Is Cosmology a Religion for Atheists? Part 2
January 03, 2016 Time: 20:07
Summary
Dr. Craig delivered a lecture in the UK on a film about Stephen Hawking. He continues his evaluation and some implications concerning the end of the universe!
Transcript Is Cosmology a Religion for Atheists? Part 2
KEVIN HARRIS: Welcome to Reasonable Faith with Dr. William Lane Craig. This is a series on a lecture delivered by Dr. Craig in the U.K. Let’s begin part two. Here’s Dr. Craig.
DR. CRAIG: The second cosmogonic model mentioned in the film is just such an attempt to marry quantum physics to General Relativity to craft a quantum theory of gravity that will enable us to describe the early universe. The so-called “no-boundary” proposal developed by Stephen Hawking in collaboration with James Hartle (who, oddly enough, is never mentioned in the film) is known as the Hartle-Hawking model.
The Hartle-Hawking model eliminates the initial singularity by transforming the conical geometry of classical space-time into a smooth, curved geometry having no edge, so that spacetime resembles a badminton shuttlecock.
This is accomplished by the introduction of imaginary numbers like the square root of -1 for the time variable in Einstein’s gravitational equations, which effectively eliminates the singularity. The laws of physics thus do not break down at any point, allowing a complete description of spacetime.
In his best-selling popularization of his theory, A Brief History of Time, Hawking reveals an explicitly theological concern. He concedes that on the Standard Model one could legitimately identify the Big Bang singularity as the instant at which God created the universe.[1] Indeed, he thinks that a number of attempts to avoid the Big Bang were probably motivated by the feeling that a beginning of time “smacks of divine intervention.”[2] He sees his new model as preferable to the Standard Model because there would be no edge of space-time at which one “would have to appeal to God or some new law.”[3] Hawking sees profound theological implications in the new model. He writes:
The idea that space and time may form a closed surface without boundary . . . has profound implications for the role of God in the affairs of the universe . . . . So long as the universe had a beginning, we could suppose it had a creator. But if the universe is really completely self-contained, having no boundary or edge, it would have neither beginning nor end. What place, then, for a creator?[4]
Hawking does not deny the existence of God, but he does think his model eliminates the need for a Creator of the universe.
In the movie the theological implications of the Hartle-Hawking model are raised in a conversation between Jane, Stephen, and their friend Jonathan:
Jane: Stephen’s done a U-turn. The big new idea is that the universe has no boundaries at all. No boundaries . . . no beginning . . .
Jonathan: . . . And no God . . . Oh . . . Oh I see, I (laughs awkwardly) I thought that, um, you’d proved the universe had a beginning and thus a need for a creator? My mistake.
Stephen: No . . . mine.
Jane: Stephen is looking for a single theory that explains all the forces in the universe. Therefore, God must die.
Jonathan: Er . . . why must God die? I don’t see.
Jane: The two great pillars of physics are Quantum Theory – the laws that govern the very small -- electrons, particles and so on – and General Relativity . . .
Jonathan: . . . Ah, yes, Einstein!
Jane: . . . Einstein’s theory – the laws that govern the very large -- planets and such. But, Quantum and Relativity . . .
Jonathan: . . . don’t tell me . . . they’re different!
Jane: . . . They don’t remotely play by the same rules. If the world were all potatoes then, easy, you can trace a precise beginning, as Stephen once did. A moment of creation . . . Hallelujah, God lives. But if you incorporate peas into the menu then, then it all goes a little . . . Haywire. This all becomes a godless mess.
Jonathan: Oh dear.
Jane: God is back on the Endangered Species list.
Jonathan: (laughs) Well, I expect he’ll cope.[5]
As Jonathan rightly discerned, the theological implications which Hawking seeks to draw from his model are highly suspect. There is no reason at all why God could not have created a universe described by the Hartle-Hawking model. When I spoke personally with James Hartle in his office at UCSB, he saw absolutely no theological implications in the model.
