4.3.2. Dawkins’s Suggested Mechanisms for Generating a World Ensemble
What Dawkins needs to say, it seems to me, is that the postulate of a World Ensemble may still be simple if there is a simple mechanism that through a repetitive process generates the many worlds. In that way the huge number of entities postulated isn’t a deficit of the theory because the entities all issue from a very simple fundamental mechanism.
An Oscillating Model of the Universe
So what mechanisms does Dawkins suggest for generating such an infinite, randomly ordered World Ensemble? First, he suggests an oscillating model of the universe, according to which
our time and space did indeed begin in our big bang, but this was just the latest in a long series of big bangs, each one initiated by the big crunch that terminated the previous universe in the series. Nobody understands what goes on in singularities such as the big bang, so it is conceivable that the laws and constants are reset to new values, each time. If bang-expansion-contraction-crunch cycles have been going on forever like a cosmic accordion, we have a serial, rather than parallel, version of the multiverse.27
Dawkins is apparently unaware of the many difficulties of oscillatory models of the universe that have made contemporary cosmologists skeptical of them. Back in the 1960s and 1970s, some theorists proposed oscillating models of the universe in an attempt to avert the initial singularity predicted by the Standard Model. The prospects of such models were severely dimmed in 1970, however, by Roger Penrose and Stephen Hawking’s formulation of the singularity theorems that bear their names. The theorems disclosed that under very generalized conditions an initial cosmological singularity is inevitable. Since it’s impossible to extend space-time through a singularity to a prior state, the Hawking-Penrose singularity theorems implied the absolute beginning of the universe. Reflecting on the impact of this discovery, Hawking notes that the Hawking-Penrose singularity theorems “led to the abandonment of attempts (mainly by the Russians) to argue that there was a previous contracting phase and a non-singular bounce into expansion. Instead almost everyone now believes that the universe, and time itself, had a beginning at the big bang.”28 Dawkins apparently labors under the delusion that a singularity does not form a boundary to space and time.
Moreover, the evidence of observational astronomy has been consistently against the hypothesis that the universe will someday recontract into a Big Crunch. Attempts to discover the mass density sufficient to generate the gravitational attraction required to halt and reverse the expansion continually came up short. In fact, recent observations of distant supernovae indicate that—far from slowing down—the cosmic expansion is actually accelerating! There’s some sort of mysterious “dark energy” in the form of either a variable energy field (called “quintessence”) or, more probably, a positive cosmological constant or vacuum energy that causes the expansion to proceed more rapidly. If the dark energy does indicate the existence of a positive cosmological constant (as the evidence increasingly suggests), then the universe will expand forever. According to the NASA website of the Wilkinson Microwave Anisotropy Probe, “For the theory that fits our data, the Universe will expand forever.”29
Furthermore, wholly apart from the physical and observational difficulties confronting oscillatory models, the thermodynamic properties of such models imply the very beginning of the universe that their proponents sought to avoid. For entropy is conserved from cycle to cycle in such models, which has the effect of generating larger and longer oscillations with each successive cycle. As 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.”30 Thus, as one traces the oscillations back in time, they become progressively smaller until one reaches a first and smallest oscillation. Zeldovich and Novikov therefore conclude, “The multicycle model has an infinite future, but only a finite past.”31 In fact, astronomer Joseph Silk estimates on the basis of current entropy levels that the universe cannot have gone through more than 100 previous oscillations.32 This is far from sufficient to generate the sort of serial World Ensemble imagined by Dawkins.
Finally, even if the universe could oscillate from eternity past, such a universe would require an infinitely precise fine-tuning of initial conditions in order to persist through an infinite number of successive bounces. Thus, the mechanism Dawkins envisions for generating his many worlds is not simple but just the opposite. Moreover, such a universe involves a fine-tuning of a very bizarre sort since the initial conditions have to be set at minus infinity in the past. But how could that be done if there was no beginning?
Looking back on the discussion of oscillating models of the universe, quantum cosmologist Christopher Isham muses,
Perhaps the best argument in favor of the thesis that the Big Bang supports theism is the obvious unease with which it is greeted by some atheist physicists. At times this has led to scientific ideas, such as continuous creation or an oscillating universe, being advanced with a tenacity which so exceeds their intrinsic worth that one can only suspect the operation of psychological forces lying very much deeper than the usual academic desire of a theorist to support his/her theory.33
In Dawkins’s case, it is not hard to discern those psychological forces at work.
Lee Smolin’s Evolutionary Cosmology
Dawkins’s second suggested mechanism for generating a World Ensemble is Lee Smolin’s evolutionary cosmology. Smolin imagines a scenario, Dawkins explains, according to which
daughter universes are born of parent universes, not in a fully fledged big crunch, but more locally in black holes. Smolin adds a form of heredity: The fundamental constants of a daughter universe are slightly “mutated” versions of the constants of its parent. . . . Those universes which have what it takes to “survive” and “reproduce” come to predominate in the multiverse. “What it takes” includes lasting long enough to “reproduce.” Because the act of reproduction takes place in black holes, successful universes must have what it takes to make black holes. This ability entails various other properties. For example, the tendency of matter to condense into clouds and then stars is a prerequisite for making black holes. Stars also . . . are the precursors to the development of interesting chemistry, and hence life. So, Smolin suggests, there has been a Darwinian natural selection of universes in the multiverse, directly favouring the evolution of black hole fecundity and indirectly favouring the production of life.34
Dawkins acknowledges that “not all physicists” are enthusiastic about Smolin’s scenario. Talk about an understatement! For Smolin’s scenario, wholly apart from its ad hoc and even disconfirmed conjectures, encounters insuperable difficulties.
First, a fatal flaw in Smolin’s scenario is his assumption that universes fine-tuned for black-hole production would also be fine-tuned for the production of stable stars. In fact, the exact opposite is true: the most proficient producers of black holes would be universes that generate primordial black holes prior to star formation, so that life-permitting universes would actually be weeded out by Smolin’s cosmic evolutionary scenario. Thus, it turns out that Smolin’s scenario would actually make the existence of a life-permitting universe even more improbable.
Second, speculations about the universe’s begetting “baby universes” via black holes have been shown to contradict quantum physics. The conjecture that black holes may be portals of wormholes through which bubbles of false vacuum energy can tunnel to spawn new expanding baby universes was the subject of a bet between Stephen Hawking and John Preskill, which Hawking in 2004 finally admitted, in an event much publicized in the press, that he had lost.35 The conjecture would require that information locked up in a black hole could be utterly lost forever by escaping to another universe. One of the last holdouts, Hawking finally came to agree that quantum theory requires that information is preserved in black hole formation and evaporation. The implications? “There is no baby universe branching off, as I once thought. The information remains firmly in our universe. I’m sorry to disappoint science fiction fans, but if information is preserved, there is no possibility of using black holes to travel to other universes.”36 That means that Smolin’s scenario is physically impossible.
These are the only mechanisms Dawkins suggests for generating a World Ensemble of randomly ordered universes. Neither of them is even tenable, much less simple. Dawkins has therefore failed to turn back the objection that his postulation of a randomly ordered World Ensemble is an unparsimonious extravagance.