As you may know, William Lane Craig debated physicist Sean Carroll in New Orleans last weekend. It was streamed live, and I watched a lot of it. As Carroll summarizes on his blog:
I mostly reached my primary goal of explaining why many of us think theism is undermined by modern science, and in particular why there is no support to be found for it in modern cosmology.
The basic point of divergence was that Carroll denied that the universe requires a cause. He writes:
[M]y major points were that the demand for "causes" and "explanations" is completely inappropriate for modern fundamental physics/cosmology, and that theism is not taken seriously in professional cosmological circles because it is hopelessly ill-defined (no matter what happens in the universe, you can argue that God would have wanted it that way).
That is, even if the universe began in time, he thinks, it requires no cause to explain the beginning of its existence. It wasn’t, then it just was. If one makes such an ontological move, it seems to me, then discussion with theists will abruptly come to a halt. After all, if the universe made itself, then by definition God is not needed as an explanation for the universe.
Of course, the move is ontologically outrageous. However, amid much discussion of math models of the universe, which could easily confuse a lay audience about what the models are even modeling, I don’t think it came across in the debate that Carroll’s is not a scientific claim. The coming into existence of the universe from nothing is not part of the equations.
What’s more, if things come into being from nothing, it’s hard to see why they shouldn’t do so continuously rather than just once. (Carroll may think they do, since he apparently subscribes to the "many worlds" quantum interpretation.) It’s also hard to see why things come into being with well-defined properties, obeying sets of laws, rather than as pure chaos.
These objections aside, it looks like the next move on the atheist intellectual chessboard may be to deny that, even if finite in time, the universe required a cause at all.