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The Kalam Cosmological Argument

William Lane Craig

...I find the kalam cosmological argument for a temporal first cause of the universe to be the most plausible argument for God’s existence. I have defended this argument in two books, The Kalam Cosmological Argument and The Existence of God and the Beginning of the Universe. Let me explain and supplement what I say there. The argument is basically this: both philosophical reasoning and scientific evidence show that the universe began to exist. Anything that begins to exist must have a cause that brings it into being. So the universe must have a cause. The argument may be formulated in three simple steps:

         - Whatever begins to exist has a cause.

         - The universe began to exist.

         - Therefore, the universe has a cause.

The logic of the argument is valid and very simple: it is the same as when we reason, “All men are mortal; Socrates is a man; therefore, Socrates is mortal.” So the question is, are there good reasons to believe that each of the steps is true? I think there are.

Whatever Begins to Exist Has a Cause

The first step is so intuitively obvious that I think scarcely anyone could sincerely believe it to be false. I therefore think it somewhat unwise to argue in favor of it, for any proof of the principle is likely to be less obvious than the principle itself. And as Aristotle remarked, one ought not to try to prove the obvious via the less obvious. The old axiom that “out of nothing, nothing comes” remains as obvious today as ever. In a sense, I find it an attractive feature of this argument that it allows the atheist a way of escape; he can always deny the first premise and assert that the universe sprang into9 existence uncaused out of nothing. For he thereby exposes himself as a man interested only in an academic refutation of the argument and not in really discovering the truth about the universe.

The late J.L. Mackie appears to have been such a man. In refuting the kalam cosmological argument, he turns his main guns on this first step: “there is a priori no good reason why a sheer origination of things, not determined by anything, should be unacceptable, whereas the existence of a god [sic] with the power to create something out of nothing is acceptable.” 1 Indeed, creation ex nihilo raises problems: (i) If God began to exist at a point in time, then this is as great a puzzle as the beginning of the universe. (ii) Or if God existed for infinite time, then the same arguments would apply to His existence as would apply to the same arguments would apply to His existence as would apply to the infinite duration of the universe. (iii) If it be said that God is timeless, then this, says Mackie, is a complete mystery.

Now notice that Mackie never refutes the principle that whatever begins to exist has a cause. Rather, he simply demands what good reason there is a priori to accept it. He writes, “As Hume pointed out, we can certainly conceive an uncaused beginning-to-be of an object; if what we can thus conceive is nevertheless in some way impossible, this still requires to be shown.” 2 But, as many philosophers have pointed out, Hume’s argument in no way makes it plausible to think that something could really come into being without a cause. Just because I can imagine an object, say a horse, coming into existence from nothing, that in no way proves that a horse really could come into existence that way. The defender of the kalam argument is claiming that it is really impossible for something to come uncaused from nothing. Does Mackie sincerely believe that things can pop into existence uncaused, out of nothing? Does anyone in his right mind really believe tht, say a raging tiger could suddenly come into existence uncaused, out of nothing in this room right now? The same applies to the universe: if there were originally absolute nothingness–no God, no space, no time–how could the universe possibly come to exist?

In fact Mackie’s appeal to Hume at this point is counterproductive. For Hume himself clearly believed in the causal principle. In 1754 he wrote to John Stewart, “But allow me to tell you that I never asserted so absurd a Proposition as that anything might arise without a cause: I only maintain’d, that our Certainty of the Falsehood of that Proposition proceeded neither from Intuition nor Demonstration, but from another source.”3 Even Mackie confesses, “Still this [causal] principle has some plausibility, in that it is constantly confirmed in our experience (and also used, reasonably, in interpreting our experience.)4 So why not accept the truth of the causal principle as plausible and reasonable–at the very least more so than its denial?

Because, Mackie thinks, in this particular case the theism implied by affirming the principle is even more unintelligible than the denial of the principle. But is this really the case? Certainly the proponent of the kalam argument would not hold (I) tht God began to exist or (ii) that God is, prior to creation, timeless? I would argue that God exists timelessly prior to creation and in time subsequent to creation. This may be “mysterious” in the sense of “wonderful” or “awe-inspiring,” but it is not, so far as I can see, unintelligible; and Mackie gives us no reason to think that it is. It seems to me, therefore, that Mackie is entirely unjustified in rejecting the first step of the argument as not intuitively obvious, implausible, and unreasonable.

The Universe Began to Exist

I we agree that whatever begins to exist has a cause, what evidence is there to support the crucial second step in the argument, that the universe began to exist? I think that this step is supported by both philosophical arguments and scientific confirmation of those arguments.

Philosophical Arguments

Argument from the impossibility of an actually infinite number of things. An actually infinite number of things cannot exist, because this would involve all sorts of absurdities, which I shall illustrate in a moment. And if the universe never had a beginning, then the series of all past events is actually infinite. That is to say, an actually infinite number of past events exists. Because an actually infinite number of things cannot exist, then an actually infinite number of past events cannot exist. The number of past events is finite, therefore the series of past events had a beginning. Since the history of the universe is identical to the series of all past events, the universe must have begun to exist. This argument can also be formulated in three steps:

         - An actually infinite number of things cannot exist.

