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About this episode:
Celebrated mathematical physicist Sir Roger Penrose talks to renowned Christian philosopher William Lane Craig about God and the Universe.
They discuss Penrose’s ‘3 realms’ view of reality and his Conformal Cyclical Cosmology. Could the fundamental nature of reality, the Big Bang and the fine tuning of the Universe point towards a creator God?
Sir Roger Penrose is Emeritus Rouse Ball Professor of Mathematics at the University of Oxford. He is the recipient of numerous awards for his work in cosmology including the Wolf Prize for physics for his work with Stephen Hawking on the Penrose-Hawking singularity theorems.
William Lane Craig is Research professor of Philosophy at Talbot School of Theology and Professor of Philosophy at Houston Baptist University. He is the founder of Reasonable Faith and is well known for defending Christian theism in numerous debates with leading atheists.
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More from this season:
- Episode 1 | Part 1: Religion: Useful fiction or ultimate truth?
- Episode 1 | Part 2: Religion: Useful fiction or ultimate truth?
- Episode 3: The story of Jesus: Can we trust the historical reliability of the Gospels?
- Episode 4 | Part 1: Is God Dead? A conversation on faith, culture and the modern world
- Episode 4 | Part 2: Is God Dead? A conversation on faith, culture and the modern world
- Episode 5: Did Christianity give us our human values?
- Episode 6: Morality: Can atheism deliver a better world?
Episode Transcript:
Justin Brierley (JB) William Lane Craig (WLC) and Roger Penrose (RP)
JB: And today our Big Conversation is on ‘The Universe: How did it get here and why are we part of it?’ My conversation partners today are Roger Penrose and William Lane Craig. Roger Penrose is a celebrated mathematical physicist. Among many accomplishments, he worked alongside Stephen Hawking to produce the Penrose-Hawking singularity theorems, which helped to confirm Big Bang cosmology. He’s described himself as an atheist but has rejected the idea that the Universe is purposeless, saying, “I think that there is something much deeper about its existence, which we have very little inkling of at the moment”.
Professor William Lane Craig is a renown Christian philosopher and the founder of Reasonable Faith, an organisation seeking to defend Christianity through reason and evidence. He’s well known for arguments for the existence of God, such as the Kalam cosmological argument and the fine-tuning of the Universe for life. He believes that God is the best explanation for the origins of the Universe and why we find ourselves in it.
So today we’ll be looking at the deep mysteries of the Universe and whether its complexity, order, origins – and the fact it produced us – points beyond itself, and if so, to what? So Bill and Roger, welcome along to the programme – it’s great to have you both with me! I feel like a kid in a sweet shop, because having you both here is something of a dream come true for me.
WLC: Well I want to say right at the beginning, how acutely aware I am of the tremendous privilege of being on the same programme with one of the world’s greatest cosmologists, and I feel honoured to be talking to Dr Penrose today…
RP: It’s a huge pleasure and honour for me too.
JB: Well I’m glad that we’re all in mutual agreement on these issues at least, of how much were glad to be here! Let’s see what we disagree on in the course of the programme…! But let’s have some introductions to you both. Roger, what drew you first of all to science and maths, in particular, as a young man?
RP: I think it was largely my father, who had a great… I mean, he was a scientist – a human geneticist mainly, medically trained, but also philosophically and mathematically trained. So he had a good understanding of maths, and I think he had a… mainly it was a sort of playful understanding, like puzzles – he certainly was a great chess problemist, and also – well, chess was big in the family; my younger brother became British chess champion ten times…
JB: Which tells me something about the way your brains are wired, perhaps, as well…
RP: Well, it wasn’t quite the same with all of us, but Oliver my older brother was also an excellent chess player, became the Cambridge University champion, for example. But I wasn’t at all; I was not interested in chess. But I was very much interested in puzzles and games – mathematical kinds of puzzles – and also physical geometrical puzzles. So that was an important feature of my upbringing I think. But we used to go for long walks, looking at plants and talking about the Universe in various ways.
JB: Did faith ever feature in your childhood, or not particularly?
RP: I would say no, it didn’t, in the sense of a particular religion, no. You see, my father came from a Quaker family, so he had that kind of background, but he had very much a sort of sympathy with Quakers… you know, he was very much a pacifist and that sort of thing; he didn’t like conflict. But he wasn’t a believer in the sense of a religious believer; he wasn’t a Christian, certainly, nor was my mother. So that was not part of the family upbringing.
JB: And did you ever have any brushes yourself with religion growing up, or as a student?
RP: No, I wouldn’t say so. I mean, maybe at the age of seven or six or something, but I’m not sure we’d count that sort of thing…. no, I wouldn’t even say that then either. I think there was a big question in what was going on, but not…
JB: I was going to say, as your scientific career progressed, did that open up any of those big questions about where did this all come from?
RP: Well there was a curious thing… I remember one time when we were in Canada during the war years, and we used to go every Sunday to Sunday School you see. And I think my younger brother Jonathan asked the question… you see, we were a bit suspicious that this was just a way of getting us out of the house, that they could have some peace, you see. And Jonathan asked my mother whether she really believed it, and she’d got this embarrassed look on her face, but this was apparently an indication that I don’t think there was any confession to us that they had actually been confident that this was the truth – it was a way of having some peace during Sundays. And Jonathan sang in the choir, so that kind of aspect of things.
JB: Has any of that filtered through to you in terms of at least appreciating the… often being talk about the majesty of choral singing; at Oxford University where you have been based for a long time there are beautiful chapels and services available…
RP: Oh I think all of that makes a huge impression on me, yes. And music, I mean, well I’m a tremendous fan of Bach and I think there’s something absolutely incredible in the music, and I can understand… I mean, he was driven by his religious faith – Christianity – and obviously it was a hugely important thing, and the expression of that in music can be extremely moving.
JB: We’ll come back – I want to talk to you about your work with Stephen Hawking, obviously, and that’ll feed into what we’re talking about on the show today. But let’s introduce you Bill on the show. It’s wonderful to have you here – I suppose in many ways, the sort of things that Roger has been working on throughout his life have been very influential in some of the important arguments you’ve been making for the existence of God. Because I think it was in the 1970s that you started to really engage with Big Bang cosmology and see that there was an interesting and fruitful relationship here with some other philosophical arguments…
WLC: Yes, interestingly my background sounds rather similar to Roger’s, in terms of my upbringing. I think you were actually more involved in church activities than I was! My parents were at best nominal Christians, but we never attended church. But when I became a teenager, I began to ask what I call the big questions in life: Who am I? Why am I here? What’s the meaning of my existence? And as I looked at the Universe, I could see no meaning to my existence. I knew that humanity would eventually perish in the heat death of the Universe – then I could see no reason for its existence, for the existence of human beings, and in particular for my existence, and I simply faced an inevitable death in which I would cease to exist. And so for me, it was these big, deep, existential-philosophical questions, that eventually – through the witness of a girl who sat in front of me in my high school German class – led me to faith in Christ.
And as a Christian – to finally get to your question Justin – it’s important for me to have a synoptic world-view; that is to say, a world-view that includes a Christian perspective on all of the different facets of human learning, of whether it be the sciences, literature, art, psychology, history, philosophy and the deep metaphysical questions. So you’re correct, when I wrote my doctrinal dissertation on the Kalam cosmological argument under John Hick at the University of Birmingham, one of the things I began to explore was whether there might not be some sort of scientific confirmation for the claim of the Kalam cosmological argument, that the Universe began to exist. And I was startled to see the degree to which contemporary astrophysics did support this premise in no small part, because of Professor Penrose’s work on the singularity theorems. So that is an important part of my world-view as a Christian.
