Lawrence Krauss, physicist and author of A Universe from Nothing, asserts that the universe arose spontaneously from nothing. Krauss appeared on an Australian television show recently to discuss his assertion. Ed Feser comments on Krauss’s arguments:
[Feser] [S]kip ahead to about 27 minutes in, where a questioner asks Krauss to explain how the universe could arise from nothing. Krauss answers:
[Krauss] [E]mpty space, which for many people is a good first example of nothing, is actually unstable. Quantum mechanics will allow particles to suddenly pop out of nothing and it doesn’t violate any laws of physics. Just the known laws of quantum mechanics and relativity can produce 400 billion galaxies each containing 100 billion stars and then beyond that it turns out when you apply quantum mechanics to gravity, space itself can arise from nothing, as can time. It seems impossible but it’s completely possible and what is amazing to me is to be asked what would be the characteristics of a universe that came from nothing by laws of physics. It would be precisely the characteristics of the universe we measure.
[Feser] This is, of course, a summary of the argument of Krauss’s book. And the problem with it, as everybody on the planet knows except for Krauss himself and the very hackiest of his fellow New Atheist hacks, is that empty space governed by quantum mechanics (or any other laws of physics, or even just the laws of physics by themselves) is not nothing, and not even an "example" of nothing (whatever an "example of nothing" means), but something. And it remains something rather than nothing even if it is a "good first approximation" to nothing (which is what Krauss presumably meant by "good first example"). When people ask how something could arise from nothing, they don’t mean "How could something arise from almost nothing?" They mean "How could something arise from nothing?" That is to say, from the absence of anything whatsoever — including the absence of space (empty or otherwise), laws of physics, or anything else. And Krauss has absolutely nothing to say about that, despite it’s being, you know, the question he was asked, and the question he pretended to be answering in his book…
Please understand that this is the best they’ve got. Krauss would make a better argument if he could. The best he can do, in reply to self-evident common sense and the irrefutable logic of the cosmological arguments, is to insist that the universe can arise from almost nothing.
Quantum mechanical laws and space-time are not nothing. A universe that arose from a quantum field and space did not arise from nothing. Quantum "instability" in space is not nothing. It’s very much something.
The universe did not and cannot arise from nothing, because "nothing" is non-existence, and non-existence cannot be a causal agent, because it cannot be anything.
Such logic, not the quantum field, is the closest thing we have to nothing.