A weak uniform microwave radiation which is detectable in nearly every direction of the sky. It is believed to be evidence of the Big Bang.
More example sentences
- Because of its near-perfect isotropy on the sky, the cosmic microwave background provides some evidence in favour of the Cosmological Principle.
- The experimental detection of the cosmic microwave background was one of the great triumphs of the Big Bang theory.
- In the past half century radio astronomers discovered remarkable things, including pulsars, quasars, molecules in space, and the cosmic microwave background, the first evidence in support of the big bang itself.
Definition of microwave background in:
- The US English dictionary