Professor Huw Price, University of Cambridge
The idea that there is no beginning of time - time is infinite - is not an entirely new idea though but, all the same, the idea of infinity, is something that baffles most. Philosopher Huw Price unpicked the meaning of infinite with Graihagh Jackson...
Huw - Well there are cosmologists who think that the big bang wasnít really the beginning. That before the big bang there were other cycles, perhaps cycles of expansion and contraction and, in that case, there is something that happened before the big bang. There was something like a big crunch, when all the matter in some previous cycle of the universe and then, instead of forming what this is called a singularity, what happened was that instead of collapsing like that, the matter bounced and so people talk about the big bounce rather than the big bang.
Graihagh - In this view, one could talk of a Big Crunch Ė the universe collapsing or re-collapses, back into a singularity and reforming another universe starting with another big bang. I tried to think of a story or an analogy to explain this but I donít think thereís anything like this in existence. Huw, on the other hand, had a good one to hand...
Huw - Well if you imagine a spring oscillating so itís expanding and contracting so. In these models, the long term history of the universe is something like that Ė itís a cycle of bounces and collapses.
Graihagh - So then, that means time is infinite and there is no beginning of time if itís continually contracting and expanding though?
Huw - Yes, exactly and thatís, I think, regard by some people as an attraction of that model that you donít have a moment in time thatís distinguished by being the first one.
Graihagh - But that brings us back round to this question, what would have caused the first one?
The way I think of it right is like a series of dominoes going out in a spiral effect and then knocking, and theyíre going round and round and continue as an infinite number of dominoes. I think what I find hard to grapple with is that there has to be a beginning point at some point, but that might just be another flaw of my human nature.
Huw - Well yes, it could be just one of these things that our human notion of causation leads us to expect, but something which, once weíve reconciled ourselves to the idea that thereís no causation in fundamental physics, we should just recognise that we can live without the idea of first causes.