The Probert Encyclopaedia of Science & Technology

RADIATION

Radiation is the emission or transfer of energy by a beam of particles or waves. It includes all electromagnetic waves, beams of elementary particles, ions, etc., and sound waves. In popular usage the the term is particularly applied to the emission of X-rays. However, sunshine is a good example of radiation. Energy from the sun is conveyed as a stream of invisible electromagnetic waves by
radiation, that energy which is absorbed - for example by a person lieing on a beach - is converted into heat, hence it feels warm.
Research Radiation