PHYSICS AND ULTIMATE REALITY
- A transcript from The Hour of Judgment radio series -
Copyright (c) 1995 Kevin Solway & David Quinn
- Paul Davies - Professor of Natural Philosophy at the University of Adelaide, and author of over twenty books including The Mind of God and God and the New Physics.
Paul Davies had only recently been awarded the Templeton Prize for "progress in religion" when he agreed to appear on the program, and we saw it as a good opportunity to question him on what exactly this progress consisted of. Has he brought mankind closer to the Ultimate Wisdom? Does he himself know what God is? Does he truly believe that physics can tell us something about reality?
Kevin happened to see Davies on television not too long back, on a program called The Big Questions, where he discussed "meaning of life" issues with self-proclaimed atheist, Phillip Adams. Not surprisingly, Kevin was so disgusted by what he saw that he immediately wrote to Davies outlining several objections to his ideas and offering him to come onto our program for a proper discussion about these things. Paul Davies replied and a phone link-up was arranged. (See correspondence below)
As with a previous program which we did with physicists (see the QUANTUM PHYSICS episode), the following conversation hinges upon the concept of cause and effect, and it illustrates the difference between the absolute thinking of Kevin and myself, and the relative thinking of scientists. As much as we tried to explain it, Paul Davies was unable to grasp the concept of "cause" in its absolute sense, and it is precisely this failure which will block every attempt of his to achieve the Ultimate Explanation he claims to seek.
From: Kevin Solway
To: Paul Davies
August 21, 1995
I am the president of the Atheist Society of Australia and the host of the philosophical radio program "The Hour of Judgment" here in Brisbane. I hope you will take a few short moments to read what I believe to be the shortcomings in your arguments concerning God and Nature.
1. You talk about a number of "possible" universes. But in reality only one universe is possible - the one which is caused to happen. So the canvassing of the idea of other "possible" universes is mistaken. You are assuming that there is some kind of free-will, or at least freedom somewhere in the picture, which is an unfounded assumption.
2. You say that there is no time before the Big Bang - that may be what your maths is telling you - but then you maths is wrong. The fact that we can conceive of a chain of Big Bangs means that time did exist before the Big Bang. Our conceiving of time brings time into existence. Your mathematics blindly ignores the importance of the observer in the creation of all that exists.
3. If you really want a "God" to explain things then why don't you just say that God is everything. There can never be a creator greater than everything. All absolute truths are a part of everything. Also, all things create each other. The concept "A" creates the concept "not-A" and vice versa. The number "one" creates the number "two" and vice versa. So there can never be a creative force, or agency, or anything at all, separate from what is created. And what is created creates the creator.
4. You wrongly say that "cause and effect occur in time". Then what about my example above where the concept "A" is the cause of the concept "not-A". This creation is outside of time. And it is correct to say that "A" is the cause of "not-A" (and vice versa) because one would not be able to exist without the other.
Would you like to be a guest on my program to discuss these issues? If you cannot make it into the studio then perhaps we could arrange a phone link-up. I look forward to hearing from you.
From: Paul Davies
To: Kevin Solway
29th August, 1995
Dear Mr. Solway;
Thank you for your letter. From the nature of your questions, I imagine that you have based your opinions about my position on the recent (necessarily superficial) dialogue between myself and Phillip Adams, rather than on the more considered discussion I give in my books, such as The Mind of God.
Be that as it may, I shall be happy to talk about these topics on your radio program. May I suggest that you phone me to discuss a suitable date? My telephone number is _________.
Kevin: Hello, I'm Kevin Solway, with me here in the studio is fellow atheist and sage, David Quinn, and welcome again to The Hour of Judgment - probably the only radio program in the world for geniuses. Tonight we'll be talking to Professor Paul Davies, author of The Mind of God, and winner of the 1.5 million dollar Templeton prize. Now, Paul Davies, are you there down in Adelaide?
Paul: Yes, hello.
Kevin: Right, perhaps you can tell us a little bit about this Templeton prize. What is the prize actually for? And how much money did you actually get for it?
Paul: Right, I'm glad to have the opportunity to explain the prize, because in spite of the fact that it's the world's largest prize for intellectual endeavour, it seems to be not terribly well known. It's been awarded for the last twenty-five years, and its official designation is that it's awarded for progress in religion. Now you may think it's odd that this has been awarded to a scientist, but in fact over the years quite a number of scientists have won it - most notably in my discipline, physics, Carl Friedrick von Weiszacker. Also Charles Birch of Sydney University is another well-known scientist who has won the Templeton prize. Now it's not awarded to people for just doing good works, or for being pious, or anything of that sort. The word "progress", I think, tells it all. Sir John Templeton, who is the benefactor of the prize, recognizes that the world's existing religions leave something to be desired, and feels that people who make a contribution towards advancing theological thought should be awarded something for their endeavours. And I think it's quite clear that scientists who work in areas like the origin of the universe, the nature of time, the nature of consciousness and so on, are tackling problems that for centuries have been part of religion. They're now part of science, and so I think it's quite reasonable that these scientists can be expected to be in the running for this prize.
Kevin: I'm curious as to what is actually regarded as religion, or theology, these days. A few years ago, someone who you probably know personally, Charles Birch, also won the Templeton prize, and he conceives of God as being a personal God, who actively loves his creation in a human sense. And he regards this as a probability, so he doesn't know this for sure; but he believes it's highly probable. And he believes that you, Paul, are on the path to where he is, and that your concept of God isn't quite as advanced as his. What do you make of this?
