Why is the cosmic background radiation found primarily in the radio part of the spectrum?
A)The visible part of it was absorbed by intergalactic dust
B)It was emitted by cool,intergalactic clouds
C)It is primarily synchrotron radiation
D)It is highly redshifted

Question

Quizplus · Accepted Answer

The cosmic background radiation is found primarily in the radio part of the spectrum because it is highly redshifted. The radiation was emitted about 380,000 years after the Big Bang, and as the universe expanded, the wavelengths of the radiation stretched out, causing the radiation to be redshifted into the radio part of the spectrum.

Why Is the Cosmic Background Radiation Found Primarily in the Radio