begin of universe andf alse assumptions

Tweet

Contents: I. Introduction II. No Reason to Regard the Theistic Hypothesis as True III. Unreasonable to Regard the Theistic Hypothesis as True IV. Conclusion I. Introduction Quentin Smith [1988] has recently argued that there is sufficient evidence at present to warrant the conclusions that (i) the universe probably began to exist and that (ii) it began to exist without being caused to do so. While I am inclined to agree with (i),{1} it seems to me that Smith has overstated the case for (ii). As part of his argument for (ii), Smith takes on the task of disproving what we may call the theistic hypothesis (TH), that the beginning of the universe was caused by God. It is apparently Smith's contention that the theist who believes in divine creatio ex nihilo must fly in the face of the evidence in order to do so. But is this in fact the case? As I read him, Smith's refutation of (TH) basically falls into two halves: (i) there is no reason to regard (TH) as true, and (ii) it is unreasonable to regard (TH) as true. Let us, therefore, examine each half of his refutation in turn. II. No Reason to Regard (TH) as True In order to show that there is no reason to think that God caused the beginning of the universe, Smith attacks the universality of the causal principle, variously construed. After arguing that ". . . it belongs analytically to the concept of the cosmological singularity that it is not the effect of prior physical events" and that "this effectively rules out the idea that the singularity is an effect of some prior natural process" (p. 48), Smith turns to the "more difficult question" of whether the singularity or the Big Bang is the effect of a supernatural cause. He presents the following argument (incorrectly attributed to me) as a basis for inferring a supernatural cause of the universe's origin: We have reason to believe that all events have a cause. The Big Bang is an event. Therefore, we have reason to believe that the Big Bang has a cause. While admitting that this argument does not violate singularity theorems, since the cause is not conceived to be a spatio-temporal object, Smith maintains that the argument fails because (1) is false. Quoting me to the effect that "the causal proposition may be taken as an empirical generalization enjoying the strongest support experience affords," Smith rejoins that quantum mechanical considerations show that the causal principle is limited in its application, so that a probabilistic argument for a cause of the Big Bang cannot succeed. For according to Heisenberg's Uncertainty Principle, it is impossible to predict precisely the conditions of the values of momentum or position of some particle x at some time t2 on the basis of our knowledge of the conditions of x at t1. Since it sufficient to understand causality in terms of a law enabling precise predictions of individual events to be deduced, it follows from Heisenberg's Principle that there are uncaused events in this sense.{2} Therefore, the causal proposition is not universally applicable and may not apply to the Big Bang. But what exactly is the causal proposition which is at issue here? The proposition which I enunciated was not (1), as Smith alleges, but rather 1.' Whatever begins to exist has a cause. The motions of elementary particles described by statistical quantum mechanical laws, even if uncaused, do not constitute an exception to this principle. As Smith himself admits, these considerations "at most tend to show that acausal laws govern the change of condition of particles, such as the change of particle x's position from q1 to q2. They state nothing about the causality or acausality of absolute beginnings, of beginnings of the existence of particles" (p. 50). Smith seeks rectify this defect in his argument, however, by pointing out that the Uncertainty relation also permits energy or particles (notably virtual particles) to "spontaneously come into existence" for a very brief time before vanishing again. It is therefore false that "all beginnings of existence are caused" and, hence, ". . . the crucial step in the argument to a supernatural cause of the Big Bang . . . is faulty" (pp. 50-51). But as a counterexample to (1'), Smith's use of such vacuum fluctuations is highly misleading. For virtual particles do not literally come into existence spontaneously out of nothing. Rather the energy locked up in a vacuum fluctuates spontaneously in such a way as to convert into evanescent particles that return almost immediately to the vacuum. As John Barrow and Frank Tipler comment, ". . . the modern picture of the quantum vacuum differs radically from the classical and everyday meaning of a vacuum-- nothing. . . . The quantum vacuum (or vacuua, as there can exist many) states . . . are defined simply as local, or global, energy minima (V'(O)= O, V"(O)O)" ([1986], p. 440). The microstructure of the quantum vacuum is a sea of continually forming