Paul: Well, I think I can only tell you what my concept of God is. I don't especially want to comment on other people's interpretation. Let me just say that, coming back to the Templeton prize, it's not tied to any particular religion. Some of the people who have collected the prize in the past have been ministers of religion, but some of them have no religion. I myself would not say that I have a religion. I don't belong to any religious organization. I don't go to church. I read the Bible occasionally for literary enjoyment. I'm fascinated by its history, but I'm not religious in any conventional sense. Now, on the question of a personal God versus other types of God, I've recently made a series of television programs with Phillip Adams. You may have seen them - they are being screened on SBS - and we devoted one of these to what I suppose we might call "meaning of life" issues - questions about God and so on. I distinguish quite sharply between two very different conceptions of God which have been around, but the same word seems to have been used for both. On the one hand, there is the personal view of God, which for many people is akin to a cosmic magician - a sort of superbeing who will intervene when times get rough - someone who you can pray to and you might expect to work miracles on your behalf. And this is the traditional God of history. It is, I think, the God you would pick up from the Old Testament of the Bible - a sort of warrior in the sky who backs one side against the other.
Kevin: Yes, and what's the alternative to that?
Paul: Now the second conception is, of course, the much more sophisticated, but somewhat more remote, and for many people less satisfactory, view of God, which I could say is something like the grand architect of the universe - the underpinning of the rationality of the cosmos. Now if you talk to scholarly Christian theologians, in a tradition going back many hundreds of years, this abstract notion of God - as a sort of timeless, rational, ground of being, underpinning the universe - is something that is very current. And in my deliberations with members of the Christian clergy - I can't speak for the other religions - for those of them that have studied theology in any sort of depth, their concept of God is very often rather close to what we might call the physicist's view of God - as rational ground of being. But this is very different, you see, from the miracle working cosmic magician.
Kevin: I'd see it this way: There are two kinds of God, in the sense that there is a finite conception of God - a conception of God as something finite - and then there's the conception of God as being infinite. So there's either one or the other. The finite God is in some way separate - to something at least - while the infinite God is in fact everything, absolutely everything. By definition, "infinite" must be inclusive of everything. So is this the kind of God you're speaking of - an infinite God which includes everything that we can possibly conceive of?
Paul: Can I approach it in a slightly different way, because I think you'll find it easier to see what I'm driving at when I use the word "God". And I must admit, I don't feel terribly comfortable using this word, but we're stuck with it. The trouble is "God" has so many different varieties of meaning, that people can seize upon it - they can seize upon a statement that has "God" in it, and think that it supports or maybe contradicts their own personal beliefs. So that's a very dangerous thing. But let me just try to give you some idea of the way that physicists, including those who would call themselves atheists, see the world. We of course understand that nature is incredibly complicated, but the hope is that beneath this surface complexity there lies some sort of pleasing and harmonious simplicity, some set of laws which are not obvious to us in daily life. When we look around we don't see these laws in front of us - we have to deduce them by intellectual processes and experimentation and so on. But we can do that. So there are these hidden mathematical laws which underpin the operation of nature. There is an order in nature, and the job of the scientist is of course to uncover that order and reach an understanding of the world by finding the law-like principles which govern the things that go on around us. That's what science is all about. Now, of course, if you do that, and if you spend a lot of time thinking about these laws which underpin everything, you're inevitably led to ask the question, "Well, could these laws have been otherwise? Could the world have been different? Might we have had a universe with, say, instead of the familiar inverse square law of gravitation, perhaps an inverse cubed law?" - or something else of that sort. You can play those intellectual games, and I think you're very soon led to the conclusion that the world could have been different - in fact, different in an infinite variety of ways. So then it's quite natural to ask, "Well, is there anything special about the actual order in the real universe, the one that we live in?" And remarkably enough, there are quite a number of aspects in which it is special. Some of these are a little bit technical, and I don't want to get into too many technical details, but just to give you some rough idea-
Kevin: Yes, just give us one example of how this universe is special.
Paul: We recognize there are four basic forces of nature. There's gravitation, electromagnetism, and two nuclear forces, called weak and strong. These four forces have certain relative strengths. You can take the ratio of the strengths of these forces, and you get four numbers. You can wonder why those numbers happen to be the ones that characterize our universe rather than some others. Imagine playing the role of God: you have at your command an infinite variety of universes with all possible strengths of forces, and you twiddle the knobs a little bit and change something. What you find from a mathematical investigation is that the slightest change in some of these ratios is enough to essentially wreck the universe as we know it. That is, the possibility of complex systems, and in particular living systems, would seem to be gravely compromised by even a slight change, say, in the strength of the nuclear force.
Kevin: Right, but we've slightly gone away from this concept of God as being infinite.
Paul: Well, I think the critical point here is that if you're led to believe, or led to deduce, that the world could have been otherwise, and if the world we actually live in seems to be rather special and rather contrived in a number of respects, then you are immediately, of course, led to ask, "Well, why this world rather than some other? How has the selection been made? What is it that has picked the particular set of laws that operate in this universe, rather than some other set from the class of all possible sets of laws ?"
Kevin: Well, we know, obviously, that there must be causes for whatever happens. Whether there's chaos or whether there's order, obviously there are causes operating.
Paul: Yes, but you see, causation as it's normally described, takes place within law. Causation is normally just the operation of the law. I'm talking of something deeper. I'm talking about how have those laws themselves have been selected?
Kevin: Well, surely, cause and effect is the most fundamental law of all. Underpinning all laws must be the law of cause and effect.
Paul: Well, now you say "must be", but we know that in the realm of quantum physics the connection between cause and effect can become very loose and fuzzy . . .
Kevin: Well, I think I'll just say that I think I have a different understanding of cause and effect to the one shared by scientists. I think you would conceive of cause and effect as happening in time, but to me cause and effect is more of a logical law - it has more to do with the existence of things. For example, a quantum particle, or anything at all actually, is dependent on, for example, an observer. Without the observer, a thing can't be rightly said to exist.
Paul: Possibly. That's one interpretation of quantum mechanics, yes.