         - A beginningless series of events in time entails an actually infinite number of things.

         - Therefore, a beginningless series of events in time cannot exist.

Let us examine each step together.

An actually infinite number of things cannot exist. In order to understand this first step, we need to understand what an actual infinite is. There is a difference between a potential infinite and an actual infinite. A potential infinite is a collection that is increasing toward infinity as a limit but never gets there. Such a collection is really indefinite, not infinite. An actual infinite is a collection in which the number of members really is infinite. The collection is not growing toward infinity; it is infinite, it is “complete.” This sort of infinity is used in set theory to designate sets that have an infinite number of members, such as {1,2,3...}. Now I am arguing, not that a potentially infinite number of things cannot exist, but that an actually infinite number of things cannot exist. For if an actually infinite number of things could exist, this would spawn all sorts of absurdities.

Perhaps the best way to bring this home is by means of an illustration. Let me use on of my favorites, Hilbert’s Hotel, a product of the mind of the great German mathematician David Hilbert. 5 Let us imagine a hotel with a finite number of rooms. Suppose, furthermore, that all the rooms are full. When a new guest arrives asking for a room, the proprietor apologizes, “Sorry, all the rooms are full.” But now let us imagine a hotel with an infinite number of rooms and suppose once more that all the rooms are full. There is not a single vacant room throughout the entire infinite hotel. Now suppose a new guest shows up, asking for a room. “But of course!” says the proprietor, and he immediately shifts the person in room #1 into room #2, the person in room #2 into room #3, the person in room #3 into room #4, and so on, out to infinity. As a result of these room changes, room #1 now becomes vacant and the new guest gratefully checks in. But remember, before he arrived, all the rooms were full! Equally curious, according to the mathematicians, there are now no more persons in the hotel than there were before: the number is just infinite. But how can this be? The proprietor just added the new guest’s name to the register and gave him his keys–how can there not be one more person in the hotel than before? But the situation becomes even stranger. For suppose an infinity of new guests show up at the desk, asking for a room. “Of course, of course!” says the proprietor, and he proceeds to shift the person in room #1 into room #2, the person in room #2 into room #4, the person in room #3 into room #6, and so on out to infinity, always putting each former occupant into the room number twice his own. As a result, all the odd numbered rooms become vacant, and the infinity of new guests is easily accommodated. And yet, before they came, all the rooms were full! And again, strangely enough, the number of guests in the hotel is the same after the infinity of new guests check in as before, even though there were as many new guests as old guests. In fact, the proprietor could repeat this process infinitely many times and yet there would never be one single person more in the hotel than before.

But Hilbert’s Hotel is even stranger than the German mathematician made it out to be. For suppose some of the guests start to check out. Suppose the guest in room #1 departs. Is there not now one less person in the hotel? Not according to the mathematicians–but just ask the woman who makes the beds! Suppose the guests in rooms ##1,3,5,... In this case an infinite number of people have left the hotel, but according to the mathematicians there are no less people in the hotel–but don’t talk to that laundry woman! In fact, we could have every other guest check out of the hotel and repeat this process infinitely many times, and yet there would never be any less people in the hotel. But suppose that the persons in rooms ##4,5,6,...checked out. At a single stroke the hotel would be virtually emptied, the guest register would be reduced to three names, and the infinite would be converted to finitude. And yet it would remain true that the same number of guests checked out this time as when the guests in rooms ##1,3,5...checked out. Can anyone believe that such a hotel could exist in reality?

Hilbert’s Hotel is absurd. As one person remarked, if Hilbert’s Hotel could exist, it would have to have a sign posted outside: NO VACANCY–GUESTS WELCOME. The above sorts of absurdities show that it is impossible for an actually infinite number of things to exist. There is simply no way to avoid these absurdities once we admit the possibility of the existence of an actual infinite. William J. Wainwright had suggested that we could reduce the force of these paradoxes by translating them into mathematical terms; for example, an actually infinite set has a proper subset with the same cardinal number as the set itself. 6 But this amounts only to a way of concealing the paradoxes; it was to bring out the paradoxical character of these mathematical concepts that Hilbert came up with his illustration in the first place. And the whole purpose of philosophical analysis is to bring out what is entailed by unanalyzed notions and not to leave them at face value.

But does the possibility of an actual infinite really entail that such absurdities are possible, or could an actual infinite be possible, as Wainwright suggests, without thereby implying that such absurdities are possible? The answer to that question is simple: the possibility of the existence of an actual infinite entails, that is, necessarily implies, that such absurdities could exist. Hilbert’s illustration merely serves to bring out in a practical and vivid way what the mathematics necessarily implies; for if an actual infinite number of things is possible, then a hotel with an actually infinite number of rooms is impossible, then so is the real existence of an actual infinite.

