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- [00:00]
A
Go beyond the verses and achieve a deeper understanding of Scripture with the Rebind Study Bible App. An audio experience of the Bible interwoven with expert commentary. The Rebind Study Bible App reads Scripture to you, enriching your comprehension with insights from the world renowned New International commentary on the Old and the New Testament in an accessible podcast episode format.
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B
Be not therefore anxious for the morrow. Matthew chapter 6. Each day will have its troubles, but by God's grace they can be survived.
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A
Use the Rebind Study Bible App's chat function to ask questions and get answers in real time. That's thought provoking discussion and analysis rooted in decades of research and wisdom from more than 40 scholars at your fingertips. The Rebind Study Bible App is a new way to experience the Bible with enhanced depth, at your own pace in the moments you have. Search the Apple App Store for Rebind Study Bible or go to rebind app.com newbooks network for a free seven day trial. Hello everybody, this is Marshall Po. I'm the founder and editor of the New Books Network and if you're listening to this, you know that the NBN is the largest academic podcast network in the world. We reach a worldwide audience of 2 million people. You may have a podcast or you may be thinking about starting a podcast. As you probably know, there are challenges basically of two kinds. One is technical. There are things you have to know in order to get your podcast produced and distributed. And the second is, and this is the biggest problem, you need to get an audience. Building an audience in podcasting is the hardest thing to do today. With this in mind, we at the NBM have started a service called NBN Productions. What we do is help you create a podcast, produce your podcast, distribute your podcast, and we host your podcast. Most importantly, what we do is we distribute your podcast to the NBN audience. We've done this many times with many academic podcasts and we would like to help you. If you would be interested in talking to us about how we can help you with your podcast, please contact us. Just go to the front page of the New Books Network and you will see a link to NBN Production questions. Click that, fill out the form and we can talk. Welcome to the New Books Network.
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B
Welcome to the New Books Network. I'm your host, Gregory McNiff and I'm excited to be joined by Liam Graham, the author of Physics Fixes all the Facts. The book was published by Springer in the United States in January of 2025. After earning a degree in theoretical physics at Cambridge and A Master's in philosophy at Warwick, Liam Graham eventually found economics to be an appealing middle ground and completed a PhD at Burbeck College, London. To pay the rent, he taught English, developed and sold trading software, and was the numbers guru for a Boutique Finance House. Liam's 15 year academic career was mostly spent as an Associate professor at University College London, working in one of Europe's top economics departments. His research involved building mathematical models of an extremely complex system, the macroeconomy, and his work was published in all the top macroeconomics journals. Whether working on philosophy or economics, he never stopped reading science and exchanging with scientists. In 2018 he left UCL to concentrate on his original question and the wide ranging, multidisciplinary and endlessly fascinating project it has become. His first book, Molecular the Physics of Star Cells and the Origin of Life, was published by springer nature in 2023 and I was thrilled to be able to interview him on that. I highly recommend to our audience they listen to it. I think it'll provide a nice introd introduction to our conversation today. I selected Physics Fixes all the Facts because it offers a deeply original perspective. Blending rigorous scholarship with accessible storytelling, the author isn't afraid to challenge conventions and follow his conclusions wherever they lead, even when they overturn comfortable assumptions. Above all, it captures the intersection of science, philosophy and history that defines the kind of work I most enjoy discussing.
- [03:53]
C
Hi Greg, it's a real pleasure to talk to you again. And thanks for arranging this interview and for saying complimentary things about my book.
- [04:00]
B
All true, all true. Liam, why did you write Physics Fixes all the Facts and who is the target reader?
