Religion in an Age of Science by Ian Barbour
Chapter 5: Astronomy and Creation
III. The New Cosmology
3. Necessity: A Theory of Everything
explanation of the fine tuning than these many-worlds hypotheses.32 These theories, he says, are all very ad hoc and unsupported by any independent evidence, whereas one can appeal to other kinds of
evidence in support of belief in God. Note that Leslie assumes here that God and chance are mutually exclusive hypotheses.
I suggest, however, that one could interpret many-worlds hypotheses theistically. It is common for theologians to understand evolution as God’s way of creating and to accept chance and the wastefulness of extinct species as part of this long process. One might similarly hold that God created many universes in order that life and thought would occur in this one. Admittedly, this gives chance an inordinately large role, and it involves a colossal waste and inefficiency if there are many lifeless universes. But then again, one might reply that for God neither space nor time is in short supply, so efficiency is a dubious criterion. In any case, the first three of these theories are highly speculative and have no experimental support. It is simpler, from the viewpoint of both
science and theology, to assume that there has been only one world.
The vacuum fluctuation theory is also speculative, but it is consistent with the fact that the creation of virtual particles occurs in the
laboratory. It has sometimes been viewed as a secular version of creation ex nihilo, because it starts with a vacuum, which is, literally, nothing. Space and time would have come into existence along with the appearance of matter-energy in a random quantum fluctuation.
However, all our experiments with a vacuum are within an already existing spacetime framework, in which a vacuum is the quiescent state of the ever-present quantum field. Most theories of an initial vacuum fluctuation assume such a framework. How do we account for the situation in which a gigantic quantum fluctuation could have occurred?
We have seen that a Grand Unified Theory (GUT) offers the prospect of bringing the two nuclear forces and the electromagnetic force into a single theory. Such a theory would help us understand that momentary era, prior to the hot quark era, when these three forces were merged. The theory already suggests that the slight imbalance between particles and antiparticles may have arisen from a slight asymmetry in the decay processes of the X and the anti-X bosons (the very heavy particles, which mediate the unified force of the GUT theory).
There are also promising new inflationary theories which may explain why the present expansion rate is so close to the critical balance
between an open and a closed universe (the so-called flatness problem).
Inflationary theories could also explain why the microwave radiation is isotropic (arriving equally from all directions). These theories entail a very rapid expansion at about 10-35 seconds, due to the tremendous energy released in the breaking of symmetry when the strong force separated out. Before inflation, the universe would have been so small that its parts could have been in communication and thus could have achieved thermal equilibrium, which would account for its later homogeneity over vast distances.33
Current theories are quite inadequate to deal with the even earlier period before 10-43 seconds when the temperature would have been so high that the fourth force, gravity, would have been united with the other three. Scientists hope to develop theories of Supersymmetry or
Supergravity, which would provide a quantum theory of gravity. We saw that String Theory, in particular, may bring these diverse
phenomena together. Because it would unite all the basic physical
forces, it has been referred to as a Theory of Everything (TOE). Perhaps the whole cosmos can be derived from one simple and all-inclusive equation. Such a theory has been called the Holy Grail of the current quest in physics.
Successful GUT and TOE theories would seem to undermine the argument from design in the early universe. Perhaps self-consistency and fundamental laws will show that only one universe is possible, that is, that the universe is necessary and not contingent. I would reply that such theories would only push the argument back a stage. For it is all the more remarkable if a highly abstract physical theory, which itself has absolutely nothing to say about life, turns out to describe structures that have the potential for developing into life. The theist could
welcome this as part of God’s design. Such an orderly universe seems to display a grander design than a universe of chance. A theory that starts with a superlaw and a singularity would leave unanswered the question, Why that superlaw and that singularity? And why the laws of logic that end with such amazing consequences? Can a TOE ever explain itself or how it comes to be instantiated in the real world?
In physics, moreover, predictions are ordinarily made from a
combination of universal laws and contingent boundary conditions (particular initial conditions). From universal premises alone one cannot derive conclusions about particulars. To be sure, in some situations an outcome is indifferent to the boundary conditions; paths from diverse initial states may converge to the same unique final state (for example, thermodynamic equilibrium). But in other situations paths diverge
because chance enters at a variety of levels. Evolution must be described by a historical account of events and not by predictive laws alone.
Contingent boundary conditions would be present even if it turned out that time is infinite and there was no beginning. At any point, however far back, there was a particular "given" situation that, along with laws and chance, affected the subsequent course of history.
But Stephen Hawking has developed a theory of quantum gravity that assumes neither infinite time nor a beginning of time. Instead, time is finite but unbounded. There is no initial singularity. The equations are relationships involving imaginary time, which is indistinguishable from the three spatial dimensions. Just as the two-dimensional surface of the earth is finite but unbounded, and three-dimensional relativistic
("curved") space is finite but unbounded, so Hawking’s spatial and imaginary time dimensions are all finite but unbounded. In that
imaginary time frame, real time gradually emerges. He grants that the interpretation of events in imaginary time is not clear. It also seems to me inconsistent to think of time as emerging, since emergence refers to changes in real time.
Hawking makes some interesting comments on the theological
implications of a self-contained universe without boundaries or initial conditions. Earlier Big Bang theory assumed a singularity at which the laws of physics break down. At the singularity, God would have had freedom to choose both the initial conditions and the laws of the
universe. But in Hawking’s universe there are no initial conditions, and the choice of laws is restricted by self-consistency and by the Anthropic Principle: the early universe must provide the conditions for the later
existence of humanity. He concludes,
[God] would, of course, still have had the freedom to choose the laws that the universe obeyed. This, however, may not really have been all that much of a choice; there may well be only one, or a small number, of complete unified theories, such as the heterotic string theory, that are self-consistent and allow the existence of structures as complicated as human beings who can investigate the laws of the universe and ask about the nature of God.
Even if there is only one possible unified theory, it is just a set of rules and equations. What is it that breathes fire into the
equations and makes a universe for them to describe? The usual approach of science of constructing a mathematical model cannot answer the questions of why there should be a universe for the model to describe.34
Hawking says here that the equations of a unified theory could not answer the question of why there is a universe at all. Yet his final paragraph seems to hold out the hope that a complete scientific theory may someday answer just that question:
However, if we do discover a complete theory, it should in time be understandable in broad principle by everyone, not just a few scientists. Then we shall all, philosophers, scientists, and just ordinary people, be able to take part in the discussion of the question of why it is that we and the universe exist. If we find the answer to that, it would be the ultimate triumph of human reason - - for then we would know the mind of God.35