"science offers a surer path to God than religion"
[my] central theme ... concerns what I call the Big Four questions of existence:
* Why are the laws of nature what they are?
* Why does the universe consist of the things it does?
* How did those things arise?
* How did the universe achieve its organisation?
[As we proceed] ... tentative answers to these questions begin to emerge - answers based on the physicist's conception of nature. The answers may be totally wrong, but I believe that physics is uniquely placed to provide them. It may seem bizarre, but in my opinion science offers a surer path to God than religion. Right or wrong, the fact that science has actually advanced to the point where what were formerly religious questions can be seriously tackled, itself indicates the far-reaching consequences of the new physics.
So Paul Davies, in the preface to his book God and the New Physics in 1983. It's quite a claim, and it's a fascinating little book, but whatever its virtues or faults it seems to me notable because it makes explicitly religious claims - not religious claims through the back door, but explicitly religious claims - for science in general, and physics in particular. It does not say, as perhaps some people from an older generation would have said, "science has disproved religion", but rather, here are a set of religious questions, and I am now going to essay some answers to those questions from a scientific base.
"Science" and "Religion"
It all depends, of couurse, on what you mean by "religion" and "science". Professor Davies' so-called Big Four questions clearly have a religious dimension - but I doubt that any of the traditions of religious thought would phrase the questions as Davies does; something different is happening. The famous and provocative phrase "a surer path to God than religion" is the key. By speaking of "a path to God" he not only concedes, but proudly claims to be on religious territory - yet he can barely find a good thing to say about religion, so for example:
The scientist and the theologian approach the deep questions of existence from utterly different starting points. Science is based on careful observation and experiment enabling theories to be constructed which connect different experiences. Regularities in the working of nature are sought which hopefully reveal the fundamental laws which govern the behaviour of matter and forces. Central of this approach is the willingness of the scientist to abandon a theory if evidence is produced against it. Although individual scientists may cling tenaciously to some cherished idea, the scientific community as a group is always ready to adopt a new approach. There are no shooting wars over scientific principles.
(Paul Davies is a theoretician; if he believes that a shooting war could not break out over a scientific dispute, he has clearly never spent any time around my experiment ... but I digress.)
In contrast, religion is founded on revelation and received wisdom. Religious dogma that claims to contain an unalterable Truth can hardly be modified to fit changing ideas. The true believer must stand by his faith whatever the apparent evidence against it. This `Truth' is said to be communicated directly to the believer, rather than through the filtering and refining process of collective investigation. The trouble about revealed `Truth' is that it is liable to be wrong, and even if it is right other people require a good reason to share the recipients' belief.
Many scientists are derisory about revealed truth. Indeed, some maintain that it is a positive evil: "Generally the state of mind of a believer in a revelation is the awful arrogance of saying `I know, and those who do not agree with my belief are wrong'. In no other field is such arrogance so widespread, in no other field do people feel so utterly certain of their `knowledge'. It is to me quite disgusting that anyone should feel so superior, so selected and chosen against all the many who differ in their beliefs and unbeliefs ..."
and so it goes on, where the fellow whom he quotes with approval at the end there is Hermann Bondi, one of the leading lights of the Steady State theory of the universe, which we might get on to later. This is such a clear example - rather, such a crass example of the old "Science versus Religion" discussion (white versus black, good versus evil, etc.) that you have to wonder why he doesn't finish the book right there (the quote is from page six!), and then go off and read a book by Huxley, or Bertrand Russel's Why I am not a Christian, or something like that. But - and this is the point about Paul Davies - he still has his Big Four questions to answer, and he can't help himself.
What we are witnessing is someone about to embark on religious thought himself, but with his feet firmly planted in the polemical tradition of "Science versus Religion". I called this an old tradition just now, although you only have to look as far as Phillip Adams to find a perfect modern specimen - I don't know if you heard him on the radio recently; he's pretty much the same as he was ten years ago, and the rhetoric almost unchanged from that being used eighty years ago in this debate. But from within that tradition Paul Davies wishes to answer religious questions:
* Why do this set of principles govern the world?
* Why does the world have these things in it?
* How did these things get here?
* How did the world come to be this way?
It's as if he were an invading general, having defeated the enemy army, staying to settle in their territory and govern it according to his own principles. We'll come back to Military Governor Davies later, to see how much he has been influenced by the local culture.
The New Physics
But first, "the new physics". I'm not sure that Davies invented the term, but he certainly brought it to popular attention; it's a handy way of saying that there are recent developments in physics which are somehow significant or special. The list I'm presenting here is adapted from a book edited by Davies and called (of course) The New Physics. I'll only make a brief sketch of each area, since I hope to make it to the pub by lunchtime.
* chaos
* low temperature physics, solid state physics, self-organisation, etc
* astrophysics
* particle physics
* relativity
* quantum mechanics
chaos
Chaos is the newest kid on the block and it constitutes a revolution in scientific thinking, a revolution which is still in progress today. The best-known example, discussed ad nauseam in popular books and Saturday paper specials, is the butterfly effect: that the smallest nudge to a system, after a certain amount of time has passed, can have a very large effect - as large an effect as the system in general allows. So for example, a butterfly flaps its wings in Cambodia: allow some reasonable amount of time to pass (in this case it's about a week) and there might be a hurricane off the American coast. Wing flap: hurricane. No wing flap: no hurricane. This is of course not to say that every butterfly that flaps its wings causes a hurricane, but rather, that if a particular butterfly is in the wrong place at the wrong time, then it can make the difference between the two states, "hurricane" or "no hurricane". Although this is a striking illustration, it doesn't go to the heart of the matter, because everyone always knew that the weather is complicated, and people outside meteorological research were sceptical about long-term weather prediction long before chaos was discovered. The shocking thing about chaos is that it can happen in the simplest of systems, even a pendulum: a ball hanging from a string and allowed to swing about. Under some conditions, the exact way a microscopic piece of dust lands on the ball today can completely change the way it's swinging tomorrow.
Simple, clockwork-like systems like pendula are the foundation on which a lot of physics has been built, and we thought we understood them. Chaos is actually new mathematics rather than new physics, and it took us completely unawares - the only analogy I can think of is discovering that while your father is your father, he has been leading a double life and has another family on the side. It's the kind of development that forces you to reappraise many, many things, and this is the effect it's currently having on the scientific community. Well, part of it anyway (the part that stares into the mirror in the morning and worries about what it's doing). I'm not going to work chaos into the talk today, but it will be hanging around in the background, and I'm happy to speak to it in the discussion later [note].
low temperature physics, solid state physics, self-organisation, etc
In the second item I've lumped together a great number of things: great advances in the physics of low-temperature systems, so-called solid state physics, systems that exhibit self-organisation ... and I've put an etcetera on the end. These developments do have some features in common, but the main connection is that I don't know much about any of them, certainly not enough to give a good pencil-sketch. They're in the list for completeness; read a good book if you're curious.
astrophysics
Astrophysics is literally "the physics of stars", although the subject includes very exotic beasties these days, in addition to stars. The difference between the old astronomy and the new astrophysics has been made by improvements in technology and advances in theory: as well as telescopes, there are now very big telescopes, telescopes in space, instruments that "see" radio waves, infrared and ultraviolet light, x-rays and gamma rays; spectrometers which allow you to study the chemistry of stars and gas clouds thousands of light-years away, and Doppler instruments which allow you to do "seismology" on the sun, feeling how it vibrates - not a bad trick, considering that it's 150 million kilometres away.
A little something added for the WWW version of this paper: This is the first direct look, in visible light, at a lone neutron star, as seen by NASA's Hubble Space Telescope.