Kevin: So this is a different way of talking about cause and effect.
Paul: I think you're quite right to draw a distinction between, let's say, a temporal sequence, or causal chain, and a logical sequence. And I'm very much talking here about the logical sequence. Because it's my belief, you see, that we do not need to invoke anything like a supernatural being, a God, a Creator, to bring the universe into being within time.
Kevin: Well, if the Universe itself - and I mean everything, the Infinite - is what we give the name of God, well then, of course we can't rightly say that God created the Universe, because the Universe itself is actually God.
Paul: That's just playing with words. I think to just say, "God is the Universe", might make some people feel they've just said something profound, but to me it just seems to be relabelling the word "universe".
David: Can I come in here? This is David Quinn. I'm interested in this word "God". To me this word "God", if it's going to mean anything at all, it must be an ultimate explanation of everything. This has to be the one basic characteristic of the word "God" - that it is ultimate, absolute.
Paul: Yes, I wouldn't disagree with that.
David: Right, well, I'm wondering about the role of science in saying anything at all about the Absolute, or the Ultimate. You were referring before to the laws of science and how this Universe seems to be special, and you were asking, "Why is this?". I was just wondering how can science, or physics, ever come to tell us anything at all about what is absolute?
Paul: It's important to realize that science deals with the facts of the world, whereas religion and philosophy deal with the interpretation of those facts. You can have the same set of facts and different people can interpret them differently. So, for example, in connection with the "specialness" of the laws of physics which I've been talking about, some of my colleagues can agree on the amount of specialness, but shrug their shoulders and say, "So what? It doesn't mean anything terribly significant to me. They could have been much more special than that." So it's a little bit like arguing whether the bottle of water is half full or half empty. Other people would take that same set of facts and say, "That's really amazing! It looks contrived, as though some sort of selection has been made." And if we're just going to restrict ourselves to science . . . of course, science can only deal with the law- like behaviour of the actual world - the facts of the world - and it can't tell us, it can't compel us, to adopt any particular interpretation. But it can, I think, provide circumstantial evidence for a certain interpretation that we should be surprised, amazed, pleased, by the specialness of these laws, by the apparently contrived nature of the world, by the peculiarity that the laws are such that they can give rise to thinking, reflecting beings like ourselves. All of these things, in my view, are very odd and very special. They're highly suggestive that the laws which we've got aren't any old rag-bag of laws, but a set that would have to be, if you had a shopping list of laws, very carefully selected - possibly in order that there might be thinking beings like ourselves, for example.
David: Well, it would appear, maybe to you, that this is the case. I mean, what I'm trying to get at is that every scientific fact, or theorizing about a fact, is inherently uncertain.
Paul: Of course.
David: So even the very idea of the specialness of this Universe . . . it's an appearance to us. It actually may not be the case.
Paul: Well, of course. All I can tell you about is the world as we understand it to the best of our ability today - and we can draw whatever conclusions we can from that. But what else can a scientist ever do?
David: Well, this is what I'm trying to get at. If we want knowledge of what is ultimately real . . . I mean, I've been following your career a little bit, and read through The Mind of God, for example, and you say that the laws of physics aren't enough to give us this ultimate explanation of everything.
Paul: Well, you see, the laws of physics, by definition, can't explain why those particular laws.
David: So science is limited in this manner.
Paul: Of course, inevitably, science by its very nature cannot provide these ultimate explanations.
David: So this is where philosophic thought comes into play.
Paul: Well, I don't think you can avoid it. You see, whether you want to adopt a scientific approach, a religious approach, or an atheistic approach, or whatever, if you want to explain the world in its entirety - which is, of course, a big project - you have to start somewhere. You have to take something as given. You've got to take a ground, a base, a set of assumptions. This could be a set of laws of nature, about which you could just shrug your shoulders and say, "Well, that just happens to be the set", and you could start at that. Alternatively, it may be some deep philosophical principle. Or it may be the existence of a God, who can in some sense select. It could be something else we haven't thought of. But you have to start somewhere. And whether you're an atheist, a theist, a deist, or a scientist, the bottom level which you start out with you have to accept as an act of faith. I often say that the whole of science is based on an gigantic act of faith - which is that we live in a universe that is not only ordered, but ordered in an intelligible way. That's a huge act of faith, even if you're an atheist.
David: Okay. But you don't think it's possible to come to this ultimate understanding of reality, so that you have one hundred percent certain knowledge of reality?
Paul: Well, I would be very dubious about anyone who claimed to have one hundred percent certain knowledge of anything.
David: Take the Buddha, for example, and those men who are regarded as wise. They claim to have this certain knowledge of reality. They called it "enlightenment", or something like that. It's a reasoned out enlightenment - I'm not talking about a mystical enlightenment here - it's a full knowledge of reality.
Paul: Yes, well, my own point of view on these things is that the logical reasoning which we all share when we're discussing the rules of logic, and what we regard as a reasonable argument, and so on - itself can be shown to have its own inherent limitations. That is, ordinary classical logic cannot grasp Ultimate Reality because of some well-known fundamental theorems about its limitations, proved by Kurt Godel and others.
Kevin: We can be made aware of those limitations through using reason itself. So it's logic itself which illustrates the limitations of logic.
Kevin: And once we've seen the limitations of logic, then, if we're brave, we can then go beyond the limitations of logic.
Paul: Well, we might possibly be able to. At the end of my book The Mind of God I discuss this issue under a section on mystical or revelatory insights. And what I say there is that in this search for ultimate explanations of things, science and logic and rational reasoning can lead us only so far. My own feeling is that you'd be best to put your faith in that sort of reasoning, and take it as far as you can go. However, because of the inherent limitations in the nature of logical reasoning you'll inevitably reach a point beyond which you can't go - a point where you'll just have to accept as an act of faith this sort of "starting point" which I was talking about a moment ago. And then the question is whether by some other mental means, some other kind of intellectual activity, can we leap beyond, can we get an inkling or grasp that ultimate reality?