- [04:06]
C
The question I've been interested in for a long time is whether physics is enough to describe the world and everything in it. Is physics enough, or do you need something else now? Whenever you read about complex phenomena, you come across the term emergence. Physical systems like hurricanes or galaxies, they're emergent. Living cells, they're emergent. The origin of life, it's an emergent process. Thought it's emergent. In the end, it's hard to find system which is not labeled by someone as emergent. So does this mean physics is enough to describe these things? Or is emergence about something beyond physics? I really needed to get grips with that question for my personal satisfaction, and the result of that, result of my attempts to do that turned into this book. Then you asked about the target reader. Well, in a way, this is a very broad book. What it's about is the most general question of all, which is what is the nature of reality. So in principle, anyone who's interested in that question should like the book. However, there's quite a lot of science, there's quite a lot of physics, there's quite a lot of philosophy of science. And it'll be a very brave reader who tackled the book without any knowledge of those.
- [05:21]
B
I agree. But I think anyone who does tackle it will learn from it. As I said in my intro, you cover both the physics very well and you do a fair job, a very fair job of presenting the counterarguments. Liam, I want to sort of jump right in here, and I'm going to ask you about the casual exclusion argument of Jae Wong Kim. You write. It shows that emergence and physics cannot coexist. Could you expand on that?
- [05:47]
C
Yeah, that's right. This is really a sort of foundation argument in the philosophy of emergence. It's interesting in itself, and it's also interesting because it really motivates the structure of my book. So let's start with the argument itself. So imagine a system which changes over time. You can describe it on different levels. You can describe it at the level of fundamental physics, or you can describe it at some higher level to see what that means. Let's take an example. A hurricane coming into existence. Either you can think about it as a bunch of atoms which interact according to the laws of physics. That's a physical explanation. Or you can think of it as two weather systems colliding and forming the hurricane. That's, if you like, a meteorological explanation. Now, Kim's argument is a philosophical one about causation, what causes what in that system. And Kim says there are two exclusive possibilities. Either the causation happens at the level of physics, at the level of atoms, or the causation happens at a higher level, the level of the meteorological level of weather systems. And then the physics just does what it's told. Now, nothing can have two causes. You're a classical scholar. I think that's somewhere in Aristotle. So these are the only two possibilities. Either it's physics or it's a higher level. The higher level is generally called emergence. So Kim's argument is either physics or emergence. Now, the link to the nature of reality is that the general definition of reality that philosophers use is having causal power. Reality is about being able to change the world. So this says either physics is real and everything else is an illusion, or higher levels have some reality too.
- [07:34]
B
Yeah, excellent. Liam, I want to ask you about the positions or the, I should say the philosophical positions around emergence that you address in your book. Namely the Six positions. I'll start with the first one, dualism, which you define as a particular configuration of matter bringing something non physical, maybe a spirit, into the concept, into the action. Could you talk about how you would address dualism as an emergent property?
- [08:03]
C
Yeah. So Kim's argument is very neat because you can use it to get these six positions. And I should say, this isn't me. I borrow this argument from Jessica Wilson, who's a philosopher at Toronto. It's a very cool way of structuring the world. So let's first take the case where the causation is at the higher level. Then you've got three possibilities. The first, as you say, dualism, which is the causation happens by something non physical. In the case of the hurricane, this will be, if you like, the spirit of the winds. Something which is non physical will never be able to reduce to physics causes a hurricane. That's dualism, strong emergence. Again, causation is at the higher level, but it's something physical that does it. It's outside physics, but it's still something potentially physical. We just don't understand it yet. You could call it a hurricane force. In these two cases, causation happens either because of the spirit or because of the hurricane force. And physics just has to do what it's told. Physics sort of catches up with a higher level, and if it does that, its laws must be violated. With both dualism and strong emergence. If they're to affect the world, they must violate the laws of physics. If they don't, physics is what's running the show. Now. The third possibility is called weak emergence. And this is kind of having your cake and eating says that the weather systems cause a hurricane, but somehow they do so without contradicting physics. It's slightly odd and uncomfortable position and we'll come back to it later. So you know, this is to summarize that what's the nature of reality? Well, dualism says there's magic, there's spirit, there's non physical things. Strong emergence says, if you like, there's potentially comprehensible magic. We just don't understand it yet. And maybe you can get away with believing in the reality of a higher level and believing in physics. And this is called weak emergence.