The Hubble results show the star is very hot (1.2 million degrees Fahrenheit at the surface), and can be no larger than 16.8 miles (28 kilometers) across. These results prove that the object must be a neutron star, because no other known type of object can be this hot, small, and dim (below 25th magnitude).
Picture from Fred Walter (State University of New York at Stony Brook), and NASA. The full-size (759KB) JPEG, the full text of the press release associated with this picture, and many other interesting things, are available at the Space Telescope Science Institute web-page; the smaller-size picture included here is reproduced with permission from the STScI.
To give you a bit of the flavour of how far things have progressed: my own experiment was inspired, in part, by a discrepancy of a factor of two, between our predictions of what's going on in the centre of the sun, and our observations of what's going on there. Consider that for a moment. We have some precise, numerical predictions concerning the centre of the sun, which is separated from us by half-a-million kilometres thickness of very hot, very dense, ionised gas, that you can't see through; we have (a few) observations of what's going on in the centre of the sun, which is separated from us by half-a-million kilometres thickness of very hot, very dense, ionised gas, that you can't see through; the prediction and the observation agree within a factor of two; and almost the entire experimental community is worried about the discrepancy, and considers it significant. So significant, that there is a large and diverse experimental effort to try to resolve the discrepancy.
We are now at the stage of dealing with remote objects, out there in the sky, in ways that were previously only supposed possible for controlled experiments in the laboratory; it's remarkable how things have progressed.
particle physics
I've listed the "new physics" by categories, although the different categories impinge on each other in sometimes surprising ways. The experiment on which I work, although it's inspired by astrophysical concerns, is actually in particle physics: the study of so-called "fundamental particles", the little bits and pieces you find when you keep pulling things apart until you can't pull them apart any further. If you like, it's the study of the very, very small, while astrophysics deals with things which are very large indeed; despite this, the two fields are very closely connected, and science is beginning to develop a bit of the flavour of the whole web of being, from the very small to the very large, all linking in with each other.
Thirty to forty years ago, particle physics was a complete mess, with two-hundred supposedly "fundamental" particles and precious little by way of a rational system even for organising our observations. In the intervening time, and several Nobel Prizes later, things are dramatically different: there are a handful of entities which we consider to be basic - not quite as few as air, earth, fire and water, but pretty close; and the theory which deals with about half of the field is one of the jewels in the crown of modern physics, making predictions down to ten decimal places or more, which agree with the experiments down to ten decimal places or more. That theory is built on the two truly fundamental developments in physics this century, both of which took place well befroe the second world war: relativity and quantum mechanics.
relativity
Relativity theory has to do with what stays the same and what changes, depending on where you are and what you're doing - standing still, spinning around, sitting in a train, flying in an aeroplane or a rocket, falling into a star, and so on. It's notable for being very difficult to believe, for the wonderfully elegant lines of reasoning which were used to deduce it, for its tricky mathematics, and the fact that almost all of the key work was done by one person - Albert Einstein of course. There are actually two theories of relativity:
special relativity (1905)
The special theory has to do with standing still, sitting in a train, flying in an aeroplane or a rocket; those sorts of things. The surprising prediction is that while a person sitting on a train will perceive the ground to be moving, and vice versa (I guess you already knew that) absolutely everybody will measure light to travel at the same speed, no matter how fast they are moving themselves, where the light comes from, whether it's overtaking you from behind or coming at you head-on. It's as if you were in one of two cars on the freeway, and no matter how fast you drove or in what direction, you always saw the other car to be travelling at 110 km/h compared to yourself. This is not how you think of things working: if you are doing 100 km/h, and the other car is doing 110 km/h, then you will only see it pulling away from you slowly - and yet, in reality, you always clock the light at 110 km/h.
Some other consequences are that nothing else can quite make it up to 110 km/h (well, actually, the real speed of light, which is very much faster) no matter how hard it tries; and that cars, trains, people etc. are seen to shrink, and time run more slowly for them, when they move very quickly - in other words, a lot of very-difficult-to-believe predictions which we accept because they have passed every experimental test that has ever been set for them. The extreme beauty of the theory, which I mentioned before, is another reason we actually believe all this, as is the way it cleared up a really fundamental discrepancy in the physics that went before it: Einstein actually worked it out by thinking about the discrepancy in the older theory.
(If you've seen the film Young Einstein: There's a scene where Young Einstein develops the theory of relativity at the same time as he invents surfing - he's chiselling a surfboard out of the trunk of a tree in a coastal forest and thinks about surfing on a wave of light - and this is surprisingly close to the how the real Einstein thought of it. He was cycling in a forest somewhere in Switzerland, and he wondered what the world would look like if you sat (or surfed, if you like) on the front of a light wave. Of course he'd thought about the subject before, and he knew the existing theory well and so on [note], but he developed the theory of relativity by taking that line of thought and following it through.)
general relativity (1915)
The general theory of relativity answers the same questions when gravity is involved - what is the same, and what is different, when you are sitting on top of a mountain rather than at sea level, orbiting the sun, falling down, and so on. It's harder to illustrate and understand: one of the simpler predictions is that time runs slightly slower at sea level than it does at the tops of mountains - not just your watch running slow, but time itself running slow, a point we'll come back to [note]. This is even stranger than the things that the special theory of relativity asks you to believe, but again, we believe it because all the experiments agree: the best observation now agrees with the theory to something like one part in a hundred million million, the limitation being that we don't have clocks better than that yet.
quantum mechanics
Finally (and it's been quite a list) there is quantum mechanics, which is the theoretical development over which the most ink has been spilt, at least in popular books. All the talk about Schrödinger's cat; about throwing a ball at a brick wall and having it go through two holes, a metre apart, at the same time [note]; the uncertainty principle; and, last and probably least, the "tao of physics", is about quantum mechanics. The reason so much gets written about it is that no-one understands it: this makes it very difficult to describe in a succinct manner (it's much easier just to keep talking!) and I'll leave it to the discussion time or to questions. I really mean that no-one (or, no-one who isn't kidding themselves) understands it properly, which is embarrasing since it has opened the door to about half of the technological developments of this century. The theory in particle physics which I mentioned before, which makes predictions which we've confirmed in experiments to one part in ten billion, was made by putting quantum mechanics together with the special theory of relativity. That's pretty good for something you don't understand.
Cosmology and Stephen Hawking
I thought I'd get the "gee whiz" factor out of my system early in the talk. This is important because someone telling you surprising things about the world, or relating impressive details such as "the theory is correct to at least one part in ten billion" runs the risk of "blinding you with science" as the saying is - you just have to switch off and believe everything they say, and you can't engage your critical faculties. If you're the person speaking, it can cause something of a rush of blood to the head. Being able to predict observable numbers to ten decimal places is impressive, and until recently it had never been done, but it doesn't mean that you're God - it doesn't even mean that you know the mind of God. Physicists have been known to lose sight of this occasionally. Those who work in the field called cosmology are, at least according to other physicists, especially prone to this sort of hubris, and there is a saying about them: "cosmologists are seldom right, but never in doubt."
I left cosmology out of the list of the "new physics" for a few reasons: it will bring us at last to the $64,000 question, "what's God got to do with it?"; cosmology needs a more extended explanation than the other fields which I've glossed over; and, an especially easy way to sketch cosmology, at least for our purposes, is to talk about Stephen Hawking.
