Over the years I have read quite a bit by and about Stephen Hawking. Hawking, a brilliant theoretical physicist and cosmologist, excels at communicating complex scientific concepts to laymen. His most well-known work, A Brief History of Time, was first published in 1988 and has sold well over ten million copies. It is among my favorite works on a scientific subject; after I finished reading it I actually understood the basic concepts behind the theory of relativity and a number of other heady cosmological subjects that had escaped my thorough comprehension previously.
Hawking’s book was more effective in broadening my understanding of the universe than twelve years of public-school science classes ever were. You can take that as a compliment for Hawking, an insult for the public schools, or some combination of both.
In 2010, Hawking and fellow physicist Leonard Mlodinow released a new ‘popular’ scientific book called The Grand Design, tackling the subjects of quantum physics, M-theory, and the origins of the universe. I picked up a copy (for the Kindle) and it finally worked its way up to the top of my reading list last month. Like A Brief History of Time, The Grand Design is an easy read that manages to communicate very complex material to regular folks like you and me. You will not find yourself bogged down in formulas or minutia, but you will find yourself soaking up the key concepts.
In describing quantum physics, Hawking and Mlodinow are as effective in The Grand Design as Hawking was in A Brief History of Time describing general relativity. Having finished the book, quantum physics no longer seems to be completely beyond my comprehension. Oh, I am no quantum physicist—I never will be—but the basics of quarks and gluons, quantum probability, and how quantum theory relates to the theory of relativity are no longer foreign to me. At least at a basic level, I get it now. This is where Hawking has always excelled, and where he and Mlodinow continue to excel. They have taken something seemingly incomprehensible and made it make a lot of sense.
Quantum physics seems to indicate that particles take all possible paths simultaneously, and that their final destinations in our universe are determined in a way best expressed with probabilities. This seems unrealistic and indefensible at the macro scale of human bodies and tables and automobiles, but at the atomic and subatomic level this truth has been verified scientifically (and the experiments that lead to this conclusion are well explained in the book). Like relativity before it, quantum theory posits things that don’t seem true in our everyday experience, but are true nonetheless and can be demonstrated either on the grand scale of the universe or the minuscule scale of the atomic (and subatomic) particle.
But these are things that can be observed, albeit with some difficulty. They are backed up by direct and indirect observation. As the book broadens to consider M-theory, and the reason for our existence, it begins to focus on things that cannot yet be observed, and will quite-possibly never be observed. The authors, to their credit, admit this . . . but as it moves into this subject area, the book loses some of its clarity.
M-theory is a very difficult concept, and I doubt I will do it justice here. It is a successor to string theory that posits the existence of eleven dimensions (the traditional three, time, and seven more). In our universe, for whatever reason, the seven ‘extra’ dimensions are all ‘curled up’ and essentially invisible to us, and yet they contribute to the overall structure of our universe. Combining M-theory with quantum theory (specifically quantum probability) leads us to the startling conclusion that the universe, like a quantum particle, takes every possible course simultaneously. As such, our universe is just one of an infinite number of universes with an infinite number of dimensional structures and an infinite structure of governing laws.
Hawking and Mlodinow, using M-theory, then claim that this underlying structure of the universe (or, rather, the multiverse) explains our existence without the need to resort to a deity or deities. This is an interesting concept, to be sure, but it is unconvincing—or at least incomplete.
Before I address some of the issues I have with this from the scientific perspective, let me first address the elephant in the room.
Many in the media have couched The Grand Design as Hawking’s ‘proof’ that there is no God. It is no such thing. Hawking and Mlodinow present a thought-provoking model for a universe without a God, and there is no question that Hawking himself is an atheist, but there is nothing in this book that would preclude the existence of God and nothing more than a few mildly critical statements about religious faith (nothing compared to the anti-religious vitriol swirling around Internet message boards and comment streams). Not only does M-theory not preclude the existence of God, but the authors’ halfhearted attempts to do so are the most scientifically weak arguments in the book.
Of course, Hawking’s commentaries on religion outside of the book in media interviews have been more direct and pointed. They make for good television, I suppose, but I fail to see the logic in asking a theoretical physicist and cosmologist for his opinions on religion. If I wanted an opinion on Oscar picks, I wouldn’t ask a Priest. If I wanted an opinion on biology, I wouldn’t ask a politician. If I wanted an opinion on illegal immigration, I wouldn’t ask a zoologist. Hawking is an absolutely brilliant man in his area of expertise. I admire and respect him very deeply for his work in his chosen field, and for his knack for making that work accessible to rubes like me. But his opinions outside of his area of expertise are of little more import than anybody else’s.