Indeed, by positing a finite (imaginary) time on a closed surface prior to the Planck time rather than an infinite time on an open surface, such a model actually seems to support, rather than undercut, the fact that time and the universe had a beginning. Such a theory, if successful, would enable us to model the beginning of the universe without an initial singularity involving infinite density, temperature, pressure, and so on. But as physicist John Barrow of Cambridge University points out, “This type of quantum universe has not always existed; it comes into being just as the classical cosmologies could, but it does not start at a Big Bang where physical quantities are infinite . . .”[6] Barrow points out that such models are “often described as giving a picture of ‘creation out of nothing’,” the only caveat being that in this case “there is no definite . . . point of creation.”[7]
Hawking’s crucial misstep is his assumption that having a beginning entails having a beginning point. Ancient Greek paradoxes about starting and stopping have long since taught us otherwise. Imagine that a cannonball has a last instant at which it is at rest before being fired from the cannon. In such a case there is no point at which the cannonball first begins to move. For at any point after its final instant of rest, there will be prior instant at which it was already in motion, ad infinitum. Yet no one would say that the cannonball does not have a finite trajectory and a cause of its motion.
Having a beginning does not imply having a beginning point. Time begins to exist just in case for any finite temporal interval you chose, there are only a finite number of equal temporal intervals earlier than it. That condition is fulfilled for the Hartle-Hawking model as well as for the Standard Model.
Moreover, it is far from clear that on any realistic interpretation of the Hartle-Hawking model, it does not in fact have a beginning point. By using the mathematical artifice of imaginary time, Hawking is able to re-describe the universe in such a way that it has no initial singularity. Hawking admits, “Only if we could picture the universe in terms of imaginary time would there be no singularities. . . . When one goes back to the real time in which we live, however, there will still appear to be singularities.”[8] Hawking’s model is thus a way of re-describing a universe with a singular beginning point in such a way that that singularity is transformed away; but it is the same universe with a beginning that is being described. Thus, Quantum Gravity models, like the Standard Model, imply the beginning of the universe.
In his later book The Grand Design, co-authored with Leonard Mlodinow, Hawking himself seems to endorse this interpretation of his model. The authors write,
Suppose the beginning of the universe was like the South Pole of the earth, with degrees of latitude playing the role of time. As one moves north, the circles of constant latitude, representing the size of the universe, would expand. The universe would start as a point at the South Pole, but the South Pole is much like any other point. To ask what happened before the beginning of the universe would become a meaningless question, because there is nothing south of the South Pole.[9] In this picture space-time has no boundary—the same laws of nature hold at the South Pole as in other places (pp. 134-5).
This passage is fascinating because it represents a rather different interpretation of the model than what we had in A Brief History of Time.
Let me explain. In his model Hawking employs imaginary numbers (like the square root of -1) for the time variable in his equations in order to get rid of the initial cosmological singularity, which is the boundary of spacetime in the standard Big Bang model. The initial segment of spacetime, instead of terminating in a point (like a cone), is “rounded off” (like a badminton shuttlecock). The “South Pole” of this rounded off surface is like any other point on that surface (hence, the idea that there is “no boundary” or edge). Since “imaginary time” behaves like a dimension of space, Hawking interpreted his “no-boundary” universe to “just BE.”
But in The Grand Design the South Pole is interpreted to represent the beginning point to both time and the universe. Hawking allows the circles of latitude to play the role of time, which has a beginning point at the South Pole. When Hawking speaks of “the problem of time having a beginning,” what he means is “the age-old objection to the universe having a beginning” (p. 135), an objection which his model removes. So what is that age-old objection? That objection, he says, is the question, “What happened before the beginning of the universe?” Hawking is right that this question is meaningless on his model; but what he fails to mention is that the question is also meaningless on the standard Big Bang model, since there is nothing prior to the initial cosmological singularity. On either model the universe has an absolute temporal beginning, so that it is meaningless to ask what happened before.
Rather the real question is, why did the universe begin to exist? The Hartle-Hawking model doesn’t address that question. How could it? Physics only begins at the “South Pole” in the no-boundary model. There is no physics of non-being. Moreover, there isn’t anything in the model that implies that that point came to be without a cause. Indeed, the idea that being could arise without a cause from non-being seems to be metaphysically absurd.
Thus, both the standard model and the Hartle-Hawking quantum gravity model are united in predicting the finitude of the past and the beginning of the universe, and Hawking’s inferences about the theological implications of the model are based on philosophical mistakes. It is sad that so gifted a scientist should have been misled by such philosophical missteps. Both models are thus perfectly in accord with the Judeo-Christian doctrine of creation out of nothing.