It is hard to overstate the importance of Stephen Hawking; of course people try to overstate his importance all the time, and sometimes succeed. If memory serves there is an episode of Star Trek: The Next Generation where Sir Isaac Newton, Albert Einstein and Stephen Hawking are summoned to the holodeck (in simulation of course) to play a game of poker (of course) with the ship's resident android (of course!) who wants to learn more about the nature of human genius. That was probably overstating his importance a little bit: in physics, grouping someone with Newton and Einstein is rather like saying that they appeared on the Mount of Transfiguration, along with Moses and Elijah, to talk with Jesus.
General relativity and the expanding universe
But he is very important - people have a reason for going on about the guy. I mentioned general relativity before: one thing about gravity in general and general relativity in particular, is that it makes the universe unstable. The universe can't "just sit there", because each of the objects attracts all of the others. If at some time everything is just sitting there, stationary, then they will begin to pull together.
As the distance between objects becomes smaller, local irregularities or "clumps" will develop (shown in black in the next picture), but then these clumps will still be attracting each other. Some objects might get "thrown clear" in close encounters with large bodies, but on average the universe will fall in on itself faster and faster. What eventually happens to it is not the point at issue right now, although this will become important shortly.
The sketches are just to give you a general idea, and obviously the situation is very different if everything is already moving around. For example, if there's a slight overall rotation in some isolated system, then eventually the system collapses into a flat disk which "holds itself up" by each of the pieces always moving sideways with respect to the centre - the whole system spins around, in other words. Both the solar system and our galaxy are like this.
(Whether it makes sense to suppose that the universe as a whole could spin around is a controversial question philosophically [note], but this doesn't concern us here.)
The instability means that something must be happening: either the universe is collapsing in on itself, or it must be expanding already (and the rate of expansion be slowing down), or some more complicated motion (such as a rotation) must be occuring. But it can't just be sitting there. This falls out of relativity theory very neatly, and Einstein worried about this a great deal, because a static universe (at least on a large scale) was taken for granted in those days.
But then in the 1920s, it was discovered that everything in the universe is flying apart from each other, as if everything was on the surface of a large balloon that was being inflated - or as if all the galaxies and so forth were raisins in a piece of dough in the oven, moving further and further apart as the dough rises ...
The "Big Bang"
That's what the universe is like. So suppose you run that backwards in time: if everything is moving apart, then some time earlier things must have been closer together; and even longer ago, they must have been closer together still. Can you keep going? What happens?
That's the "Big Bang". If the whole universe is expanding like that, at some point in the past there must have been a "big bang" that everything came from. You may have noticed the flaw in this: what's to stop everything from coming together (as in our previous series of sketches) but move sideways a little and "miss each other", and fly apart again? ...
Stephen Hawking. Together with Roger Penrose - an equally significant person in these matters, but someone who doesn't get as much press - he proved a set of mathematical propositions called singularity theorems. One consequence of these theorems is that there is no escape from the "big bang" conclusion: the expanding universe we observe cannot be due to objects falling together, and then flying apart again.
So it's not just the idea that everything must have come from a big explosion - it really seems that it must have been that way. It appears that the universe started at some definite time in the past.
Black holes
The other thing Stephen Hawking has been associated with is black holes, the sexy end of astrophysics. There are other versions of the singularity theorems which say that when a star gets into a sufficiently bad state of gravitational collapse, there is a "point of no return", beyond which it will fall in on itself forever. Eventually the star collapses into a body only a few kilometres across, distorting the space around it so badly that not even light can escape from its vicinity. That means that nothing can escape: you are left with a "hole" in space ... things can fall into it but nothing can ever come out of it. And the material "inside" the hole continues to fall in on itself, and finally collapses down to a point - of infinite density? (a question we'll come back to).
A caveat:
I made some mention earlier of three basic theories in physics: quantum mechanics, special relativity and general relativity. Everything we've discussed so far concerning Stephen Hawking, the big bang and black holes is taken from general relativity. The area where I work, particle physics, takes its theoretical base from an uneasy combination of special relativity with quantum mechanics. And I am no theoretician, but an experimentalist, and a fairly humble one at that: together with about 150 other physicists, I help look after one of the big pieces of experimental equipment, and worry about the data which it provides. This is just to put my own comments into some perspective - particularly as I will be saying some critical things about Stephen Hawking very shortly. The man is one of the principal workers in his field, whereas I'm a rather small figure working a few doors down the road.
Hawking radiation
Stephen Hawking is one of the key people trying to work in general relativity and quantum mechanics at the same time, treating problems where the theories overlap. We really don't know how to fit these areas of physics together: individually they work, and give some of the spectacular results I mentioned earlier, but they are radically different and (on the face of it) incompatible. A way forward in this sort of situation is to address a specific problem and to see if one can make some progress. This may (or may not) show the way forward with the wider problem. It's perhaps like making a single trip of exploration into unknown territory.
The spectacular example in which Stephen Hawking has brought general relativity and quantum mechanics together has to do with black holes, but we need a small digression before it can make much sense. The following illustration is something I dreamt up last night - I hope it can make the situation clear.
Suppose you take a block of glass in the shape of a triangular prism, cut square at one corner and at 45 degrees at the other two corners; it has two faces at right angles to each other, and a third, diagonal face.
Now if you shine light squarely into the first face, it will bounce off the diagonal face of the glass, as if from a perfect mirror, and emerge from the second face, back into the air.
The phenomenon is called total internal reflection, and is used to make mirrors for periscopes and optical instruments, and so on. (You can polish glass much flatter than you can polish a piece of metal, which is why this technique is used.)
No light emerges from the diagonal face of the glass into the air. But if you bring another piece of glass very close to the first one, the light can "leak across" from one piece of glass to the other and come out the other side, even though there is no light "in the middle", between the two pieces of glass.
This phenomenon of objects "passing through" regions "where they can't be", on their way to somewhere else "where they can be", is a well-known effect in quantum mechanics. (It's usually called tunneling, from the following metaphor: how do you get to the other side of a mountain range, if it's impossible to climb over the mountain? You tunnel through the mountain.)
What Stephen Hawking proved was that the same thing could happen with a black hole.
From the point of view of general relativity, nothing can ever come out of a black hole: it's as if there is a boundary around the black hole (the "event horizon"), and nothing from inside can cross that boundary.
But suppose you also take quantum mechanics into account: if an object inside were to come close to the boundary, and there were something on the other side of the boundary, to "catch" it - could it leak from inside to outside the black hole, even though it can't cross the boundary?
In fact it turns out, when you do the calculations, that the space around the black hole is so distorted by the enormous gravity of the thing, that it can provide the other piece of glass (if you like) and so particles in fact leak slowly out of a black hole.
Rather than being "black", then, a black hole actually glows dull red. A very dull red, in fact: a black hole with the mass of the sun would have a "temperature" of about a millionth of a degree above absolute zero, so it would glow such a dull red as to be black for all intents and purposes. But a "black" hole with the mass of a mountain would be not so much glowing white-hot, as blazing white-hot, radiating energy away so fiercely that it would evaporate in a very short time ... with complicated (and not entirely clear) results.
Stephen Hawking didn't believe this result at first, and went to a lot of effort to prove that it couldn't be true, but was eventually convinced of it. When he first presented it to his colleagues the chairman of the seminar told him it was total rubbish ... but since then, everyone has gone back and checked the work, and it seems to be true. It's called Hawking radiation now, this dull glow leaking from otherwise-black holes, and that in itself is quite an achievement, having a physical effect named after yourself. But as we mentioned before, very little work has been done at the junction of quantum mechanics and general relativity, and this one piece of work has been a spectacular success, so the fuss is probably justified.
"What place, then, for a creator?"
