How did the Universe begin?

Is there an origin to time itself, and if so, what did it look like?

“In the beginning the Universe was created. This has made a lot of people very angry and been widely regarded as a bad move.” -Douglas Adams

It’s only human to ask the most fundamental of all questions: where did all this come from? And we like to think we know the answer; it all came from the beginning.

Image credit: Google image search, which appears to agree.

But if you think about it for a little while, that simplistic answer — an answer that at first glance, might appear to be a tautology — presumes something very important about our Universe: that it had a beginning!

For a long time, scientifically, it didn’t appear that we knew whether that was true or not. The Universe could have had a beginning, before which nothing existed (or, at the very least, nothing as we understand it to be), or it could have existed eternally, like an infinite line extending in both directions, or it could have been cyclic like the circumference of a circle, repeating over and over again infinitely.