What is The Origin of The Black Body Radiation in The Universe?

Question

300 words or less, unless few paragraphs.

Google it is not an answer.

Answer 1

If you mean the Cosmic Microwave Background, its origin is the hot, opaque gas that filled the very early universe.

Answer 2

I assume you refer to the cosmic microwave background radiation, which reflects a black-body temperature of 2.7225 K. From the ref., "... most cosmologists consider this radiation to be the best evidence for the Big Bang model of the universe."

Answer 3

You can't say Black Body Radiation...that's racist.