and dissolving particles which borrow energy from the vacuum for their brief existence. A quantum vacuum is thus far from nothing, and vacuum fluctuations do not constitute an exception to the principle that whatever begins to exist has a cause. It therefore seems that Smith has failed to refute premiss (1'). Let us pursue Smith's argument further, however. He proceeds to argue that there is no reason to think that the causal principle applies to the Big Bang, whether one adopts a model based exclusively on the General Theory of Relativity or whether one uses a model adjusted for quantum effects during the Planck era. Consider on the one hand a model in which quantum physics plays no role prior to 10-43 second after the singularity. Since the classical notions of space and time and all known laws of physics break down at the singularity, it is in principle impossible to predict what will emerge from a singularity. If we regard the Big Bang as the first physical state,{3} then the particles that constitute that state must be regarded as being randomly and spontaneously emitted from nothing at all. Smith states, "This means, precisely put, that if the Big Bang is the first physical state, then every configuration of particles that does constitute or might have constituted this first state is as likely on a priori grounds to constitute it as every other configuration of particles. In [this] case, the constitution of the Big Bang1 is impossible in principle to predict and thus is uncaused (for 'uncaused' minimally means 'in principle unpredictable')" (p. 52). Moreover, since spacetime curves cannot be extended beyond the singularity, it cannot have causal antecedents. On the other hand, consider a model in which quantum processes do predominate near to the Big Bang. If the defender of the causal principle maintains that the proposition 4. There are some uncaused beginnings of existence within spacetime is irrelevant to and thus cannot increase the probability of 5. The beginning of the existence of spacetime itself is uncaused, then Smith will respond that the same holds for the parallel argument for a supernatural cause of four-dimensional spacetime. For the proposition 6. All beginnings of existence within spacetime are caused would by the same token be irrelevant to and thus not increase the probability of 7. The beginning of the existence of four- dimensional spacetime is caused. So whether one adopts a classical relativistic model or a quantum model, there is no reason to postulate a cause, natural or supernatural, of the Big Bang. Is this a sound argument? It seems to me not. To pick up on a point noted earlier, Smith's argument throughout his paper appears to be infected with positivism, so that it is predicated upon a notion of causality that is drastically inadequate. Smith assumes uncritically the positivistic equation between predictability in principle and causation. But this verificationist analysis is clearly untenable, as should be obvious from the coherence of the position that quantum indeterminacy is purely epistemic, there existing hidden variables which are in principle unobservable, or even the more radical position of die-hard realists who are prepared to abandon locality in order to preserve the hidden variables. Clearly, then, to be "uncaused" does not mean, even minimally, to be "in principle unpredictable." This single point alone seems to me to vitiate Smith's entire argument for his conclusion (ii) and against (TH) in particular. For now we see that Smith's argument, even if successful, in no way proves that the universe began to exist without a cause, but only that its beginning to exist was unpredictable. What is ironic about this conclusion is that it is one with which the theist is in whole-hearted agreement. For since according to classical theism creation is a freely-willed act of God, it follows necessarily that the beginning and structure of the universe were in principle unpredictable even though it was caused by God. The theist will therefore not only agree with Smith that "That there are uncaused events in this sense follows from Heisenberg's uncertainty principle" (p. 49), but even more insist that such uncaused events are entailed by classical theism's doctrine of creation. He will simply deny that this is the relevant sense when we are inquiring whether the universe could have come into being uncaused out of nothing. When we ask that question, we are asking whether the whole of being could come out of non-being; and here a negative answer seems obvious. Concerning this question, even genuine quantum indeterminacy affords no evidence for an affirmative response. For if an event requires certain physically necessary conditions in order to occur, but these conditions are not jointly sufficient for its occurrence, and the event occurs, then the event is in principle unpredictable, but it could hardly be called uncaused in the relevant sense. In the case o