- [10:00]
B
Yeah, and I'll ask you to define those terms in a moment. I do want to talk about an insight you have again in the early part of the book that discusses dualism, physicalism and emergence. You write, however defined emergence involves relations between different levels. Could you talk about that?
- [10:20]
C
Yeah, absolutely. Kim's argument shows how emergence depends on the idea of levels. Kim's argument is about a higher level and a lower level. The problem with that is there are no levels in the world. Instead, levels are just a function of our interests and we pick the level which suits us. So let's continue with the hurricane example. I talked about a meteorological explanation. You can also think of a explanation in terms of fluid dynamics. There's a whole load of aggregate equations of fluid dynamics. And you can write these down to describe the atmosphere and describe the hurricane, or you can go a bit further down and do a molecular simulation where you can model the hurricane as a set of interacting molecules. Now, these different levels don't exist in reality. They're just approximations that we choose and which are useful for particular purposes. If you're trying to get a paper in a physics journal, you'll do the molecular simulation. If you're trying to predict what the hurricane's going to do, you'll probably use a meteorological level. We need such approximations to be able to think about the world. We can't do everything in terms of quantum physics, but these explanations are in our heads. They're not in the world.
- [11:37]
B
Excellent. Two side questions there. One, it's your belief, and I think most physicists would agree with you, that everything comes down to quantum vibrations. Right. At the most basic level, that is what we are made up of, is that.
- [11:52]
C
I certainly think that. I'm not sure whether all physicists would agree. I mean, that's really the thing about emergence. Does emergence mean that all there is is quantum physics or is there something else?
- [12:03]
B
Yeah, that's a great point. I should have qualified prior to you. I introduced a physicist that I interviewed, a physicist at Oxford who was along those lines of thinking that everything was quantum vibrations at its most basic level. And then my second question for you is these layers or levels you talk about, they're really mental constructs on. In our heads. Correct. To explain the phenomenon. Could, could you talk a little bit more about that? I mean, there's the reality and then how we perceive it and explain it and maybe classify it. Could you, could you talk about that for a minute?
- [12:39]
C
So we structurally cannot do everything in terms of quantum physics. Just the idea is completely mad. You know, we, we can't. With the best computers in the world, we can't manage more than a few dozen part model a few dozen particles. Yet. Yet we're surrounded by endless zillions of particles. So we cannot do it in terms of quantum physics. We need simplifications that's what I'm talking about. All our concepts fall into that category. Everything is an approximation to reality because we just can't deal with the infinite complexity of the world.
- [13:10]
B
Yeah, no, that's an excellent point. I just wanted to make that point. There's a difference between reality and how we perceive it. So let's move into these definitions. You really already touched on them. But just to clarify.
- [13:21]
C
Actually, Greg, before we do that, can I make another comment about levels?
- [13:24]
B
Oh, please. Yeah, please.
- [13:27]
C
So I've been talking about the fundamental level as if we know what it is, but the trouble is we don't. You know, at the moment, the fundamental level in physics is quantum field theory. Quantum physics. But there are a whole load of unsolved problems in physics. There are regular suggestions about what could replace quantum field theory, string theory, quantum gravity, or whatever. But let's. So that suggest quantum field theory is not the fundamental, but there's something below it. But then let's imagine that my personal theory of quantum gravity explains all the problems of the universe, and there are no unsolved problems in physics, thanks to it. That's my next book. The trouble is that even if there are no open questions in physics, we never know whether just outside the range of our experiments is lurking something we don't understand. So not only are there no higher levels, but we can never know what the fundamental level is. All we've got is our current best guess at it. We just cannot know. Ever. Ever.
- [14:28]
B
Yep. Nope. That's a great point. And it does seem like, at least in terms of particle physics, we keep learning more and more and drilling further down from the atom to gluons, quarks, and, you know, I think there are 17 different particles. Very good point, Liam. Like I said, you've already sort of defined some of these terms. But just for our audience, could you briefly talk about how you define weak emergence?