These considerations also show how superficial Mackie’s analysis of this point is.7 He thinks that the absurdities are resolved by noting that for infinite groups the axiom that the whole is greater than its part does not hold, as it does for finite groups. But far from being the solution, this is precisely the problem. Because in infinite set theory this axiom is denied, one gets all sorts of absurdities, like Hilbert’s Hotel, when one tries to translate that theory into reality. Hence, I conclude that an actually infinite number of things cannot exist.

A beginningless series of events in time entails an actually infinite number of things. This second point is pretty obvious. If the universe never began to exist, then the series of events would be infinite. If the universe never began to exist, then prior to the present there have existed an actually infinite number of previous events. Thus, a beginningless series of events in time entails an actually infinite number of things, namely, events.

Therefore, a beginningless series of events in time cannot exist. If the above two premises are true, then the conclusion follows logically. The series of past events must be finite and have a beginning. Since, as I said, the universe is not distinct from the series of events, the universe therefore began to exist.

Argument from the impossibility of forming an actually infinite collection of things by adding one member after another. It is very important to note that this argument is distinct from the foregoing argument [Argument from the impossibility of an actually infinite number of things], for it does not deny that an actually infinite number of things can exist. It denies that a collection containing an actually infinite number of things can be formed by adding one member after another. Basically, the argument goes like this: you cannot form an actually infinite collection of things by adding one member after another because it would be impossible to get to infinity. The series of past events is a collection that has been formed by adding one event after another. Therefore, the series of past events up till now can only be finite, not infinite. Otherwise, it would be an actually infinite collection formed by adding one member after another. This argument, too, can be formulated in three steps:

         - The series of events in time is a collection formed by adding one member after another.

         - A collection formed by adding one member after another cannot be actually infinite.

         - Therefore, the series in time cannot be actually infinite.

Let us take a look at each step.

The series of events in time is a collection formed by adding one member after another. This is the crucial step. It is important to realize that this impossibility has nothing to do with the amount of time available: no matter how much time one has available, an actual infinite cannot be formed.

Now someone might say that while an infinite collection cannot be formed by beginning at a point and adding members, nevertheless an infinite collection could be formed by never beginning but ending at a point, that is to say, ending at a point after having added one member after another from eternity. But this method seems even more unbelievable that then first method. If one cannot count to infinity, how can one count down from infinity? If one cannot traverse the infinite by moving in one direction, how can one traverse it by moving in the opposite direction?

Indeed, the idea of a beginningless series ending in the present seems absurd. To give just one illustration: suppose we meet a man who claims to have been counting from eternity and who is now finishing: . . ., -3, -2, -1, -0. We could ask, why didn’t he finish counting yesterday, or the day before or the year before? By then an infinite time had already elapsed, so that he should already have finished by then. Thus, at no point in the infinite past could we ever find the man finishing his countdown, for by that point he should already be done! In fact, no matter how far back into the past we go, we can never find the man counting at all, for at any point we reach he will already have finished. But if at no point in the past do we find him counting, this contradicts the hypothesis that he has been counting from eternity. This illustrates that the formation of an actual infinite by never beginning but reaching an end is as impossible as beginning at a point and trying to reach infinity.

Hence, set theory has been purged of all temporal concepts; as Russell says, “classes which are infinite are given all at once by the defining properties of their members, so that there is no question of `completion’ or of `successive synthesis.’” 8 The only way an actual infinite could come to exist in the real world would be by being created all at once, simply in a moment. It would be a hopeless undertaking to try to form it by adding one member after another.

Mackie’s objections to this step are off the target. 9 He thinks that the argument illicitly assumes an infinitely distant starting point in the past and then pronounces it impossible to travel from that point to today. If we take the notion of infinity “seriously” he says, we must say that in the infinite past there would be no starting point whatever, not even infinitely distant one. Yet from any given point in the past, there is only a finite distance to the present.

Now I know of no proponent of the kalam argument who assumed that there was an infinitely distant starting point in the past. On the contrary, the beginningless character of the series of past events only serves to underscore the difficulty of its formation by adding one member after another. The fact that there is no beginning at all, not even an infinitely distant one, makes the problem worse, not better. It is not the proponent of the kalam argument who fails to take infinity seriously. To say the infinite past could have been formed by adding one member after another is like saying someone has just succeeded in writing down all the negative numbers, ending at -1. And, we may ask, how is Mackie’s point that from any given moment in the past there is only a finite distance to the present even relevant to the issue? The defender of the kalam argument could agree to this without batting an eye. For the issue is how the whole series can be formed, not a finite portion of it. Does Mackie think that because every finite segment of the series can be formed by adding one member after another that the whole infinite series can be so formed? That is as logically fallacious as saying because every part of an elephant is light in weight, the whole elephant is light of the argument, that an actually infinite collection cannot be formed by adding one member after another, remains unrefuted.

Therefore, the series of events in time cannot be actually infinite. Given the truth of the premises, the conclusion logically follows. If the universe did not begin to exist a finite time ago, then the present moment would never arrive. But obviously, it has arrived. Therefore, we know that the universe is finite in the past and began to exist.

