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

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.

What I?m suggesting ? this is where things depart from the conventional view ? is that the laws of physics themselves are subject to the same quantum uncertainty. So that an observation performed today will select not only a number of histories from an infinite number of possible past histories, but will also select a subset of the laws of physics which are consistent with the emergence of life. That?s the radical departure. It?s not the backward-in-time aspect, which has been established by experiment. There?s really no doubt that quantum mechanics opens the way to linking future with past. I?m suggesting that we extend those notions from the state of the universe to the underlying laws of physics themselves. That?s the radical step, because most physicists regard the laws as God-given, imprinted on the universe, fixed and immutable. But Wheeler ? and I follow him on this ? suggested that the laws of physics are not immutable.

People often ask, What happened before the Big Bang? The answer is, Nothing. By this, I do not mean that there was a state of nothingness, pregnant with creative power. There was nothing before the Big Bang because there was no such epoch as "before." As Stephen Hawking has remarked, asking what happened before the Big Bang is rather like asking what lies north of the North Pole. The answer, once again, is nothing, not because there exists a mysterious Land of Nothing there but because there is no such place as north of the North Pole. Similarly, there is no such time as "before the Big Bang."

The birth of science as we know it arguably began with Isaac Newton's formulation of the laws of gravitation and motion. It is no exaggeration to say that physics was reborn in the early 20th-century with the twin revolutions of quantum mechanics and the theory of relativity.

The universe is just a big information processor. Wheeler calls this ?it from bit.? Now if you take that view ? that the universe is a gigantic computer ? then it leads immediately to the conclusion that the resources of that computer are limited. The universe is finite. It?s finite because the speed of light is finite. There?s been a finite time since the big bang. So if we have a finite universe, we have a computer with finite resources, and hence, finite accuracy. So once you recognize that the universe is a gigantic computer, then you see that the laws of physics can?t be infinitely precise and perfect. There must be a certain amount of wiggle room or sloppiness or ambiguity in those laws. And the key point here is that the degree of error, which is inherent in the laws, depends on time. As the universe gets older, there are fewer errors because it?s had longer to compute. If you go back to the first split second after the big bang, then the underlying errors in the laws of physics really would have been very large. So instead of thinking of the universe as beginning magically with a bang, and the laws of physics being imprinted magically on the universe with infinite precision right from the word go, we must instead think of the laws as being emergent with and inherent in the universe, starting out a little bit vague and fuzzy, and focusing down over time to the form that we see today.

When I was a student, the laws of physics were regarded as completely off limits. The job of the scientist, we were told, is to discover the laws and apply them, not inquire into their provenance.

People take it for granted that the physical world is both ordered and intelligible. The underlying order in nature - the laws of physics - are simply accepted as given, as brute facts. Nobody asks where they came from; at least not in polite company. However, even the most atheistic scientist accepts as an act of faith that the universe is not absurd, that there is a rational basis to physical existence manifested as law-like order in nature that is at least partly comprehensible to us. So science can proceed only if the scientist adopts an essentially theological worldview.

The epoch before about a billionth of a second, however, remains murky territory, with plenty of scope for disagreement.

The vast majority of terrestrial species are in fact microbes, and scientists have only begun scratching the surface of the microbial realm. It is entirely possible that examples of life as we don't know it have so far been overlooked.

Where do we human beings fit into this great cosmic scheme? Can we gaze out into the cosmos, as did our remote ancestors, and declare: ?God made all this for us?? I think not. Are we then but an accident of nature, the freakish outcome of blind and purposeless forces, incidental by-product of a mindless, mechanistic universe? I reject that, too. The emergence of life and consciousness, I maintain, are written into the laws of the universe in a very basic way. True, the actual physical form and general mental make-up of Homo sapiens contain many accidental features of no particular significance. If the universe were rerun a second time, there would be no solar system, no Earth, and no people. But the emergence of life and consciousness somewhere and somewhen in the cosmos is, I believe, assured by the underlying laws of nature.

Perhaps the best motivation for going to Mars is political. It is obvious that no single nation currently has either the will or the resources to do it alone, but a consortium of nations and space agencies could achieve it within 20 years.

The general multiverse explanation is simply naive deism dressed up in scientific language. Both appear to be an infinite unknown, invisible and unknowable system. Both require an infinite amount of information to be discarded just to explain the (finite) universe we live in.

The very notion of physical law is a theological one in the first place, a fact that makes many scientists squirm. Isaac Newton first got the idea of absolute, universal, perfect, immutable laws from the Christian doctrine that God created the world and ordered it in a rational way. Christians envisage God as upholding the natural order from beyond the universe, while physicists think of their laws as inhabiting an abstract transcendent realm of perfect mathematical relationships.

Words like ?meaning? and ?purpose? are human categories, derived from human experience, and so we?re projecting them onto nature and saying, well, the best way of understanding the universe is to say it behaves in a purpose-like manner.

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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