Religion in an Age of Science by Ian Barbour
Chapter 5: Astronomy and Creation
III. The New Cosmology
1. Design: The Anthropic Principle
set before each one the ways of life and death." Or consider the prayer in one of the communion services in the Episcopal prayer book. These lines could not have been written before the space age, yet they express traditional themes. The celebrant (C) is at the altar and the people (P) respond:
C: God of all power, Rule of the Universe, you are worthy of glory and praise.
P: Glory to you for ever and ever.
C: At your command all things came to be: the vast expanse of interstellar space, galaxies, suns, the planets in their courses, and this fragile earth, our island home.
P: By your will they were created and have their being.
C: From the primal elements you brought forth the human race, and blessed us with memory, reason, and skill. You made us the rulers of creation. But we turned against you, and betrayed your trust; and we turned against one another.
P: Have mercy, Lord, for we are sinners in your sight.22
Here again the focus is on the significance of human life in relation to God and the world. That is what is important religiously.
universes allowed by the laws of physics.
A striking feature of the new cosmological theories is that even a small change in the physical constants would have resulted in an
uninhabitable universe. Among the many possible universes consistent with Einstein’s equations, ours is one of the few in which the arbitrary parameters are right for the existence of anything resembling organic life. Thus Carr and Rees conclude that the possibility of life as we know it "depends on the value of a few basic constants" and is "remarkably sensitive to them."23 Among these fine-tuned phenomena are the following:
1. The Expansion Rate. Stephen Hawking writes, "If the rate of
expansion one second after the Big Bang had been smaller by even one part in a hundred thousand million million it would have recollapsed before it reached its present size." 24 On the other hand, if it had been greater by a part in a million, the universe would have expanded too rapidly for stars and planets to form. The expansion rate itself depends on many factors, such as the initial explosive energy, the mass of the universe, and the strength of gravitational forces. The cosmos seems to be balanced on a knife edge.
2. The Formation of the Elements. If the strong nuclear force were even slightly weaker we would have only hydrogen in the universe. If the force were even slightly stronger, all the hydrogen would have been converted to helium. In either case, stable stars and compounds such as water could not have been formed. Again, the nuclear force is only barely sufficient for carbon to form; yet if it had been slightly stronger, the carbon would all have been converted into oxygen. Particular elements, such as carbon, have many other special properties that are crucial to the later development of organic life as we know it.25
3. The Particle/Antiparticle Ratio. For every billion antiprotons in the early universe, there were one billion and one protons. The billion pairs annihilated each other to produce radiation, with just one proton left over. A greater or smaller number of survivors -- or no survivors at all if they had been evenly matched -- would have made our kind of material world impossible. The laws of physics seem to be symmetrical between particles and antiparticles; why was there a tiny asymmetry?26
One could list other unexplained "remarkable coincidences," such as the fact that the universe is homogenous and isotropic. The simultaneous
occurrence of many independent improbable features appears wildly improbable. Reflection on the way the universe seems to be fine tuned for intelligent life led the cosmologists Dicke and Carter to formulate the Anthropic Principle: "What we can expect to observe must be restricted by the conditions necessary for our presence as observers."27 The principle does underscore the importance of the observer, to which quantum theory also testifies. But it does not in itself provide any causal explanation of those conditions. However, this fine tuning could be taken as an argument for the existence of a designer, perhaps a God with an interest in conscious life.
Some physicists see evidence of design in the early universe. Stephen Hawking, for example, writes, "The odds against a universe like ours emerging out of something like the Big Bang are enormous. I think there are clearly religious implications."28 And Freeman Dyson, in a chapter entitled "The Argument from Design," gives a number of examples of "numerical accidents that seem to conspire to make the universe habitable." He concludes, "The more I examine the universe and the details of its architecture, the more evidence I find that the universe in some sense must have known we were coming."29 2. Chance: Many-World Theories
One way of explaining the apparent design in these "remarkable
coincidences" is to suggest that many worlds existed either successively or simultaneously. If there were billions of worlds with differing
constants, it would not be surprising if by chance one of them happened to have constants just right for our forms of life. That which is highly improbable in one world might be probable among a large enough set of worlds. There are several ways in which many worlds could, occur.
1. Successive Cycles of an Oscillating Universe. Wheeler and others suggest that the universe is reprocessed in each Big Crunch before the next Big Bang. The universe and all its structures completely melt down and make a new start as it expands and cools again. In the quantum uncertainties entailed by those very small dimensions, indeterminate possibilities are present. If the constants vary at random in successive cycles, our particular combination will eventually come up by chance, like the winning combination on a Las Vegas slot machine. As indicated earlier, present evidence does not favor cyclic theories, but they cannot be ruled out.
2. Multiple Isolated Domains. Instead of multiple bangs in successive cycles, a single Big Bang might have produced multiple domains existing simultaneously. The domains would be like separately expanding bubbles isolated from each other because their velocity of separation prevents communication even at the speed of light. The universe might have split into many domains with differing constants or even differing laws.30 Some of the new inflationary models of the
universe involve infinite time and regions very unlike ours, beyond our horizon of possible observation. Perhaps this just happens to be one of the few regions in which life could be present.
3. Many-Worlds Quantum Theory. In the previous chapter we noted Everett’s proposal that every time there are alternative quantum potentialities in an atom, the universe splits into several branches.31 This interpretation of quantum theory involves a mind-boggling
multiplicity of worlds, since each world would have to split again into many branches during each of the myriad atomic and subatomic events throughout time and space. But being mind-boggling is not enough to disqualify an idea, though this proposal violates Occam’s Razor with a vengeance. More to the point, it seems to be inherently unverifiable, since no communication could take place between the various branching worlds.
4. Quantum Vacuum Fluctuations. A strange feature of quantum theory is that it permits very brief violations of the law of conservation of energy. It is permissible for a system’s energy to go into debt if the debt is rapidly paid back -- so rapidly that it could never be detected within the limits of the uncertainty principle. This means that empty space, a vacuum, is really a sea of activity in which pairs of virtual particles come into being and almost immediately annihilate each other again.
Since the magnitude of the allowable energy debt is inversely proportional to the repayment time, the energy needed to create a universe could be borrowed for only a fantastically brief instant, but conceivably this could get things going. Moreover, the energy needed might be small or even zero if the negative gravitational energy is taken into account.
All four of these theories -- many cycles, many domains, many quantum worlds, or many quantum fluctuations -- would allow us to explain the combination of constants favorable to life as a chance occurrence among a set of worlds, most of which would be lifeless. John Leslie has argued that the God hypothesis is simpler and more plausible as an
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?