We thus have two separate arguments to prove that the universe began to exist, one based on the impossibility of an actually infinite number of things and one on the impossibility of forming an actually infinite collection by successive addition. If one wishes to deny the beginning of the universe, he must refute, not one, but both of these arguments.

Scientific confirmation. Now some people find philosophical arguments difficult to follow; they prefer empirical evidence. So I should now like to turn to an examination of two remarkable scientific confirmations of the conclusion already reached by philosophical argument alone. This evidence comes from what is undoubtedly one of the most exciting and rapidly developing fields of science: astronomy and astrophysics.

Confirmation from the big-bang model of the universe.

The big-bang model. Prior to the 1920s, scientists had always assumed that the universe was stationary. But in 1929 an alarming thing happened. An astronomer named Edwin Hubble discovered that the light from distant galaxies appears to be redder than it should. The startling conclusion to which Hubble was led was that the light is redder because the universe is growing apart; it is expanding! The light from the stars is affected because they are moving away from us. But this is the interesting part: Hubble not only showed that the universe is expanding, but that it is expanding the same in all directions. To get a picture of this, imagine a balloon with dots painted on it. As you blow up the balloon, the dots get farther and farther apart. Now those dots are just like the galaxies in space. Everything in the universe is expanding outward. The staggering implication of this is that at some point in the past the entire known universe was contracted down to a single mathematical point, from which it has been expanding ever since. The farther back one goes in the past, the denser the universe becomes, so that one finally reaches a point of infinite density from which the universe began to expand. That initial event has come to be known as the “big bang.”

How long ago did the big bang occur? Only since the 1970s have accurate estimates become available. In a very important series of six articles published in 1974 and 1975, two scientist, Allan Sandage and G.A. Tammann, estimated that the big bang occurred about 15 billion years ago. More recent studies conducted at Harvard University suggest that it may have occurred only nine billion years ago. Therefore, according to the big-bang theory the universe began to exist with a great explosion from a state of infinite density about 9-15 billion years ago. Four of the world’s most famous astronomers describe that event in these words:

The universe began from a state of infinite density....Space and time were created in that event and so was all the matter in the universe. It is not meaningful to ask what happened before the Big Bang; it is like asking what is north of the North Pole. Similarly, it is not sensible to ask where the Big Bang took place. The point-universe was not an object isolated in space; it was the entire universe, and so the only answer can be that the Big Bang happened everywhere.9

Thus, the term big bang and the terminology associated with an explosion can be misleading, because it is not correct to suppose that the expansion can be visualized from the outside. There is no external vantage point from which the expansion could be observed because what is expanding is the entire universe. Space itself is expanding in the sense that the separation between any two galaxies grows with time.

The event that marked the beginning of the universe becomes all the more amazing when one reflects on the fact that a state of “infinite density” is synonymous to “nothing.” There can be no object that possesses infinite density, for if it had any size at all, it could be even more dense. Therefore, as astronomer Fred Hoyle points out, the big-bang theory requires the creation of matter from nothing. This is because as one goes back in time, one reaches a point at which, in Hoyle’s words, the universe was “shrunk down to nothing at all.”11 Thus what the big-bang model requires is that the universe had a beginning and was created out of nothing.

Now some people were deeply disturbed with the idea that the universe began from nothing.12 That is too close to the Christian doctrine of creation to allow atheistic minds to be comfortable. Einstein wrote privately, “This circumstance of an expanding universe irritates me....To admit such possibilities seems senseless.” Another scientist, Arthur Eddington, wrote, “I have no axe to grind in this discussion, but the motion of a beginning is repugnant to me....I simply do not believe that the present order of things started off with a bang....The expanding universe is preposterous...incredible...It leaves me cold.” The German chemist Walter Nernst declared, “To deny the infinite duration of time would be to betray the very foundations of science.” Phillip Morrison of the Massachusetts Institute of Technology said, “I find it hard to accept the Big Bang theory; I would like to reject it, but I have to face the facts.”

Alternative models. But if one rejects the big-bang model, he has only two alternative theories; the steady-state model or the oscillating model. Let us examine each of these.

The steady-state model. The steady-state model holds that the universe never had a beginning but has always existed in the same state. Ever since this model was first proposed in 1948, it has never been very convincing. According to S.L. Jaki, this theory never secured “a single piece of experimental verification.” It always seemed to be trying to explain away the facts rather than explain them. According to Jaki, the proponents of this model were actually motivated by “openly anti-theological, or rather anti-Christian motivations.”13

Against this theory is the fact that a count of galaxies emitting radio waves indicates that there were once more radio sources than there are today. Therefore, the universe is not in a steady state after all. But the theory was decisively discredited when in 1965 A.A. Penzias and R.W. Wilson discovered that the entire universe is bathed with a background of microwave radiation. This radiation background shows that the universe was once in a very hot and very dense state. In the steady state model no such state could have existed, since the universe is supposed to be the same from eternity. Therefore, the steady state model has been abandoned by virtually everyone. According to Ivan King, “The steady-state theory has now been laid to rest, as a result of clear-cut observations of how things have changed with time.”14