So what's all this got to do with God? Well: we said before that everything was moving apart, earlier on it was closer together, and you can't get away from the fact that ultimately, it must have come from an individual point at some time in the past. The singularity theorems force you back, not to a small exploding region, but to a point. So if you go back to the very beginning and "count backwards" in some appropriately small unit of time (perhaps ten-to-the-minus-forty-something seconds, or something ridiculous-sounding like that), you will eventually hit a "zero" at which the universe, not just the matter in the universe but space itself, is contained in a point.
Now theologians don't wander about making claims on this basis (well, not very often) but scientists get very, very nervous about this because it says that the universe began 15 billion years ago (give or take 5 billion years - there are some numbers in the "distance scale", and hence the time scale, that are hard to pin down). What happened before that? Did God put it there - did we just find the moment of creation? Do we have to say that God created the Big Bang?
Once you get everything down to a point, it doesn't make sense any more. If the universe is very dense, one can still work out how it operates, but if you say that absolutely everything is contained in a point of zero size, you are down to where the theory itself fails. So for all of those years, general relativity has been saying "there is a point somewhere in the past where I give up": there is a point at which science gives up, and we have no further answers, and that's where the universe came from.
This is the sort of thing that makes scientists very, very nervous indeed, because by agreeing to that statement, you're giving up on your explanatory power.
No boundary, no beginning?
Now according to general relativity "nothing can come out of a black hole," but in fact it can: particles can leak out as Hawking radiation. Stephen Hawking has applied some of the same thinking to the beginning of time.
General relativity gives up at the beginning of time, not just because there's nothing earlier than the beginning, but because the beginning is a point where the theory stops making sense. Hawking claims that there is one way we can get around this problem: instead of coming down to a point, where the theory no longer makes sense, the same line of reasoning that allows him to turn what is in general relativity a solid boundary that nothing can get through (the event horizon of a black hole) to something that leaks very slowly, allows him to picture the beginning of the universe as a curved contour, a blunt point if you like. This is a picture, of course, but the four-dimensional geometry it represents corresponds to a universe smoothly and continuously appearing from nothing.
There are still no times earlier than "the beginning", t-zero, but it's a continuous surface on which the laws of physics apply, rather than a "point" at which the laws of physics stop working. This is a proposal. One has to use principles that aren't already there, but on a technical level it seems to work: one can make the universe start like this, although funny things happen to your idea of time. Hawking's point is that instead of the theory pushing you back to a very early time where it stops working and you have to invoke God, you can make sense of it as a whole - the universe, from beginning to end, can just "sit there" (if you like) and the equations of general relativity and quantum mechanics can describe it from beginning to end.
Hawking calls this the "no boundary proposal", because there isn't a boundary to the universe, the way there was before. There's not a beginning in quite the way there was before, and this is where the famous phrase "what place, then, for a creator?" comes from.
No creator??
So you don't need a creator any more, to explain that "I give up" point at which the whole theory stops making sense. The whole universe hangs together quite happily by itself: this is the Big Idea that all of A Brief History of Time moves towards. You don't need a creator, so maybe there's no creator.
No reason???
But you haven't avoided the need for a reason for the universe: Hawking claims that you don't need a creator for the universe, but he doesn't claim that you don't need a reason for it. And he quite fairly asks, what is the whole thing doing there in the first place? It might be "just there", but what is it doing there?
So despite the fact that he is often depicted as having disproved God, or as claiming that there's no God, what he's claiming is that there's no need for God to create things. He still allows some idea that God might be needed, or that something like a god might be needed to provide a reason for the universe's existence.
The universe as a self-winding watch
Having all of these theories is like knowing how a piece of clockwork operates. You have a very elaborate piece of clockwork which does everythng for you: makes galaxies and stars, develops life, becomes conscious. The "I give up" point in the past represents the clockwork running in such a way, that when we project it backwards, we discover that it must have been "wound up" in the past. At some point in the past someone or something must have wound up the clockwork, or it wouldn't be running now. So you ask, "who wound up the clockwork?"
What Hawking has done is the equivalent of saying that the universe is a self-winding watch. You don't need to say that there was someone 15 billion years ago, or however long ago it was, who wound it all up. You don't need that. But you still, of course, have the question "what is the watch doing there?" Who made the watch, who made the clockwork - who made the laws of physics, why do they take the form that they do, and why is there a universe there that obeys them?
time, imaginary time, and Time
There are a few surprises hiding on that "blunt point", too. On the type of cartoon we drew earlier, time is on the vertical axis, and a contour that slopes upward corresponds to what we'd call time "passing" or "flowing" normally. (Well, more or less.) The blunt point at the "beginning" where the contour is horizontal doesn't correspond to time passing, but to the dubious-sounding idea of imaginary time. Now, anyone with university-level mathematics will have some idea of what this looks like in the equations. But what is it supposed to correspond to in reality?
Stephen Hawking knows, and a fraction of the scientific community knows, how to handle all of the mathematics of this "no boundary" proposal, but I think it's fair to say that no-one really knows what to make of it. What is it really? Stephen Hawking irritates philosophers when he talks about things like imaginary time, because he has this scientist's pragmatism that says, you don't need to worry about what's really going on, because the maths works, it all hangs together, it's well-defined. That would be fine as far as it goes - physicists often have to "trust the maths", without knowing entirely what it corresponds to, if anything. But then Hawking makes claims, not just about time (the thing that physicists put on graphs, and use in equations) but "Time", time-with-a-capital-T.
For example, he once speculated aloud that it was "imaginary time" that was "real" or fundamental, while the time that we know - as in, "Time, time, time, see what's become of me", the time that songwriters and poets talk about - is a figment of our imaginations. This is a very bold statement concerning one of the notorious problems in philosophy: is there such a thing as "God's time", what is the relation between time and eternity, time and change and so forth.
With someone like Stephen Hawking you often have this problem. There is something that has just shown up in a piece of mathematics, and you don't really know what you're doing yet - but let's run with it and see if it works - but then he slips into giving orders to philosophers and theologians, as to what they're allowed to talk about, without doing the philosophy and theology himself. This is a case of a scientist "trespassing" on other people's territory [an idea discussed earlier in the conference].
This point shouldn't be overstated: if the universe really did begin 15 billion years ago, and it seems to have done so, then this is relevant for thelogy and philosophy and the rest of it, but it doesn't give scientists carte blanche to waltz into a philosopher's office, or a theologian's office, and start telling them how to use their own language, or what the issues are.
A "human interest" story
I said that Stephen Hawking is very important, but that he can be over-rated. This ties in with the discussion earlier in the conference about scientists in the media and Hollywood and so forth, since Stephen Hawking is a very big human interest story. He suffers from amyotrophic lateral sclerosis: his motor neurones have been slowly dying and wasting away for the last thirty years, to the point where he can barely move. He should have been dead twenty-five years ago, but he's one of those lucky (or unlucky!) people for whom the disease progresses very slowly.
Now this picture of a man who lives in a wheelchair, and speaks with a synthetic voice, with a mind that soars out to encompass the way the universe works, and to say rude things about God, is a profoundly romantic picture: and it's played as a human interest story. Stephen Hawking is played as a human interest story. It's important to remember that there are other figures whom you haven't heard of - there are other figures in the field whom I haven't heard of, and I work "a few doors down" from the cosmologists.
So it's not just that the implications of what he's talking about are significant, because they are, and it's not just that he's making speculations about how they fit together with God, because he is, and (after all) he knows more about cosmology than I do, and is worth listening to: but there is a media element to Stephen Hawking. Suppose that a cosmologist with equivalent credentials - well, there's no-one with equivalent credentials, but another big name in the field - wrote a book, even if he called it something as racy as A Brief History of Time and had it published in airport bookstalls and so forth, it wouldn't sell in the same way. It wouldn't get the notice, because it wouldn't have the human interest of Stephen Hawking's work.