- [14:53]
C
Yeah, this is my confrontation with the philosophy of science literature. It's all a bit of a tangle. In the appendix to the book, I list 75 definitions, most of which count as weak emergence. But actually the most intuitive one is the simplest. And the one that's heard most often is that weak emergence is when more is different. The properties of whole are different from the properties of the parts. Take our friendly hurricane. The hurricane does loads of weird stuff which individual atoms can't do. More is different. Now, the problem with that for me, is that Moore is always different. Let me give the simplest example I can think of. This is a gravitational example. Imagine You've got an empty universe and you've just got one planet sitting in the middle of it. That planet just sits there and does nothing. Then introduce to the universe another planet. What's that planet going to do? It's going to start orbiting the first. And you've now got Kepler's laws, which tell you about the properties of orbits. So more is different. With one body you had nothing. With two bodies, you've got an emergent property called an orbit and an emergent physical laws, Kepler's laws. But can you think of an example which is a purer case of just physics? You know, that's the archetypal physics problems. More is different because interactions matter. Weak emergence just says that interactions matter. But physics is always about interactions. That's if you like. The discipline of physics is studying the interactions between particles. So more is different just means more is physics. Describing systems as weakly emergent adds nothing.
- [16:44]
B
Liam, I'm sure you address this, and I know you do, in the book here, but how would you, if someone came to you and said, what about thought? What about the brain? We have 86 billion neurons in our head and each one fires, sort of has a firing rate. That's binary, but collectively it produces thought. And I hate to use the consciousness word because I believe that invites a whole nother problem. But briefly, how do you think about the brain and thought relative to the neurons that make up the brain?
- [17:12]
C
So, funny you should mention it. That's my next book, which I'm busily writing at the moment. Which is which. The working title, which I haven't quite agreed with my publisher yet, is Thinking Exploring Intelligence from the Bottom Up. When I intend to do exactly that. I intend to take a physicalist position on. On thought. I want to identify a whole load of basic mechanisms, simple neural networks, which, when they're put together in large quantities, explain our cognitive capacities. But I actually think. I think the analogy with the hurricane works perfectly. A hurricane is made up of lots of molecules of air, but it has lots of extraordinary properties in the way in. In terms of its dynamics. The brain is made up of lots of molecules which form lots of neurons, and that gives it a whole set of extraordinary properties, too. I don't see any philosophical difference, any metaphysical difference, if you like, between the two cases. They're two complex physical systems. Of course, the brain is overwhelmingly more complex than the hurricane, and that's why we don't understand it very well yet.
- [18:20]
B
No, you're very consistent about that throughout the book, and that makes sense. Liam, would you Agree that interactions matter. Would you suggest, and I think you've just answered this, that's what's quote creating the hurricane or produces thought. It is the interactions of the basic building blocks or levels of the atoms.
- [18:39]
C
Exactly. Interactions are not just what matters. They're all that matters.
- [18:43]
B
They're all that matters. Yeah, maybe that could be the subtitle of the next book.
- [18:47]
C
How bad? Actually, I'll write it down.
- [18:50]
B
As long as we'll have you back for that. Okay. Liam, could we briefly talk about strong emergence, how that differs from weak emergence?