JB: And hence why you’ve been engaging with Roger’s work really a lot of your life. And I know that you yourself have had a number of discussions and dialogues with significant scientists and philosophers – it’s obviously a hugely contested argument, but one that I think we’ll get to some of the interesting aspects of it in the course of todays’ discussion. Thank you very much both for joining me on the show today.
Roger, I said I wanted to ask you about Stephen Hawking of course, who was a brilliant mind – a convinced atheist though, and especially latterly he came to believe that science had ruled God out or at least as an explanation of the Universe. How far did you agree with your former colleague on that?
RP: Well you see there’s a huge irony in this of course, which is my view about the origin of the Universe. And I remember hearing… there was a new book of Stephen’s posthumously published, and there’s a chapter in which he talks about the origin – the Big Bang – and I thought it was the most unconvincing part of the whole thing. Well you see the huge irony here is that I’ve changed my mind on all this. So the singularity theorems were – as you described – these were confirmation of this singular origin, and the world singular has to be explained here: it means a place essentially where your equations go to infinity and you have to give up; or in other words, it’s where your equations cease to work and they stop telling you what to do, if you like. And the idea is you go… we take observations about the expansion of the Universe and the equations of Einstein, and try to extrapolate backwards and use general theorems, which show that you really can’t evade the singular origin. So that’s where the equations blow up and you can’t rely on the equations to tell you what happened at the beginning state. And Stephen had a particular was of looking at that, which was an interesting way; I don’t think it works myself. He developed an idea with James Hartle, an American in California – very interesting man, and I think the idea is a very interesting one, but I have some problems with it…
JB: You have some major reservations…?
RP: Yes. But the main thing is that my current view is that the Big Bang, although it existed – there was a Big Bang – was not the beginning. And so there was something prior to the Big Bang. But if you like, the original reasons for my thinking about this are a bit like the kind of thing you’re talking about, about what the Universe is for – what is it doing? That kind of question. Shall I go into that?
JB: Well, let’s leave it for the moment, because I do want to go into where you are now with your cosmology, which is utterly fascinating and mind-bending at some level. But maybe we should start at a more sort of fundamental level, because I quoted in my introduction from a quote of yours, I’ll read it out in full now: “there’s a certain sense in which I would say the Universe has a purpose. It’s not there just somehow by chance. Some people take the view that the Universe is simply there and it runs along; it’s a bit as though it just sort of computes and we happen by accident to find ourselves in this thing. I don’t think that’s a very fruitful or helpful way of looking at the Universe; I think there’s something much deeper about it – about its existence – which we have very little inkling of at the moment”.
And you’ve obviously written as well at length and spoken of the fact that you see that there’s a sort of three-ways in which you can look at reality: the mental, the physical, the abstract. And in some sense, you actually believe there is more to this reality than simply the physical aspect, that many people – many of your atheist colleagues – would say well that’s all that ultimately exists here. Roger, do you want to just begin by sort of spelling that out – what your world-view is in that sense?
RP: Well when you say my world-view, and you mentioned the three words which I often use to describe… these things are also the three mysteries, if you like. There’s the physical world – things like tables and so on and what we think of as the physical world – although it’s not quite clear when we go deeply into what’s going on, what that really means, but never mind about that. And then there’s the mental world – that’s our experiences, consciousness, feelings about things and so on. And then there’s what you call the abstract world – I would be more specific about that, it’s a mathematical abstraction. So we’re thinking about how it is that… well let me secondly explain the mysteries, you see. Mystery number one is the fact that this world of physics seems to depend so extraordinarily precisely – and the more we explore it, the more precise we see this is – it’s so precisely guided by mathematical equations. So we have these mathematical… it’s not just equations – that’s a bit too specific – mathematical principles, which govern in such a precise way – the way this physical world operates – and there is, if you like, a huge mystery – I’m calling it a mystery, these things we’re never quite sure…
JB: Is this what Eugene Wigner famously spoke of as the “unreasonable effectiveness of mathematics” – it just seems to be an extraordinarily remarkable fact, that the Universe seems to be written in that language and that we can discover it.
RP: That’s exactly it, yes. And the more we know about how things operate… I mean now there is such extraordinary precision in measurements… Well, Einstein’s general relativity is very very precisely determined. And laws of quantum mechanics and how they interrelate even with gravity in some respects… well, clocks: one of the Einstein’s predictions was that a clock up high will run more slowly than one down here. And the precision in that… I’m sorry I got it the wrong way round…(!)
JB: Yes, I know what you mean, but the precision there is extraordinary…
RP: The precision even from down here to maybe a centimetre above, and they can measure the difference. So these are extraordinarily precise. It just shows that the mathematical theories, when we really understand them and when we get them right – they’re still not quite right, that’s clear. But nevertheless, the precision is extraordinary. So that’s mystery number one.
Mystery number two is how is it that conscious experience can arise when these circumstances seem to be right. Now I’m just guessing, but I don’t think it’s present in that water in the glass(!), but nevertheless, it seems to come about certainly with human beings and I think with other animals; I don’t think it’s unique to human beings…
JB: Certain brain structures somehow seem to give rise to this consciousness.
RP: And there is a genuine mystery, I think, and it’s not just a matter of complicated computations; there’s something much more subtle going on. So that’s mystery number two. And mystery number three is our ability to use our conscious understanding to comprehend mathematics and these very extraordinary self-consist but deep ideas, which are very far from my experiences. So that’s how we comprehend mathematics, if you like.
JB: And in that sense you believe that mathematics, for instance, is discovered, rather than invented by us, in that sense. It exists independently of us.
RP: That’s right, yes.
JB: And one of those great mysteries as you say, is the fact that we can access it, seems itself a remarkable feat of reality.
RP: That’s right, because it’s so indirectly connected with our existence and how we get along in the world and how natural selection has helped us to survive and so on – it’s really hard to see how these things come about from that.
JB: Well there are three big mysteries there to kick us off with. Bill, what is your response to some of these huge huge areas?
WLC: Well I want to say first and foremost that one of the most exciting things about Roger’s thinking is this deep metaphysical vision of reality that he has. It’s in such contrast to the sort of positivistic and verificationistic pronouncements of many scientists, who think that philosophy is dead and that these metaphysical questions are meaningless. Roger is engaged in questions that are not simply physical or scientific; these are metaphysical questions. And I think that the fundamental issue that is raised by this tripartite metaphysics, is the ancient philosophical problem of the one and the many – that is to say: what is the underlying unity of these three seemingly disparate realms of reality: the mental, the abstract and the physical. These realms of reality are so different, so causally unconnected it seems, that one wonders what is the underlying unity for all of these.
So how are these three realms related? For example, the mathematical abstract realm cannot be the source of the physical or conscious mental realm, because abstract objects, by definition, are causally effete – that’s part of what it means to an abstract object. The number seven, for example, has no effect upon anything. So the abstract realm cannot provide the source of unity. Could it be the physical realm that provides the source? Well Roger’s already mentioned the second mystery: how does the physical give rise to consciousness, particularly intentionality – the intentionality is the aboutness of our mental state. I can think about my summer vacation – no physical object has intentionality. So the mental is difficult to derive from the physical. And the abstract it seems to me is impossible, because the mathematical realm is characterised by necessity – these aren’t logically necessary truths, and by its plenitude – there are infinite realms of mathematic objects. And the physical realm, by contrast, is contingent and therefore cannot ground these logical and mathematical truths, and it’s plausibly finite as well.
So the physical can’t be the source. Now what about the mental – could the mental be the source of these other two realms? Well, in mental causation, we do have the experience of the mental causing physical changes in our brain. I can will to get up, or to speak. Similarly, many philosophers have thought that the abstract realm is not really a separate realm that exists by itself, but they are ideas in the mind of consciousness, that they are the result of intellection by a mind. Now the problem is that no human mind could be the source of the abstract realm, because of its plenitude and necessity – whereas we are contingent and finite. So what I want to invite Roger to come in on is why couldn’t the mental realm include an infinite consciousness. That is to say, an omniscient mind, which has created the physical realm, and which is the source of the abstract mathematical realm. This would solve the problem of the one and the many, and give you an underlying unity for this tripartite metaphysic that you affirm.
