dvunkannon
Posts: 1377
Joined: June 2008
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Wow, made the mistake of following the BA^77 link to the Bruce Gordon physics video.
In the first part, Fr. Spitzer concludes with a bit about the BVG Theorem, which I readily admit I had never heard of before. Googling around, I can't find it on Wikipdeia either. (Shock. Horror.) Something of an implied commentary on its importance to physics if there is no Wiki page for it...
The original paper seems to be
http://arxiv.org/PS_cache/gr-qc/pdf/0110/0110012v2.pdf
A money quote:
| Quote | | Whatever the possibilities for the boundary, it is clear that unless the averaged expansion condition can somehow be avoided for all past-directed geodesics, inflation alone is not sufficient to provide a complete description of the Universe, and some new physics is necessary in order to determine the correct conditions at the boundary [20]. This is the chief result of our paper. |
If I can attempt a layman's version - a universe that is inflating (or just expanding, on average) eternally can have an eternal future, but inflation alone can't create a situation where it has an infinite past (presumably occupying a smaller and smaller space as you go backwards). There is still a beginning.
This appears to get some play by William Lane Craig, et al, but of course there are caveats that they usually don't mention. It only applies to some models, and is itself classical GR, not quantum mechanical. Not taking QM into account as things get ever smaller would seem to doom the idea to irrelevance, IMHO. Most people don't think a boundary condition in the past necessitates God, anyway.
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I’m referring to evolution, not changes in allele frequencies. - Cornelius Hunter
I’m not an evolutionist, I’m a change in allele frequentist! - Nakashima
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