cosmic background radiation

noun

, Astronomy.

1. electromagnetic radiation coming from every direction in the universe, considered the remnant of the big bang and corresponding to the black-body radiation of 3 K, the temperature to which the universe has cooled.

cosmic background radiation

1. Weak radio-frequency radiation traveling through outer space with equal intensity in every direction. It is thought to be residual radiation from a period shortly following the big bang , when the universe was very hot.
2. Also called microwave background