I mentioned that physical eschatology makes scant appearance in the film The Theory of Everything. It comes only in the poignant, penultimate scene of the movie. Hawking is asked, “You have said that you do not believe in God. Do you have a philosophy of life that helps you?” He answers by appealing to the religion of cosmology:
It is clear that we are just an advanced breed of primates on a minor planet, orbiting around a very average star, in the outer suburb of one among a hundred billion galaxies. But, ever since the dawn of civilization, people have craved for an understanding of the underlying order of the world. There ought to be something very special about the boundary conditions of the universe. But what can be more special than that there is no boundary? And there should be no boundary to human endeavor. We are all different. However bad life may seem, there is always something you can do and succeed at.[10] While there is life, there is hope.
Yes, applause for this remarkable man’s courage and perseverance in the face of almost impossible obstacles. But even if it were true that while there is life, there is hope, the lesson of physical eschatology is that, absent God, there will someday be no life and, hence, no hope. Already in the nineteenth century, scientists realized that the application of the Second Law of Thermodynamics to the universe as a whole implied a grim eschatological conclusion: given sufficient time, the universe will eventually suffer “heat death.” Yale University astronomer Beatrice Tinsley described the fate of an expanding universe:
If the universe has a low density, its death will be cold. It will expand forever at a slower and slower rate. Galaxies will turn all of their gas into stars, and the stars will burn out. Our own sun will become a cold, dead remnant, floating among the corpses of other stars in an increasingly isolated Milky Way.[11]
Elementary particle physics suggests that thereafter protons will decay into electrons and positrons, so that space will be filled with a rarefied gas so thin that the distance between an electron and a positron will be about the size of the present galaxy. Eventually all black holes will completely evaporate and all the matter in the ever-expanding universe will be reduced to a thin gas of elementary particles and radiation. There is no hope of a reversal of this descent into oblivion. The universe will inevitably become increasingly cold, dark, dilute, and dead.
Reflection on this eschatological conclusion has led some philosophers to question the meaning of life itself. In a famous passage, the British philosopher Bertrand Russell lamented,
That man is the product of causes which had no prevision of the end they were achieving; that his origin, his growth, his hopes and fears, his loves and his beliefs, are but the outcome of accidental collocations of atoms; that no fire, no heroism, no intensity of thought and feeling, can preserve an individual life beyond the grave; that all the labours of the ages, all the devotion, all the inspiration, all the noonday brightness of human genius, are destined to extinction in the vast death of the solar system, and that the whole temple of Man’s achievement must inevitably be buried beneath the debris of a universe in ruins -- all these things, if not quite beyond dispute, are yet so nearly certain, that no philosophy which rejects them can hope to stand. Only within the scaffolding of these truths, only on the firm foundation of unyielding despair, can the soul’s habitation henceforth be safely built.[12]
Russell’s keen philosophical mind saw more clearly than Hawking the correct implications of a godless universe.
Russell, however, was unaware of the evidence for a beginning of the universe and thus of the need for a cosmic Creator. When asked to explain the existence of the universe, Russell replied, “The universe is just there, and that’s all.” This response is understandable on a pre-Einsteinian view of the universe, but it becomes inept when confronted with the fact of the universe’s temporal beginning. Such a beginning points beyond the universe to its ground in a transcendent Creator. If such a Creator does exist, then he offers the best hope of deliverance from the somber implications of physical eschatology.
KEVIN HARRIS: Thank you so much for joining us. We’ll pick it up there next time where we will begin with some very probing questions from the audience. You’ll hear not only some great answers from Dr. Craig, but you’ll also hear how diverse the audience was who attended this event. That is next time on Reasonable Faith with Dr. William Lane Craig.[13]
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[1]
[13]Stephen Hawking, A Brief History of Time (New York: Bantam Books, 1988), p. 9.
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[2]
Ibid., p. 46.
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[3]
Ibid., p. 136.
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[4]
Ibid., p. 140-1.
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[5]
5:02
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[6]
John D. Barrow, Theories of Everything (Oxford: Clarendon Press, 1991), p. 68.
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[7]
Ibid., pp. 67-68.
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[8]
Hawking, A Brief History of Time, pp. 138-9.
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[9]
10:08
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[10]
15:05
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[11]
Tinsley, “Big Bang,” p. 105.
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[12]
Bertrand Russell, “A Free Man’s Worship.”
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[13]
Total Running Time: 20:09 (Copyright © 2016 William Lane Craig)