I spent the first half of this talk giving an outline of how physics has progressed: to genuinely understand this material takes years of study, not to mention natural ability. Regarding cosmology, I work in a neighbouring field, and yet I am just an interested observer of these matters. And in a year's time I'll be Dr Yabsley. This is not accessible material. So the human interest makes a real difference to the amount of attention which is given to cosmological speculations.
Paul Davies and The Mind of God
This is where we come to Paul Davies again - remember we left him fulminating against the evils of Religion-with-a-capital-R. Nine years after he wrote God and the New Physics, he wrote another book called The Mind of God: Science and the Search for Ultimate Meaning. The quotation which serves as a frontispiece to the book is the last paragraph of A Brief History of Time:
If we do discover a complete theory, it should in time be understandable in broad principle by everyone, not just a few scientists. Then we shall all, philosophers, scientists, and just ordinary people, be able to take part in the discussion of the question of why it is that we and the universe exist. If we find the answer to that, it would be the ultimate triumph of human reason -
(Do you hear the edge to that?)
- for then we would know the mind of God.
The last sentence of A Brief History of Time, and a good summary of its vision. But then a funny thing happens. If you listen to the subjects Paul Davies discusses in The Mind of God, these are some of the words and ideas that crop up regularly:
* mystery
* purpose
* reason, and "the rational"
* being and becoming
* time and eternity
Philosophers get discussed in The Mind of God, quite a lot of them, actually, including Christian ones: Augustine and Aquinas are discussed; St Thomas Aquinas is actually discussed in historical context - those of you with a background in the humanities may not find this remarkable but for a scientist to discuss a Christian philosopher in historical context is pretty rare. To many scientists, and particularly to those who write for a popular audience, philosophers before Sir Isaac Newton were just people who didn't know any physics. I know that sounds silly, but that's how people talk. Whereas in Davies ...
There is a discussion [in this book] of the relationship between Greek categories of thought and the worldview of the Bible: that in Biblical thought history proceeds from Creation, through the Fall, then the world we know, where God intervenes in history, leading up to the Incarnation, and finally coming to a climax at the end of time; that Greek philosophy works very differently, and yet the western tradition is a development from both sources. This from the same person who was coming out with the capital-S-Science versus capital-R-Religion arguments nine years earlier.
Paul Davies went native in those nine years. He went native.
Do you remember Dances With Wolves? There are two scenes in that film which particularly struck me. One of them is only in the extended cut: it's what happens after the buffalo hunters have slaughtered an entire hillside's worth of buffalo and taken only the tongues and the skin; they haven't just slaughtered these buffalo which are the province of the Sioux, but they've wasted what they've taken, treated it with contempt. It's a horrible scene. But what's only in the extended cut is that the Sioux make a war party, and go out and kill the hunters and scalp them, and then spend the night dancing around the fire, rejoicing at the fact that they've killed these men.
You see Dances With Wolves off in his own tent, feeling for the first time since he's been with them, and he's moved closer and closer to them in life and thought, how distant he is from these people. Despite all that they've come to know of each other, there is a profound divide: "I cannot rejoice with them". It was right to kill these men, but I cannot rejoice with them over the killing.
The other thing that struck me about the film was the point where he is captured by the soldiers who have reoccupied the fort, who see from the way he's dressed, and from the the fact that he doesn't want to come back with them, and that he was with indians, that he has another set of loyalties now. That whatever else you might say about him, he has a set of loyalties other than to the American nation pushing westwards. And they say to him, "you went Indian, didn't you," and it's like a curse.
Those two things are, in my view, what has happened to Paul Davies. He has gone native: I described him as going in as a general to conquer religious territory, but he has gone native, and started talking like, and thinking like, a writer on religious matters. But at the same time he has all of the sensibilities of the scientist he still is - and you still find him thinking in scientific terms, and getting irritated with the way theological and philosophical writers do things, and the way they give the science short shrift.
Very briefly some high points of the discussion in the book:
"laws of nature"
All of this talk about laws of nature: special relativity, general relativity, quantum mechanics, they are all laws of nature and we are using them to work backwards, and see how the universe was in the beginning. He steps back for a minute and asks, why do we call them "laws"?
What was the cultural and religious background to this way of speaking: what were people thinking about legalism and freedom, and what it means for God to act, when scientists started talking about laws? What was happening to laws in society, to the structure of government and the rule of law in society, when people started talking about laws of nature? How did we come to think in these terms?
"initial conditions"
A related point: he writes
The separation into "laws of nature" and initial conditions that has characterised all past attempts to analyse dynamical systems may owe more to the history of science than to any deep property of the natural world.
This way of doing things, having a set of laws, knowing how things start, and then running them forwards to see what happens: this is an idea that comes from having an experiment that you can place on a table. You set up the situation at the beginning, predict what happens in the middle, and see what happens at the end. Can you apply that sort of thinking to the whole universe?
The idea that a limited set of objects is in such-and-such a state when an experiment, or a thought-experiment starts - that there are "initial conditions" to the physics problem in mind - is much more humble than the project of specifying how the universe began. And as Stephen Hawking tries to do, can you apply this sort of thinking to why the whole universe is there in the first place? It makes sense to start off an experiment, and see what happens at the end. How do you "set off" a universe, there is no table-top on which you can set it off: and it's important to remember that we're not just talking about a big explosion in the sky, which might be like setting off an experiment. The Big Bang, despite its name, is not supposed to be an explosion in empty space like an overgrown firework, but instead is the point where space itself, and time itself came from ... [note]
What he's doing through all of this is stepping back: he knows all of the science, and talks about it, and wrote maybe fifteen books between God and the New Physics and The Mind of God, containing all of the science and all of the speculation; and it's as if he says, Fine, we've seen all that, and we've heard all that: why do we think this way, and is it appropriate, and what might it mean?
No conclusion yet
Conclusion? Well, there isn't a conclusion yet:
What does God have to do with it?
That list of things which I gave in "the new physics" is a list of technical developments. The fact that we know about what's going on at the centre of the sun doesn't tell you anything about God straight away - it might not tell you anything about God if you thought about it all of your life. It's not obvious, interesting as the developments are, that one can go from a set of developments in a technical discipline, and extrapolate them to begin talking about God. And when you speak in that way, many scientists actually get annoyed: it's not just the religious people who object to this.
What does it have to do with God?
Well clearly it has something to do with God: if we knew rigorously that the universe had to begin at a certain point, that would have implications, certainly, one might say "God has done it". But it's unlikely to be the only reason you believe in God. Or, if the whole universe can sit there "by itself", as Stephen Hawking claims, this didn't just knock out the foundations of the world's traditions of religious thought: this is not the basis on which people decided, how-ever-many-thousand years ago, that there is a God.
In the beginning?
Did you notice that through all of this, Stephen Hawking is working with the idea the God is irrelevant beyond that "I give up" point? The only way in which God enters into the discussion is as someone to wind up the clockwork at the beginning: despite the fact that God appears on every second page of A Brief History of Time, it all comes down to the question, did God "wind everything up" at the beginning, or did he not.
This is a small question - granted it is an interesting question, and it matters, but it is only part of the story. God, in any recognisably Christian system - even in any theist system - does a lot more than start things off at the very beginning. Genesis 1-3 is not about God winding up the universe at the beginning of time and letting it go: it has a lot more to do with purposes and relationships and the meaning of the world, and it's crass to suppose that "winding the universe up" is what it's all about. That's something that Paul Davies now appreciates, for example, but many other people seem not to.
