Atheism is unreasonable

[pocaracas]

Thanks for that, Poc. It's what I've been saying all along, but it's cool that you got it all in one place like that.

I know... but we like to see it all in a simplified format... no second or thirdt hand accounts, right?

Mind, I dunno how effective it'll be. His_Majesty has gone on to argue that the conclusions of the BGV theorem aren't the conclusions of the BGV theorem because, though it specifically called it the chief conclusion, it didn't do so in strong enough language.

I don't know...
Why don't we just put the actual conclusions of the paper where this theorem is explained?

First, the full text, just in case anyone can follow.... I can't, and I have a college degree in physics, so there's that...
http://arxiv.org/PS_cache/gr-qc/pdf/0110/0110012v2.pdf

V. Discussion.
Our argument shows that null and time-like geodesics are, in general, past-incomplete in inflationary models, whether or not energy conditions hold, provided only that the averaged expansion condition H_av > 0 holds along these past-directed geodesics. This is a stronger conclusion than the one arrived at in previous work [8] in that we have shown under reasonable assumptions that almost all causal geodesics, when extended to the past of an arbitrary point, reach the boundary of the inflating region of spacetime in a finite proper time (finite affine length, in the null case).

What can lie beyond this boundary? Several possibilities have been discussed, one being that the boundary of the inflating region corresponds to the beginning of the Universe in a quantum nucleation event [12]. The boundary is then a closed spacelike hypersurface which can be determined from the appropriate instanton.
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. The result depends on just one assumption: the Hubble parameter H has a positive value when averaged over the affine parameter of a past-directed null or noncomoving timelike geodesic.
The class of cosmologies satisfying this assumption is not limited to inflating universes. Of particular interest is the recycling scenario [14], in which each comoving region goes through a succession of inflationary and thermalized epochs. Since this scenario requires a positive true vacuum energy ρ_v , the expansion rate will be bounded by
H_min = sqrt(p 8 πGρ v / 3 )
for locally flat or open equal-time slicings, and the conditions of our theorem may be satisfied. One must look carefully, however, at the possibility of discontinuities where the inflationary and thermalized regions meet. This issue requires further analysis.
Our argument can be straightforwardly extended to cosmology in higher dimensions. For example, in the model of Ref. [15] brane worlds are created in collisions of bubbles nucleating in an inflating higher-dimensional bulk spacetime. Our analysis implies that the inflating bulk cannot be past-complete.
We finally comment on the cyclic universe model [16] in which a bulk of 4 spatial dimensions is sandwiched between two 3-dimensional branes. The effective (3+1)-dimensional geometry describes a periodically expanding and recollapsing universe, with curvature singularities separating each cycle. The internal brane spacetimes, however, are nonsingular, and this is the basis for the claim [16] that the cyclic scenario does not require any initial conditions. We disagree with this claim.
In some versions of the cyclic model the brane space-times are everywhere expanding, so our theorem immediately implies the existence of a past boundary at which boundary conditions must be imposed. In other versions, there are brief periods of contraction, but the net result of each cycle is an expansion. For null geodesics each cycle is identical to the others, except for the overall normalization of the affine parameter. Thus, as long as H_av > 0 for a null geodesic when averaged over one cycle, then H_av > 0 for any number of cycles, and our theorem would imply that the geodesic is incomplete.

y'all enjoy