Wednesday, May 2, 2012

Carroll on creatio ex nihilo

I acknowledged physicist Sean Carroll's take on the Krauss debacle in my last post, and I was tempted to critique it at the time, but decided that doing so required a new post.  This is that post.

Carroll is critical of Krauss, but he also tries to defend him by putting his work in context.  He says the physics Krauss is talking about does have something to add to "the atheism vs. theism popular debate."  I find that unlikely, and Carroll's argument offers a good opportunity to explore why.

According to Carroll, quantum field theory shows that you don't need a Creator in a complete cosmological model of the universe.  Of course, we're talking about a complete and coherent scientific model of the universe.  But did we need quantum field theory to show us that?  Hardly.

Does quantum field theory actually show it, even?  To do that, wouldn't it have to have an empirically definable notion of a Creator?

Furthermore, is Carroll suggesting that you could have a scientific model of the universe that did include a Creator God?  If so, I think he is quite wrong.

The physics is interesting.  I have nothing against the physics.  And I have no sympathy for theistic arguments about origins and the necessity of a Creator, as I've already explained.  But, contrary to Carroll, I don't see quantum field theory helping out in the atheism vs. theism popular debate.  I see it confusing the debate, producing a lot of heated exchanges and hurt feelings, and, possibly, selling some books.  I also see it doing damage to the reputation of philosophy and I appreciate that Carroll makes an effort to fight against that tendency, but his explanation of the interplay between physics and the atheism/theism debate is not simply weak.  It is profoundly confused.

Carroll's assumption is this:  If you can show that something can come from nothing, then you have delivered a blow to theistic arguments for a Creator God.

I'm not sure that's a fair assumption. I certainly don't like the corollary assumption, that, if you can't show that something can come from nothing, then arguments for a Creator will have more traction.  That's definitely not a fair assumption.

Atheists should feel no pressure at all to show that something can come from nothing.  No such demonstration is called for in the popular debate.

But Carroll thinks this is a relevant question.  And he thinks that something can come from nothing.  He discusses two ways contemporary physics teaches us how this might happen.  Of the first possibility, he writes:

if your definition of “nothing” is “emptiness” or “lack of space itself,” the laws of quantum mechanics provide a nice way to understand how that nothing can evolve into the marvelous something we find ourselves inside.
Unfortunately, this is terribly misleading.  It may be that a lot of people think of "nothing" and "emptiness" as equivalent, but if you tell them that what they think of as emptiness has all sorts of properties, then they are likely to say, "oh, in that case, it's not nothing."  It seems intellectually dishonest to read your advanced science into the way ordinary people talk, which is what Carroll is doing if he supposes that this possibility has any relevance to the popular debate.

Of the second possibility, Carroll writes:
there is literally a moment in the history of the universe prior to which there weren’t any other moments. There is a boundary of time (presumably at the Big Bang), prior to which there was … nothing. No stuff, not even a quantum wave function; there was no prior thing, because there is no sensible notion of “prior.”
So, on this view, we cannot say that there was nothing prior to the beginning of time, because there is no coherent concept of "prior to the beginning of time."  And yet, Carroll says that this is a possible way of thinking about how something came from nothing, a nothing which was . . . prior to the beginning of time.  This is incoherent.

Sean Carroll, if you are reading this, please do me a favor.  Either reconsider your analysis or help me understand how it is supposed to make sense.  Because it seems like a no-brainer.  You have not shown how contemporary physics has anything to say about something coming from nothing in the way ordinary people understand those terms.  And saying that they should understand them differently is, really, just to say that they should change the subject.  You're saying they should talk about quantum field theory instead of theology.  I agree that they should--and if not quantum field theory, perhaps lacrosse.  But how is quantum field theory relevant to their theistic belief?  That's not something you've shown, and I suspect Krauss doesn't fare better.

[Update: I just noticed that Krauss has responded in a comment to the effect that Carroll has misrepresented him by taking him to be answering a "why" question and not a "how" question.  I don't see any misrepresentation.  Carroll presents two possible ways (he thinks) that something can come from nothing.  The question, then, he is answering is, "how could something come from nothing?" That's a "how" question, presumably of the sort Krauss is interested.]