Question

What evidence do scientists have to explain the Big Bang Theory?

Answer 1

The MAIN evidence consistent with the Big Bang Theory is the Cosmic Background Radiation.

Explanation:

The CBR was unknown during the development of the theory, is consistent with Einstein's Theory of Relativity, and was discovered while scientists were looking for something else. Thus, its discovery and agreement with the theoretical implications of both the Big Bang Theory and General Relativity make it the single best piece of current evidence that such an event occurred.