The oscillating model. John Gribbin describes this model:

The biggest problem with the Big Bang theory of the origin of the universe is philosophical–perhaps even theological–what was there before the bang? This problem alone was sufficient to give a great initial impetus to the steady state theory; but with that theory now sadly in conflict with the observations, the best way round this initial difficulty is provided by a model in which the universe expands, collapses back again, and repeats the cycle indefinitely.15

According to this model, the universe is sort of like a spring, expanding and contracting from eternity. This model has become a sort of “Great White Hope” for atheistic scientists, who terribly want it to be true so as to avoid an absolute beginning of the universe. You may have seen Carl Sagan, for example, in his popular “Cosmos” program on public television propounding this model and reading from the Hindu scriptures about cyclical Brahman years in order to illustrate the oscillating universe. There are, however, at least two very well-known difficulties with the oscillating model, which Sagan did not mention.

First, the oscillating model is physically impossible. That is to say, for all the talk about such a model, the fact remains that it is only a theoretical possibility, not a real possibility. You can draft such models on paper, but they cannot be descriptive of the real universe because they contradict the known laws of physics. As the late Professor Tinsley of Yale explains, in oscillating models

even though the mathematics says that the universe oscillates, there is no known physics to reverse the collapse and bounce back to a new expansion. The physics seems to say that those models start from the Big Bang, expand, collapse, then end.” 16 More recently four other scientists, themselves obviously in sympathy with the oscillating model, admitted, in describing the contraction of the universe, “The major difficulty for the bounce model is to understand how an extraordinarily inhomogeneous...universe of isolated, coalescing black holes can be smoothed out [after the bounce]; for that matter, there is no understanding of how a bounce can take place.... We have nothing to contribute to the question of whether and/or how the universe bounces.”17 In order for the oscillating model to be correct, the known laws of physics would have to be revised.

Second, the observational evidence is contrary to the oscillating model. Let me explain two respects in which the observational evidence does not support the oscillating model. The first was alluded to in the quotation just cited, namely, there is no way to account for the observed even distribution of matter in the universe on the basis of an oscillating model. This is because as the universe contracts, black holes begin to suck everything up, so that matter becomes very unevenly distributed. But when the universe supposedly rebounds from its contracting phase, there is no mechanism to “iron out” these lumps and make the distribution smooth. Hence, the scientists cited above confess that even if there is some unknown mechanism that could cause the universe to bound back to a new expansion, it is still not clear that it would prevent the unevenness that would result from the black holes formed during the contraction phase. 18 The present evenness of matter universe begins with matter unevenly distributed. 19 The oscillating model therefore cannot satisfactorily account for the presently observed evenness of the distribution of matter in the universe.

A second respect in which the observational evidence is contrary to the oscillating model concerns the question of whether the universe is “open” or “closed.” If the universe is closed, that means that the expansion will reach a certain point, halt, and then gravity will pull everything back together again. But if the universe is open, that means that the force of the expansion is greater than the force of gravity, so that the expansion will never stop but will just go on and on forever. An illustration of this difference concerns the escape velocity needed by a rocket to escape earth’s gravity. If a certain speed is not attained, the force of gravity will pull the ship back to earth again. But if the rocket attains or exceeds escape

velocity, then the force of the earth’s gravity cannot prevent its flying off into space. Similarly, if the universe is expanding, so to speak, at escape velocity or faster, then it will overcome the internal pull of its own gravity and will expand forever. Now clearly, the oscillating model, even in order to be a possibility, must posit a closed universe, one that is expanding slower than escape velocity. But is it?

The crucial factor in answering that question is the density of the universe. For density determines the gravitational force of an object. Scientists have estimated that if there are more than about three hydrogen atoms per cubic meter on the average throughout the universe, then the universe will be closed. Now that may not sound like very much, but remember that most of the universe is just empty space. The scientific evidence up to the time of writing my earlier works on this subject indicated that the universe would have to be about ten times denser than it is in order for the universe to be closed. Since that time, however, scientists have embarked on a quest to find the “missing mass” needed to close the universe, and have discovered more mass in the universe than was previously known. A halo of non-luminous matter (matter that does not give light) has been discovered surrounding our galaxy. This halo is one to two times the mass of the galaxy itself. The non-luminous matter associated with each of the galaxies might supply an additional 5 to 10 percent of the mass needed to close the universe. Clusters of galaxies may also have associated with them additional halos of non-illuminous material were in the form of ordinary matter, “standard big-bang nucleosynthesis calculations would be in gross conflict with observation.... This is not the case if the missing mass were in the form of massive neutrinos.” 20 This had led to the hypothesis that the non-illuminous material may actually be neutrinos. If that is the case, however, light neutrinos with a mass of four electron volts or less would not have been pulled into galactic halos. On the other hand, heavy neutrinos with a mass of 20 electron volts or more could have been pulled into such halos, but then there would be more non-luminous mass than there actually is. Hence, only neutrinos with a mass between 4 and 20 electron volts could supply the non-luminous mass around groups and clusters of galaxies. But if Stecker and Brown’s estimates are correct, this is insufficient mass to close the universe.

