Which statement about the cosmic microwave background is not true?
A) It is the result of a mixture of radiation from many independent sources, such as stars and galaxies.
B) Its spectrum corresponds to a temperature of just under 3 degrees above absolute zero.
C) With the exception of very small variations, it appears essentially the same in all directions in which we look into space.
D) It is thought to be radiation that began its journey to our telescopes when the universe was about 380,000 years old.

Question

Quizplus · Accepted Answer

The cosmic microwave background (CMB) is not the result of a mixture of radiation from many independent sources, but rather it is the remnant heat left over from the Big Bang. The CMB is the oldest light in the universe, and it was emitted when the universe was just a few hundred thousand years old. It permeates the entire universe and has a nearly uniform temperature of just under 3 degrees above absolute zero, with small fluctuations due to the way matter was distributed in the early universe.

Which Statement About the Cosmic Microwave Background Is Not True