Kevin: Have you had any insights on that particular point?
Paul: Personally, no, I never have. But I am perfectly aware that many people claim to have had these sort of mystical or revelatory experiences - you mentioned the Buddha, and of course there's a long history of Christian Saints and others who claim to have had these deep revelations.
Kevin: What do you think of the idea - this is a Buddhist teaching now - that all things that we can perceive are actually illusory. For example, we perceive boundaries around things, we perceive things to be limited - and this is part of standard logical reasoning as well - we perceive these things, but when you actually analyse them you discover that the appearance is not real.
Paul: Well, of course, it's an old idea going back to Plato. So much of the Western tradition, including the scientific tradition, has this Platonic legacy. Plato had a notion of an alternative realm of perfect forms. If we take something like mathematics, which is dear to the heart of every physicist, Plato asserted that mathematics has an abstract existence. Think of a number, like eleven: this number really exists, but it doesn't exist within space and time. It exists within a realm of perfect forms. And the actual manifestation within what we might call the everyday world of our perceptions, Plato saw as being some sort of pale imitation of this world of perfect forms. Scientists have taken this way of looking at the world on board because most physicists who work in fundamental physics have in mind that these laws which I've been talking about are mathematical in nature. The laws, and the mathematics which describe them, have a sort of abstract existence in this realm of perfect forms, and our everyday observations only imperfectly mirror these perfect forms.
Kevin: Yes, well, let's make this a little bit more personal. Let's take Paul Davies, for example. Now you certainly appear to us in some sense - we can hear you speaking to us, and we can read your books and so on. And in some sense you appear to have had some kind of a beginning, and presumably one day you'll have some kind of an end . . .
Paul: I imagine so, yes.
Kevin: But when we actually look at it a bit more closely we discover that when we try to find this beginning of Paul Davies, we can't find it. When we try to find this actual, real end to Paul Davies, we can't really find this either. So the closer and closer we look at what Paul Davies actually is, the more and more infinite he becomes - the more and more his body merges with the whole universe around him. So, in a sense, while Paul Davies appears to us and for practical purposes we speak of you as existing, in actual fact his existence is illusory.
Paul: Well, I'm not sure about illusory, but perhaps "ill- defined" might be a better expression.
Kevin: Well, I would say it is impossible to be defined, because we cannot put boundaries on you absolutely anywhere.
Paul: You're picking, of course, a notoriously slippery concept which is that of personal identity. But we could take something less contentious, like an electron or something--
Kevin: Yes, any object at all, actually.
Paul: Well, it's quite true that on the sub-atomic level we have problems in the identities of objects. Two electrons can be indistinguishable from each other, and can in some sense swap locations.
Kevin: You see, I think scientists, generally speaking, are very dishonest on this whole issue. You said somewhere yourself in The Mind of God that science is uncompromisingly honest, and I think it is honest . . . within very narrowly defined limits . . .
Paul: Well, it sets its own rules.
Kevin: It's consistent within its own rules, to some extent. But actually it's very dishonest - and, I would say, irrational. Everybody thinks of science as being extremely rational, and that this is its problem, whereas I regard science as being incredibly irrational.
Paul: Can you give me an example?
Kevin: Well, scientists refuse to become aware that the things they're looking at are not so clear cut. It doesn't matter whether we're talking about electrons or species, or whatever.
Paul: I think scientists are very much aware of this. In particular, physicists are extremely aware of the ill-defined nature of reality at the sub-atomic level - the whole quantum physics frolic, you know.
Kevin: But if they were aware of this, then their lives would be entirely different to the way they are. For example, if a person knows that they themselves, personally, are infinite, and that their own self has no beginning or end - well then, they would not feel all the emotions of anxiety and fear, and they would in fact become fully enlightened Buddhas.
Paul: Well, quite possibly, but I think you're confusing scientists with the practice of science. Individual scientists are flawed human beings like the rest of the population.
Kevin: So in fact they're not totally honest in that sense.
Paul: Well, of course, individual scientists can have all sorts of irrational beliefs, and feel passionately about something, and have hunches and intuitions, and can go about practicing science in a sloppy way, and still get it right. But science as a discipline, and the scientific community as a whole, I believe, is practicing something that can be justified. For example, you've been talking about the slipperiness of the concepts of certain things, and let's just take something I'm familiar with, say, the electron or another sub-atomic particle, and the well- known problems of its lack of definition, of its fuzziness, compared to everyday reality. And we can ask: what is it the scientists are trying to do when they experiment with the sub-atomic world of electrons and so on? Well, what we're actually trying to do is to link together really rather concrete things. You can make the measurement of the position or the motion of an electron. You can observe a pointer on a meter, or a click in a geiger counter or something of that sort, which can be very, very precise. And the job of a physicist is to relate all these clicks and pointer readings and so on to each other, through some sort of mathematical and conceptual framework, using, in an informal way, like "atom" and "electron" and what have you. And, of course, although we recognize that individual electrons or atoms may well not have a well-defined identity, nevertheless, what we end up with is a whole lot of predictions about concrete measurements. You know, if you go and measure such and such a thing - have a beam of electrons along here, and scatter from a target over there - you'll see twenty percent scattered at some particular angle. You can go and check that. All of that holds up very well.
Kevin: There's a big difference though between not having a well-defined boundary and not having a boundary at all. You see, I would say that things - and I include every thing here - have no boundaries around them at all, other than what our senses or our reasons create. Because when you actually analyse anything at all, it becomes very obvious, very quickly, that finding any kind of a real boundary at all - a fuzzy one, or a well-defined one - is absolutely impossible.
