What Happened Before The Big Bang?
.: This kind of stuff absolutely fascinates me. From Penn State Live:
Penn State researchers look beyond birth of universeThe full press release is here.
Monday, May 22, 2006
University Park, Pa. -- According to Einstein's general theory of relativity, the Big Bang represents The Beginning, the grand event at which not only matter but space-time itself was born. While classical theories offer no clues about existence before that moment, a research team at Penn State has used quantum gravitational calculations to find threads that lead to an earlier time.
"General relativity can be used to describe the universe back to a point at which matter becomes so dense that its equations don't hold up," said Abhay Ashtekar, holder of the Eberly family chair in physics and director of the Institute for Gravitational Physics and Geometry at Penn State. "Beyond that point, we needed to apply quantum tools that were not available to Einstein."
By combining quantum physics with general relativity, Ashtekar and two of his post-doctoral researchers, Tomasz Pawlowski and Parmpreet Singh, were able to develop a model that traces through the Big Bang to a shrinking universe that exhibits physics similar to ours.
In research reported in the current issue of Physical Review Letters, the team shows that, before the Big Bang, there was a contracting universe with space-time geometry that otherwise is similar to that of our current expanding universe. As gravitational forces pulled this previous universe inward, it reached a point at which the quantum properties of space-time cause gravity to become repulsive, rather than attractive.