible light is near the center of the spectrum. |