JB: And what you’ve just described sounds suspiciously like God?
RP: Well yes, it does sound suspiciously like that yes…
JB: Roger, what do you say to that?
RP: Well you see you’re putting it in the mental world, if you like, whereas I tend to put it in the Platonic mathematical world, you see, that I don’t quite see why… I mean, how do you drive the precision, you see, just a mental thing doesn’t seem to me… I don’t quite see why it helps, if you like. I mean, you can postulate – a super-mental being or something. I mean, does it have a mental existence without a physical one, is that the idea?
WLC: Yes, it’s so that this mind – this omniscient mind – has created a contingent physical realm, and is the source of the conceptual realm as well.
RP: I can’t quite see… well, you could say that it contains all that because it’s so infinite that it contains the entire mathematical world. But where does it come from?
WLC: Well it would have to be metaphysically necessary, in order to be the source of broadly logically necessary mathematical truths, and I would say other sorts of truths – ethical truths – that are plausibly necessary.
RP: This is very curious you see, you have the mental world sort of being a necessity, and I have the mathematical world somehow being a necessity, because it somehow…
WLC: I appreciate the necessity, but the problem is that the abstract realm has no causal powers. These are casually effete objects that never come into contact with things physically; they can’t move them or shove them or pull them. They exert no forces, they are not minds, and so they can’t make decisions to cause things that are not causal agents. So it seems to me that positing the abstract realm as fundamental is causally inadequate, and what one would gain from what I’m proposing would be a solution to these three mysteries – it would give explanatory depth to your world-view.
RP: I don’t quite see how it explains… I mean, you’re talking from a perspective of a religious person, and therefore one’s thinking of this is somehow… Specific religions are much more specific…
WLC: Right, and that’s why I grimaced a bit when you said, “from a religious perspective” – it’s a philosophical perspective, but it is…
RP: Ok, I’m happier with that, because then… you see, I have more trouble if one’s trying to make it specific in certain directions as regards one religion or another. But if it’s just such an abstract notion, it’s not that I’m necessarily unhappy with it, except that I don’t know what to do with it, because it’s so vague.
JB: That’s interesting. I mean, just for my benefit, this abstract realm of mathematical objects and so on, you say it’s there, it’s a mystery why it’s there/how it’s there…?
RP: I wasn’t calling that the mystery. You see, the mysteries are the connections – I like to draw this picture with the three worlds, you see. The worlds are there and the mysteries are the connections between the worlds. So mystery number one was how somehow out of a small part of this mathematical totality, we see physical laws, and it’s only a very small part. I mean, you look at any old journal pretty well mathematical journal and you see it’s full of things – I’m talking about pure mathematics – it’s full of things which certainly don’t purport to have any connection whatsoever with the physical world. I mean, some of those seem to have, and it seems to be a very tiny part of that world, which has to do with the operation of the physical world. So that’s one of the mysteries.
And then the next mystery is why it is that a very small part of what we call the physical world, organised in just a very specific way, comes about very rarely… I mean, all these planets around, well how many of them actually do we think has life of any sort on it, conscious life – that’s a huge question. But anyway, whatever, it’s a very tiny part of that which gives rise to mentality as far as we can see. And then it’s a very tiny part of our mentality… I mean even mathematicians don’t spend their whole time thinking about mathematics, they have other activities – they go to the movies sometimes, they have a love life, some of them at least!
JB: So when Bill tries to solve that mystery by saying, well what if there is an underlying explanation to it, it’s all contained within a divine mind – you find it difficult?
RP: Well it’s putting the divine mind in one of these worlds, you see, which I find that a little bit… not just asymmetrical, I just find it not very explanatory.
JB: Why not? Why do you find that this doesn’t help?
RP: Well you just say, oh there is somehow super-mentality, and it can do anything… I don’t know, I don’t know… I think I would need to have more of an explanation about exactly…
WLC: Well for example, take mystery number one – the applicability of mathematics. I think this is a huge issue, because on Platonism, you have this abstract, atemporal, non-spatial realm of causally effete objects. And the physical world happens to operate according to certain mathematical principles that you’ve described. And as Mary Leng, who is a philosopher of mathematics at the University of Liverpool has said, on Platonism the applicability of mathematics to the physical world is a happy coincidence, which just seems incredible. By contrast, we know that minds can design things, and the view that there is an omniscient mind who has designed the physical world on the mathematical blueprint that it had in mind, is a very ancient perspective that goes back to middle Platonism and people like Philo of Alexandria, who said that the intelligible world – the intelligible cosmos – exists first in the mind of the logos – the divine intellect – and then is substantiated in the physical world by the logos who creates a world on this blueprint. And that seems to me to be a good solution to the one and the many problem.
RP: I think you call it a solution, the trouble is I think my problem is it’s too vague. I don’t see how you can do much with this particular view. You see when it comes to the explanation of how our physical world operates in terms of mathematically, it’s extraordinarily precise, and one can say an awful lot about that. But a statement like the one you make here worries me, because you give quite a solution, but it doesn’t tell us very much.
WLC: But it solves the mystery?
RP: You say that…
JB: Is it because it’s very hard to then investigate this explanation itself, that you feel like there’s a mystery behind the mystery…
RP: You’d need to be able to say, how could you contradict such a view, you see? It’s so so vague, in a way. I mean why wasn’t there a mind which was in some way malicious – well maybe it is malicious, I don’t know. It’s just saying it’s a mind, without telling us…
WLC: Right. I haven’t said anything about the moral properties of this intellect, but I would be prepared to. I mentioned earlier that among the logically necessary truths that this mind would know and ground, would be not only mathematical truths, but certain ethical truths. I think certain ethical principles are not contingent but are necessarily true. And so this would provide a grounding for the objectivity of moral values and duties in a paradigmatic good. This being would be not only the source of the mathematical realm, but of the ethical realm and being the supreme good. And so now we’re beginning to add a little more content to this notion. As the creator of the physical realm, this mind would have to be uncaused, timeless, spaceless, immaterial, enormously powerful. In order to cause the ethical realm it would have to be good, perfectly good, and to cause the mathematical realm it would have to be omniscient. And so we’re winding up I think with a very rich, theological ultimate.
RP: Yes, I mean of course you’re touching on these other Platonic aspects like morality, and well you didn’t refer to the beauty aspect too…
WLC: Good point – aesthetic values as well…
RP: So one has those three Platonic aspects, and one can extend the idea of the truth, if you like – which is perhaps another mathematical part of the Platonic notions – to the other three as well, which I’m quite happy to consider. But I guess that my problem is that it’s just – I said this before – it’s just too vague to know what to do with it. You can make these words, you say well it does this and it does that and it does that, and explain it’s this and that – but in a way which I don’t quite see what it buys us…
JB: Is it because, I mean speaking to a scientist, let’s say Bill has this hypothesis that God is the ultimate explanation and grounds these various phenomena that you believe in and you see – is it that you find the hypothesis itself, it’s because you can’t investigate that particular hypothesis?
RP: Yes, I think that’s the main problem I have with it – it’s hard to know what to do with it.