Some might argue that theoretical physics and religion are the same field, but this reflects a misunderstanding of one subject or the other. Theoretical physics will never tell us why we are here, or how we should live with one another in moral society. Likewise, religion will never tell us how the universe got to its present state from its creation or allow us to travel to the moon or build a quantum computer. Science is at its worst when it tries to step into the territory of religion and ethics. Religion is at its worst when it attempts to step into the territory of science. In truth, when each is practiced properly, they only collide on very rare occasions . . . and those real collisions are almost exclusive to biological and medical fields, where the science deals with human life and must navigate very serious moral issues. Theoretical physics doesn’t collide with religion unless its physicists decide to try and be theologians. Religion doesn’t collide with theoretical physics unless its theologians decide to try and be physicists.
With that out of the way, we can continue to the real meat of the matter. The quintessential quote from The Grand Design that got picked up by the media was this:
“Because there is a law such as gravity, the universe can and will create itself from nothing. . . . Spontaneous creation is the reason there is something rather than nothing, why the universe exists, why we exist. It is not necessary to invoke God to light the blue touch paper and set the universe going.”
This quote was selected by the sensationalist media for its apparent anti-religious sentiment, as if “not necessary to invoke” somehow means “precludes the existence of.” In truth, the quote is more notable for its invalid, circular logic than for its supposed anti-religiousness (which I don’t find particularly anti-religious anyway). It makes no claim as to why spontaneous creation would occur, except to point to gravity. It leaves us wondering why gravity, which we generally consider to be part of our universe, should have existed before (or outside) of it.
I had sincerely hoped and expected that the quote was taken out of context, and that its underlying thesis would be properly explained by the rest of the book. It was not. Once The Grand Design moves from its lucid explanations of quantum theory into M-theory and trying to answer the age-old ‘why are we here?’ question, it degrades into apparently contradictory statements on the nature of existence. Hawking and Mlodinow explain that the universe is actually a multiverse, and that each of the infinite number of universes within has its own dimensional structure and, thus, its own laws of nature. But if each universe has its own dimensional structure and laws, why should the law of gravity predate and transcend those universes and be the harbinger of spontaneous creation? If there is an answer to this question, it was nowhere to be found in The Grand Design. The apparent contradiction is never resolved, or even acknowledged.
The hypothesis that we are here due to a ‘spontaneous creation’ for which there is no observable evidence is no more or less scientifically defensible than ‘creation by the hand of God.’ In all likelihood, if you subscribe to either of these positions, Hawking and Mlodinow will not convince you to change it. The sad truth is that it is probably impossible for beings in this universe to properly test either hypothesis. In this respect, The Grand Design ends up being more theological than scientific. The authors posit a universe that poofed into existence along with an infinite number of other universes for no reason whatsoever. It is possible that this is exactly what happened, but there is no reason that we should assign that hypothesis any more weight than any other. If you choose to believe in the theory of the spontaneous creation of the universe, you are making a leap of faith . . . one that is really no different from the one we religious folks make when we say that God created it.
In fact, even if we accept the authors’ arguments in The Grand Design, they (inadvertently) leave plenty of room for God in their picture of the universe. They have not made a convincing case for spontaneous creation from nothing, leaving plenty of space for him (or anything else, for that matter) in the void that predated the universe’s existence. Likewise, M-theory’s multiverse—where the universe develops in every possible way simultaneously—hardly precludes the development of deities within those universes through those universes’ natural processes and the laws that arise within them. If this were the case, it would require serious theological reconsideration within the world religions . . . but it would still be a universe closer to what Christianity expects than to what Hawking expects. That Hawking and Mlodinow do not acknowledge this as a serious possibility is curious, as they are quick to acknowledge that nearly anything else is possible in the “vast universe full of the amazing variety that we see.”
Lastly, one of the key concepts in The Grand Design is the concept of a model-dependent realism. As the authors explain:
“According to model-dependent realism, it is pointless to ask whether a model is real, only whether it agrees with observation. If there are two models that both agree with observation . . . then one cannot say that one is more real than another. One can use whichever model is more convenient in the situation under consideration.”
This concept has much scientific validity, of course . . . but once again it is a concept that the authors have applied selectively to support their particular view of the universe while denying it to other equally valid views. Billions of Christians around the world would say that their model of the universe agrees with their observations, myself included, and there have been a number of studies on prayer and faith that would (at least circumstantially) support that model. It is the height of hubris to dismiss it outright as invalid, while simultaneously stating that any model that agrees with observation is equally real.
But, despite these flaws, The Grand Design is worth reading. It is not as enlightening or fair-minded as Hawking’s own A Brief History of Time, and it is unfortunate that Hawking and Mlodinow have allowed their faith in atheism to cloud their dedication to dispassionate science. But the book still provides a useful primer on quantum physics and M-theory. These are concepts, like relativity before them, that are notoriously difficult for average folks like me to grasp, but they have become the linchpins of modern theoretical physics. I doubt M-theory is the panacea that the authors make it out to be; in all likelihood, it will be supplanted by new and more exciting theories in time. But if you want to get the gist of what the top physicists are working on these days, The Grand Design is a good place to start; just don’t pay too much attention to the amateur theology.