Paul: What you suggest is certainly true in one sense. Scientists recognize that there is a subtle quantum connection or linkage even between widely separated parts of the universe. A famous example is where two sub-atomic particles collide and then move a long way apart, but they are still in some sense entangled. [This is often referred to as the Einstein-Rosen- Podolsky (or EPR) correlation]
Paul: And this is recognized, and indeed not only is it recognized, but you can specify very precisely, mathematically, by how much they're entangled and you can do careful experiments to confirm that entanglement. But I think there is another important point here, and you've touched upon it. I've tried to discuss it in some of my books. It is this. Science wouldn't work at all if there wasn't a sense in which we could know something without having to know everything.
Kevin: Well, in a sense, ordinary everyday life is a kind of science. For example, I'm drinking a cup of coffee in front of me now. When I put the cup to my lips, if the coffee is too hot then I obviously have to put the cup down again. This is a kind of scientific experiment, which everybody does all the time, every day. So, in a sense, everybody is a scientist because we're treating things as they appear, and we're getting the results of little experiments, and we're behaving based on the results of those experiments. So would you agree, in that sense, that everybody is doing science, and it's necessary to actually live?
Paul: Yes, well, of course, the practice of science is a refinement of what started out as common sense and systematic observation of the world, and trying to organize our observations into categories and laws and so on - but it's moved a long way from that and taken on a life of its own. I can just come back to this point of nothing having any boundaries or edges, one of the features that I would describe as a remarkably special feature of the world is precisely that these entanglements, whilst they undoubtedly exist, and in a sense connect everything to everything else, nevertheless don't prevent us from making sense of the world by quasi-isolating certain parts. The example I like to talk about is Galileo and the law of falling bodies. If you drop two bodies, a heavy and a light one - together, and they'll hit the ground together. Of course, if you actually try and do that experiment, you very often don't get that result. It's only by effectively isolating the falling bodies from their environment - for example, dropping them in an evacuated tube, and neglecting other things - that you actually establish this law.
Kevin: Yes, well, you know you were saying earlier how you regard some things in this universe to be special--
Paul: This is one of them!
Kevin: Well, I must say that I personally don't find anything in the universe as being "special", because--
Paul: But it's easy to imagine a universe in which you couldn't do that.
Kevin: What I mean is that no matter what we actually observe, everything happens because it is entangled by cause and effect with everything else in the Universe.
Kevin: I remember a little story. A few years ago, I met a fellow who was a bit eccentric and he invited me back to his place for a chat. As we went in the front door, he grabbed the light switch and turned the light on and off several times, and he said, "It's a wonder!" That's all. "It's a wonder, isn't it?" And he'd switch it on and off about twenty times - "It's a wonder." I mean, this fellow didn't need drugs! But I was telling him that, no, it's not a wonder at all. Once you know the chain of cause and effect, once you know the interrelationships between things, that there's no free-will, that everything happens because it has to happen--
Paul: Well, yes, of course.
Kevin: There's no choice in the matter. I'm not full of wonder that the light comes on. I'm not full of wonder that the human species has evolved to the state it has, because I know that there's no choice in the matter. Everything that happens has to happen.
Paul: But that's simply not true!
Paul: Well, firstly, because there is a choice in the matter. The laws of physics don't have to be what they are. Given those laws of physics, you're quite right, the chain of causation is layed down to you - with the exception, of course, that I've alluded to many times, that quantum physics shows this linkage of cause and effect isn't quite as sharp as most people believe.
Kevin: But there are causes to the laws of physics!
Paul: We're coming right back to the issue we started out with. If, by normal causation - and you've been referring to the case of switching on and off the light - what we're talking about is that physical process "A" gives rise to physical result "B", and we find that this is invariably the case, and we would then say there is a causal relationship between them. We might find a law of physics that, as it were, legislated that that were so. So in the case of the falling body, we drop the body, it falls towards the ground, and we feel that that's a law- like principle, a law-like encompassing of this cause and effect. But, of course, we can then ask about these laws. Where do the laws come from? Why is the law of gravitation what it is, and not some different type of causal relation, for example, one in which heavy objects fall faster?
Paul: This is the essential point which I was trying to make. I wouldn't use the word "causation" when referring to selecting the actual laws from the set of all possible laws, because that does imply something in time, I would use the word "explanation". You have just hit the nail on the head by saying, "We would require an explanation for why those laws are what they are."
Paul: That's precisely my point. That's why I think that we need - I hesitate to use the word God, because it's so loaded - but something like a deeper level of explanation, a meaning, a purpose . . .
Kevin: The problem is, if we say we want an explanation for the laws of physics, then this means we have to find something, some other "thing" which is other than the laws of physics in order to explain them.
Paul: That's right.
Kevin: But the thing is, there is nothing "other". As long as we're living in a world where things exist, there is nothing other, or separate, because nothing is ultimately separate from anything else. There is nothing separate from the laws of physics. So we can never, ever find an explanation for the laws of physics, because there's nothing separate from them.
Paul: Well, I don't know when you say there's nothing separate from them . . .
David: For example, if the laws of physics were programmed . . . Some scientists like to speculate that the Universe could be a computer simulation, or something of that nature.
Paul: They do. Some of them.
David: Then all the laws of physics would be programmed into it, and everything that happens is the running of the program.
Paul: So we could imagine programming it differently and having a different set of laws!
David: So you could say there's a definite cause of these laws of physics - the actual programmer.
Paul: Right, so the question is, what attitude should we take to the rather special way in which, as it were, our universe has been programmed. And one is to shrug your shoulders and say: "Jolly good job we got programmed, or we wouldn't be here to know it."
Kevin: But hang on, the programmer himself is a part of the laws of physics.
Paul: Well, I wouldn't say that. He may be part of a meta- universe of which the laws of physics are a component.
David: Yes, we'll assume the laws of physics are sort of programmed formulae.
