The Big Bang Theory explains how the universe began. The Big Bang Theory stands as the most widely accepted explanation for the origin of the universe. According to this theory, the universe began ...

Belgian cosmologist and Catholic priest Georges Lemaitre made that connection by realizing that the theory of general ... 200 million years after the big bang, when the universe was 20 times smaller ...

Hubble revealed a universe of galaxies that existed beyond ours — but he couldn't have done it without a little help.

It wasn't until 1949 that the term "big bang" came into fashion. This was a relief to Edwin Hubble's contemporary ... He was partly right in that Einstein's theory of special relativity explained ...

Hubble's discovery of expanding galaxies confirmed the universe's vastness, laying the foundation for the Big Bang theory and ...

Belgian cosmologist and Catholic priest Georges Lemaitre made that connection by realizing that the theory ... the big bang, when the universe was 20 times smaller than it is now. Edwin Hubble ...

The Andromeda galaxy helped Edwin Hubble settle a great debate in astronomy. Stocktrek Images via Getty Images ...