JB: And inevitably goes beyond science in that sort of way…
WLC: Exactly. I mean we’re doing metaphysics here – not physics. This is a metaphysical version of reality consisting of a tripartite division of realms that have very mysterious interconnections. And so what I’m suggesting is a metaphysical hypothesis that will provide unity in the diversity, and solves the one and the many. And I think it’s pretty specific; I’ve rattled off a number of the properties that this mind must possess, and I think that’s not…
RP: Let me raise an issue with you, because if we’re putting this thing in the mental world, then to me that means it would be possible to be that thing; so that means one could be this entity – this God, or whatever one calls it. And I find that really hard to perceive. I mean, somehow a being with this kind of total control of the whole thing, it’s so much at odds with my own… well certainly experiences of what conscious experience is.
WLC: Do you believe in freewill? Do you believe we have freewill?
RP: I think there is something there which is not explained by… but this goes into some technical issues here about the operation of the world, and where our understanding of physics might have a gap in it and so on. And maybe one could call that a freewill – I would maintain an open mind when it comes to that question.
WLC: Right, well then if this being has elected to create agents with freedom of the will, then it’s not true that it’s in control of everything…
RP: But does the being have the freedom not to have all this…could it not do that somehow?
WLC: Well I think that that’s a further question to be explored. It would seem to me that as the creator of the physical realm, it would be very easy for this mind to have created a world with no free moral agents in it; a world in which the highest form of life is, say, rabbits. And there wouldn’t be any freewill. But if this…
RP: Oh well maybe rabbits do have, I’m not sure…!
WLC: Well, however that may be(!), if this being has elected to create significant moral agents that are endowed with freedom of the will, then it means that not everything that happens is controlled by this being in very marionette sort of fashion. And that would gel I think nicely with our experience; I think that this gels with our experiences of beauty, of ethical norms and obligations that press upon us, and with respect too, our own freedom to transcend the physical realm and not be simply determined. So this really fits beautifully with our experience I think.
JB: What would it take to move you from acknowledging the mystery and the depth of what is the reality we live in, to acknowledging a source of the sort that Bill is pointing to?
RP: I just don’t see why it’s a solution to these problems, I think that’s my real issue. I mean, you can postulate that there is some kind of a thing which one could call a god I suppose, and that that thing is supposed to inhabit this world which is the mental world. To me that’s a hypothesis which I can’t quite see what to do with. I mean, I’m not saying it’s wrong, I just can’t see why one should attribute this thing, which is somehow the answer to all questions – should inhabit the world of…
JB: It sounds like you’d rather have the questions than put that sort of an explanation to the questions?
RP: Yes, I mean there could be a truth in such a view, but I don’t see why I’m driven to believe that, and I don’t see why it should be a conscious thing, you see. I mean it could be – I’m not saying I deny it. I just don’t see why this explains very much, to say that this entity – godlike entity, whatever it is – is something with a consciousness of its own. Now I’m not saying it’s wrong, and it might be that there is such a thing – maybe like some religious views, after death somehow one’s consciousness becomes part of that thing. I’m not saying I think that’s a wrong view; I don’t necessarily think it’s a wrong view…
JB: Let’s have one response and then we’ll move onto some of the specifics of cosmology here…
WLC: I’m not trying to drive anyone to a conclusion. I’m offering a metaphysical solution to what you admit are profound mysteries in your own world-view, where we have these three disparate realms of reality that don’t seem to connect very well. And given that you’ve already got the mental realm – you’ve already got the realm of mind – it’s a small step to postulate an omniscient mind.
RP: But you see we’ve already got a physical world, you could say why don’t we put it there? Or the mathematical world, why don’t we put it there?
WLC: Right, I already spoke to that, because you can’t put it in the abstract realm because that realm is causally effete. You can’t put it in the physical realm, because the physical realm is contingent and finite, and therefore cannot explain the logically necessary and infinite abstract realm, and it’s very difficult to explain the mental realm too on the basis of purely physical causes.
RP: But I think you’re just saying that it’s not here and it’s not there, it doesn’t mean it’s in the third place…it might not be anywhere.
WLC: Well no, no. I mean if there are these three realms of reality, and the unity – the underlying unity – can’t be found in two, it follows logically that it’s going to be found in the third, unless there is no unity to be found at all.
RP: Well maybe the unity is something much deeper than any of these pictures; it’s contained, it has to do more with totality of all three… in some sense, rather than putting it in the mental world? Putting it in the mental world is giving it… I mean, degrading it in a way, I think that’s what I feel about it…
JB: It feels imbalanced to you in some way?
RP: It’s imbalanced, and if it has freewill then that’s somehow degrading it, because it says it could somehow have done something else – it’s like us; it’s too much like us. It’s too much like putting it like the ancient views – well the Greek views of the gods, in some sense – they were too much like us.
WLC: We’re finite and contingent; we’re talking about a metaphysically necessary source of the Platonic realm and the physical word. This is not…
JB: And perhaps significantly the Judeo-Christian traditions of course do speak of humanity being made in the image of God. That there is that sense in which we reflect that…
RP: I think that’s the kind of thing I’m having trouble with.
JB: You’re having trouble with this. Well it’s been a fascinating conversation already gentleman, I’ve really enjoyed it. Why don’t we move to one of these specific worlds – the physical world.
RP: That’s the one I’m happier with!
JB: Because obviously we’re entitling this discussion: “The Universe: How did it get here and why are we part of it?” Let’s talk about the fact that we know now things we never could have dreamed of knowing 100 years ago about the nature of the Universe we live in. It must have been an extraordinarily exciting time when you were developing those theorems with Stephen Hawking, and seeing them confirming what had already obviously been meeting you from the observational evidence of the Big Bang, the background microwave radiation and so on. Can you just describe a little bit what it felt like in those very significant years?
RP: Well you see, there’s also an evolution of my thinking which changed. You see… how do I start… I mean really my entry into this was more from the gravitational collapse, black hole, things like that. And there was this argument… I mean, we knew that there were these solutions of the Einstein equations, which tell you you have a collapse – this was the Oppenheimer-Snyder model, just before the war in 1939, when Oppenheimer and Snyder – Snyder was a student of Oppenheimer, who of course was famous for the atomic bomb and work during the war; he was a controller of that project. But he did this work which… the only thing I know that he did on general relativity was this model of a collapsing body. And the thing was in this solution, the material fell inwards – it was what they called dust, means it didn’t have any pressure – so this material fell inwards, nothing to stop it, and it was completely symmetrical. So it fell right in towards the centre and therefore the density became infinite and then you got stuck, because what happens – singularity, things go infinite.
But the question was whether that was really what happened. Because it could be a little bit irregular, it wouldn’t focus in its middle point, it might have pressure, it wouldn’t be necessarily this dust stuff – much more realistic. Now what happens in realistic solutions? And this was interesting, because this was in 1962 I think when quasars were discovered, and these objects which seemed to be hard to explain unless they were concentrations of material which would be of the nature of this thing that Oppenheimer and Snyder had discussed. And the question is “was it real?” with these singular states. And then the comparison with the Big Bang was made; you have this singularity in the collapse, and this singularity in the expansion, which Lemaitre and people had already postulated. Einstein produced his equations and then Friedmann and Lemaitre and people had actually shown this, you get these solutions where you get this singular origin. Einstein didn’t like the idea at all originally, but then he got persuaded and then it was the observations of the expansion of the Universe, which suggests maybe it was really like that.
And then this view of the Big Bang – which again, you see, is this a very specific thing which only happens with this really great symmetry and very particular kind of material, or is it generic? And I studied the collapse situation and I came across – well there was some Russian work which seemed to indicate it wasn’t, that it was not generic, and that turned out to be a mistake – there was a mistake in their calculations. But I was able to produce a general type of argument which showed that that collapse, you couldn’t get away from it – it really did produce singularity. And then Stephen Hawking picked up on this and applied it to cosmological situations and showed that the singularity… and then we got together and had a paper which we wrote on this. But it showed that the singularity – that is to say these places where everything seemed to go infinite and equations went all wrong – was a generic phenomenon.