David: Okay, so immediately, to my mind, the cause of these laws is the programmer, and then we need an explanation for the programmer, and then we go back for ever and ever, Amen.
Paul: Well, of course, we come back to the point I made earlier - whether you're an atheist, a theist, a scientist, a philosopher, an artist, whatever your explanation of the world, if you want an ultimate explanation you have to start somewhere. And the question is, where do we feel comfortable starting? Do we simply start with the laws of physics as given - the great cosmic program if you like - or--
David: Well, it doesn't matter, does it. We could start with anything at all.
Paul: You could even just start with the present state of the world as it is, and not look deeper. But then you would never even do science if you just accept the phenomena of the world as they are, and not bother to inquire "why?". The whole scientific enterprise exists because people have not been satisfied with just accepting things as given. They've wanted to know why things are the way they are. And they found underlying laws. Now we want to know why the laws are what they are - and that takes us into this metaphysical realm, where we might start legitimately using words like God.
Kevin: Why don't we start then with the law of cause and effect rather than the laws of physics, because fundamental to the laws of physics is the law of cause and effect. So if we were seriously interested in understanding Ultimate Reality, surely we should start with that very basic law of cause and effect, and with existence itself, because all of the laws of physics operate on existences.
David: Yes, without cause and effect, the laws couldn't operate at all, could they?
Kevin: Nor without existence.
Paul: You may wonder why I'm a little bit hesitant about this cause and effect.
Paul: It's just that physicists actually don't recognize cause and effect. The law-like linkages which we spot between physical phenomena are only in a rough and everyday sense reducible to cause and effect. You see, very often, what you're really talking about is just a correlation. You're saying "A" happens over here, "B" happens over there, and we find a correlation between them - and in certain circumstances this reduces to the sort of everyday notion of cause and effect, but correlation is a much broader notion. But anyway, let's go with your assumption that mostly when we're talking about explaining things we want to say "A" explains "B" and so on. And you're going to point out, of course, as has been known since the dawn of history, that if you have a chain of explanation you're stuck with this chain either going back in an infinite regress, or stopping somewhere. And one of the well-known arguments which is often used against the existence of God is to say that if God is the beginning of this causal chain, well then, what caused God? This is something we all learn as children. And Christian theologians have struggled for a long time to see whether the notion of an uncaused cause has any sort of philosophical sense.
David: Well, I think we should actually try and establish, if we can, whether the statement "everything has a cause" is actually valid. Because if that's the case - if everything has a cause - then, obviously, the causes must go back forever.
Paul: Well, no, they don't. You see, what we now understand is that, because space and time are part of the physical universe and themselves caught up in this "web of causation" - if we must use the term - then we recognize that we can't push cause and effect (in the normal sense of a chain of events in time) back forever and ever. Because the universe itself, including time, came into existence only a few billion years ago.
Kevin: Just a minute. This is one scientific theory, isn't it? This is the Big Bang theory.
Paul: That's right.
Kevin: But it strikes me as very unlikely that all the matter in the Universe - and I use the word Universe to mean absolutely everything--
Paul: I agree, yes.
Kevin: It seems unlikely to me that there's just one Big Bang. It's more likely that there are an infinite number of Big Bangs.
Paul: You could imagine an infinite number of parallel universes.
Kevin: It would be egocentric of us to think that ours is the only one. In which case our Big Bang, this little bang, so to speak, this infinitely small bang, is actually not the beginning of time because--
Paul: No, no. There I must contradict you. I agree entirely that we can speculate on the possibilities of an infinity of universes. But each of these universes has its own space and time, with its own temporal beginning.
Kevin: But why can't we all have a shared time?
David: A meta-time.
Paul: Well, there's no particular reason to postulate this meta-time. Even without it we can still imagine something like a "meta-verse" in which there are space-times, and we can imagine the collection of all space-times.
David: Yes, all right, but time is a "thing". It's a conceivable thing.
Paul: Time is a measurable thing - it's part of the physical world. And if we're talking about the origin of the physical world, the Big Bang, we must include the origin of time in that.
David: But because time is a conceivable thing it must have a cause - even if it's we who are the cause of time.
Paul: Here I come back to my what you may regard as hair- splitting - the distinction between cause and effect and what the physicist would regard as a law-like correlation. This point is absolutely crucial to understanding how the universe can come to exist from nothing. Quantum physics shows that events can occur in the microscopic realm without having what we would regard as well-defined prior causes. That is, they are genuinely spontaneous events in the sense that they "just happen". This is not cosmic anarchy, because the probability of various alternatives happening is something which is made mathematically precise. But if you take a typical example - why, say, a radioactive nucleus of uranium decays at some particular moment rather than some other - well, there is no reason I'm afraid. It "just happens" at that moment, uncaused. It's just a spontaneous event.
David: Well, actually, this ties-in to what Kevin was saying before about how he regarded scientific enterprise as essentially a dishonest one . . .
Paul: I don't think there's anything dishonest in what I have said. It is simply a fact about the world that can be tested.
David: I think there is something dishonest.
Paul: It's just the way the world happens to be.
David: Well, for one thing, because quantum mechanics is a scientific theory, it's inherently uncertain. In other words, no one knows whether some new data could come along in the future and overturn the whole quantum theory.
Paul: Yes, of course. This is the big difference between science and fanaticism, or science and dogmatic religion. All scientific knowledge is tentative. All scientific knowledge is provisional. What we're trying to do here is to understand things at the deepest level we can, to the best of our ability, given our current knowledge. Now, I'm trying to convey the party line. There's nothing idiosyncratic about what I'm saying. It's just the party line on our current understanding of basic physics and cosmology. Of course, in a hundred years it may all be swept away.