Therefore, Schramm and Steigman calculate, that after adding up the contributions of ordinary matter, heavy neutrinos, and light neutrinos, the best estimate for the density of the universe is that it is about one-half needed for closure. 21 And remember, this assumes that unknown “heavy” neutrinos exist and that neutrinos have mass. Physicist James Trefil reports in a recent article,

A few years ago...it appeared that the neutrino...might have a small mass after all. Cosmologists have speculated that if such were the case, there might be enough invisible mass in the form of neutrinos to close the universe.... Unfortunately, a new generation of experiments has weakened the evidence, and the question of what, if anything, will provide the unseen mass remains unanswered.22

Therefore, although we await eagerly further developments in this area, it does not seem that neutrinos suffice to close the universe.

I might mention, too, that further work on the speed of the expansion re-confirms previous evidence that the universe is expanding at escape velocity and will therefore not re-contract. The findings of Sandage and Tammann still stand: “Hence, we are forced to decide that...it seems inevitable that the Universe will expand forever.” Therefore, they conclude, “the Universe has happened only once.” 23

The oscillating model, therefore, is seriously flawed. It contradicts both the known laws of physics and the current observational evidence. It therefore provides no plausible escape from the beginning of the universe.

Confirmation from thermodynamics. Now if this were not enough, there is a second scientific confirmation for the beginning of the universe, the evidence from thermodynamics. According to the second law of thermodynamics, processes taking place in a closed system always tend toward a state of equilibrium. In other words, unless energy is constantly being fed into a system, the processes in the system will tend to run down and quit. For example, if I had a bottle that was a sealed vacuum inside, and I introduced into it some molecules of gas, the gas would spread itself out evenly inside the bottle. It is virtually impossible for the molecules to retreat, for example, into one corner of the bottle and remain. This is why when you walk into a room, the air in the room never separates suddenly into oxygen at one end and nitrogen at the other. It is also why when you step into your bath you may be confident that it will be an even temperature instead of frozen solid at one end and boiling at the other. It is clear that life would not be possible in a world in which the second law of thermodynamics did not operate.

Heat death of the universe. Now our interest in the law is what happens when it is applied to the universe as a whole. The universe is a gigantic closed system (closed in the thermodynamic sense, not in the sense of expansion and re-contraction), since it is everything there is and there is nothing outside it. What this seems to imply then is that, given enough time, the universe and all its processes will run down, and the entire universe will come to equilibrium. This is known as the heat death of the universe. Once the universe reaches this state, no further change is possible. The universe is dead.

“Hot” death. There are two possible types of heat death for the universe. If the universe is “closed,” it will die a hot death. Dr. Tinsley describes such a state:

If the average density of matter in the universe is great enough, the mutual gravitational attraction between bodies will eventually slow the expansion to a halt. The universe will then contract and collapse into a hot fireball. There is no known physical mechanism that could reverse a catastrophic big crunch. Apparently, if the universe becomes dense enough, it is in for a hot death.24

If the universe is closed, then as it contracts the stars gain energy, causing them to burn more rapidly so that they finally explode or evaporate. As everything in the universe grows closer together, the black holes begin to gobble up everything around them, and eventually begin themselves to coalesce. In time, “All the black holes finally coalesce into one large black hole that is coextensive with the universe,”25 from which the universe will never re-emerge.

“Cold “ death. But suppose, as is more likely, that the universe is “open.” Dr. Tinsley describes the final state of this 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.26

At 1030 years the universe will consist of 90 percent dead stars, and 9 percent supermassive black holes formed by the collapse of galaxies, and 1 percent atomic matter, mainly hydrogen. 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. At 10100 years, some scientist believe that the black holes themselves will dissipate by a strange effect predicted by quantum mechanics. The mass and energy associated with a black hole so warp space that they are said to create a “tunnel” or “worm-hole” through which the mass and energy are ejected in another region of space. As the mass of a black hole decreases, its energy loss accelerates, so that it is eventually dissipated into radiation and elementary particles. 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. Equilibrium will prevail throughout, and the entire universe will be in its final state, from which no change will occur.

Now the question that needs to be asked is this: if given enough time the universe will reach heat death, then why is it not in a state of heat death now if it has existed forever, from eternity? If the universe did not begin to exist, then it should now be in a state of equilibrium. Its energy should be all used up. My wife and I have a very loud wind-up alarm clock. If I hear that the clock is ticking–which is no problem, believe me–then I know that at some point in the recent past it was wound up and has been running down since then. It is the same with the universe. Since it has not yet run down, this means, in the words of one baffled scientist, “In some way the universe must have been wound up.”

