Thursday, 25 November 2010

The Second Law of Theologico-thermodynamics

Roger Penrose's Cycles of Time (2010) addresses the oddness of the big bang, with respect to the Second Law of thermodynamics. That law applies to discrete systems, and does so, the physicists assure us, ubiquitously. But as Penrose notes, the Big Bang presents a problem. For the Second Law to hold, the Big Bang 'must have had, for some reason, an extraordinarily tiny entropy' [51]. He goes on: 'the issue of the Big-Bang specialness is central to the arguments of this book'; and his explanation for the counter-intuitive low-entropy initial cosmic singularity is an idea he calls 'Conformal Cyclic Cosmology', according to which our Big Bang is merely a transition in the longer history of the universe, such that the Second Law obtains in the larger system.

Now, it goes without saying that another way of solving the apparent problem of the Big Bang and the Second Law of thermodynamics would be theological. That, in a nutshell, it is not the case that the Big Bang developing into the Cosmos is a closed system; because God was there too, a kind of mega Maxwell's demon,* to steer the high entropy big bang into a low entropy early universe which could then, Second-Law-ishly, gradually become high entropy again. It should also go without saying that I do not personally see the merit in this explanation, although of course many people do, implicitly or explicitly. But what interests me is the broader parameters of this explanation; or more specifically, what those broader parameters mean for theological explanation.

In a nutshell what I mean is this: we may think of God as initiating the Big Bang, turning a high-entropy starting point into the lower entropic early Cosmos. But according to the Second Law, the total system (God + Big-Bang-Singularity → God + Our Cosmos) must increase in entropy. As with Maxwell's Demon, this would mean that by creating the cosmos God increased his own entropy. That the act of Creation was a kind of dimunition in the perfect harmomy and order of the divine. There's a kind of poetic rightness to this notion, I think: that making the Cosmos took something out of God, that it was not 'cost free' -- a poetic truth restated in the price paid by God as Christ in redeeming our suffering. But it is not compatible with the tradition understanding of the omnipotence of God. If this is right, then God wounded himself making us. And if he did so, he is no longer perfect, omnipotent and unscathed.
*'Several physicists have presented calculations that show that the Second Law will not actually be violated, if a more complete analysis is made of the whole system including the demon. The essence of the physical argument is to show, by calculation, that any demon must "generate" more entropy segregating the molecules than it could ever eliminate by the method described. That is, it would take more energy to gauge the speed of the molecules and allow them to selectively pass through the opening between A and B than the amount of energy saved by the difference of temperature caused by this.'


mahendra singh said...

My brain's a bit addled by this one but isn't it really an attempt to evade an infinite regression scenario?

The latter is the great boogey-man (or even Boojum) of all Western thinking. I think the West needs to chill out on this one. Don't get your entropy in a knot, man.

Adam Roberts Project said...

I'm afraid I refuse to believe that your brain is capable of being addled, Mahendra. You have an un-addleable brain. Or is that 'inaddleable'?

It's not very clearly expressed in this post, I concede, but Penrose's point is simpler than 'infinite regression'. The Second Law of Thermodynamics says that entropy always increases. That means, if you run time backwards, entropy decreases the closer we get to the big bang, which is fine, and accords with scientific observation. But, as Penrose notes, we eventually reach the 'explosion' itself -- something the Second Law says must have been a very low entropy (or if you prefer: very highly ordered) event, something that can hardly have been true.

No ... that's no clearer, is it.

mahendra singh said...

Just call me Black Addled! ha!

I thought he implied that the initial, perversely low entropy BigBang could be explained by being the result of another cycle ending.

Maybe we should do what the Scholastic always did and just stick god in the equation and then go out for a mead.

Adam Roberts Project said...

Snark-adder, more like.

I see what you mean: you're right, that is Penrose's argument, more or less. And yes, there is something a little tedious about throwing up one's hands in awe and helplessness in the face of infinity.