Review: The Grand Design
- Published: 12 December 2010
- Written by Nicholas C. DiDonato
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It often seems that religion and philosophy have been fighting a losing battle. They're no longer seen as credible in terms of addressing questions like “How old is the universe?” and “How does human anatomy work?” They propose an answer only to find it later discredited by a more accurate, more precise, scientific answer. Nowadays, it seems that the only questions left for religion and philosophy to answer are the “ultimate” questions of “Why is there something rather than nothing?” and “Why are we here?” In his latest book, The Grand Design (Bantam, 2010), Stephen Hawking, along with Leonard Mlodinow, argues that science can answer even these questions, leaving little room for religion and philosophy at all.
The first page of the book states that "philosophy is dead. Philosophy has not kept up with modern developments in science, particularly physics. Scientists have become the bearers of the torch of discovery in our quest for knowledge." The rest of the introductory chapter goes on to outline the book’s thesis: a version of string thoery known as M-theory successfully explains why there is a universe and why the universe is the way it is. The rest of the book details what that means.
Chapter Two tells a brief history of science, from the pre-Socratics to Descartes and Newton. The point of the history is that scientific explanations have replaced religious ones through the discovery of natural law. That is, as humanity explained more and more of nature through law, there no longer was a need to appeal to divine agency. Objects do not fall because of the will of the gods and goddesses but because there are laws of gravity that dictate the objects’ behavior. Natural law excludes divine agency.
Hawking and Mlodinow conclude the chapter by answering three objections that may create space for God. First, in response to the question, “what is the origin of natural laws?” the authors do not here provide an answer (they will attempt one later) but instead argue that God cannot be the answer. They point out that unless God is given attributes in addition to “the origin of natural laws,” then God is merely a definition of the origin of natural law and not an explanation. Second, they preclude all miracles by advocating a strict scientific determinism. Concerned that “free will” is a violation of natural law and thus a miracle, the authors state that “…our understanding of the molecular basis of biology shows that biological processes are governed by the laws of physics and chemistry and therefore are as determined as the orbits of the planets.” They further their point by citing neurological research that shows that when certain parts of the brain are stimulated, certain parts of the body move—natural law at work. They mitigate their determinism a bit by appealing to “effective theory,” which is a model of a phenomenon that ignores some of the details. Thus, for supposed free will, human decision making is too complex for one to accurately predict, and these complexities can be safely abstracted. Humans are machines, but ones that make more sense to talk about on the “free will” level than on the molecular level – even though that free will is ultimately an illusion. Finally, the authors answer the question “are the laws of nature unique?” with an emphatic No—there are many possibilities, but this does not mean that God chose one.
The third chapter dives into the heart of the authors’ philosophy of science. They propose a “model-dependent realism,” which states that all scientific theories are models with rules that correspond to observations. In other words, there is no such thing as a God’s-eye view of reality: all perceptions of reality are filtered through a model. In order to avoid the realism/anti-realism debate, the authors say that no model is more real than any other model. For example, the model where the Earth rests at the center of the solar system and the model where the sun rests at the center of the solar system are equally valid models. The only constraint is that models must agree with observation. Of course, the authors do want to prefer some models over others (e.g., heliocentric models over geocentric ones) and so list four criteria by which to judge models: (1) elegance, (2) minimal changeable elements, (3) explanation of, rather than contradiction by, all known observation, and (4) ability to make falsifiable predictions. The authors admit that the criteria are subjective and imprecise but point out scientific models that exemplify them.
Chapter Four contains the key move for the authors’ overall argument that humanity needs neither philosophy nor religion but only science to answer questions of ultimacy. It starts by explaining the basics of quantum mechanics: the fundamental particles of the universe behave as both solid particles (e.g., a ball) and waves (e.g., the wave created by dropping a ball in a lake). Due to their unusual dual nature, quantum particles operate under the Heisenberg Uncertainty Principle: the more one knows about where a quantum particle is going, the less one knows about where it currently is, and vice-versa. Put another way, the more one knows about a quantum particle’s speed, the less one knows about its position, and the other way around. Since quantum mechanics appears to be fundamentally probabilistic, the authors modify their scientific determinism: the laws of nature dictate the probability of a future state given a past one. Invoking their model-dependent realism, the authors ask if there is another way of looking at quantum mechanics other than pure probability. The answer is yes! Following Richard Feynman, they advocate a view that rather than quantum states probabilistically choosing one state over another, they choose all possible states at once. Obviously, scientists only observe one of these possible states, but this is because, Feynman reasoned, those other states are triggered in other possible universes. Since scientists can only live in one possible universe, they will see only one state occur when in fact every possible state occurs (one each in a near-infinite number of universes).
