What is the cosmic microwave background radiation?

1 Answer

As per astronomers universe began with a huge expansion called big bang.

Explanation:

The temperature and pressure was very very high from the BIG bang...AS time passed the universe began to expand and cooled .as per estimates the big bang started about 13.82 billion years ago.The universe still have the heat from the big bang,It is about 2.7 degree K every where in the universe..In 1947 George Gamow predicted this to be about 4.5.degre K. from wikipeda"On May 20, 1964, American radio astronomers Robert Wilson and Arno Penzias discovered the cosmic microwave background radiation (CMB), the ancient light that began saturating the universe 380,000 years after its creation. And they did so pretty much by accident.M"