Old questions, newer questions
So rather than getting new answers to the questions we've had all along (which is what Paul Davies was claiming in the opening of God and the New Physics), we have new questions added on to the old questions. Consider the "new physics" we briefly discussed: we know immeasurably more about the universe than we did even 50 years ago, and it provides a larger base for speculation and questions, and maybe even answers. But that's still what it's providing: you can't do theology without doing theology, you can't just do the physics: theological and philosophical questions need to be tackled on their own terms.
A parable
Enter through the narrow gate; for the gate is wide and the road is easy that leads to destruction, and there are many who take it. For the gate is narrow and the road is hard that leads to life and there are few who find it.
(Matthew 7:13-14, NRSV)
As my friends will tell you, I have a tendency to moralise most issues, and I'm going to moralise this one: I think it is irresponsible and self-indulgent to take a field that you know very well (as Stephen Hawking undoubtedly knows cosmology very well indeed), stick almost entirely within the field the whole time, combine that with whatever your own personal agenda is (and I have no great insight into Stephen Hawking's psychology), and then start saying what all of this means about God.
There are many who take this broad path. Has anyone read Richard Dawkins' The Blind Watchmaker? It takes certain things about evolution and beats everybody over the head with them, as if they were the answer to everything, or as if natural selection were the one path towards reaching some religious answers - or some irreligious answers, in his case, since he has an (understandable) axe to grind against creationists, and maybe against God too, I don't know.
Whereas for the narrow path ... what Paul Davies is doing is very difficult - as well as knowing the physics, he knows a lot of theology and a lot of the history and he's trying to think them together. And it's probably about as hard as living in a cross-cultural situation like Dances With Wolves, and probably about as comfortable.
But in the end, I believe that it's the only way to approach these matters. There are enough people in the world who know a lot about a few things, sitting on bar stools and telling you what the meaning of Life, the Universe, and Everything is: there are relatively few people who genuinely worry about what the issues are, and try to get their own thinking straight before they start speaking -
and I know to whom I'd rather listen.
Discussion and Questions
Discussion with Andrew Katay (from SIFT):
A.Katay: Just a comment, really: I thought you brought it out well, that the idea of it all going back to a point where it all stops, and God coming in only at that point, is an old argument ...
But has anyone thought about these things as being (calling on all of my high school maths here) an asymptote, an asymptotic phenomenon, an infinite regress that never really stops?
B.Yabsley: Stephen Hawking has made some attempts at interpreting [that "blunt point" beginning] which have produced violent reactions from philosophers who have tried to understand what the words might mean.
But yes, some people who have tried to make sense of his beginning have done so in precisely those terms, that you can get closer and closer and closer to the start, but that there is no actual zero point. That is how some people view this, yes.
D.Mitchell: [That is more a question of interpreting or picturing the mathematics, which crops up in other disciplines too] - it's no longer "pure science" ...
B.Yabsley: Yes, you get into all sorts of tricky philosophical territory here, because you're handling infinities, where you take an indefinitely large number of indefinitely small intervals as you get closer to zero ... there have been a number of mathematical developments this century on these questions, but [as I read it] the [philosophical] situation is quite confused.
A.Katay: Helpfully, again, you point out that in the end we have the God of the Gaps, that what Hawking is arguing against is the God of the Gaps: God is only relevant where we don't know, where there's a gap in our knowledge, put God in there [to explain what we don't know, so that] where there are no gaps, there is no God. Of course if you start by rejecting the God of the Gaps in the first place, then what Hawking is arguing against I'm happy to argue against as well.
But what that does is to leave Hawking with the same questions that Davies is putting: the four questions, which (at least 2 of them) are "why" questions. I'm just wondering what it is that makes people think that science and "meta-science", metaphysical questions, are connected to each other? How is it that, why do people make the leap to saying, because I know all of this about science, I can now talk about the why-questions - where are the connections between these things?
B.Yabsley I think this is where Laurence's argument comes in [regarding scientists "trespassing" on the territory of other disciplines] - if you are going to do theology, you have to do theology.
A. Katay Because Davies wants to make that kind of leap, he wants to go from physics to God ...
B.Yabsley The point is the following: Hawking sits there and spends the whole time doing nothing but physics, or nothing but models, and then turns around and says what the implications are for God, and reads them straight off, as if this were obvious. Whereas, as you've said, if you didn't already believe in a Deist God, who started everything off [and then left it alone] then what Hawking's talking about [is not so relevant] ... if you are fundamentally disturbed by Hawking's result then you have already given up on so much that any religion believes about God ... that you might as well have gone home already. And Hawking seems completely insensible of this fact.
Whereas Davies is talking about the new physics in the same way that a Biblical writer might make reflections on Israel's history, or a philosopher or theologian might think about the way things worked in the past, or someone might contemplate the way the Second World War turned out, and [draw conclusions about] human nature - they then go on to do the further thinking, which is where all of those [questions and speculations come from].
The stuff in the Bible is about things, it's not just people sitting there and thinking "What is God like?", it's about things, it's about issues, which serve as some sort of basis or impetus for religious reflection, if not theological reflection. And that's my point about Davies, that he's actually doing that properly, at some level.
Questions and answers
(The following is a selection of the questions-from-the-floor. The quality of the tape is very poor at this point, so some of the questions and answers have been lost, or are restored from memory, between square brackets. Occasionally, I've expanded one or two of my responses, also between square brackets, where the verbatim text is less than clear.)
Q1.
[In that first picture], where you have everything coming down to a point, is that general relativity ... is it just general relativity which is failing there?
A1.
General relativity is what you're working with, but it's general relativity which describes space and time, it's the theory of the "fabric" of the universe ... if you've heard people talk about "the space-time continuum", that's general relativity that they're talking about [so that that "beginning" is where space and time begin, it's where they come from.] If space and time stop making sense, then you've just lost the whole ball-game: that's the idea.
Q2.
When you've got the space-time diagram rounded off there at ten-to-the-minus-forty-something seconds, isn't there an article of belief in physical cosmology that in that very small time, the universe multiplied itself by ten-to-the-hundred-something times, so that in one of those many universes all the physical constants just happened to take on the right sort of values that allow us to be here and talk about it, whereas any other combination would not?
A2.
Okay. I didn't want to talk about inflation today: that's what it's called, [the rapid expansion at the beginning]. This ties in with [the question of] doing speculation responsibly.
There are a lot of things about the universe that look rigged. Things where, if a number were slightly different one way, or slightly different another way, then not just that the universe would be different, but the universe would be boring, i.e. it would collapse back to nothing very quickly, or there'd be nothing but gas, and there'd certainly be no stars and planets, and therefore (most probably) no life. There are a whole lot of things like that, which look like they've been "set up"
There are various ways of understanding this, and Hawking is a particularly (I think) bad example of someone who will happily use things like the Many Universe Interpretation where there are billions, uncountable numbers of universes out there, and it's only in the very few where everything turns out right that there are people to worry why it's turned out right, so, you know - no mystery. Or, there's some system that happens in the beginning that rigs everything [and ensures a sensible outcome: this is one of the motivations behind the "inflation" idea.]
Now, he's not a realist, and so he doesn't get particularly bothered by tossing off ideas like this, but [the rest of us have to ask] where did all of these universes come from? I mean, where are they? Other people are left there scratching their heads and thinking, "Hang on a minute, what are we committing ourselves to?". And he's doing the equivalent of saying, you can make it work out in the maths, so what's your problem? Again, it's the difference between a pragmatic approach, something that allows you to get the predictions right, which you do all the time - there are things that we don't understand, we know how to work the maths but we don't understand them, and so that's alright - but one can't do metaphysics that way, and [the speculations] you're referring to are an example of [the problems one can get into in this area].