- [19:00]
C
Yeah, so strong emergence. So the thing about weak emergence is it, it claims that, that higher levels are real, but they somehow don't contradict physics. It's never quite explained how this happens. I actually don't think it's possible. Strong emergence is the idea that high levels boss physics around. And if you dig a bit deeper, the idea always comes down to there's some discontinuity in the world, some, some break in how causation happens. So let's go back to the hurricane that there was some British philosopher scientists in the 1920s who talked about compositional forces. Now the idea of a compositional force is it's something that switches on when matter is in a particular configuration. So if you've just got a few atoms or zillions of atoms arranged randomly, you've got no compositional force. But if they come together in the form of a hurricane, this force just switches on. That will be something that's strongly emergent. And the idea there is you've got a break with atoms arranged in a non hurricane fashion. You haven't got this hurricane force. The minute atoms start to be arranged like a hurricane. This hurricane force, miraculously I shouldn't use that word, it's too pejorative. But suddenly switches on. And now that is a perfectly reasonable scientific hypothesis that there are such things that they're discontinuities like that. On my reading, there's absolutely no evidence for such forces. But let's just imagine there was, that some meteorologist measured this hurricane force and proved that it meant that quantum physics was violated. What would happen then? Well, this would be very, very, very exciting. What would happen is every physicist in the world piles in and tries to find an explanation and get their trip to Stockholm. Either these physicists would develop a new theory, in which case this hurricane force will be integrated into physics, or they'd fail to explain it, in which case it would suggest dualism. It was just some non physical magic, which we don't understand. So I think the term strong emergence doesn't get us anything either. If we found a phenomena which would be classed as strongly emergent, it would turn out to be either new physics or dualism. And this is really the conclusion that my book draws about the nature of reality. It's either physics or dualism. There's no middle ground. And I don't want to criticize dualism. Dualism is perfectly coherent philosophical position.
- [21:41]
B
And Liam, you touch on this in the book. By dualism, do you include a religious, a spiritual, a metaphysical property there? Absolutely, yeah. Okay. I have to say, you are so consistent in the book. I felt like I was reading a legal brief. How you lay it out, I'm not.
- [22:01]
C
Sure that's very flattering given how dull legal briefs usually are.
- [22:06]
B
Methodical. Methodical and deliberate. I meant that as a compliment. You know, sometimes you read books on particularly these subject matters where it's a bit all over the place. And this was very thoughtful. And you built upon one assumption upon the other, not surprisingly. I asked you previously about thought and I should say part of my question about the brain was this quote from George Ellis that you have emergence must be real because of the causal power of thoughts. And we've really talked about that there. That, as you said, the brain, like the hurricane at the end of the day, it's the interactions at the. At the basic level, the holidays are.
- [22:42]
A
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- [23:44]
C
We talked about it a bit, but if it's okay, should we go into a bit more detail? Because I think I've got a neat, a neat way of explaining that. So yeah, Ellis talks about the causal power of thought. So what he's got in mind there is that I decide to lift my arm to reach for a pint of beer and the zillions of atoms in my arm just do what they're told. I mean, this sounds like strong emergence. It sounds like what is doing. The causation is something in my head. And physics just follows the power of my thoughts. Now, as you said, the brain is mind bogglingly complex. So let's take a simpler example. Bacteria do something called chemotaxis. They chemically sense food and swim towards it. Since a bacteria is simple, we can look inside and identify the precise molecular mechanisms which cause it. It's a sequence of chemical reactions of nanomachines. If you like. We can understand exactly how the behavior of bacteria arises from chemistry. Now I'd argue that the analogy between that and what my brain's doing is precise. There's no mystery, there's no causation. The bacteria senses the world, processes that information and swims towards food. I observe the beer, process that information and reach for it. We're just talking about physical systems interactions. We're just talking about strings of chemical reactions. There's no magic, there's no dualism. So I don't think there's such a thing as a causal power of thought or. Well, no, that's not very exact. One physical system, my brain has an influence on another physical system interactions.
- [25:32]
B
Yeah, that's interesting. That does seem like that's the underlying theme here. And I want to ask you a little bit more. How much of this is semantics? What would the counter argument be to you when you say that? But I want you. We've talked about these six different positions and you sort of said if you want to avoid the supernatural, you're left with the eliminativist or the austere physicalism position. I think we know what that means. But could you define what is austere physicalism?
