Thursday 22 February 2007

Pies, Porridge and Everything

I have a mate at work and we go to lunch each day in
the campus canteen.
Over our pies and occasional puddings we have conversations about all sorts of stuff, preferably of a scientific ilk. For example we have a long running disagreement over the nature of the universe - I don't believe that time and space were created at the time of the big bang and are not features of what we call our universe but merely some where (and some when) for our universe to happen in. While the 'big-bang' was undoubtedly a pretty momentous event in our history I think that it is just one of many in the infinite reaches of nothingness and boundless time of the 'everything' that it happens 'in'.

I've started to put words into quotes a lot because language starts to break down when we try and talk about infinity and everything. The human brain is ill equipped for considering, let alone comprehending, infinite anything and so also can't handle infinite nothing. We measure, we compartmentalise, we compare. None of these things work with infinity; there's no measure to be made, you can't put it in a compartment and can't make a compartment out of it. Don't even try and compare anything to it because next to everything, all else is nothing.

There is a concern among many scientists with an interest in cosmology. It seems that this universe is just right for us. I know, that sounds like a good thing, so what's all the concern about? The more we learn about the universe (the rocks, burning gas and other debris that are left after this very big bang) and how it was just after the explosion, very small parts of a second after it, the more we learn that if one of the properties were just very slightly different we would have had no chance of existence. If gravity had been just a little weaker then the gasses and other bits wouldn't have started clumping up and getting all hot, so they wouldn't have started burning and spewing out heavier elements. Lumps of dusty stuff wouldn't have got together to make rocky stuff. And so on. Make gravity a tiny bit stronger and the whole lot collapses back into some kind of implosion or other very nasty situation.

So, we're just lucky? Well, no, there's no co-incidence that we should happen to evolve in a universe that is the cosmological equivalent of Momma Bear's porridge. If it weren't we wouldn't be here to observe it. One is the product of the other, no luck or fate brought the two together.

Why are they concerned? Taking the gravity thing further we find that not only is it set just right for clumping the bits into bigger bits and having some bits spin happily around other warm bits but while it's all getting bigger it is slowing down and might stop. It might not. It might reverse. We don't know, not just because it's incredibly difficult to measure but also because with each new measurement it gets closer to the incredible balancing point.

Imagine a huge smooth dome the size of a house, and imagine rolling a snooker ball up the side. If you roll the ball gently it will roll back to to you. If you roll it herd enough it will roll right over and down the other side. If you roll it just right you could, just maybe, get it to come to rest balancing right on the top of the dome. That's easy compared to the balancing act the universe seems to be trying.

Here's where my theory comes in. Imagine trying that snooker ball thing again, but you have to do it first time. Not very likely at all. How about if I said you could have as many goes as you like in an hour, or a year? you might get it if you stuck at it for a whole year. Even more likely if you did it every day of your life. How about you got some friends to help, and their friends too, everyone with their own dome and ball? Or maybe an infinite number of people with an infinite number of attempts. Surely with that amount of time and resouces then if it's possible then it is bound to happen.

So that's it; we're here because this universe is just right for us. This universe is here because it's possible for it to be. The real kicker here is that this means that it is also possible for an infinite number of other universes to exist. They don't have to be in 'parallel dimensions' just somewhere else, over there somewhere.

My mate doesn't agree with me about this, but then what does he know? He only used to be a nuclear physicist. We do agree on what makes a good apple crumble though, and that's what's important.

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