David Brooks links to some of the best magazine writing of the past year, and one of the articles is about the origin of the universe. In The Accidental Universe, Alan Lightman tells the story of how the fine-tuning of our universe has driven theoretical physicists to postulate the idea of a multiverse to escape the implication that our universe was designed. Ours is just one of an infinite set of universes that just happened to instantiate the right conditions for life. That is, there is nothing particularly special about our universe; given infinity, it was likely to come about at some point.
The fine-tuning of our universe is described well:
For example, if the nuclear force were a few percentage points stronger than it actually is, then all the hydrogen atoms in the infant universe would have fused with other hydrogen atoms to make helium, and there would be no hydrogen left. No hydrogen means no water. Although we are far from certain about what conditions are necessary for life, most biologists believe that water is necessary. On the other hand, if the nuclear force were substantially weaker than what it actually is, then the complex atoms needed for biology could not hold together. As another example, if the relationship between the strengths of the gravitational force and the electromagnetic force were not close to what it is, then the cosmos would not harbor any stars that explode and spew out life-supporting chemical elements into space or any other stars that form planets. Both kinds of stars are required for the emergence of life. The strengths of the basic forces and certain other fundamental parameters in our universe appear to be “fine-tuned” to allow the existence of life.
This data cries out for explanation, and almost no one has the gumption to write off as sheer dumb luck. Some scientists agree with theologians that it is best explained by a divine act of design. Francis Collins, while skeptical of intelligent design in biology, warmly embraces the idea that the physical constants of the universe were orchestrated by a higher power to make the evolution of life possible. Even the long time atheist philosopher Antony Flew could not explain away the data and changed his mind about the existence of God. But this sort of move is not a popular one with leading physicists.
The multiverse offers an explanation of the fine-tuning conundrum that does not require the presence of a Designer. As Steven Weinberg says: “Over many centuries science has weakened the hold of religion, not by disproving the existence of God but by invalidating arguments for God based on what we observe in the natural world. The multiverse idea offers an explanation of why we find ourselves in a universe favorable to life that does not rely on the benevolence of a creator, and so if correct will leave still less support for religion.”
That, however, is a big "if." To make matters worse, the mutliverse explanation is not the sort of thing "we observe in the natural world." Near the end of his article Lightman writes:
Not only must we accept that basic properties of our universe are accidental and uncalculable. In addition, we must believe in the existence of many other universes. But we have no conceivable way of observing these other universes and cannot prove their existence. Thus, to explain what we see in the world and in our mental deductions, we must believe in what we cannot prove.
Sound familiar? Theologians are accustomed to taking some beliefs on faith. Scientists are not. All we can do is hope that the same theories that predict the multiverse also produce many other predictions that we can test here in our own universe. But the other universes themselves will almost certainly remain a conjecture.
If scientists are thinking like theologians, then what sort of "theology" are they operating under? Is it not atheism? Or is it just methodological naturalism, the practice of searching only for natural causes? If that’s the case, then the goal of science is not necessarily the pursuit of truth. Naturalism could very well be false and the mutliverse theory the sort of thing that would be true if naturalism is (wrongly) assumed to be the case. But even if the mutliverse theory really is the case, it does not necessarily eliminate the need for fine-tuning because it is possible that the conditions for generating universes have to be finely tuned themselves. It is plausible to suppose that at some point, a first cause lies behind it all.
At bottom, I suspect that there is a scientistic type of fundamentalism at work here. Multiverse theorists are more certain that divine causation can’t happen than they are of any of the premises of an argument that concludes divine causation can happen. I am not sure what else could explain their believing that the multiverse is the best explanation of the fine-tuning of our universe.
This brings me to Bradley Monton’s book Seeking God in Science: An Atheist Defends Intelligent Design (recently discussed here) A Princeton-trained philosopher of science who teaches at the University of Colorado (Boulder), Monton carefully weighs the evidence and fairly evaluates the explanations and comes to the conclusion that design arguments are “somewhat plausible.” They don’t defeat his atheism, but they make him less certain of it. I can relate with this as I find arguments from the problem of evil to be somewhat plausible, making me less certain of, though not defeating my belief in God. No matter what one ultimately thinks of Monton’s book, the takeaway should be that truth is the goal of inquiry, not whether we are “doing science” or “being religious.”