Approximately how long ago was the big bang thought to have occured?

Answer 1

First of all, the Big Bang was NOT an explosion; certainly not an explosion of dense matter into empty space.

Secondly, all observational evidence points to the expansion having begun about 13.7 billion years ago.

Answer 2

There is no "when" for the end of the universe per the Big Bang Theory; i.e. the end of the universe is the end of Time, per the reality of the existence created within this fourth dimensional SpaceTime continuum. However the Big Bang Heat Death timeline projects the end of the Big Bang at 300 x 1E1000 years.

Answer 3

The "Big Bang" refers to the beginning of the Universe; depending on what events you choose to include, the answer might be a tiny fraction of a second, a few thousand years... or we might say that we are still in the "Big Bang". There is really no consensus how long it lasted - in other words, what parts of the development of the Universe should be considered "the Big Bang".

Answer 4

The big bang was said to have taken place 13.7 billion years ago.