Cosmic Conundrum

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A vocal sector of the religious community, on the other hand, has seized on the anthropic principle as further evidence that God created the universe just for us — adding intellectual support to the so-called intelligent-design movement, which believes that the staggering complexity of nature can be explained only by assuming that some higher intelligence had a hand in designing it. Over the past several years, pitched battles have been fought in school boards in Ohio, Kansas, Georgia and Montana and, just weeks ago, in Dover County, Pa., over whether to give intelligent design and Darwin's theory of evolution equal time in classrooms.

Although intelligent design may appear to have found tiny pockets of support in the scientific community, most scientists consider appeals to a supernatural designer to be an intellectual dead end. Over and over in our history, natural phenomena — lightning, the changing of the seasons, the nature of the sun and moon — have been explained simply by saying God (or Zeus or Odin) did it, only to have that explanation fall away as science provided a more satisfying answer. Maybe we really have reached the limits of intellectual understanding, but few scientists are willing to give up quite yet, even on seemingly intractable problems.

In fact, lots of astrophysicists think the anthropic issue, rather than signaling a problem with modern science, points toward a deeper understanding of the universe. Rees likes to use our solar system as an analogy. Says Rees: "If Earth were the only planet in the universe, you'd be astonished that we just happened to be exactly the right distance from the sun to be habitable." That would be absurdly improbable, but it becomes much less so when you realize that the Milky Way almost certainly has millions of planets. With so many possibilities, it's not surprising that at least one planet is friendly to life.

And so, he contends, it might be with the cosmos. What we think of as the "universe," argues Rees, could well be just one of trillions of universes on an indescribably vaster stage called the multiverse. Each of those universes would have different laws and characteristics. Most of them are totally unlivable; like Earth, ours just happens to be one of the lucky ones.

On its face, the idea that multiple universes exist simultaneously in some parallel spheres of being sounds as farfetched as Gardner's biocosm theory. But scientists have been warily edging toward that conclusion from other directions for reasons that originally had nothing to do with the anthropic principle.

Take black holes. In the 1960s, Princeton physicist John Wheeler coined the term to describe a region where matter is so dense and gravity so intense that even light can't escape. At the core of a black hole is a singularity, a spot where density and gravity appear to become infinitely great-- unleashing forces that could rip a hole in the very fabric of space-time and send a brand-new universe expanding in a direction undetectable and imperceptible to us. Since giant black holes lurk at the cores of many billions of galaxies and smaller holes are left behind by many billions of individual exploding stars, that could mean our cosmos has given birth to a staggering number of baby universes. And each of those could give birth in turn to billions more.