If you're going to do metaphysics (for example, to talk about God), you have to have some sort of idea of what's real and what's not.
Q3.
Having looked at Hawking's work briefly ... the conclusion is not very scientific [not ...] a rigorous scientific proof ... he makes an analogy ... with quantum mechanics ... [but there are many technical problems, it doesn't really work].
A3.
It's a proposal, yes, it's not a proof. I'd read it as having more mathematical and physical content than you've suggested ... [but it does posit new principles, you can't just get it from current theory without additions. But many things are like that.]
Q4.
Has Hawking made any response to the writings of Davies? Any comments in reply to what he's said?
A4.
Paul Davies actually admires Stephen Hawking - these are my criticisms that are being made here, not Davies' [I didn't mean to imply that there was any controversy between the two of them].
Q4, continued.
But has Hawking said anything about Davies' work?
A4, continued.
Not that I've noticed. More of what I've seen has been in controversy with Roger Penrose, the other person who did a lot of that work on singularities, which we referred to regarding black holes and the Big Bang ... the two of them have almost diametrically opposed views on all of these matters.
A comment from Laurence Emmett (from SIFT):
I think one of the reasons that scientists confuse themselves with theologians - and this does have something to do with surfing - is that there's a point in your life when what you are doing is very much being a useful and productive part of your environment, things like surfing, or being in a relationship, or some such. Things where you suddenly think, "This is what it's all about - here I am in a proper relationship with my environment" - and the tendency is to confuse this [with fundamental insight ...]
Religious people often subscribe to that kind of experience, and I wonder if work in a fundamental science ... comes with [that experience of] being in a harmonised relationship with your environment: making a significant scientific discovery, finding out something true about the universe must feel like that [for the scientist] ...
This may be one of the reasons for the "rush of blood to the head" [that Bruce described.]
Endnotes:
* (Note to "About this document ...")
There's a proposed HTML Version 3 footnote element (
[Back to main text.]
*
Extended note to "chaos"
One disturbing effect of the "discovery" of chaos was a very subtle undermining of determinism. The problem is difficult to put one's finger on, and what follows is my best attempt:
Chaos and determinism
Chaos is sometimes called "deterministic chaos": a chaotic system is one whose state at some point in the future is completely determined by its state in the present (through some mathematical equation), but in such a way that a tiny change in the present state will have an unlimited effect on the state in the future. This makes the system unpredictable in its detail: where the pendulum will be in its swing, what the temperature will be in Florida, etc.
A chaotic system is not just unpredictable "in practice", but unpredictable by any finite being - a hitherto unimagined kind of impossibility-in-principle. If you had a wind speed, temperature and air-pressure monitor in every cubic metre of the earth's atmosphere, and a computer the size of a galaxy, you still couldn't do long-term weather prediction. Nor could you predict the behaviour of certain simple pendula, or electrical circuits, even with knowledge of the system to any level of detail. This was an unexpected property for a deterministic system. One can find the idea sketched out, without it's present mathematical rigour, in some writers (e.g. Richard Feynman's Lectures on Physics, Volume I, Section 38-6; and I understand that Poincaré was well aware of it at the turn of the century) but it does not appear to have influenced the thought of the scientific community.
The clockwork universe
For a long time, physics was founded on Newton's deterministic equations of motion, and physicists worked mostly on simple, well-behaved systems - bridges, engines, rockets, stars, etc. This encouraged the belief that the entire universe, without exception, was like a clockwork, determined in every detail on the microscopic scale, and as a consequence of this, determined and well-behaved (at least in principle) on the large scale. This is not the sort of proposition which you can prove, and it's not even easy to test, but it has been widely believed.
Even though quantum mechanics, which contains a non-deterministic element, has long been accepted as a more basic physical theory, many physicists have persisted in supposing that the universe is deterministic "for all practical purposes": that the universe, on the scale of rocks, rockets, cells, and animals, is pretty much like a clockwork anyway, so any apparent indeterminism at the foundation of physics doesn't matter, or doesn't have large-scale consequences. (Not to mention the continuing attempts to brush the non-deterministic element of QM under the carpet.)
The discovery of chaos has undermined determinism at this "macroscopic" end: once we discovered that there were deterministic systems which were not like clockwork, it became hard to ignore the extent to which physics has focussed on "special cases", i.e. systems which are both
1. deterministic, and
2. predictable.
Now we know about systems which are
1. deterministic, but
2. not predictable,
and we have a fundamental theory which is, at least in part, non-determinstic. It is no longer easy to be confident that this indeterminism "doesn't matter"; and there is the additional prospect that indeterminism and chaos could interact, say that a 50% / 50% quantum mechanical event on the other side of the galaxy could influence the weather, or some other event, on the earth.
The revival of spirit?
It is tempting to go on to declare that physics demonstrates that the world is
1. non-deterministic, and
2. non-predictable,
and moreover that spirit, final causes, God, the interconnectedness-of-all-things, or what have you, are all influencing the roll of the dice. Maybe this is true (and I believe in all of these things), but it is far too bold to suppose that physics has demonstrated this. What has happened, rather, is that the mechanistic vision of the world which (for all practical purposes) excluded spirit, final causes, God, etc., is no longer easily tenable. The argument on all of these questions thus has to be re-opened. My own view is that physics provides both an input and a control to the discussion, but that it will not be decisive on these questions.
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* (Note to "special relativity (1905)")
In other words, contrary to the impression one is sometimes given, and despite the fact that Einstein was working as a clerk at the time (the turn-of-the-century equivalent of a graduate student doing a pizza delivery run, perhaps?) he didn't rush into the university one day with one of those "I have a new theory" photocopied sheets, that comes out of nowhere and claims to solve all known problems. Being a genius is one thing; being a crackpot is another.
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* (Note to "general relativity (1915)")
Time (to paraphrase St Augustine of Hippo) presents no problems until you try to explain it, whereupon you discover how little you understand it. How to describe time, what to make of our experience of time (e.g. the way in which we experience the flow of events, our own reactions and thoughts, which are often different to the even ticking pace of the clock), and how to relate it to eternity, or unchanging things, are all longstanding questions in philosophy.
The time of the physicist - the axis of a graph which we label "t", which is measured out with the tick of a clock, or the cycles of an oscillator - may be only one aspect of the phenomenon, but at least it's an aspect about which we can be precise. And it's worth clearing up a common misunderstanding of the idea of time running slowly in some places (regions of high gravitational field) and some conditions (motion close to the speed of light). It is not a case of seeing the hands of the clock "move slowly", or observing your body to respond slowly to your wishes; nor is it a case of being in a disorienting state where the experience of time is confused (as happens during Nearly-As-Fast-As-Light travel in the novels of Ursula K. LeGuin).
Everything we know of relativity argues that time-running-slowly would feel completely normal: you would only discover the discrepancy after meeting up with someone with a different history. The classic illustration is of twins, one of whom stays on the earth, while the other embarks on a round trip at (say) 80% of the speed of light. While the stay-at-home lives through 17 years, the travelling twin would live through only 10 years. Both would experience those years "normally".