Kevin: I must say that just a few weeks ago David and I were speaking to a creation scientist, who believes in Noah's ark, and that the whole world was covered in a flood, and I must say that, to my mind, when the physicists say that they're observing events which have no cause . . . I think you used the term "no prior . . ." - what was the phrase you used?
Paul: "No well-defined prior cause."
Kevin: Yes . . . well, that's fair enough. But they seem to go that extra step further and say that there actually is no cause at all!
David: It's a big leap, isn't it.
Kevin: It seems a little bit along the same lines as the creationists.
Paul: No it's not! It's been known for nearly a hundred years now that there's a sort of randomness, an unpredictability at the level of atoms and molecules - anybody can do these observations - and you see that, in any given case, the laws which govern roulette or dice are obeyed by, for example, radioactive nuclei. This is something that can easily be tested. And then in the 1920's, the question arose as to whether this unpredictability, this randomness, really was a bit like trying to predict the stock market, or the weather, or the throw of a dice. Was it just that we didn't know enough about these atomic systems at a sufficient level of detail to be able to predict them? This is in fact what Einstein believed. He insisted that if only we could probe to a fine enough level of structure, a fine enough level of detail, we would find the causal reasons why the particle decayed at that moment rather than at some other.
Kevin: The thing is, the whole Universe is unpredictable. I mean, we can do any experiment whatsoever, and we can't predict with one hundred percent certainty what will happen.
Paul: Hang on, I'm only half way through this little story, and it's an absolutely crucial point.
Paul: So Einstein took the point of view that the unpredictability of the quantum world was essentially like roulette or the stock market - it had its causes in something, but we just didn't know what because we weren't smart enough. The opposing camp, led by Niels Bohr, said: no, this is uncertainty is absolutely inherent in nature; it represents a fundamental limitation to what can, even in principle, be known about the future; there are certain things that simply cannot be predicted. Even with complete knowledge of the entire universe you would still find that particular events occurred entirely spontaneously, in an unpredictable manner.
David: But they're not entirely unpredictable, are they. I mean, if these particles were entirely unpredictable then the quantum equations wouldn't be able to work.
Paul: Yes, but as I said earlier, by "entirely unpredictable" what I mean is that you can specify the laws of probability. In the same way, I would say that when I toss a coin it is unpredictable whether it comes down heads or tails, but if I did it a million times it would be quite likely that I would get roughly half of each.
Kevin: Only quite likely, though.
Paul: That's right. The point is that in the last ten years or so it's been possible to test whether Einstein was right or Bohr was right, and the experiments unequivocally show that it was Bohr who was right.
Kevin: I think this is wrong because--
Paul: Well, I'm afraid the experiments have been done.
Kevin: The reason is this. There's no way in the world that we, as individuals with finite mind, can know every piece of information in the Universe. But, in a sense, the Universe itself has all the information available to it. So you could say, in a very abstract sense, that the Universe "knows" everything that is happening.
Paul: That's what Einstein wanted, you see.
Kevin: My point is that even though we as human beings cannot know everything, and it's not very practical for a scientist to want to know everything, from a logical point of view everything still has a cause.
Paul: Well, that's where I must say that the experimental evidence is against it. You see, Einstein wanted that point of view. He often used the word "God". He said that, "God does not play dice with the Universe."
Kevin: Yes, I absolutely think he was right!
Paul: The thing is that the experiments, I'm afraid, have really knocked this view on the head.
Kevin: Can we talk about these experiments a little bit more? Because I've read some of them, and all they illustrate to me is that we cannot explain the results of these experiments. That's all the experiments suggest to me.
Paul: Well, let me tell you about them, and then you'll be able to change your mind. Most of the experiments used to discriminate between Einstein's and Bohr's view of the world involve two particles that interact and then move a long way apart, and then measurements are performed simultaneously on these separated particles. Now it's possible to prove a very general theorem, making only three assumptions. One is that normal logical rules apply. So if we agree that we want to be bound by ordinary logical reasoning then the theorem follows. And then the two physical assumptions are, one, that there should be no faster than light signalling - that's a consequence of Einstein's theory of relativity, and Einstein for one would be reluctant to give that up--
Kevin: Well, I wouldn't be reluctant to give it up.
Paul: --and the other is that there is some type of reality of the type you were talking about, in which objects have well- defined properties prior to our making measurements - in other words, they really exist in certain states and so on. Normal, old-fashioned, cause and effect if you like. You can show that, subject to those three conditions, there are strict mathematical limits to the degree of correlations that can exist between these separated particles. And you can do the experiment and what you find is that those limits are violated. The limits are called "Bell's Inequalities", after John Bell. And so you have three choices. One is to abandon ordinary logical reasoning - most people wouldn't want to do that. The other is to say that there's some sort of faster than light signalling - "ghostly action at a distance" is what Einstein called it.
Kevin: Or that they're somehow connected.
Kevin: And so there doesn't need to be any signal between them.
Paul: Well, they have to transfer information, because what you're seeing with these correlations is basically that the particle on the left knows what the particle on the right is doing.
Kevin: Well, if we postulated that there was actually no distance between them, and that the distance which we perceived between them was in fact only illusory--
Paul: Well, of course, you could do that, but what I'm telling you is that if you make these three assumptions, the experiments violate them. So you can abandon any one of them. Now most scientists would abandon this naive view of reality - of everything having a well- defined cause and effect and so on - adhering to a tradition going back to Bohr. But one or two mavericks want to take your line. They want to say, well, maybe there is some sneaky way in which you can get signals faster than light. The problem that gets you into - if you stick with something roughly like Einstein's theory of relativity - is if you can get signals faster than light, you can send them back in time as well. And then you're stuck with all sorts of causal paradoxes about changing the past and so on, which is even more horrible than the sort of quantum uncertainty that worries you. So these seem to be the choices. Now, it's possible that we'll discover that there is some sort of faster than light signalling, and that there are causal loops and things like that, and that some sort of naive, pre-nineteenth century view of reality is closer to the truth. I can't say. All I can do is to tell you what the party line is.
