Katie Freese
Theoretical Astrophysicist, University of Michigan
02:20

What Came Before the "Big Bang?"

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"It is really a high density situation that we call the big bang, but there is really no explosion," says Freese. "There is no 'bang.' There is no singular point."

Katie Freese

Katie Freese is a professor of physics at the University of Michigan, and the associate director of the Michigan Center for Theoretical Physics. Her work deals with a wide variety of topics in both theoretical cosmology and astroparticle physics. Her research is largely involved in trying to identify the dark matter and dark energy that permeate the Universe, and to build a successful model for the early universe immediately after the Big Bang.
Transcript
Question: Does it make sense to ask what preceded the Big Bang?

Katie Freese: I think people have the misconception that the big bang is the universe starting from a point.  In fact, it is very different from that.  Probably you know that the Universe is expanding, so if we go backwards in time then you can watch the Universe contract as you go backwards in time.  So for example, if you took a tabletop then any two points would get closer together, but the points that are way far apart if you had…  Let’s say it’s an infinite tabletop, so as these points get closer and closer together you still have a tabletop that is infinite in extent.  It’s not like everything comes into one point, but eventually you reach such a high density.  Things are so compact and right on top of each other that we lose our description.  Physics fails.  That is what the big bang is, so it’s actually we would need to have a theory of quantum mechanics and gravity simultaneously to be able to discuss physics going backwards in time any further, so it is really a high density situation that we call the big bang, but there is really no explosion.  There is no bang.  There is no singular point.  But so yes, it does make sense to ask well what happens when you reach that density and that is what people are trying to do in theories of quantum gravity such as string theory or well some of the cosmology that I’ve done also is in the context of brains where our observable universe is living on a three dimensional surface in a higher dimensional universe and there could be other brains out there and how these brains intersect one another and their motions and so on has been…  So there are different avenues to try to push back our level of knowledge and they are very active, but very difficult.

Everything was more dense and then there is a certain point where… which we call the big bang and it’s from that point forward that we start our clocks, so that’s…  And then so and we say the universe is 13.7 billion years old is relative to that very high density situation.

Recorded May 7, 2010
Interviewed by David Hirschman


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