how does weak background radiation coming from every direction in the sky support the big bang theory?

Question

It provides evidence of universe contraction
it provides evidence of the universe's increasing mass
it provides evidence of the universe's decreasing mass
it provides evidence if universal expansion

Answer 1

It provides evidence of universal expansion. The weak background radiation that is detected coming from every direction in the sky is known as the cosmic microwave background (CMB) radiation. This radiation is a remnant from the early stages of the universe, around 380,000 years after the Big Bang. The fact that this radiation is uniformly distributed in all directions suggests that the universe expanded and cooled down from a hot and dense state, supporting the idea of the Big Bang theory.