There have been many models of the universe in past centuries, but today we now know that the universe is expanding and has been expanding since the Big Bang. But what caused the Big Bang? And what happened before the Big Bang itself? Stephen Hawking has theories, as it turns out, that could answer both questions.
And, as it turns out, his theory involves complex numbers and is derived from quantum mechanics (see my last blog post). The "imaginary time" he refers to is the component of time that has an i attached to it. A brief overview was given in an interview with the BBC:
So basically, Hawking proposes that the universe in imaginary time is self-contained. That is, the question of "when did it begin?" or "what happened before?" makes no sense physically.SUE: To oversimplify your theories hugely, and I hope you'll forgive me for this, Stephen, you once believed, as I understand it, that there was a point of creation, a big bang, but you no longer believe that to be the case. You believe that there was no beginning and there is no end, that the universe is self-contained. Does that mean that there was no act of creation and therefore that there's no place for God?
STEPHEN: Yes, you have oversimplified. I still believe the universe has a beginning in real time, at the big bang. But there's another kind of time, imaginary time, at right angles to real time, in which the universe has no beginning or end. This would mean that the way the universe began would be determined by the laws of physics. One wouldn't have to say that God chose to set the universe going in some arbitrary way that we couldn't understand. It says nothing about whether or not God exists - just that He isn't arbitrary.
Real time, as we know it, makes far less sense. But then again, as Einstein proved, time is all relative anyway. Everyone has their personal time, (ex. someone in orbit around Earth would age slower relative to someone on Earth). So, perhaps imaginary time makes more sense in the respect too.
It's something to think about anyway.