Questions regarding the cosmic microwave background, or CMB, the leftover radiation that is taken by many as proof of the Big Bang.

The cosmic microwave background, or CMB, is radiation formed in the early stages of the universe. Currently at a temperature of 2.7 Kelvin, it is hailed as strong evidence for the Big Bang theory. The cosmic microwave background was first observed in detail by Arno Penzias and Robert Wilson in 1964. It is highly redshifted, which is why it is currently in the microwave region of the electromagnetic spectrum.