Paul Davies


English Physicist, Author and Broadcaster, Professor at Arizona State University, Chair of SETI, Director of BEYOND: Center for Fundamental Concepts in Science

Author Quotes

Scientists have no agreed theory of the origin of life - plenty of scenarios, conjectures and just-so stories, but nothing with solid experimental support.

The origin of life is one of the great unsolved problems of science. Nobody knows how, where or when life originated. About all that is known for certain is that microbial life had established itself on Earth by about three and a half billion years ago. In the absence of hard evidence of what came before, there is plenty of scope for disagreement.

To expect alien technology to be just a few decades ahead of ours is too incredible to be taken seriously.

Searching for alternative life on Earth might seem misconceived, because there is excellent evidence that every kind of life so far studied evolved from a common ancestor that lived billions of years ago. Yet most of the life that exists on Earth has never been properly classified.

The popular image of mathematics as a collection of precise facts, linked together by well-defined logical paths is revealed to be false. There is randomness and hence uncertainty in mathematics, just as there is in physics.

Traditionally, scientists have treated the laws of physics as simply 'given,' elegant mathematical relationships that were somehow imprinted on the universe at its birth, and fixed thereafter. Inquiry into the origin and nature of the laws was not regarded as a proper part of science.

No planet is more earth-like than Earth itself, so if life really does pop up readily in earth-like conditions, then surely it should have arisen many times right here on our home planet? And how do we know it didn't? The truth is, nobody has looked.

Should we find a second form of life right here on our doorstep, we could be confident that life is a truly cosmic phenomenon. If so, there may well be sentient beings somewhere in the galaxy wondering, as do we, if they are not alone in the universe.

The position I have presented to you today is radically different. It is one that regards the universe, not as the plaything of a capricious Deity, but as a coherent, rational, elegant, and harmonious expression of a deep and purposeful meaning. I believe the time has now come for those theologians who share this vision to join me and my scientific colleagues to take the message to the people.

Until now, I've been writing about now as if it were literally an instant of time, but of course human faculties are not infinitely precise. It is simplistic to suppose that physical events and mental events march along exactly in step, with the stream of actual moments in the outside world and the stream of conscious awareness of them perfectly synchronized. The cinema industry depends on the phenomenon that what seems to us a movie is really a succession of still pictures, running at twenty-five [sic] frames per second. We don't notice the joins. Evidently the now of our conscious awareness stretches over at least 1/25 of a second. In fact, psychologists are convinced it can last a lot longer than that. Take he familiar tick-tock of the clock. Well, the clock doesn't go tick-tock at all; it goes tick-tick, every tick producing the same sound. It's just that our consciousness runs two successive ticks into a singe tick-tock experience?but only if the duration between ticks is less than about three seconds. A really bug pendulum clock just goes tock . . . tock . . . tock, whereas a bedside clock chatters away: ticktockticktock... Two to three seconds seems to be the duration over which our minds integrate sense data into a unitary experience, a fact reflected in the structure of human music and poetry.

Nobody can really object to the ?weak anthropic principle.? It just says that the laws and conditions of the universe must be consistent with life; otherwise, we wouldn?t be here. But if we combine it with the multiverse hypothesis, then we?re in business. The multiverse hypothesis says that what we?ve been calling the universe is nothing of the kind. It?s just a bubble, a little local region in a much vaster and more elaborate system called the multiverse. And the multiverse consists of lots of universes. There are different ways you can arrange this. One way is to have them scattered throughout space, and each universe would be a gigantic bubble, much bigger than the size of what we can see at the moment, but there would be many, many bubbles. And each of these bubbles would come with its own set of laws.

So how can we test the idea that the transition from nonlife to life is simple enough to happen repeatedly? The most obvious and straightforward way is to search for a second form of life on Earth. No planet is more Earth-like than Earth itself, so if the path to life is easy, then life should have started up many times over right here.

The problem with this neat separation into ?non-overlapping magisteria,? as Stephen Jay Gould described science and religion, is that science has its own faith-based belief system. All science proceeds on the assumption that nature is ordered in a rational and intelligible way. You couldn?t be a scientist if you thought the universe was a meaningless jumble of odds and ends haphazardly juxtaposed. When physicists probe to a deeper level of subatomic structure, or astronomers extend the reach of their instruments, they expect to encounter additional elegant mathematical order. And so far this faith has been justified.