Now the thing is that this had been there for a long time, and I began to worry… Well you know, people study about the models of the Universe, and they were always only studying the one where Lemaitre – the very symmetrical Universe models – where you didn’t even need these singularity theorems if you like. Because they were all looking at the cases which were completely symmetrical, at least in idealisation. And it worried me, why are they so different – that is to say, the singularity in the Big Bang, when detail – when you look at what happens in the collapse case – completely different. I mean, the similarity was what sort of started us off, but when you look at it in detail, it’s completely different.
Now this has to do with this fundamental principle of physics known as the second law of thermodynamics. Now the second law of thermodynamics tells us roughly speaking that things get more and more randomised as time goes on; there’s a thing called entropy which is a measure of this randomisation. And so this is the general principle – it’s a very fundamental principle of physics, and it’s all over the place. And you see this in this singularity – it’s the Big Bang with this very very special idealised singularity, and in the black hole it’s almost the complete opposite: the low entropy at the beginning and the high entropy singular states.
JB: Incredible order in the beginning…
RP: Yes, this incredible order. And the nature of that order seemed to be in paradox with the observations of the cosmic microwave background – this is the early observations of radiation coming in all directions. This is microwave radiation – like in your microwave oven – and this radiation seemed to be very uniform over the sk. And not only that, it had a spectrum – that is, the intensities of different frequencies were such, that it showed that there was this maximum entropy state; highest randomisation you could have. So it was completely randomised. But yet it had to be ordered. And so I puzzled about this for a long, long time. And you have this order – the explanation is, and I think it’s more or less accepted now – is that the explanation is that the order is in gravity, and not in anything else.
So you have this very, very gravitationally ordered structure; that is to say, the gravitational degrees of freedom did not take part in this thermalisation. Everything else – all the photons or all the matter – everything else was randomised. But not gravity. And this struck me as a huge paradox… how do you have this imbalance between one and the other? And that had been sort of in the background for a long time in my thinking. Now there was a particular moment – I’m about to actually describe this – well I mean it’s a bit like the questions you raise, you see, where I was thinking about the future of the Universe. And what we’ve come to understand in recent years is that there are these black holes; not only are they there, but they’re absolutely huge ones. In the middle of our galaxy is a black hole which is about 4 million times the mass of the sun, and it’s just there and you can see the stars going around – I mean, you can measure them in real time, you can make a movie of the stars going around, and then there’s something in the middle there.
JB: Is this the one that was even imaged recently?
RP: The image they showed was of a different galaxy with a much, much bigger black hole. I can’t remember how much bigger it is than this one; a lot, lot bigger. So you see these huge black holes in the centres of galaxies. Now what’s going to happen? Well, they’ll start swallowing more and more material… some of it will escape – maybe about half, I don’t know what the figures are exactly – will get swallowed up.
Now in a cluster of galaxies you get many… we’re in a cluster – it’s certainly got about three or four, I can’t remember how many. The biggest one is the Andromeda galaxy, and we are on a collision course with the Andromeda galaxy. It’ll take a few thousand million years before we encounter it, but then the black holes will fill each other up – they will collide, swallow each other up; it will be mainly the one swallows us up. And when I say us, I mean our black hole. And the material in the cluster, most of it will get swallowed up eventually. You get much bigger clusters, then most of the material gets swallowed up. So it’s a pretty boring state, because you’ve just got these black holes sitting there, and most of the matter is all swallowed up – pretty boring.
And then I thought, well… this thing interesting just happened, because Stephen Hawking explained – this is his greatest contribution, it’s a very important thing – that the black holes are not entirely black. They have a very, very… they’re pretty black. But they have a very, very low temperature, but over the years and years and years – not thousands, millions, zillions – you have to think in terms of googols, if you like. Tens of the hundred ten… think of 1, followed by hundred zeros – that number of zeros; probably more with the really big ones. And after that period of time, the radiation from these black holes will take all the energy away and then disappear with a little pop. When I say pop, ok a nuclear explosion or something, depends on how you measure it – it doesn’t matter too much. Anyway, they disappear. And we just had this very boring time when the black holes were the most exciting thing around. Then it got really deadly boring…
JB: And this is what you’ve (WLC) described as the heat death of the Universe, in that sentence…
RP: It’s the cold death of the Universe…
WLC: Thermodynamic death…
RP: No, it’s in…well it’s…
JB: But whatever it is, it’s a very boring sort of…
RP: It’s unbelievably boring.
JB: Nothing of any interest exists at this point.
RP: So I got depressed by this, you see. Why should I be depressed with this exciting Universe that we live in…? And that’s interminable tedium, that’s what we’re in for…
JP: If that’s what we’re in for, what’s the point of all that then…
RP: Exactly. And that’s your sort of question. But then I thought…
WLC: Yes, though it’s worse in a… well, I don’t know if it’s worse than tedium, but I mean, we won’t be there to experience it. It’s not as though it’s boring, it extinguishes…
RP: But let me go on, you see, because that’s a key point you’re making. You’re making a key point. We won’t be there, but who will be there? Photons, mainly. Now you see, it’s very hard to bore a photon. Not just because photons – I don’t think – have experiences. But they don’t actually – if I can use experience again perhaps in the appropriate sense – they don’t experience the passage of time. So time does not… it’s the way relativity works. The time from the creation of that photon to infinity, is nothing.
JB: As far as that photon’s concerned…
RP: That’s right, it has no… as a clock, it doesn’t have any time experience…
JB: Is this because it doesn’t have any mass, essentially…
RP: That’s right…
JB: And for something to act as a clock, it has to have mass. But at the point where you’ve got no mass in the Universe, it’s just photons, then you’ve got no time, essentially.
RP: No time. And if there is no time and if there is no measure of space either, because of how space is measured now – it’s in terms of time: how long does it take light to get from here to here – that distance is a time, and the measures of distances are in terms of times. So that’s the way physics is understood, and that’s the way distances are measured. Much as a metre rod in Paris is no good as a thing anymore – if you think of a metre – you define it in terms of light, and how long it takes light to go from here to there, and how far that is. So if you don’t have any measure of time, you don’t have any measure of scale. And that means that big and small are equivalent. So in this remote future, times/distances become irrelevant… you have to understand a bit more of the detail, which I can’t go into here of course. But it’s what’s called a conformal picture.
And what’s quite useful to think of, many of our listeners might have seen some of these escher pictures, the things called circle limits – you can have these angels and devils, and they get more and more crowded along to the boundary of this thing, and they get smaller – extraordinarily precisely done, right up to the boundary, and that’s the infinity of the world that these beings inhabit. But nevertheless, you could see it as a finite boundary. And it’s a conformal map – they’re squashed this way as much as that way. And in space time it means the time and space are squashed by the same amount. So the infinity is somewhere; that’s the point I’m making. There is actually a place – or a time, I should say – which is the infinity; and if you were massless, you’d get there. It’s like the angels and devils… that the boundary of this escher picture is a thing which is there; even though it represents the infinity of that world, it’s there still. And you could imagine the continuation to something on the other side.
And the picture I have, which is put forward about 15 years ago – not that many people pay any attention to it – is that there was something on the other side, or there is to be something on the other side, and that is the Big Bang of a subsequent eon. Similarly, our Big Bang was the continuation of the remote future of a previous eon – and I’m using the word eon now, I looked it up in the dictionary to make sure that the word eon didn’t mean a definite number of years. So I’m using it now…
JB: It just means an unimaginably vast period of time…
RP: Exactly.
JB: And this is what you’ve called the conformal cyclical cosmology. And in that sense, it shouldn’t be confused with, but it sounds a little bit like the sort of Bang Crunch idea that was in fashion at one time. But this is actually a sequential series of bangs, essentially…
RP: There is no collapse, you see, it’s different… I mean, that’s right. One of the Friedmann models, early after Einstein produced his equations, had a universe which expanded out of collapse, and then it could bounce and have another.