In the next chapter, the authors set the stage to apply Feynman’s theory of quantum mechanics to the universe as a whole rather than just to quantum particles. They reply to the scientific objection that Feynman’s theory leads to the absurd conclusion that electrons have infinite mass and charge. After all, adding all the electrons from an infinite number of histories will naturally give an infinite result. A process called renormalization solves this problem by subtracting certain infinite quantities considered to be negative from the infinite positive quantities leading to the correct mass and charge of an electron. As the authors themselves admit, “These manipulations might sound like the sort of things that get you a flunking grade on a school math exam, and renormalization is indeed, as it sounds, mathematically dubious.” However, since this technique gives the desired result, it is acceptable according to model-dependent realism. They conclude the chapter with an explanation of how M-theory allows for different universes with different natural laws (10500 to be exact) depending on, among other things, how the dimensions of a universe are curled.
Chapter Six puts all the pieces of the puzzle together to argue for a universe that needs no Creator. They make two major moves in this regard. First, they argue that time arose simultaneously with the universe. Their worry is that some may think that God existed in time before the universe and set the universe in motion. Instead, they liken time to the South Pole: it makes no sense to ask what is south of the South Pole; “southness” starts at the South Pole and nothing exists more south than it. Likewise, time starts with the universe, and it makes little sense to ask what happened before beginning of time.
Oddly enough, in Chapter Two the authors seemed to dismiss St. Augustine's argument that there was no time before the creation, although they seem to make the same exact claim here. (To be fair, the sentence in question is somewhat ambiguous as to what they’re dismissing: alternatively, they could have been dismissing Augustine’s “literal” reading of Genesis. But Augustine did not, in fact, interpret Genesis literally, so this interpretation of the sentence seems less likely.)
Their second major move shows that the universe’s initial state was a quantum state. As such, Feynman’s multiverse interpretation of quantum mechanics applies. Since the beginning of the universe was a quantum state and, according to Feynman, every possible quantum state is realized, the beginning of the universe is actually the beginning of the multiverse—a multitude of universes were born.
Chapter Seven draws out the implications of the multiverse model for the existence of a Creator. The reason the universe appears fine-tuned for life is not because of a benevolent God but because we must live in a universe that supports life. No life can exist in a universe that does not support life. With about 10500 possible universes, it is not surprising that some of them support life. Multiverse theory explains the supposed “fine-tuning” of the universe without any need for a Creator.
Chapter Eight concludes the book by arguing that (1) intelligent life can arise from a variety of different laws, and (2) all laws of nature must conform to certain characteristics. Starting with a few simple rules, the authors show that larger, more complex patterns will emerge, and that these patterns can appear to be intelligent. Simple laws can lead to intelligent-seeming behavior at a higher level. In short, there’s no reason to think that this universe is the only universe with life. Regarding their second point, they argue that a gravity-like law is necessary. Creating an object must have an energy cost—if it does not, then objects could appear anywhere, resulting in an unstable universe. Gravity, by attracting every object to every other object, imposes an energy cost to object creation and movement, thus stabilizing the universe. However, gravity mandates only local stability—the universe as a whole can be unstable even though each region is stable. As such, the universe can appear out of nothing because of the global instability: “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.”
Of all of Hawking’s works, it is fair to say that The Grand Design is the most clearly written. Suitable for a wide audience, it maintains the reader’s interest through its intriguing thesis of atheism. In building this thesis, the book covers an astonishingly wide array of topics, including Heisenberg’s uncertainty principle, observer interference in quantum mechanics, the famous double-slit experiment, special relativity, general relativity, the four fundamental forces (gravity, electromagnetism, strong nuclear force, and weak nuclear force), Big Bang theory, and the anthropic principle, among many others. This is an impressive amount of information made readily accessible to the interested reader.
