[David Bailey has a professional background in computer science and experimental mathematics. He has published a number of articles discussing science and religion in Dialogue: A Journal of Mormon Thought and elsewhere (see sidebar link). He offered the following review for posting.]
I just finished reading physicist Paul Davies’ new book “Cosmic Jackpot: Why Our Universe Is Just Right for Life” (Orion Publications, 2007).
In this book Davies joins physicists Leonard Susskind (“The Cosmic Landscape: String Theory and the Illusion of Intelligent Design”) and Alex Vilenkin (“Many Worlds in One: The Search for Other Universes”) in laying bare an incredible paradox of modern physics and cosmology. One way out of this paradox (advocated by Susskind and Vilenkin) is to posit a vast multitude of actually existing universes along side ours, and further to posit that the remarkable life-friendliness of our universe is due only to an observer selection effect (the “anthropic principle”) -- we exist in a life-friendly universe, because if it were not, we would not be here discussing the issue.
The paradox mentioned above derives from the fact that when one calculates, based on known principles of quantum mechanics, the “zero-point mass density” (or, equivalently, the “dark energy mass density”) of the universe, focusing for the time being on the electromagnetic force, one obtains the incredible result that empty space “weighs” 1093 grams per cubic centimeter (the actual average mass density of the universe is 10-28 grams per cc). Stephen Hawking quipped that this is the most spectacular failure of a physical theory in history. Closely related to the zero-point mass density of the universe is the “cosmological constant,” which until recently was thought to be precisely zero. Physicists have noted that calculations such as the above only involve the electromagnetic force, and so perhaps when the contributions (positive and negative) of the other known forces are included, all terms will cancel out to exactly zero, as a consequence of some unknown physical principle.
These hopes were shattered with the recent discovery that the expansion of the universe is accelerating, which implies that the cosmological constant must be slightly nonzero. In other words, physicists are left with the startling conclusion that the positive and negative contributions to the cosmological constant exactly cancel to 120-digit accuracy, yet fail to cancel beginning at the 121-th digit.
This stupendous coincidence joins a growing list of remarkable facts (such as the observed flatness and longevity of the universe, and the nuclear resonance that makes carbon atoms and all heavier elements possible) that suggest our universe possesses exceedingly rare characteristics that make atoms, stars and life possible.
At the same time, string theorists, who for 20 years have been earnestly seeking a complete and unique “theory of everything” that encompasses all known physical interactions, have instead deduced the existence of an enormous ensemble of possible universal laws, numbering (by one reckoning) more than 10500. The vast majority of these universes are utterly hostile to any conceivable form of long-lived information-rich structure, much less life, and thus must be completely devoid of observers. But with so many universes to choose from, so these physicists theorize, inevitably one (ours) beats the one-in-10120 odds and is life-friendly. Needless to say, such reasoning requires a dramatic departure in philosophy from the traditional program of physics, and many physicists and other scientists are dead-set against it.
Davies discusses all of this in detail, and then lists six possible solutions:
A. The absurd universe. There is no God, no designer, no teleological principle, and no destiny. Life in general, and human beings in particular, are an “irrelevant embellishment” in a vast and meaningless cosmos, the existence of which is an “unfathomable mystery.” The main difficulty of this view is that if there is no coherent scheme of things, then the success of the scientific enterprise to date (which shows no sign of abating) is completely enigmatic.
B. The unique universe. There is some compelling and logically consistent mathematical theory (say string theory) that permits one to unambiguously derive all the laws and constants of physics. One obvious difficulty of this view is that the recent developments of string theory, for instance, point in the opposite direction, to an enormous variety of possible physical laws, and no particular reason for preferring any one of them. The other difficulty with this view is that even if such a theory is ultimately produced, it would still leave open the question of “why that theory.” In any event, the observed bio-friendliness of the universe would remain unexplained.
C. The multiverse. As mentioned above, some scientists argue that we inhabit one of an infinite multitude of pocket universes, each with different physical laws and constants, and that the life-friendliness of our universe is simply an “observer effect” -- i.e. the anthropic principle. The main difficulty here is that this theory invokes an extravagant “overabundance of entities” (in the sense of Occam’s razor) -- an infinite collection of universes that can never be observed (although some scientists argue that we may be able to test this hypothesis indirectly). This strikes many scientists as an exceedingly profligate way to explain bio-friendliness. It has also been criticized as a “science stopper,” because it suggests there is no need to seek any further explanation for either our physical laws or the life-friendliness of the universe.
D. Intelligent design. Many theologians and some scientists argue that the universe is created by God (or some Intelligent Designer) and is specifically designed to be a habitat for us. One disadvantage with this philosophy is that it is a “science stopper” -- the declaration “God did it” provides no real explanation for anything, not even how or why God did what he did. It also begs the question of who designed the Designer. In any event, this version of the Designer appears to bear little relation to the traditional God of Christian religions, who interacts with the world and influences the lives of mortals.
E. The “life principle.” Here, the bio-friendliness of the universe arises from an overarching law that constrains the universe to evolve toward life and mind. The disadvantage is that the “teleology” involved here represents a sharp break with traditional scientific thinking, epitomized by the writings of Stephen Jay Gould, which has eschewed, with quasi-religious fervor, any notion of goal-oriented or directional evolution (cosmic or earth-bound), even the notion that evolution leads to ever-growing complexity and intelligence. This theory also suffers from the difficulty of singling out life and/or mind as the goal of cosmic evolution, without explaining why.
F. The “self-explaining” universe. Some scientists have hypothesized a “causal loop,” in which the ultimate life- and intelligence-friendly destiny of an intelligent universe has a backwards-in-time or equivalent effect on its creation. The disadvantage here, aside from the fact that we know of no means how this might be accomplished, is that we are still left not knowing why this universe exists, or why it contains sentient observers who not only observe the universe but who, in large measure, understand its operation.
G. The fake universe. Some sober-minded scientists have hypothesized that we are all living in a Matrix-style simulation, run on a super-duper-computer in some advanced civilization. In fact, at least one scientist has argued that if the multiverse theory (option C above) is real, then fake universes should outnumber real ones. Curiously, this theory has religious overtones -- the Great Simulator is also a transcendent designer, creator, sustainer, and, possibly on occasion, miracle worker. Critics have derided this theory as tantamount to solipsism (the notion that the universe is completely contained in someone’s mind), or as Intelligent Design upgraded for the information age. More importantly, scientists note that this theory utterly undermines the scientific quest -- if the universe is a sham, why bother to figure out how it works?
H. None of the above?
Davies expresses his personal preference for E and F, although he fully recognizes their speculative nature, not to mention that they too leave numerous questions unanswered.
Continue reading...
Posts