David: Yes, Paul, but these objections, or these problems brought up by the party line, to my mind pale into insignificance when confronted with the basic fact that these quantum equations work. Scientists often say that the quantum theories are probably the most sophisticated and useful ones in all of history, and they have created a lot of technology. And so they actually do work. They predict the particles--
Paul: In a statistical sense.
David: Right, okay - but total uncausation? If these particles were to arise totally uncaused then they would be totally unpredictable. This is a logical truth.
Paul: Yes, that's what I've been saying - subject to that caveat earlier. Like when we toss a coin we would normally say that the particular coin toss was unpredictable but that over a million trials we would predict, quite accurately, that roughly half would be heads and half would be tails. That's how it works in the quantum realm.
David: Yes, we don't have to even go into that kind of complication. It's just a basic logical truth here, that a totally uncaused event is totally unpredictable . . .
Kevin: And things are either caused or they're not caused. You can't have something being partially caused.
Paul: No, well, you see, this is why I don't like this word "cause", and I think most physicists would feel the same. Aristotle showed us that there are at least four different types of causation. If we take something like the radioactive nucleus, and ask: well, why did it decay at that particular moment rather than some other? Well, you might say that what caused it to decay was that it was--
Kevin: It was old.
Paul: No, no, that's the whole point! It's got no memory - that's the whole essence! But you might say that this particular object did what it did because it had a big nucleus - it has a lot of protons and neutrons in it. So in a sense the cause of its decay is that it's big and unstable, that the cause of its decay is that it lives in a universe with a low temperature - I mean, there are all sorts of things which contribute--
Kevin: And also the observer as well. Another thing you could say is that the thing decayed because the observer said that it decayed.
Paul: Well, that's a slippery one, and I think that if we get into that we're going to go down a very obscure path - the entanglement of observer and observed.
David: All right, but I want to concentrate on this subject of cause and effect. To me, it's fundamental to the understanding of everything. These four types of causes which you outlined, Paul, are really just sub-categories of the basic notion of "cause".
Paul: Well, they're drawing attention, I think, to the fact that the word "cause" can cover a multitude of sins. So if you ask, "Well, what caused a house to be built?" - this is Aristotle's example - well, you might say the bricks had something to do with it. He called that the material cause. But then you might say the blueprint of the house--
David: Alright, but what I'm interested in is that when something is caused it is not uncaused.
Paul: Well, I can't argue with that.
David: So if everything is caused, if everything is not uncaused, then we can approach an ultimate explanation of everything. This is why it's a very important point. And this is why I think the quantum physicists are misleading us in this area.
Paul: No. I think that what the quantum physicists have done is shown that your somewhat naive view of cause and effect is an unsatisfactory one for understanding the universe and they have given us a wonderful opportunity now to progress this whole tired debate, which goes right back to Plato and before - this chain of causation. We can now see, that if you get away from a naive notion of cause and effect - if we concentrate instead on explanation--
David: How is it naive?
Kevin: An explanation is a category of cause, though, isn't it.
Paul: No, no! I don't think so. Because I would say that we can explain how the universe comes into existence on the basis of the laws of quantum physics. Given the laws of quantum physics, the spontaneous coming into being of the universe, or the spontaneous decay of a radioactive nucleus, are things that can be explained.
Kevin: You see, I would define a cause as something that is necessary for the existence of something else. So if, in fact, the laws of physics are necessary for the existence of a particular event, then we can speak - and don't forget that "cause" is just a word that we use for practical purposes - then we can say that the laws caused a particular something.
Paul: Yes, I can't quarrel with that, except that I would never myself use the word "cause" in that context. But if you'd like to stick with it, well then, okay, make your point.
Kevin: So then because anything we can conceive of necessarily has a cause, in the sense that it's dependent on something else for its existence - even if that has to be an observer . . .
Paul: . . . yes . . .
Kevin: Then we can say that nothing - nothing that we can conceive of - exists independently as a finite thing, because it's linked by its dependency to something other than itself. You want to call it an explanation or something . . .
Paul: That's true.
Kevin: It's at least linked to an observer. So in fact anything that we can conceive or perceive as being something finite, as something existing, is definitely an illusion. In fact, the thing is actually infinite, because it's linked to everything else in the Universe. So I think this is a very important thing to understand, and it's based on a knowledge of cause and effect. It's the only way to actually arrive at the infinite - which is the explanation of everything.
Paul: Well, I'm not sure what you mean by "the infinite". This is the problem.
Kevin: Well, the infinite means "everything". There is nothing else other than the infinite.
Paul: Is this the set of all things which exist or something?
Kevin: Not a "set". Because as you said in your book The Mind of God you can't really call it a "set", because it doesn't exist relative to something else.
Paul: You have to be awfully careful, that's right, because the infinite set of all sets is not actually a set.
Kevin: That's right. It's just a word. It's like the word "God". I use the word "everything" similar to the word "God". It's not a thing - it's the totality.
Paul: I'm not quite sure where this is leading us. I guess, to pull it back to the point where we opened at, which is that if we agree that to explain the world, including its coming into being from nothing, we need something like the laws of physics. That's the point I would take. And then, of course, if we want a deeper explanation for the world, rather than accepting it as a brute fact, we should concentrate on those laws, and their particular form and their specialness- -
Kevin: Well, I'm sorry but I'm going to have to interrupt you there, Paul. We've run out of time. We've come up to sixty minutes, but I reckon we could do another sixty hours on this one.
Paul: I wouldn't be surprised.
Kevin: Thanks very much for your time.
Paul: Well, it's a great pleasure, and I'm very pleased to have been asked on your program.
David: Thank you.