Why does the Big Bang theory predict that the cosmic background radiation should have a perfect thermal radiation spectrum?
A)The background radiation came from the heat of the universe,with a peak corresponding to the temperature of the universe.
B)The spectrum of pure hydrogen is a perfect thermal radiation spectrum.
C)The spectrum of 75 percent hydrogen and 25 percent helium is a perfect thermal radiation spectrum.
D)The light from all the stars and gas in the sky averaged over the entire universe is a perfect thermal radiation spectrum.
E)It doesn't predict that the cosmic background radiation should have a perfect thermal radiation spectrum.

Question

Quizplus · Accepted Answer

The Big Bang theory predicts that the universe was extremely hot and dense in its early stages, and as it expanded, this energy cooled and released as light, which we observe as the cosmic microwave background radiation (CMB). Therefore, the CMB is thermal radiation with a perfect thermal spectrum, with a peak corresponding to the temperature of the universe.

Why Does the Big Bang Theory Predict That the Cosmic