Oscillating model. Some scientists have tried to escape this conclusion by arguing that the universe oscillates back and forth from eternity, and so never reaches a final state of equilibrium. Now I have already observed that such a model of the universe is a physical impossibility. But suppose it were possible. The fact is that the thermodynamic properties of this model imply the very beginning of the universe that its proponents seek to avoid. For as several scientists have pointed out, each time the model universe expands it would expand a little farther than before. Therefore, if you traced the expansions back in time they would get smaller and smaller and smaller. One scientific team explains “The effect of entropy production will be to enlarge the cosmic scale, from cycle to cycle.... Thus, looking back in time, each cycle generated less entropy, had a smaller cycle time, and had a smaller cycle expansion factor then [sic] the cycle that followed it.” 27 therefore, in the words of another scientific team, “the multicycle model has an infinite future, but only a finite past.”28 As another writer points out, this implies that the oscillating model of the universe still requires an origin of the universe prior to the smallest cycle.29

So whether you choose a closed model, an open model, or an oscillating model, thermodynamics implies that the universe had a beginning. According to the English scientist P.C.W. Davies, the universe must have been created a finite time ago and is in the process of winding down. Prior to the creation, the universe simply did not exist. Therefore, Davies concludes, even though we may not like it, we must conclude that the universe’s energy was somehow simply “put in” at the creation as an initial condition.30

So we have two scientific confirmations that the universe began to exist. First, the expansion of the universe implies the universe had a beginning. Second, thermodynamics shows the universe began to exist.

God and the astronomers. But that brings us back full circle to Leibniz’s question: Why? It is futile to say the universe just exists and never had a beginning, for that is contrary to all the evidence. Now this is very embarrassing for atheistic scientists. When I was at the 16th World Congress on Philosophy in Dusseldorf in 1978, I found that the only scientists who opposed the big-bang theory were Marxists from communist nations. They were committed to the doctrine of materialism and had to maintain, in spite of and contrary to all the evidence, that the universe was eternal. They could not explain away the evidence; rather they accepted the eternity of the universe by faith. Never before had I so clearly seen the religious nature of Marxist beliefs.

But if we are honest and accept that the universe did begin to exist, how are we to explain it? The atheist has no explanation. As Anthony Kenny of Oxford University urges, “a proponent of the Big Bang theory, at least if he is an atheist, must believe that the matter of the universe came from nothing and by nothing.”31

Because of this, most scientists simply ignore the question. Fred Hoyle explains that the big-bang theory cannot explain either where matter came from or why the big bang occurred. Then he comments, “It is not usual in present day cosmological discussions to seek an answer to this question; the question and its answer are taken to be outside the range of scientific discussion.”32 Another scientist admits that the big-bang theory only describes the initial conditions of the universe, but it cannot explain them.33 As astronomer concludes, “The question, `How was the matter created in the first place?’ is left unanswered.” 34

The scientific team that discovered the microwave background radiation sums it up: “we cannot understand the origin of matter or of the universe.”35

This then is the question that the scientists cannot and will not answer: Why does the universe exist?

Robert Jastrow, director of NASA’s Goddard Institute for Space Studies, in his book God and the Astronomers explains that many scientists are simply running away from God. He writes:

There is a kind of religion in science....Every event can be explained in a rational way as the product of some previous event....there is no First Cause. This religious faith of the scientist is violated by the discovery that the world had a beginning...as a product of forces or circumstances we cannot discover. When that happens, the scientist has lost control. If he really examined the implications, he would be traumatized. As usual when faced with trauma, the mind reacts by ignoring the implications–in science this is known as “refusing to speculate”–or trivializing the origin of the world by calling if the Big Bang, as if the universe were a firecracker.

Consider the enormity of the problem. Science has proven that the universe exploded into being at a certain moment. It asks, what cause produced this effect? Who or what put the matter and energy into the universe?....And science cannot answer these questions....The scientist’s pursuit of the past ends in the moment of creation.36

I do not mean to imply that all scientists are running away from God. For example, another scientist, Sir Edmund Whittaker, said, “It is simpler to postulate creation ex nihilo–Divine will constituting nature from nothingness.” The British scientist Edward Milne wrote, “As to the first cause of the universe,...that is left for the reader to insert, but our picture is incomplete without Him.”37 And astronomer Icko Iben asserts that when we remember that at the beginning most of the energy of the universe was in the form of radiation or photons, it gives “added meaning to the phrase, `And God said, “Let there be light.’” 38

The discovery that the universe began to exist, Jastrow says, surprised everybody except the theologians. The Bible says, “In the beginning God created the heavens and the earth” (Gen. 1:1). For thousands of years, those who believed what the Bible says have known the truth that scientists have discovered only within the last fifty years. Or as Jastrow puts it,

For the scientist who has lived by his faith in the power of reason, the story ends like a bad dream. He has scaled the mountains of ignorance; he is about to conquer the highest peak; as he pulls himself over the final rock, he is greeted by a band of theologians who have been sitting there for centuries.39

Thus science points us to the Creator God of the Bible. It is interesting that this fact has been inadvertently endorsed by the U.S. judiciary. In ruling against the Arkansas law allowing creation science to be taught in public schools, the judge wrote:

The argument that creation from nothing...does not involve a supernatural deity has no evidentiary or rational support....Indeed, creation of the world “out of nothing” is the ultimate religious statement because God is the only actor....The idea of sudden creation from nothing, or creatio ex nihilo, is an inherently religious concept.40

Since this is precisely what modern cosmology teaches, then, if the judge is right, the existence of God is inherently implied by the standard model of the universe.