JB: But this is essentially a continually expanding universe…
RP: It never collapses, that’s right.
JB: But at the point where time sort of becomes irrelevant, it’s almost indistinguishable from the Big Bang where time is also…
RP: And you might say are they very different? Because the Big Bang is hot and dense – very concentrated and extremely hot – whereas the remote future is extremely cold and rarefied. But you see, when you lose the scale, it applies to the mass; it applies to the temperature if you like. So when you squash down, the temperature goes up; when you stretch out, it goes down. And they’re completely equivalent.
JB: I want to return to this, it’s a fascinating idea. Before we do that Bill, let’s talk briefly first of all about your work with the Kalam cosmological argument, which has been very much focused on Big Bang cosmology, as it’s been traditionally understood up until now, and if you like, Roger’s thesis is something of an extension of that. But your view has been that actually what we do know of cosmology – what appears to be verified from science – supports this idea that the Universe had a beginning, that there was a cause to the Universe, and philosophically we can speak of that cause being God.
WLC: Yes, this is a very ancient argument for a creator that goes back to the attempt of early philosophers to rebut Aristotle’s doctrine of the eternity of the Universe. And during the middle ages, it was developed in great detail by medieval Islamic philosophers, and then mediated through Jewish philosophers back into the Latin-speaking West. And finally came to be enshrined in the thesis of the first antinomy of Immanuel Kant, concerning time. And it basically goes like this, it’s a very simple argument – whatever begins to exist has a cause. Secondly, the Universe began to exist. And then the conclusion follows, therefore the Universe has a cause. And in support of that second premise – that the Universe began to exist – the medieval proponents of the arguments appealed primarily to philosophical problems with the infinitude of the past. And they raised a number of I think very cogent objections to the notion of the finitude of the past. But now with the advent of modern cosmology, we seem to have pretty dramatic empirical evidence in support of the second premise as well. So the premise I think is more probable than not, both in the light of philosophical argument and scientific evidence.
JB: And that’s where a lot of your discussions have ranged around, you know, whether if there is a beginning to the Universe – if there is a sort of a boundary if you like, to time and so on – whether we can speak of a cause of that universe coming into existence, and whether that cause could have been God…
WLC: Yes, though the question of the beginning of time is a subsequent question to the beginning of the Universe. I think that time is a metaphysical quantity that is different than our measures of time. The fact that a photon doesn’t measure the passage of time I think is irrelevant to the fact that the photon exists in time. I agree with Newton on this respect, that time itself is a metaphysical reality, and what physics discusses – physical time – is our best attempts to provide some measure of this time. And these measures may be accurate or inaccurate, affected by gravitational fields, affected by uniform motion and so forth. But time itself is not something that is a physical quantity; it is a metaphysical reality.
JB: Do you want to respond to that Roger…
RP: I’m having trouble with that. I mean, the view we have in relatively is certainly we don’t have time in the sense that we talk about time in normal language, because it doesn’t run the same for everybody, if you like. You use experiments with clocks…
WLC: Those are measures of time; measurements are affected by motion…
RP: I don’t know that I’ve understood what you’re saying exactly, but it’s as though somehow there is a time in the sense that progresses universally – is that it?
WLC: Yes, right. So for example, these photons in the far distant future are temporally later than the photons that exist now. Indeed some of them may have had emission events in the past. Well if they have a past, and they’re in the future, they’re clearly in time, even if a photon itself…
RP: I’m not agreeing with you. No, no, you see it’s suggesting there is a kind of time progressing… you can have a temporal order, without having a time associated with that. And if you have distant events, then they go according to a different… which is earlier or later, for a particular thing. I mean which is earlier or later in an event on the Andromeda galaxy you see, for example, depends on if I start moving forwards it’s now different from when I move backwards – by weeks, probably. So how does one… you say that there is somehow a universal concept of time?
WLC: I would be a Laurencian, with respect to that I think, as a number of other contemporary physicists.
RP: When you say a Laurencian, you mean…
WLC: A.J. Laurents ?(1:02:18)
RP: Yes, I’m not quite sure… when you say that…
WLC: I mean that there are relations of absolute simultaneity in the world, even if our measuring devices are affected by uniform motion in the typical relativistic way.
RP: Yes, I know what you mean. I’m disagreeing with that then.
JB: You’re disagreeing with that. We’re probably not going to get to the bottom of this, but…
WLC: Can I raise an issue which I think is more fundamental. I noticed that when you spoke of these symmetrical predictions of a singularity – and your work in showing that even in a universe that is not isotropic and homogenous, that this singularity would occur – you spoke of whether or not they were realistic solutions or not. And I think this is one of the fundamental questions to ask about your conformal cyclical cosmology: to what degree do you think this is a realistic depiction of the Universe, as opposed to a mathematical model? I noticed in 2006 you said: “so far we regard the conformal space time prior to the Big Bang as a mathematical fiction. However, my outrageous proposal is to take this mathematical fiction seriously, as something physically real”. Now I’m suspicious of that outrageous move…
RP: Well you see, I use the word outrageous as a defence against people who would think, “that’s an outrageous idea”, you see – I’ve already said that. Because it’s outrageous in the sense that it’s very different from the conventional view. I don’t think it’s… in fact, if you ask me what I think about it, I think it’s correct. I think that there is sufficient evidence now – this is very different from those days – sufficient evidence now to indicate that it makes predictions which are not made by the conventional view, and which we are beginning to see are actually present in the observations. Now this is a pretty new… there are things which are a few years old, which had to do with signals…
You see, I had this view – and you’re going back to whenever it was, 2006 or something, when there was no observational indication of this particular view, apart from, ok, it seemed to make sense of certain things which were puzzles and which other schemes don’t seem to make sense of. I mean, I think I mentioned earlier in the fact that the gravitational degrees of freedom are highly supressed in the early universe, where the others are not. In this scheme, that is explained, where in other models of the Universe – inflationary cosmology and so on – I don’t see an explanation. But that’s not the point I’m making here. These are subsequent… I mean I used to give lectures on this, taking the view that you more or less described, that this is an interesting idea, nobody will ever know whether it’s right or not, I’ll be able to go on giving lectures on this until the end of my time at least, without contradiction.
But then I started to think, well maybe there are observations/observational tests. And I began to worry about what is the most violent possible thing apart from the Big Bang itself. And I was thinking about… ok, I mentioned our collision with the Andromeda galaxy which would take place eventually, and our black holes which would feed each other out and eventually they will swallow each other up. And there will be one fantastically huge emission of energy in a form that we might not even feel if we were present at that time, in the form of gravitational waves – an absolutely enormous release of energy. And that enormous release of energy will spread out through the Universe but would be detectable in principle by beings in the succeeding eon. Now I’m claiming that these things happened in the eon prior to ours, and that the signals produced by these collisions between supermassive black holes, are these signals actually observed. And with an Armenian colleague Vahe Gurzadyan, I wrote an article on this. A paper quite independent of ours by some Polish colleagues headed by Krzysztof Meissner, and a more recent paper that they did on… this was originally on this satellite which was called the WMAP satellite, which was looking at the micro-background. And then the more refined observations of the Planck satellite were analysed by this Polish group later on, and they found that with a confidence of 99.4%, these signals were real, and not artificial or random.
JB: So you think there has been physical confirmation in that sense, of the cyclical model…
RP: And the newer observations – things which are called Hawking points…
JB: Let’s not get into too much more detail there. But Bill, let’s say that possibly this model could be a potential sort of way of understanding the Universe. I suppose my question – one question I have is – would that mean it is infinite into the past, and would that mean that you kind of avoid the need for a divine sort of starting point or anything like that?
