Quote:
Originally Posted by KeithT
I think the theorists have got that **** about face, OldBoy. Surely we are here because the Universe first came into being? 
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According to the strong anthropic principle, we see the universe the way it is because we exist. The universe came into being with all the parameters set so that we could exist. If the size of the electric charge of the electron was different or, the ratio of the masses of the proton to the electron was changed slightly then, we would not exist to ask the question. If gravity was slightly stronger then the universe would have collapsed before it expanded. On the other hand, if gravity was slightly weaker then the stars, planets and galaxies couldn't have formed, and we wouldn't be here to ask the question.
No theory can predict these values, we can only get them by measurement, but this is regarded as adhoc so theorists believe, the values must have been set by us being here. Not all theorists accept this theory and have put forward different versions, to try to account for these parameters been set the way we see them. Some even suggest that at the time of the big bang, billions and billions of universes were created but only one had the right parameters for us to exist.
Quote:
Originally Posted by KeithT
We may well always have the universe, but that doesn't stop it from evolving and changing. Stars come and go as supernova burns them out. If our sun burns out, and it will do at some point in time (hopefully not ours) then we can kiss the world goodbye as we know it (or knew it). To coin a cliche of my wise old grandmother ... 'nothing lasts for ever'. 
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The universe would last for ever if it is flat or slightly curved on the plus side. If it is slightly curved on the negative side then, it will collapsed into a big crunch. Some even think our universe could be cyclical, that at some point in the collapse it will reach a critical mass and rebound thereby, creating our universe again and so on for ever. Our sun will destroy the earth in about six billion years time thus, giving us plenty of time to find other earths to live on.