(see electromagnetic radiation) radiation - The emission or transmission of energy in the form of waves through space or another medium radiative zone or layer - About 70% of the sun; the section where energy travels outward by radiation
also called electromagnetic energy, made up of two fields (electrical and magnetic), existing in a range of wavelengths that extends from radio waves that many be thousands of meters long to gamma rays with wavelengths as short as a million-millionth (10^-12) of a meter