Another popular view is that physics has shown time to be "just another dimension of space", the famous "fourth dimension": I have heard people dismiss all philosophical investigation of the concept of time, on the grounds that physicists had now explained time in this (hitherto unimagined) way. In my view this is extremely misleading. It is true that physicists, when they mean to be completely precise, no longer deal with time and space separately, but with a four-dimensional "structure" (it's not clear what word to use) called space-time. But the three "spatial" dimensions are still distinguishable from the "temporal" dimension: they do not behave in the same way. At the risk of being prosaic, one can move to the left or right, forwards or backwards, up or down in space - we still have absolutely no reason to believe that one can move backwards in time. We cannot even control the "pace" at which we move forwards in time - if such language even makes sense.
[Back to main text.]
* (Note to "quantum mechanics")
This doesn't actually happen, of course. But an "equivalent" thing does happen with light, electrons, atoms, and so forth: if you aim a beam of electrons at a solid wall with two holes cut into it, and then look at the electrons which reach the other side, the pattern cannot be interpreted as electrons passing through hole 1 or hole 2, but only makes sense if the electrons "wash" through both holes at once, like waves hitting a break-water at the beach.
The troublesome thing is that the effect still occurs if the "beam" of electrons is made very faint, so that only one electron is travelling at any given time - and electrons (at least under some circumstances) have definite, trackable positions, so you wouldn't suppose they could wash through a barrier like that. Yet they can, and so it appears we can't "keep track" of everything (even in principle) as we used to believe we could. Precisely what the "old physics" is assuming at this point - and which of the assumptions is wrong - is a very interesting question, to which there is not an agreed answer. The fact that many physicists treat it as a non-question - usually by waving the word "paradox" around in some way - doesn't help .
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* (Note to "General relativity and the expanding universe")
The problem is with that word "isolated". It's fine for the solar system to be rotating, because there is an everything-else "out there" which you can use to get your bearings and decide that you (the solar system) are spinning around. But once you are speaking of the universe, there isn't an everything else - since "the universe" means we are including everything - so how can a rotation make sense? With respect to what "system" would the universe be rotating?
To my mind there is no obvious answer to that last question - but this is not the same thing as saying, that the idea of the universe rotating obviously makes no sense. This is a very interesting subject, close to the heart of physics and its philosophy; but the fact that (as it turns out) the universe is expanding tends to push such questions to the perimeter of the discussion, as matters of "philosophy" (in the derogatory sense).
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* (Note to "initial conditions")
My comments on this issue in September were perhaps too sweeping. There isn't anything intrinsically unreasonable about the idea of a "law of initial conditions", or some principle which says, the universe must begin in such-and-such a state. After all, the laws of physics, which we hold to be absolute for all intents and purposes, govern the shape and development of the universe just as certainly as the particular configuration in which things "began".
But one does have to be clear as to what one is about. A "law of initial conditions" would be something on the same level as a "law of physics": like the theory of relativity, or the principle of superposition in quantum mechanics, or some other very fundamental idea. We can "see" those laws or principles at work in the laboratory, and set tests for them, and the like ... but how does one conduct an experiment on a law of "initial conditions"? The universe, so far as we have any reason to believe, began only once ...
This does not mean that the idea is to be rejected. What it suggests is that the criteria by which one would judge candidate "laws" of this kind will have to be different to, or at least more extensive than, those by which we judge proposed physical laws. Physics as a discipline, and physicists as practitioners, are not well-adapted to discussion of unique, unrepeatable, or otherwise "particular" events, and getting at their logic or inner life. By contrast, this is the regular business of history.
So considering Hawking's "no boundary" proposal from this point of view: he puts forward a particular (mathematical) "way" for the universe to begin, claims that it gives an outcome consistent (in some admittedly non-trivial ways) with what we observe, and then elevates the proposal to the status of a law, claiming the consistency as evidence. What are the "quality controls" on such a procedure? One cannot repeat the situation in the laboratory, so one is thrown back onto a rather narrow set of facts concerning which one just has to make a judgement. Notoriously, there is room for disagreement in such judgements: the practice of history (for example) can be learned, and we rightly call it a "discipline", and it has standards ... but it's not a "science" in the same way that physics is a science.
To make a possibly unfair analogy: do you believe that the Warren Commission said the last word on the Kennedy assassination? Perhaps not. But does that mean that you believe the conspiracy theory put forward in the film JFK? And if so, why that conspiracy theory? Might it have something to do with the powerful and skilfully-employed means of persuasion used by Oliver Stone? Or the fact that your parents were impoverished dirt-farmers in Montana, who taught you distrust of Washington and all American federal bodies from an early age? What is the standard of "consistency" being applied: what sort of coincidences or loose ends do you consider to be reasonable, what sort do you consider to be "suspicious" or to point towards some underlying principle at work - and which explanatory principles (such as the American tradition of theories of shadowy inter-agency conspiracies) are you prepared to countenance?
Perhaps it would be a good idea to ask a professional historian for some advice on this question!
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Bibliography:
* William Lane Craig and Quentin Smith, Theism, atheism and big bang cosmology. Oxford: Clarendon Press, 1995.
* Paul Davies, God and the New Physics. London: J.M. Dent and Sons, 1983.
* Paul Davies, The Mind of God: Science and the search for ultimate meaning. London: Simon and Schuster, 1992.
* Paul Davies, ed., The New Physics. Cambridge: Cambridge University Press, 1989.
* Ray d'Inverno, Introducing Einstein's Relativity. Oxford: Oxford University Press, 1993.
* Kitty Ferguson, Stephen Hawking: Quest for a Theory of Everything. London: Bantam, 1991.
* Stephen Hawking, A brief history of time: From the big bang to black holes. London: Bantam, 1988.
* Stephen Hawking, Black Holes and Baby Universes and Other Essays. London: Bantam, 1993.
* Stephen Hawking, Hawking on the Big Bang and Black Holes. Singapore: World Scientific, 1993.
* Stephen Hawking and Roger Penrose, The nature of space and time. Princeton, NJ: Princeton University Press, 1996.
A note on further reading:
After I gave this talk a friend drew my attention to the book by David Wilkinson, God, The Big Bang and Stephen Hawking: An Exploration into Origins (Crowborough, UK: Monarch, 1996, 2nd edition), and asked me to comment on it, since our topics are so similar. The first thing to note is that our approaches are rather different: I've taken a very limited subject - Hawking's "no boundary" proposal and its interpretation - and plumbed it as deeply as I feel able, while Dr Wilkinson addresses a much broader range of issues. He also sets out a positive Christian position on the relation of God and the universe, which I haven't done.
Beyond this - and I should say that I don't have any substantial disagreement with what Dr Wilkinson says - I find his approach rather glib. I'm sorry to say this, because my friend chose this book as one of the few sensible-looking publications on the "Science" shelf of a popular Christian bookshop, the rest being creationist material etc. of the most depressing kind. Good published material on scientific issues that seeks to set out a Christian position is still pretty rare in my experience, although anything written by John Polkinghorne would be a good start for someone interested in more reading.
My guess is that Christian writers are too defensive when it comes to scientific issues, and that the more popular the presentation, and the more positive or "evangelistic" the writer's intention, the more strongly they feel the force of entrenched "science has disproved religion" prejudices. The presentation of issues then becomes lop-sided, with all sorts of criticisms and caveats attached to the discussion of scientific topics, while the explicitly "Christian" material is given a clear run. I think this is counter-productive - you are unlikely to be taken seriously by a critical reader with a differing view - but more importantly I believe you're kidding yourself if you take this path. Having said all this, I should repeat that I don't want to take issue with Dr Wilkinson's specific statements; and Dr Polkinghorne, whose approach I find more coherent, was after all happy to "strongly recommend" the book.
First written 22nd November 1997; last modified 29th July 1998
Send comments about this page to bruced@physics.usyd.edu.au
© 1998, Bruce D. Yabsley
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