Why is the universe, like the porridge in the tale of Goldilocks and the three bears, “just right” for life? Even cosmologists have said it looks like a fix or a put-up job. Is it a fluke or providence that it appears set up expressly for the purpose of spawning sentient beings?
Until recently the Goldilocks question was almost completely ignored by scientists. But dramatic developments in our understanding are propelling the issue to the forefront of the agenda, according to the acclaimed British physicist and bestselling author Paul Davies. To stoke the fire, he is to chair a debate between advocates of alternative theories at Oxford on Friday.
Anyone expecting Davies to recant his non-religious views and join the intelligent design lobby will be disappointed. “We can’t dump all this in the lap of an arbitrary god and say we can’t inquire any further,” he says. “The universe looks ingenious, it looks like a fix, and words like meaning and purpose come to mind. But it doesn’t mean that we’re going to have a miracle-working cosmic magician meddling with events.”
What concerns him in his new book The Goldilocks Enigma is science and the universe’s stringent conditions for existence, so finely tuned that even the slightest twiddle of the dials would wreck any hope of life emerging in the universe. “No scientific explanation of the universe can be deemed complete unless it accounts for this appearance of judicious design,” he says.
Beyond the obvious prerequisites such as water, the sun’s energy and the various chemical elements (oxygen, hydrogen, nitrogen, etc) needed to make biomass, there’s the tricky stuff. If protons were a tiny bit heavier they would decay into neutrons, and atoms would disintegrate. No carbon would have been formed by nuclear reactions inside stars if the nuclear force varied by more than a scintilla.
This is where the acrimony starts. Some cosmologists claim the bio-friendliness of the universe is explained by a multitude of universes, known as the “multiverse”. Lord Rees, a leading proponent and president of the Royal Society, believes the laws of physics are merely local bylaws that hold good for our universe but will be different among our neighbours.
Such speculation has infuriated some particle physicists, particularly adherents of string theory, who aspire to a final theory that will unify all physical laws and tie up the loose ends.
Their scorn for the multiverse theory is echoed by Frank Close, professor of theoretical physics at Oxford and a participant in Friday’s debate, although he is no string theorist: “It’s a cop-out. To my mind it’s no different from the idea that God did it. If we cannot do any scientific experiments to prove what one of these other universes would be like, it’s beyond science. It’s just giving up.”
Then there’s the viewpoint of Richard Dawkins, the ardent Darwinist and recent author of The God Delusion, who holds that life is essentially pointless and came about by chance before natural selection took over. Close compares Dawkins to religious fundamentalists, “who know they are right in their position, just as Richard knows he is right in his position”.
Davies wants to rise above such bickering. “I want to get away from this notion that something has to be accepted on faith,” he says. “That just becomes a sterile argument. These people can argue all night, but you’re never going to prove or disprove the other person’s position.”
He is fascinated by an alternative answer to the Goldilocks question. “Somehow,” he writes, “the universe has engineered, not just its own awareness, but its own comprehension. Mindless, blundering atoms have conspired to make, not just life, not just mind, but understanding. The evolving cosmos has spawned beings who are able not merely to watch the show, but to unravel the plot.”
What exactly is Davies saying? His starting point is the “highly significant” fact that the universe supports people who understand its laws. “I wanted to get away from the feeling in so many scientific quarters that life and human beings are a completely irrelevant embellishment, a side issue of no significance. I don’t think we’re the centre of the universe or the pinnacle of creation, but the fact that human beings have the ability to understand how the world is put together is something that cries out for explanation.”
Davies’s big idea goes back to the Big Bang. According to the standard picture, the laws of physics were already in place at the explosive origin of the universe. But he contends that perhaps the universe and its laws emerged together in malleable form: “We would expect that these laws were not infinitely precise mathematical statements, but they would have a certain sloppiness or ambiguity that could lead to observable effects from the earliest universe, when these laws were still congealing.”
So how did compatible life and mind come into being? Davies’s explanation, involving quantum mechanics and something called backwards causation, is impossible to compress without sounding “ludicrous”, he confesses. He’s right: it’s impenetrable.
But this scenario requires an act of faith as great as that of any religious believer. So hasn’t he sidestepped the God question? Science can meet religion on middle ground, he says, but a superbeing who intervenes in events is anathema to most scientists. “You have to understand that science deals with hypotheses that can be tested, and religion proceeds from acts of faith that can’t be tested.”
Davies has just left an academic job in Australia to delve further into the origins of things at the provisionally named Blue Sky think tank in Phoenix, Arizona. One of his first projects is to investigate the possibility that life emerged not just once on Earth, but thousands of times. The accepted wisdom is that all the planet’s life derives from a common ancestor, ranged on the tree of life.
“The question is whether there’s just one tree in the forest. If life is easy to get going, we might expect many trees of life but maybe only one tree survived. But maybe there are members of other trees under our noses, but we don’t appreciate what they are.” He conjectures a fertile phase starting four billion years ago when ferocious cataclysms caused by comets and asteroids repeatedly zapped emerging life on Earth before the present “tree” took root 3.5 billion years ago.
In writing his book, Davies was struck by how “ridiculous” all the theories and options seemed. Perhaps, he muses, we have evolved to think about the world in a certain way and we are posing the wrong questions. “I wonder if we’re just stuck in certain patterns of thought and we’re doomed to forever have these discussions and arguments. Perhaps the real answers lie utterly beyond our ken.”
The Goldilocks Enigma: Why is the Universe Just Right for Life? by Paul Davies is published by Allen Lane, £22. A debate, Confronting the Goldilocks Enigma, will be held at the Oxford Playhouse at 5pm on Friday (www.oxfordplayhouse.com)
