Lingua franca

SPACE RACE

In the nineteenth century, Darwinism killed the "design argument" for the existence of God. The wing of the eagle, the shape of the orchid, the speed of the antelope--all of these were produced by the blind gropings of evolution, Darwin showed, not by an all-powerful and beneficent deity as theologians fondly hoped.

In this century, however, the design argument has been resurrected in a new form. Physicists have discovered that the fundamental laws of nature are fine-tuned to yield a universe that would give rise to creatures like us. If the number that determines the strength of gravity were infinitesimally larger, for example, the cosmos would have collapsed within an instant of the big bang. Or, if the ratio of the proton's mass to that of the neutron weren't precisely what it is, the nucleus of the atom would not hold together and the molecules necessary for life would not exist. There are some twenty such parameters built into the standard model of physics, and someone appears to have set each one of them at precisely the right value to produce a world congenial to the emergence of wretched sinners like us. As the Cambridge cosmologist Fred Hoyle once put it, the universe looks like "a put-up job."

But can the revamped design argument prevail? Today, it seems, the corrosive acid of Darwinism has begun eating away at this bit of neo-teleology. In his new book The Life of the Cosmos (Oxford), Penn State cosmologist and professor of physics Lee Smolin deploys Darwin's dangerous idea on a trans-cosmic scale. Like organisms, he argues, universes reproduce, and the most fecund universes are the ones that happen to bring into being--as a mere by-product, an afterthought--Homo sapiens and such.

Smolin's scenario hangs on that increasingly familiar enigma, the black hole. When a giant star collapses under the force of its own gravity at the end of its life, it supposedly contracts to a single point of infinite density where time itself comes to an end--so, at least, says Einstein's theory of relativity, which governs how things behave in the large. But quantum theory, which governs how things behave in the small, cannot account for these infinite densities. Although physicists have not yet managed to unify these two theories into a "theory of everything" that would reveal exactly what goes on inside a black hole, there has been some informed speculation that a black hole's gravitational collapse stops short and takes what's been called a "bounce"--an explosion occurring just before infinite density is reached. The result: a baby universe with its very own space-time. Indeed, the big bang that began the universe we live in may well have been just such a bounce within a black hole inhabiting another universe.

As if this weren't audacious enough, Smolin adds a kicker. Each time a baby universe is born, he submits, the parameters in its physical laws randomly shift their values a bit from those of the parent universe. With these parameters playing the role of genes, both of the elements necessary for the Darwinian algorithm to do its thing--differential reproduction and heritable mutation--are in place. A universe whose physical laws make it an efficient nursery for black holes will spawn a lot of baby universes, argues Smolin. But to make black holes you need big stars--big enough to cook up the chemicals necessary for life in their cores. And before their gravitational collapse, they must explode in a supernova, spewing these biochemicals out into space. That's where the atoms in our bodies came from.

Smolin admits most of this is "frankly speculative." But when reached by phone at home one recent Sunday morning, he took great pains to explain its foundation in state-of-the-art cosmology and physics--a task at which he succeeds admirably in his book. It was not surprising that Smolin wasn't at church, given his avowed aim of enabling science "to finally transcend the religious and metaphysical faiths of its founders." His intellectual adversary, though, is not so much God as Plato--specifically, the Platonic conceit that absolute laws of nature exist in a "timeless, transcendent realm." His own evolutionary account of these laws--reflecting disparate influences like Leibniz, Wittgenstein, Milan Kundera, and the legal theorist Roberto Unger--makes them "historical, contingent."

If Smolin is correct, historicity would certainly apply to the parameters in the physicists' standard model--the value of the gravitational constant, for instance. But wouldn't the form of the laws, valid for the entire community of universes, retain its Platonic stature? And wouldn't this entire cosmic assemblage posited by The Life of the Cosmos exist timelessly, since the notion of time is meaningful only within each bubble universe? Confronted by these questions, Smolin insisted that he had at least made "partial progress" against the "nostalgia for the Absolute." He was also careful to deny that he believes the cosmos is literally alive, as his popularizer John Gribbin claimed in his 1993 book In the Beginning. The possibility of universes reproducing themselves sexually was not broached.

Whether Smolin has dealt the coup de grāce to teleology will not be clear until physicists work out a consistent theory of quantum gravity. In the meantime, he is content to have used Darwinian logic to undermine the idea of a cosmic fine-tuner: "As a friend of mine says, the whole show of the universe is so extraordinary that the absence of God is God enough."

by Jim Holt