Therefore, the Universe Has a Cause Of Its Existence

Both philosophical reasoning and scientific evidence point to a beginning of the universe. But since whatever begins to exist has a cause, the universe must have a cause. From what we have already said this cause would have to be uncaused, eternal, changeless, timeless, and immaterial. Moreover, I would argue, it must also be personal. For how else could a temporal effect arise from an eternal cause? If the cause were present from eternity, why would not the effect also be present from eternity? To give an example, if a heavy ball’s resting on a cushion is the cause of a depression in the cushion, then if the ball is resting on the cushion from eternity, the cushion should be depressed from eternity. However, the only way to have an eternal cause but an effect that begins at a point in time is if the cause is a personal agent who freely decides to create an effect in time. For example, a man sitting from eternity may will to get up; hence, a temporal effect may be caused by an eternally existing agent. In fact, the agent may have purposed eternally to do some act in time. Thus, the Bible speaks of the eternal plan, hidden for ages in God who created all things, which God has realized in Christ Jesus our Lord (Eph 3:11). Therefore, we are brought, not merely to a First Cause of the universe, but to the Personal Creator of the universe.


Footnote numbering and slight formatting has been adjusted for this excerpt.

 1. J.l. Mackie, The Miracle of Theism, p. 94.

 2. Ibid., p. 89.

 3. David Hume, The Letters of David Hume, 1:187

 4. Mackie, Theism, p. 89.

 5. The story of Hilbert’s Hotel is related in George Gamow3, One, Two, Three,...Infinity, p. 17.

 6. William J. Wainwright, review of The Kalam Cosmological Argument, pp. 328- 34.

 7. Mackie, Theism, p. 93

 8. Bertrand Russell, Our Knowledge of the External World, p. 170.

 9. Mackie, Theism, p. 93

10. J. Richard Gott, et al., “Will the Universe Expand Forever?” p. 65.

11. Fred Hoyle, Astronomy and Cosmology, p. 658.

12. See Robert Jastrow, God and the Astronomers, pp. 28, 112-13.

13. Stanley L. Jaki, Science and Creation, p. 347

14. Ivan R. King, The Universe Unfolding, p. 462.

15. John Gribbin, “Oscillating Universe Bounces Back,” p. 15.

16. Beatrice Tinsley, personal letter.

17. Duane Dicus et al., “The Future of the Universe,” p. 100; idem, “Effects of Proton Decay on the Cosmological Future,” pp. 1-9.

18. Dicus, “Cosmological Future,” p. 8.

19. Ethan T. Vishniac, “Relativistic Collisionless Aparticles and the Evolution of Cosmological Perturbations,” p. 472.

20. Adrian L. Melott, “Massive Neutrinos in Large Scale Gravitational Clustering,” p. 59.

21. David N. Schramm and Gary Steigman, “Relic Neutrinos and the Density of the Universe,” p. 6

22. James S. Trefil, “How the Universe Will End,” p. 78.

23. Allan Sandage and G.A. Tammann, “Steps Toward the Hubble Constant VII,” pp. 23, 7. See also idem, “Steps Toward the Hubble Constant. VIII.”

24. Beatrice Tinsley6, “From Big Bang to Eternity?” P. 103.

25. Dicus, “Future of the Universe,” p. 99.

26. Tinsley, “Big Bang,” p. 105.

27. Discus, “Cosmological Future,” pp. 1,8.

28. I.D. Novikov and Ya. B. Zeldovich, “Physical Processes Near Cosmological Singularities,” pp. 401-2.

29. Gribbin, “Oscillating Universe,” p. 16

30. P.C.W. Davies, The Physics of Time4 Asymetry, p. 104.

31. Anthony Kenny, The Five Ways, p. 66.

32. Fred Hoyle, Astonomy Today, p. 166.

33. Adrian Webster, “The Cosmic Background Radiation,” p. 31.

34. J.V. Narlikar, “Singularity and Matter Creation in Cosmological Models,” p. 136

35. R.H. Dicke, et. Al., “Cosmic Black-Body Radiation,” p. 31.

36. Jastrow, God and the Astronomers, pp. 113-15.

37. Cited in ibid., pp. 111-12.

38. Icko Iben, Jr. “Globular Cluster Stars,” p. 39.

39. Jastrow, God and the Astronomers, p. 116.

40. Memorandum Opinion, Maclean v. Arkansas, 1981. Judge Overton’s opinion is reprinted in full in Norman Geisler, The Creator in the Courtroom (Milford, Mich.: Mott Media, 1982), pp. 165-89.

Taken from Apologetics: An Introduction (pgs. 73-93) by William Lane Craig. Copyright © 1984 by The Moody Bible Institute of Chicago. Permission kindly granted to Faith and Reason Forum by Moody Publishers, 820 N. LaSalle Blvd., Chicago, IL 60610-3284.