WLC: Well I can’t resist saying, first, that the observational data is undeterminative. The majority of cosmologists don’t explain the data through this particular model. In fact, I mean most cosmologists – as I understand it from my reading – don’t think that the entropy ever will disappear, the way that this model requires. And particle physicists don’t think that electrons will decay, so that there will never be just be photons.
RP: I don’t think they will decay either…
WLC: But you do think that they disappear, right?
RP: No, no. Sure, the view is not currently accepted by modern cosmologists, and I agree with that. But I have never had any explanation of… let’s take the Polish work, because they are most explicit about the probabilities there. The Polish work… I haven’t seen anybody contradict what they’ve done; I haven’t seen any answer to this probability confidence level of 99.4. Now ok, this paper came out earlier this year, but there was an earlier paper they had, and there was an earlier paper we had, and I haven’t heard anybody say there’s anything wrong with it.
WLC: But the point was that the data is undeterminative. You said that it was 99% sure that the signals were real, right. But the question is how do you best explain this imprint?
RP: Yes, I would like to see another one actually. Have you seen one?
JB: My bigger question, as it were, about this is I suppose it’s the question let’s say that we are living in this CCC model…
RP: I think you’re right, we shouldn’t be talking about…
JB: Exactly. The fundamental perhaps most obvious question is: well if that is the case, where did it come from? Why is there a universe at all, whatever particular sort of reality it takes. I mean, Bill, I suppose for you, the Big Bang cosmology and so on has served to reinforce that idea of the idea that there is a mind behind the Universe; that there is a cause.
WLC: Yes, yes.
JB: And would the cyclical model sort of, if it were in any way shown to be a good representation of reality, undermine that? Undermine the idea that we have to have a cause behind the Universe?
WLC: Well it doesn’t show that the past infinite; it only talks about two eons. I’m sceptical again that it’s proper to speak of this other universe as existing temporally prior to ours, because if time disappears, then they’re not temporally related – you can’t say that one is earlier than later…
RP: Can I just object here to something: when you say time disappears, it doesn’t… temporal order does not disappear. You see, I think there’s a misunderstanding here. If the notion of the length of time may be not preserved in a sense, but time order – whether something was before or after – still is preserved, in the sense of causal relationships. And that’s not affected by the conformal maps. So you can squash time or stretch it, but which is earlier and which is later is still preserved.
WLC: So you’re talking about the metric of time, as opposed to temporal order of earlier than and later than. Ok, that’s clear.
JB: Ok. I mean, how does that play in as far as you’re concerned to your overall picture of the idea of the Universe being caused by God?
WLC: Yes, well the question would be can it be extended to past infinity or not. That would be the question.
RP: Yes, as you say, there could have been a first 73… if you go back, then that was the first one, you see. It’s interesting because I actually talked about this in a meeting in the Vatican a few years ago, I can’t remember when it was exactly. And they came up with what I thought was from their point of view the correct answer; namely, that I suppose this infinite succession of eons is the correct explanation of physical world. Sure, God created the whole lot, and that the temporal order of these things was not the important point. And I thought, yes, that’s from your perspective, that’s the right answer.
JB: Is that satisfactory to you?
WLC: Well, that would be a different form of the cosmological arguments, such as was defended by Leibniz. Leibniz held that even if you have any eternal universe from the past, that doesn’t explain why there is any universe rather than nothing.
JB: Why is there something rather than nothing…
WLC: Right. And so for Leibniz the eternality or infinitude of the past was irrelevant to the question of whether there is a metaphysically necessary being that explains why the universe exists. But this would be relevant though to the Kalam cosmological argument, because if it turned out to be correct – and could be extended to past infinity – then it would not be true, at least scientifically, that you could give good evidence that the universe began to exist. You would still have all of the philosophical arguments in place against an infinite regress of these sorts of eons.
JB: Obviously we don’t have time to play out in detail the argument as to whether we can establish that particular model. But there is an aspect of it that I’d love to dig into in the final time we have together gentleman, which is, why this particular universe and the way in which it appears to be governed by these fundamental constant forces that seem incredibly fine-tuned to allow for the existence of life to appear at some point – this is often called the fine-tuning of the universe for life… Bill do you want to very briefly explain from your perspective why you see this as an interesting argument for the existence of God?
WLC: Well in the contemporary literature on fine-tuning there are basically three explanatory options. Either physical necessity – that these constants and quantities must have the values they do, that it’s not contingent. Or secondly, chance – and the form that this normally takes would be a kind of multiverse hypothesis, and then an appeal to an observer selection/self-selection effect, that we can only observe universes that are finely-tuned for our existence, so we shouldn’t be surprised that somewhere in the infinite multiverse, that we should appear in such a universe. And then the third one would be design, that there is an intelligence that designed the Universe. And Roger’s special contribution I think to this, has been to place a very significant objection and question mark behind the explanation of the multiverse hypothesis, with the self-selection effect. Because if we were just a random member of a multiverse, we ought to be observing a much different universe than we do.
JB: I want to come to that. I mean first of all on this question of fine-tuning which again might be worth just spelling out a little bit for the audience, you yourself have contributed interestingly to this; there’s a certain aspect of reality – the initial low entropy distribution of mass and energy. Now without getting too technical at this point, this is essentially the idea that you were sort of alluding to earlier, that at that very earliest moment – that singularity in Big Bang cosmology – there’s an incredible amount of order versus the disorder – the entropy – that appears later on, that needs to be there in order for a life sustaining universe to be possible. In fact you put this extraordinary number on it, of the precision needed to be 1 in 10 to the power of 10 to the power of 123. Which I’m told, if you were to try to write that down and you put a zero on every single particle in the observable universe, you still wouldn’t have enough zeros…
RP: Not even close!
JB: And so this is mind-boggling stuff, but it appears as though someone, as you know, who was it who said this – “someone’s been monkeying with the physics” – Fred Hoyle said. It looks as though, as Bill has said, some sort of design is there to ensure that we got here. Now what do you say to that idea?
RP: Well I’m agnostic I would say on that one. You see, it’s not clear to me… I mean, people talk about there being mass ratio between the protons and the neutron and the fact that the neutron is just a little bit more massive than the proton, and it goes that way round than the other way around. But it’s very difficult to… since we only know one kind of life, you see, or one kind of the reduction of consciousness, it may be very rare throughout the universe – I mean the numbers might not be all that good, you see. You can imagine fiddling with them so that they were consciousness’s all over the place, you see. I don’t know, you see. We don’t know enough about that.
And there are some nice examples from science fiction which show different alternatives… I like the one, Fred Hoyle’s idea of the black cloud you see, where this was a completely different way of imagining a conscious being, which is this huge cosmic cloud which communicated by electromagnetic signals and things. The other story which I like to refer to is one by Robert Forward, which was Dragon’s Egg – I think was the name of the story – where there was a neutron star which came close to the sun, and the people on the earth went to explore it and it turned out that there were living beings on this neutron star, which instead of using chemistry, they used nuclear processes. And this means that their lives and evolution took place millions of times faster than us. And how you can make a story with this complete imbalance was an amazing achievement I thought! But they even had a religion, which took place in the Cheela’s, which were the inhabitants of this neutron star. And when the earth then came close to them they built a complete religion on this star which appeared in the sky…
JB: I mean these are obviously stories, but do you think it’s possible in the sense that some sort of conscious reality could exist, even in the absence of the physical, carbon-based life that we obviously need…
RP: It could have been done very differently, in a totally different… you see there are many different parts of the universe, where the physics is very different from what it is on earth. And maybe a different kind of life could evolve there and… I have no idea. Just that we don’t know… there are puzzles which look like coincidental things, and one of the first ones was Hoyle’s thing about the energy level of carbon, which if it hadn’t been there then you couldn’t have got beyond evolution…
JB: Bill, what’s your response to these sorts of ways of dealing with the fine-tuning?
