Quote: Originally Posted by Reverend Blair
If there are alternate universes, as string theory seem to suggest, do you think they'll take a form fundamentally like this one, Dexter?
I dunno Rev, there's no reason to think they'd be any particular way at all, as far as we know now. Good question though. The way our universe is, is defined pretty closely by a few so-called fundamental constants that control such things as the strength of nuclear interactions and the strengths of the forces like gravity and electromagnetism. If nuclear forces were a little weaker than they are, for instance, no element heavier than lithium could form, and neither could stars, so life as we know it would be impossible. If they were a little stronger, stars would burn up so fast there'd be no time for life to evolve on planets around them. Similarly, if gravity were a little stronger or weaker, stars would be very different than they are, much smaller and hotter or much bigger and cooler on average. Our universe appears fine-tuned to allow life as we know it to develop.
If there are multiple universes, I'd expect those fundamental constants to vary among them, so some of them could lead to life, some would be perpetually cold and dead, some would be unimaginably explosive, and so on. The possibilities I suspect are infinite, and we just happen to be in a universe that's relatively friendly to our kind of life in a few places, though obviously most of our universe too is pretty hostile to life. Or at least our kind of life. String theory may eventually provide an explanation for why those fundamental constants are what they are, and show that they can't be anything else, or it might demonstrate that there's an infinite range of possibilities for them and we just got lucky in this universe.
But then, if this universe wasn't such as to allow life to develop, there'd be nobody here to think about such things. That "fine tuning" observation is often used in the argument from design to demonstrate the existence of some higher power guiding all this stuff, but all it says to me is that if things were different then things would be different, but they aren't, so I don't see the point of that argument. But it's fun to speculate.
One of the ideas from physics I particularly like is this one: in nature, everything not forbidden is compulsory. Nobody knows if it's actually true or not, but it certainly seems to be from what we can see. I take that to mean that anything that's allowed by the laws of physics not only *can* happen, it *must* happen. There's nothing in the laws of physics as we currently understand them that forbids multiple universes, so...well, draw your own conclusions.
See, reality is way more interesting than anything the mystics ever dreamed up...