I'm sticking my neck out here because this is an area in which I'm ignorant, but I'll use the blog to try to educate myself. Anyone who can help me along on this, please do; because I just don't get the following form of argument, from an article by Johnjoe McFadden, professor of molecular genetics at the University of Surrey. He's writing about the 'anthropic principle', and he says:
This is the point of the anthropic principle, which starts from the fact of our existence and then argues backwards to claim that the precise properties of the universe that emerged from the big bang had to be those that made the eventual emergence of humans inevitable. The unique properties of water depend on an exquisite level of fine tuning of the fundamental constants. So why are these constants just right? Because if they weren't we wouldn't be here.What?! Now, hold on there. Why 'had to be'? Why not: those properties might have been different and then we wouldn't be here? So what? Don't get me wrong I'd regret it as much as the next person, or the last one. I don't mean, 'So what, I wouldn't care' (though, of course, in that case I wouldn't, because I couldn't; but I do care now that we wouldn't be here). No, I mean: so what from the point of view of the necessities and non-necessities of existence? We wouldn't be here, it's a great shame, but how does it show that the properties had to be like that and not otherwise?
Johnjoe McFadden repeats the argument, but in a way that doesn't help me, and he then goes on:
Opponents claim that the principle betrays a lack of imagination for assuming that other forms of life wouldn't be possible.I'm with the opponents (so far anyway), though for sure I'm less well-informed than they are. And, being less well-informed, I'll go further and ask: what about a universe without any form of life? McFadden again:
But this [the claim of the opponents] is harder to sustain when considering some of the more cosmic consequences of tweaking the constants. If the weak force that binds atomic nuclei had been just a bit weaker, all hydrogen would have turned to helium without making any of the heavier elements. If the strong force had been a bit stronger, the universe would not even have had any atoms.I'm not a particular fan of huge black holes, so this black-holes-only universe doesn't sound at all inviting to me. I prefer the universe whose corner we inhabit - you know, with jazz, and country music, and cricket, and Shakespeare, and pickled cucumbers. But I'm still not getting why the universe has to be the one that produced Shakespeare and Shane Warne and Thelonious Monk because otherwise it would be all empty(ish).
New research is making even the sceptics grudgingly accept the anthropic principle. A paper by Mario Livio and Martin Rees, the astronomer royal, explores the value of the cosmological constant, a measure of how much energy is contained in empty space. Without this value being tweaked to an extraordinary level of precision, the universe would be filled only with huge black holes or entirely empty of stars.
Johnjoe McFadden throws in a sentence which, to my untutored eye, even seems to support the doubts I've been trying to formulate:
Physicists such as Martin Rees and Stephen Hawking prefer [a] scenario [in which] an infinite number of universes exist, each with different values of the fundamental constants. In just a few of them the constants have taken on the right values for the creation of stars, life and evolution.Well, there you are then. So, if universes can exist where the fundamental constants have the wrong values for stars, life, evolution and (presumably) rock stars, why couldn't they all (the universes) have had the wrong values? Can anybody help here?