A Facebook friend linked to this blog post from a Wesleyan pastor named Matthew Rose about a recent Stephen Hawking speech. Hawking says that we can explain the apparent design of the universe—which he at least concedes is a potential problem for atheists like himself—by resorting to the theory of the multiverse: that our universe is one of a nearly infinite number of universes, which have no physical continuity with one another.
Why does Hawking think that this helps his cause? Because he believes it explains our universe’s apparent fine-tuning. In other words, there are a number of physical constants in the universe, which, if they varied even slightly, would prevent the formation of life. (When I say slightly, I mean slightly. Click here for more on the fine-tuning argument.) If, however, a nearly infinite number of universes exist, then at least one of them—fortunately, ours—is bound to have these seemingly finely-tuned constants. Lucky for us!
Rev. Rose writes:
Take a second to think about the move Hawking is making here. To avoid belief in an invisible God, Hawking is willing to believe in the existence of a near infinite amount of universes that he can’t see or observe. Not only does this require far more faith than most any religious system… it also doesn’t happen to explain the origin of the universe, which was the whole purpose of the lecture! Indeed, it multiplies the problem. If you thought it was hard to explain the origin of one universe… try explaining a billion or more!
He’s right. Keep in mind: If all these universes are physically discontinuous with our own (and if they aren’t discontinuous, then there’s still only one universe; it’s just larger than we thought), what on earth can a scientist possibly say about them—as a scientist, I mean, speaking scientifically? Absolutely nothing.
Hawking is free to believe in a multiverse if he wants, but he’s not doing so on scientific grounds. He has left the realm of physics and entered metaphysics. Again, that’s fine. But the reason we care about what Hawking has to say in the first place is that he’s a brilliant physicist, not a brilliant metaphysician or philosopher. Belief in a multiverse is purely a leap of faith.
But even if Hawking is right about the multiverse’s accounting for the fine-tuning of our universe, what about the mechanism that generates the multiverse itself? How finely tuned does it have to be in order to produce nearly infinite numbers of universes such that it produces our universe? And what accounts for that fine-tuning? I posted the following on Facebook in response to my friend (click to enlarge):
As William Lane Craig says, if the mechanism that generates the multiverse is itself fine-tuned, then Hawking is merely “kicking the problem upstairs.”
Now this recourse to the World Ensemble [or multiverse] will be in vain if it turns out that the mechanism that generates the World Ensemble must itself be fine-tuned, for then one has only kicked the problem upstairs. And, indeed, that does seem to be the case. The most popular candidate for a World Ensemble today, the inflationary multiverse, does appear to require fine-tuning. For example, M-theory, the theory which supposedly governs the multiverse, works only if there are exactly eleven dimensions—but it does nothing to explain why precisely that number of dimensions should exist.
Beyond fine-tuning, the main question that Hawking’s multiverse theory can’t answer is “why something and not nothing.” Hawking appears to make a philosophical mistake here. Nothing means nothing—not gravity, not a vacuum, not energy, no sort of milieu in which a Big Bang of any kind can take place. For him, however, “nothing” means “space filled with vacuum energy.” I don’t know from vacuum energy or quantum gravity or whatever else he talks about, but I know that these things are still something. And the question remains, why? Here’s Craig again, referring to the book Hawking co-authored last year:
Hawking and Mlodinow seem to realize they have not yet answered the question, “Why is there something rather than nothing?” They return to this question in their concluding chapter and give a quite different answer. There they explain there is a constant vacuum energy contained in empty space, and if the universe’s positive energy associated with matter is evenly balanced by the negative energy associated with gravitation, then the universe can spontaneously come into being as a fluctuation of the energy in the vacuum (which, by a clever sleight of hand, they say “we may as well call … zero”).
This seems to be a very different account of the universe’s origin, for it presupposes the reality of space and the energy in it. So it is puzzling when Mlodinow and Hawking conclude, “Because there is a law like gravity, the universe can and will create itself from nothing in the manner described in Chapter 6” (page 180). Here it is said that the nothingness spoken of in Chapter 6 is not really nothingness after all but is space filled with vacuum energy.
Finally, here’s what is potentially most tragic: Stephen Hawking would be on our culture’s short list of “world’s smartest person.” (If Einstein were still alive, Hawking would probably finish second.) Given that most people’s skepticism doesn’t result from carefully reasoned arguments, most skeptics will hear that the “world’s smartest man” has proven that God doesn’t exist, and think, “Well, that’s settled, then!”
By the way, years ago I read an article about our culture’s veneration of Einstein. We mistakenly believe that if a person is a genius in one field of learning, he is therefore a genius in all fields of learning. This popular belief doesn’t correspond to current research about geniuses.
So, if it makes you feel any better, while Einstein was a genius in physics, he—along with all other geniuses, Hawking included—was about as dumb as the rest of us in all other parts of his life. Therefore, when geniuses say something outside of their specialty, their words, in principle, shouldn’t carry more weight than anyone else’s.
This applies to Hawking’s metaphysical musings.