Problems with an Infinite Universe

Hi nipok1) the Universe is expanding. The galaxies are moving away from one another. Every point in space is moving away from every other point in space.2) If we were to run the clock backwards we would therefore see the galaxies move towards one another3) At a point approx 14 billion years ago, all points in space meet up in an infinitely dense singularity. Note there is no space outside this singularity - all the points in space coincide.4) It has been shown that the initial state of the Universe must have been a singularity. The predictions made by the theory are borne out experimentally to a quite fantastic degree (variations in background radiation).5) Tough bit - space and time are inextricably linked. To understand why this is so, you'll have to understand Einstein's theories of relativity. Plenty of websites do that far better than I could. It is more correct to talk of "space-time" rather than space and time and to say that spacetime began at the Big Bang.added by edit: following developments in String theory, there seem to be several theories emerging in the past few years about a Big Bang prehistory (Veneziano). Maybe I should hold judgement as to whether time itself began at the Big Bang?6) We can have no information as to what happens beyond the singularity - in fact this doesn't even seem like a meaningful question. It is possible that the Universe we see (the Hubble sphere) is only one of many "universes" comprising a "multiverse". There has been much speculation on this (it also makes the most sense to me personally), but not a single shred of proof. I think there are 2 ways that you can test this, but one involves killing yourself (quantum suicide) and the other involves building a sentient computer (David Deutsch).(Apologies to Eta for the above).PEThis message has been edited by Primordial Egg, 08-05-2004 11:34 AM

Hi nipokSo you think that we live in an infinite space where Big Bangs are occurring all the time (and in this case - each Big Bang is simply an explosion producing matter)? And we don't see these Big Bangs because they occur outside of our visible Universe?Why then does the Universe look different the farther away we look?Why do we see such large scale homogeneity in the visible Universe?What's the mechanism for how these "little bangs" occur? In an infinite universe why are these bangs likely to occur where they do and not somewhere else?If one of these little bangs occurred in our solar system right now, would we know about it (i.e are these universes connected)?Space (or spacetime), the backdrop upon which matter and energy "sits" has physical properties of its own (e.g matter can warp it). Where did this space and its properties come from?One of the little repeated but obvious issues with an infinite universe is that it allows for an infinite number of possibilities. As long as something is physically possible, the chance of it happening in an infinite universe is 1.This means that there are an infinite number of doppelgangers of yourself for example. Weirder still, there are regions of the Universe where the probabilistic laws of the quantum world are actualised at a macroscopic level.Somewhere in an infinite Universe, Saddam Hussein has walked through the wall of his prison, evaded capture, quantum tunnelled through the Earth and ended up in Washington to poke Bush in his eye, for example.This is a pretty outlandish consequence - is this what you believe to be happening somewhere?PEPS You know its never really been proved to my satisfaction that the earth is not supported by invisible rotating turtles, but unless I can use turtle theory to explain all the data currently explained by Big Bang cosmology and GR, its of no use to anyone. Yet.This message has been edited by Primordial Egg, 08-06-2004 04:39 AM

Ringokid, for some reason, I can't get that link to work (404 error). Could you check it please?PE