One of my favorite subjects is the meaning of "nothing." Two good books to begin to study nothingness are: Nothing: A Very Short Introduction, by physicist Frank Close; and Why Does the World Exist? An Existential Detective Story, by Jim Holt.
Physicist Lawrence Krauss added his voice to the discussion, in A Universe from Nothing: Why There Is Something Rather than Nothing. Krauss picks up on Stephen Hawking's claim that physics can now explain how the universe came from nothing. Krauss writes:
"For over 2,000 years the question "Why is there something rather than nothing?" has captured theologians and philosophers. While usually framed as a religious or philosophical question, it is equally a question about the natural world. So an appropriate place to try and resolve it is with science."
And: "As a scientist, I have never quite understood the conviction, at the basis of essentially all the world's religions, that creation requires a creator. Every day beautiful and miraculous objects suddenly appear, from snowflakes on a cold winter morning to rainbows after a late afternoon summer shower."
But semantically, "creation" requires a "creator." On philosophical naturalism the idea of nature as a "creation" is a vestige of Judeo-Christian theism. The artist's painting is his "creation." Simply put: no artist, no creation. Minimally, it's misleading to speak of "creation" without a "Creator." Surely Krauss understands that.
But what about the idea that, without a Creator, our universe not only can, but has come out of nothing? Krauss writes that:
1) We live in a "flat universe." A closed universe is dominated by matter and will one day collapse; an open universe will expland forever; but a flat universe "is just at the boundary - slowing down, but never quite stopping."
2) Observations of the cosmic microwave background from the Big Bang have unambiguously confirmed that we live in a precisely flat universe."
3) The dominant energy in our universe is "dark energy."
Now watch Krauss make much ado about nothing. :
"The existence of dark energy and a flat universe has profound implications for those of us who suspected the universe might arise from nothing. Why? Because if you add up the total energy of a flat universe, the result is precisely zero. How can this be? When you include the effects of gravity, energy comes in two forms. Mass corresponds to positive energy, but the gravitational attraction between massive objects can correspond to negative energy. If the positive energy and the negative gravitational energy of the universe cancel out, we end up in a flat universe.
Think about it: If our universe arose spontaneously from nothing at all, one might predict that its total energy should be zero. And when we measure the total energy of the universe, which could have been anything, the answer turns out to be the only one consistent with this possibility."
This, thinks Krauss, is no coincidence. It's what one would expect if the universe came out of "nothing at all." Thus, he thinks, we have an explanation for why there is something rather than nothing.
Many have responded to Krauss's claim. William Lane Craig does so here. Craig says:
1) Krauss doesn't have a clue about the philosophical and metaphysical questions he is trying to address here. If by "nothing" Krauss means literally non-being, "then physics is impotent to explain how being can arise from non-being."
2) Surely Craig is correct here. Because "physics explains the transition from one physical state to another physical state, according to certain laws of nature operating on the initial state's conditions... In absolute origination there is nothing that endures from non-being to being." Physics, therefore, is impotent to explain how one could have an "absolute origination." Pause on this point and ponder...
3) The idea that there would be predictability if the universe just popped into existence from nothing is nonsensical, for then there would not be a reason why the universe could not be anything. From "nothing," no prediction can be made re. the universe's total energy. If non-being is taken philosophically seriously, it has no properties and no constraints, hence the laws of physics do not apply, and nothing can be predicted from it.
4) Krauss is guilty of the fallacy of equivocation; viz., he has equivocated on the term "nothingness." He has changed the meaning of the word "nothingness."
When philosophers and theologians ask the question, "Why is there something rather than nothing?" they mean, by "nothing," "non-being." From non-being, nothing can come.
Krauss's equivocation is this: "nothing" does not really mean "nothing." Our universe came out of "relativistic-quantum-field-theoretical vacuum states." These fields are not property-deficient; they "are particular arrangements of elementary physical stuff." (David Albert, Columbia University, "On the Origin of Everything.") Hence, Krauss has failed to explain explained why there is something rather than nothing, since his version of nothing is, it turns out, something.