WLC: Well this is fascinating to me, because as I understand you Roger, you’re not advocating either physical necessity, nor chance by the multiverse hypothesis and self-selection effect, nor design – but rather you would simply deny the fact of fine-tuning altogether; that the Universe is not fine-tuned for…
RP: I think ‘deny’ is too strong, I said I don’t know.
WLC: You don’t know. To me that is highly implausible; we just find example after example of fine-tuning in contemporary physics, and it seems to me to be a desperate expedient to deny that it exists. In the absence of fine-tuning, there wouldn’t even be matter; there wouldn’t be chemistry. So the idea that other forms of life would evolve I think is logically possible but it’s not I think the most plausible solution to the problem.
RP: Well I mean we just know so little about what constitutes life and how… I mean, we have the universe we have, and you could imagine fiddling with the numbers and making them… to what extent that freedom is even there mathematically isn’t clear. I mean I can see the arguments and I can see there’s a case for the arguments, to say that, ok, from certain points of view, it looks as though there are accidental things about the constants of nature which have allowed things to happen which if they hadn’t happened we wouldn’t be here, and that’s true. But maybe some other thing would be here, which could have… it’s not at all clear to me.
JB: I was wondering whether the conformal cyclical model in any way sort of does the job of a multiverse, in as much as well, if the Universe has sort of had these rebirths time and time and time again, perhaps we’re living in the one that was habitable for human life.
RP: That’s a possibility, yes. I mean this was an idea that John Wheeler put forward, not with this model but with other models with a sort of bouncing universe models. That maybe each time there was a new set of constants produced, and they were different each time, and we happen to be living in the particular eon – if I can use that word here – in which the constants happen to see the kind of life at least that we experience.
JB: So that is potentially a solution, what do you think Bill?
WLC: That solution seems to me to fall prey to the very argument that you give against using the anthropic principle with respect to the multiverse. Because what you’ve done in trying to push the conformal cyclical model to past infinity is in effect establish a multiverse, except it’s sequentially ordered rather than simultaneously. And in that case then the question is: why do we observe a fine-tuned universe like this, instead of the one which is unfathomably more probable, that is say no larger than our solar system – a patch of order that is that big; that would be unfathomably more probable than a fine-tuned universe, and indeed maybe we’re all just Boltzmann brains with illusions of the external world around us. It falls prey to this very objection that you’ve raised!
RP: No, it’s an answer. You see I’m not giving this answer, because I don’t like it…
JB: Ok. So this isn’t your favourite…
RP: It’s not my favourite, but it is a possible answer, that the eons are different than the numbers that differ… they can’t differ by very much from an observational point of view, but I mean some of they don’t differ by very much. But they could differ, and they could evolve… it’s certainly possible. I don’t like it, but it’s a possibility.
WLC: Right, but then it doesn’t explain our observations. Because the most probable, observable universes are not like this one – a fine-tuned one like this.
RP: But I mean we use the other argument, you say that we happen to be in the one where they are nice, you know. Ok there are the eons where this is this and one in every five million or so has nice conditions in it. I mean that’s an explanation – I don’t like it, but it’s an answer to this question.
JB: I mean, in a sense, you’ve said from the outset though that you’re agnostic, essentially, on this whole question of the fine-tuning. You acknowledge that we do appear to live in a universe that is finely-tuned for life to at some point develop, but at this point you don’t think we have any adequate way of explaining that.
RP: I don’t think the evidence is that convincing. Because we don’t even know what constraints there are and what these numbers could be, for theoretical reasons. It’s a big question mark. But a possible answer to the question – I don’t quite see you’re objecting to this – would be that every so often in these succession of eons the numbers come out right for life to work, and we happen to be in one of these – because we have to be in those, because we can’t be in the dead ones.
WLC: Well, but we can be in observable universes that are not finely-tuned for our existence, and those are in fact unfathomably more probable. You yourself in your work have said that the odds of our solar system falling together by the random collision of particles is around 10 to the 10 to the 60th, which is utter chicken feed.
RP: Oh no that part of it is completely explained by the model – that’s not the point. I thought you were talking about small effects… life might depend on certain chemical processes which are…
WLC: No, what I’m saying is that appealing to an observer self-selection effect isn’t sufficient to explain why we observe a finely-tuned universe.
RP: No, but if you’re calling out the one part in 10th of the 10th of the 124 or whatever it is, I mean that is perfectly explained by the model – that’s not a question.
JB: How do you mean it’s perfectly explained by the model?
RP: Oh no, the CCC model gives you that. That number I’m not taking as a question.
WLC: I was using that as an illustration of the fact that an observer self-selection effect isn’t sufficient to explain why we observe a finely tuned universe. And there are a multitude of other finely-tuned constants…
RP: But I want to know you see which finely-tuned you’re talking about. If we’re talking about the 10 to the 10 to the 124 – rather than 3 because of the dark matter, but never mind, doesn’t matter too much – that that number, yes, is a huge puzzle. That’s one of the reasons for CCC – I’m not including that fine-tuning…
WLC: Yes right, we don’t need to include that, that was just an illustration.
RP: That’s done, you see. Ok nobody believes me, but I’m saying this thing is done!
WCL: Yes, I understand.
JB: Nonetheless, there are other aspects that appear to be finely-tuned, that even the CCC model wouldn’t directly explain, only in the sense of we happen to live in the eon in which potentially this particular…
RP: Well the question takes a different form, you see. You might argue that you have a propagation; there is a kind of instability, some of these numbers mean that the evolution goes away and you don’t have nice continuing eons which were similar to each other. So there are different questions that could be raised on this point.
JB: It’s probably time to start drawing our conversation to a close – it’s been utterly fascinating and I’ve so enjoyed it, thank you very much. Perhaps we’ll start with you, Roger. I sort of hinted at this at the beginning, but is there anything that would sort of cause you to cross the line from mystery to perhaps there really is a divine mind behind all this incredible order, complexity and the unfathomable uniqueness of who we are in this universe?
RP: Gosh. You know, some divine thing could appear and I could have a vision of something or other. But then you see would I trust that? Not sure whether that would convince me. You see it’s more could one twist the views about what I think… you see, I don’t have a clear view about an overreaching, overarching picture of what’s really going on in all this. And I do say, ok maybe there is… I talk about the three mysteries of the connecting worlds, but there’s a bigger mystery, which is what on earth is the whole thing all about, you see. And it’s just that I’m not disagreeing with anyone on that question, but I’m not quite sure to say there’s a sort of mind, which is supposed to answer this question, is really an answer to it – I don’t find that satisfying.
JB: I mean, your colleague Hawking was certain at the time that he passed away that there would be nothing on the other side to greet him. If it were the case that you found that there was a divine mind…
RP: Put like that, if there was somebody on the other side to greet me when I reach my end, I don’t believe that experiences can continue. You see, because one’s memories you see… one’s experiences involve one’s memories and all that stuff, and I can’t imagine coming as some other being later and having the same experiences as I’ve had, so that doesn’t quite make sense to me. But whether experience in some abstract sense can continue is another question…
JB: And you’re open to that possibility, you haven’t closed that door?
RP: No I haven’t closed off any of these things, I just haven’t the foggiest idea.
JB: Bill, what are your thoughts as we draw this conversation to a close?
WLC: Well I suppose my overall impression would be that theism provides a kind of metaphysical fundamental unity to the world, that is absent in the absence of the existence of a creator and designer of the Universe and the source of moral goodness. The theistic hypothesis has a tremendous unifying force to making sense of reality, and therefore I think deserves serious consideration by any thinking person today.
JB: Well Roger and Bill, thank you so much for joining me on the programme today.