Question: How did time begin?

Keith Brain answered on 24 Jun 2010:

The most like explanation is that it started at the “Big Bang” about 15 billion years ago. Before that, we really don’t have any idea whether time existed at all – certainly not in the way we understand it. However, the “Big Bang” is a scientific theory which not everyone agrees with – some scientists believe that there was no beginning.

Hard for me to understand how this can happen, but then again, lots of things in astrophysics are pretty tricky, like General Relativity – mind bending, and space bending!