[Oberon]

At the conference Hawking dismissed the idea of a series of big bangs on the grounds that it extended into the infinite past and so could never have a beginning.

That's a laughable notion. One would presume that Hawking has no problem with infinities in space, so why should his cosmology stumble over an infinity in time?

Or, to put it another way, our current cosmology (for this universe, at least...in itself a curious notion...) traces back to a singularity of infinitely dense, infinitely hot matter at time T=0. What makes this idea any less metaphysical than the idea of the existence of a time T=-1 femtoseconds?

[wotan]

An infinite series of big bangs follows naturally from three assumptions (1) the universe is infinite, (2) superluminal inflationary big bangs occur whenever the energy density becomes high enough, and (3) inflation slows to subluminal as the energy density falls.

Hawking just has a hang-up about infinite time.