But in order to do this there is a hypothesis Hawking does need: that there are multiple universes.
The argument in Hawking's article is far from lucid, and one assumes that the argument in his book is couched in clearer terms, but he seems to argue that if you assume certain cosmological theories, then we don't need God to explain how the universe got here, since these theories would account for it. We don't need God to explain the universe because we can explain it without God.
But exactly how is this to be done?
No one except physicists should do anything but fear to tread on matters as mathematically complicated as what Hawking only hints at in the Journal article. But he is offering his argument in public, in an organ of opinion directed at the intelligent non-scientific laymen, and therefore we should expect that he has an argument understandable to the public to make.
So let's try to make sense of this--and by the way, I'm perfectly open to correction on this, but it will have to come from someone who states the argument better than Hawking.
As best one can tell, Hawking seems to argue that if you assume there are multiple other universes than our own, then an explanation of how the universe got here without God is possible. And if there is a possible explanation of how the universe got here without God, then we need not bother about God.
What Hawking never explains is why the theory that there are multiple universes is any more rational an explanation than that God created the universe. Nor does he explain why one possibility necessarily excludes the other.
Let's grant him for the sake of argument that multiverse theory is a possible explanation. Why is it a better explanation than the God hypothesis, if the God hypothesis is also a possible explanation? Why choose the former over the latter? John Lennox makes somewhat the same point:
So the first problem with Hawking's conclusion--that God is not required to explain the universe--is that Hawking so far is having a hard time explaining himself. If Hawking is going to convince the rest of us that he can explain the universe, then he should at least be able to explain the theories he says explain the universe, and he hasn't sufficiently done that yet (at least not in the public pronouncements he has so far made. Maybe the book can accomplish this).
The second problem is that, as we have said, there are a lot of questions about whether multiverse theory is any less fantastic than the God theory. As another physicist, Paul Davies, points out:
The multiverse comes with a lot of baggage, such as an overarching space and time to host all those bangs, a universe-generating mechanism to trigger them, physical fields to populate the universes with material stuff, and a selection of forces to make things happen. Cosmologists embrace these features by envisaging sweeping "meta-laws" that pervade the multiverse and spawn specific bylaws on a universe-by-universe basis. The meta-laws themselves remain unexplained – eternal, immutable transcendent entities that just happen to exist and must simply be accepted as given. In that respect the meta-laws have a similar status to an unexplained transcendent god.The third problem is the status of multiverse theory as science. In fact, all of the things we are told science should do--be observable, testable, and have predictive power--are absent to a large degree from multiverse theory. In other words, there not only a questions at to whether this scientific theory can explain God away, but there is a debate about whether the theory is even scientific. Once all the purported advantages of science are no long possessed by a scientific theory, then why are we to prefer the scientific theory of the origin of things any better than the religious theory of the origin of things?
Writing before the Hawking comments made the news, Adam Frank, an astrophysicist and science journalist pointed out:
What happened to all the pro-science putties who jump your case about your religious beliefs because they are not falsifiable? Stephen Hawking has to merely hiccup, and they all go scurrying away.
The core problem is that, as of this writing, there is no experimental evidence that hidden dimensions or alternate universe exist. Proponents will justifiably point to the rich theoretical insights that a field like String Theory has provided. They also rightly argue that Einstein's relativity seemed overly mathematical and abstract when it was first introduced and took time before people figured out how to test its veracity. These are valid points but it seems to me there is more at work here than simply technical abstraction. There is an unspoken metaphysics in the new theories that manifests itself as shift in the focus of science. That shift needs to be brought out in the open as part of the debate lest we end up in a very dead end. As Unger says "When we imagine our Universe to be just one out of a multitude of possible worlds we devalue this world, the one we see, the one we should be trying to explain."
I think I would have to agree. There might, indeed, be a multiverse and I like alternative universes as much as the next science fiction groupie. But I wonder how long we should wait before a field yields real, experimentally verifiable fruit. It may well be that String Theory's hidden dimension's are real. Still how much effort do we put into explorations based on the potentially unobservable while shifting away from the tradition of exploring only the actual? More importantly what do we make of the ontological status of theories that need what might be permanently hidden to explain what is always visible?
In fact, the whole way in which these kinds of theories are used brings up important questions. If you read around a bit on this, what you find is that you have scientists concocting an explanation of something, and simply concocting however many other logically prior assumptions it takes to make that explanation plausible. For example, Frank points out that one of the theories employed to explain quantum gravity was string theory. But, it turns only, string theory cannot do this in a world of only three dimensions. But it could be explained with an additional seven dimensions--ten in all. Do we therefore automatically accept that there are ten dimensions? What if string theory is just wrong? Then what happens to the dimensions that string theory required to explain quantum gravity? And at what point do the required assumptions become so preposterous that scientists simply decide to abandon string theory and wait for another explanation to come along?
Or maybe just accept--at least on a tentative basis--the Oldest Theory about how the universe got here?
Physics comes to its conclusion largely through mathematical abstraction, and it may be for reasons like above that Einstein said in 1921, "Insofar as the propositions of mathematics give an account of reality they are not certain; and insofar as they are certain they do not describe reality."
It isn't as if no one has tried to explain Hawking's thesis. Sean Carroll has taken a stab at it. "You don't need to go outside the universe to explain the universe," He says:
You could imagine an understanding of the universe--why it came into existence--without ever leaving the laws of nature--without ever invoking some divine, some supernatural being. The universe could just obey its own laws. It could be a natural, physical, real universe, obeying the laws of physics, and that can be a complete explanation of everything.Well, the first and perhaps most obvious point is that just because you can imagine something does not make it true. You would think that would go without saying in a scientific discussion, but such is the allure of atheism.
Furthermore, if you invoke natural laws to explain the universe and then, based on your assumptions about those laws, start doing your atheist end zone dance celebrating your victory in explaining the universe, exactly how long does it take for you to realize that those laws themselves require an explanation?
The point apparently never occurred to Carroll. In fact, he goes further than Hawking seems himself to go: "The question 'Why is there something rather than nothing," he says, "has been answered."
It has? How exactly do you answer the question of why there is something rather than nothing by simply pointing to the something? C. S. Lewis once asked how someone, simply on the basis of studying nature, can say anything about what is beyond nature.
In fact, we seem to have here the perennial problem here of scientists making forays into philosophy without any actual expertise. The question "Why is there something rather than nothing?" is simply not a scientific question.
It's a bad mistake to make, since science and philosophy are two entirely different universes.