CRAB NEBULA: Without star debris like this, life would not be possible
That's why the case of James Gardner is so surprising. He seems to fit the profile perfectly: he's a Portland, Ore., attorney, not a scientist, who argues — are you ready for this?--that our universe might have been
|
|
||||||||||||||
|
||||||||||||||
manufactured by a race of superintelligent extraterrestrial beings. That is exactly the sort of idea that would normally have experts rolling their eyes, blocking e-mails and hoping the author won't corner them at a lecture or a conference.
But when Gardner's book Biocosmcame out last year, it carried jacket endorsements from a surprisingly eminent group of scientists. "A novel perspective on humankind's role in the universe," wrote Martin Rees, the astronomer royal of Britain and a Cambridge colleague of Stephen Hawking's. "There is little doubt that his ideas will change yours," wrote Seth Shostak, senior astronomer at the Search for Extraterrestrial Intelligence (SETI) Institute in California. "A magnificent one-stop account of the history of life," wrote complexity theorist John Casti, a co-founder of the Santa Fe Institute. Since then, Gardner has been welcomed at major planetariums and legitimate scientific conferences, explaining his ideas to a surprisingly interested public.
It's not that anyone actually buys Gardner's theory. He admits it's "farfetched," and even those scientists who find it stimulating think it's wildly improbable. But it does have one thing in its favor. The biocosm theory is an attempt, albeit a highly speculative one, to solve what just might be science's most profound mystery: why the universe, against all odds, is so remarkably hospitable to life.
Given that we haven't found any life beyond Earth yet, "remarkably hospitable" may sound a bit strong. At a deep level, though, it's true. Many of the most fundamental characteristics of our cosmos — the relative strengths of gravity, electromagnetism and the forces that operate inside atomic nuclei as well as the masses and relative abundances of different particles — are so finely tuned that if just one of them were even slightly different, life as we know it couldn't exist.
If the so-called weak nuclear interaction were a tiny bit stronger or weaker than it is, for example, stars wouldn't blow up in the mammoth supernovas that spread elements like carbon and oxygen out into space — and without those elements, there would be no water and no organic molecules. If the strong nuclear force were just one-half of 1% stronger or weaker, stars could not make carbon or oxygen in the first place. In 1999 Martin Rees postulated that there were "just six numbers" that make life possible, although other theorists have since added several. And because there is no known law that requires those forces to have the values they do, scientists figure that there must be another explanation for how we got so lucky.
The proposition that the cosmos is — against all odds — perfectly tuned for life is known as the anthropic principle. And while it has been getting a lot of attention lately, there is no consensus on how seriously to take it. Some scientists are confident that there is a law that dictates the values of those key cosmic numbers, and when we find it, the anthropic problem will go away. Others think the answer is even simpler: if the numbers were any different than they are, we wouldn't be around to argue about them — case closed. "The anthropic principle," complains Fermilab astrophysicist Rocky Kolb, "is the duct tape of cosmology. It's not beautiful or elegant, and it sure as hell is not going to be permanent."