Cosmology: time begins (Introduction)

by dhw, Tuesday, May 27, 2014, 18:54 (3622 days ago) @ David Turell

Dhw: The website you've quoted contradicts you. 
DAVID: Not really. It is now considered that the hot big bang followed inflation. I was sloppy in what I said. From whatever began this universe for 10^-43 seconds there was inflation and then the hot big bang. Time begins with these events we theorize about. -Here you say "time begins", but you are very careful in the following exchange to talk of 'our time':
 
dhw: On the assumption that you would regard inflation as an event, this can hardly be said to support the claim that time itself began with the BB. He is making the same point as me: we do not and cannot know when time began.-DAVID: Your interpretation is confused. We don't know what caused the inflation that began our universe but that is the beginning of our time. It is the first event (in theory) we count as in 'our' time. Further Einstein treats our universe as space-time and it is shown to work. Our space-time began with inflation.-Let me repeat my objection to this. You've explained "our" time as "we measure time by a succession of events". Since we humans cannot measure anything unknown to us, of course our human mode of time measurement begins with the BB, but that doesn't mean no events and therefore no time before the BB. You might as well argue that since God's existence is unknowable, there is no God! If we don't know whether there were events, we don't know whether there was time. The author of the article you recommended points out that inflation may stretch back FOR EVER, and "it's even possible that time is cyclical, and that the cycles change with each iteration." Yes, it's all "mays"and "possibles" ... we simply don't know. That means we don't know when time began. We only know (or think we know) of an event through which time became measurable by us humans.-The distinction becomes important when we relate it to George's atheistic argument that nothing preceded the birth of our universe: he says there was no before, no cause, no time. The theistic argument depends on there being a before and a cause, and you cannot have a before or a cause-and-effect sequence without time. That is part of the reason why I'm so surprised at the rigidity of your argument