While the book’s presentation of the science is clear and informative, its philosophy is not as sophisticated as one might hope. More specifically, its philosophy of science and philosophy of religion are its most glaring weaknesses. The authors’ entire philosophy of science centers around their model-dependent realism. Model-dependent realism states that no model is better than any other model as long as it agrees with all known observation. Yet, this assertion completely runs against their thesis of replacing God with science. If the scientific view is just one valid interpretation or model among others, how can it exclude other views that also agree with observation? Since God is immaterial, the theory that God created the universe cannot in principle disagree with observation. What could one observe that would lead one to definitively conclude that God does not exist or was not present at the beginning of the creation? Hawking and Mlodinow can argue that it could be “spontaneous creation” but it seems that ex nihilo says exactly the same thing observation-wise with a different model (one with God). In other words, for the book’s thesis to work, it cannot allow alternative models to live peaceably side-by-side but must say that only the “best” model (whatever that may mean) should be taken seriously. They provide criteria to distinguish “good” models from “poor” models, but readily admit the criteria are subjective, and it would be effortless to propose equally subjective criteria wherein the ex nihilo model wins. Again, since it’s trivial to have God not clash with observation, the theistic thesis can never be challenged under model-dependent realism—it's just one more model among many others that agrees with observation.
Even more problematically from a philosophy of science point of view, the authors seem unaware of how complex “agreeing with known observation” is. They lambaste 19th-century scientists who continued to believe in the existence of the ether after an experiment showed that the speed of light is constant. Scientists post-Einstein saw this as evidence against absolute space (an ether), but, pre-Einstein, scientists developed “ad hoc” hypotheses to handle the problem. It’s easy to call these hypotheses ad hoc in hindsight, but at the time there weren’t considered ad hoc at all. And therein lies the problem: how does one know if an experiment truly falsified a theory or if it simply uncovered nuances of that theory? This is no small problem in philosophy of science. Ironically, by appealing to renormalization to account for the discrepancies in Feynman’s theory, the authors appear to appeal to an ad hoc hypothesis themselves. It is simply unfair to criticize the 19th-century scientists for not discontinuing to believe in the ether before Einstein, much like it would be unfair to criticize the authors for appealing to renormalization (at least until a better theory surfaces). An hypothesis can only be pejoratively labeled ad hoc with hindsight.
As for philosophy of religion, there is a great distinction between God as “necessary being” and gravity as a necessary law. In the first case, the sense of “necessary” is logical necessity—it simply cannot be conceived any other way (much like 1 + 1 = 2). However, in the case of gravity, the argument is that no stable universe can exist without a gravity-like law. While this universe would preclude life, it is not a logically impossible universe. Unstable universes are logically possible, along with the other unimaginable number of other universes that cannot support life. So the authors do not really answer the question “why is there something rather than nothing?” Furthermore, if the authors were to argue for a logically necessary law, gravity wouldn’t do the trick—it would need to be quantum mechanics. Why? Because the whole premise is that quantum mechanics (according to Feynman) actualizes all possibilities. If the question “Why does quantum mechanics actualize all possibilities?” is not answered in some logically necessary way, then the question remains open and God can easily creep back into the equation. Even if every possible universe is actualized, it remains fair to ask why the laws of the quantum mechanics are such that it produces multiple universes.
More troubling is that the authors seem to picture God as a human-like being in the sky in the vein of the gods and goddesses of the Greek pantheon. They think that natural law excludes God because it leaves no room for divine agency, but in the Judeo-Christian tradition God is both transcendent and immanent—thus it makes little sense to say that natural law excludes this sort of God. Does natural law exclude a rain god that controls the rain? Sure. Does it exclude a sun god that regulates the sun? Of course. Does it exclude a God who is both beyond the universe and yet closer to the universe than the universe is to itself? It’s difficult to see how. At best, ignoring the fact that model-dependent realism lacks the edge to exclude alternative theories, The Grand Design successfully argues against the anthropomorphic gods and goddesses of old; but no one believes in them anymore anyway.