We can now see that Augustine was right, and popular religion wrong, to envisage God as a super-being dwelling within the stream of time prior to the creation. Professional theologians acknowledge this. The doctrine of creation ex nihilo (out of nothing) does not mean God pushing a metaphysical button and making a Big Bang, then sitting back to watch the action. It means God sustaining the existence of the universe, and its laws, at all times, from a location outside of space and time.

Of course, science has a cultural aspect; but if I say that planets moving around the sun obey an inverse-square law of gravitation and I give a precise mathematical meaning to that, I think it is really the case. I don't think it?s a cultural construct - it's not something we have invented or imagined just for convenience of description - I think it's a fact. And the same for the other basic laws of physics.

So if life can exist under the ground on Earth, maybe it can exist under the ground on Mars, too.

The really amazing thing is not that life on Earth is balanced on a knife-edge, but that the entire universe is balanced on a knife-edge, and would be total chaos if any of the natural ?constants? were off even slightly. You see,? Davies adds, ?even if you dismiss man as a chance happening, the fact remains that the universe seems unreasonably suited to the existence of life?almost contrived?you might say a ?put-up job?.

We have to find a framework of ideas that provides ordinary people with some broader context to their lives than just the daily round, a framework that links them to each other, to nature, and to the wider universe in a meaningful way, that yields a common set of principles around which peoples of all cultures can make ethical decisions yet remains honest in the face of scientific knowledge; indeed, that celebrates that knowledge alongside other human insights and inspirations. The scientific enterprise as I have presented it may not return human beings to the center of the universe, it may reject the notion of miracles other than the miracle of nature itself, but it does not make human beings irrelevant either. A universe in which the emergence of life and consciousness is seen, not as a freak set of events, but fundamental to its law-like workings, is a universe that can truly be called our home.

Only in the last few years all this is happening. Now that we all have the time.

So where is God in this story? Not especially in the big bang that starts the universe off, nor meddling fitfully in the physical processes that generate life and consciousness. I would rather that nature can take care of itself. The idea of a God who is just another force or agency at work in nature, moving atoms here and there in competition with physical forces, is profoundly uninspiring. To me, the true miracle of nature is to be found in the ingenious and unswerving lawfulness of the cosmos, a lawfulness that permits complex order to emerge from chaos, life to emerge from inanimate matter, and consciousness to emerge from life, without the need for the occasional supernatural prod; a lawfulness that produces beings who not only ask great questions of existence, but who, through science and other methods of enquiry, are even beginning to find answers.

The religious interpretation is that God made the universe just as it is in order that life and conscious beings could emerge. The other way, which I suppose would be anti-religious, is to say that the emergence of life and observers causes the universe to have the laws that it does. In the causal sense, it puts the cart before the horse. It makes the emergence of life and observers later on in the universe have some responsibility for the way the laws come into being at the beginning.

We will never fully explain the world by appealing to something outside it that must simply be accepted on faith, be it an unexplained God or an unexplained set of mathematical laws.

Over the years I have often asked my physicist colleagues why the laws of physics are what they are. The answers vary from ?that?s not a scientific question? to ?nobody knows.? The favorite reply is, ?There is no reason they are what they are -- they just are.? The idea that the laws exist reasonlessly is deeply anti-rational. After all, the very essence of a scientific explanation of some phenomenon is that the world is ordered logically and that there are reasons things are as they are. If one traces these reasons all the way down to the bedrock of reality -- the laws of physics -- only to find that reason then deserts us, it makes a mockery of science.

Standard quantum physics says that if you make an observation of something today ? it might just be the position of an atom ? then there?s an uncertainty about what that atom is going to do in the future. And there?s an uncertainty about what it?s going to do in the past. That uncertainty means there?s a type of linkage. Einstein called this ?spooky action at a distance.?

The strong anthropic principle says that the universe must bring forth life and observers at some stage. So even if there?s only one universe, it must be the case that this universe will end up being observed by beings such as ourselves. Now, that?s much harder for scientists to swallow because it seems to turn everything upside down. Most scientists think that the universe came into existence by some happy coincidence, or maybe from this multiverse selection there were beings who emerged. But these beings don?t play a central role even in the multiverse theory. They don?t play a creative role, whereas in the strong anthropic principle, the observers are in the central position. They are the ones dictating how the universe is put together. And that seems too much for people to swallow. It gives mind and consciousness a central place in the great scheme of things.

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English Physicist, Author and Broadcaster, Professor at Arizona State University, Chair of SETI, Director of BEYOND: Center for Fundamental Concepts in Science