- [26:00]
C
Yeah. So Kim, actually Kim's argument leads to three types of physicalism. It doesn't really matter what they are. I think they will collapse to eliminative elimitivism. Now the idea of elimitivism, well, it's been around a long time, but it comes from a paper sort of modern incarnation comes from a Paper by the philosopher neuroscientist Paul Churchland, talking about psychology. Now, we describe our behavior in terms of beliefs, in terms of desires. You take the example of the beer. I believed there was a pint of beer. I perceived there was a pint of beer out there. I was thirsty. Desire. So I reached for my beer. That's the sort of terms of common sense psychology. Churchland said that when we understand neuroscience, we'll realize these are just approximate ways of describing phenomenally complex processes going on in the brain. We'll eliminate from our discourse terms like belief and desire because we'll know what's really going on. Now, eliminativist physicalism says you don't just apply this to psychological concepts, it applies to everything. All are familiar concepts, everything are just approximations, are just illusions. And this is why it's austere, because all that is real in this world is fundamental physics, or our best guess at fundamental physics.
- [27:29]
B
Right again, going back to whether it's atoms or quantum vibrations or whatever the lowest or most basic level of physics is, that effectively is the only reality. And then as we talk about the interactions or what produces what we describe as emergent properties or some would describe as emergent properties.
- [27:49]
C
Exactly. And these interactions are perfectly described by that lowest level. Yeah.
- [27:53]
B
And I do want to come back again. I think you're addressing this in your third book. You would ascribe the same view to consciousness as well. That seems to be the real, the hard problem these days, for really anyone, I guess for AI physicists and neurobiologists, is this notion of consciousness. You'd have the same answer, right. At the end of the day, it's interactions among the most basic properties or systems.
- [28:16]
C
Well, yes, but I think the problem with consciousness is the study of it is a complete and utter mess. I mean, it makes emergence look respectable. I've got 75 definitions of emergence. Last year, a paper was published which listed 350 definitions of consciousness.
- [28:37]
B
I totally agree with it.
- [28:39]
C
Yeah. Why is it such a mess? It's because there's not a shred of objective evidence. We're all convinced we have it, we all think we know what it is, but there's no objective evidence. This means for me that it's outside science. And maybe we shouldn't be discussing it until we've got some objective evidence. But I can't resist saying something about it like everyone else. An austere physicalist view of consciousness. And my guess is it's just a weird side effect of the way our brains are built to us, it's the most important thing in the universe. But I think it's probably like a magic trick, which seems miraculous until it's explained. That's a great point, but you know, that's worth no more than any of the other 350 definitions. I haven't got a clue. No one's got a clue. And until we've got some objective evidence, I wish people would just shut up and do something more useful.
- [29:31]
B
Yeah, it is definitely producing lots of scientific papers and keeping peer review in, but employment. I just want to go back, Lian, and maybe ask you to compare and contrast physicalism with materialism.
- [29:51]
C
This is just an annoying point of terminology. Philosophers made the change sometime over the last few decades and I think the thing that drove the change was it became evident that physics is about much more than matter. It's about fields, it's about energy, it's about all the exotic things out there. So calling the philosophical position materialism started to seem a bit out of date. Also, if philosophers call it physicalism, implicitly this is delegating to physicists. What matters. Actually, I shouldn't have said what matters, because that sounds like too what the entities that physicalism describes are. So I think it's just a change of terminology. There's no real change in the meaning, and it just says that modern physics is about much more than matter.
- [30:40]
B
I want to get back to this reality versus our perception of it. Do you subscribe to Kant's view that we can never know intrinsic properties?
- [30:49]
C
Absolutely. We're trapped in our senses and we just see some vague shadow of what is probably a insanely complex high dimensional world, which is just simply impossible for us to conceive of.
- [31:04]
B
You know, reading your book and you say this in the book and you have that quote from Kant, I started walking around wondering, is all of this real? Like, is it just how I perceive it? I mean, we know color, right? The electromagnetic spectrum, right? We invent or create color, you know, based on these waves. And I wonder, does the same apply to reality? Is this just how our brain is processing it and giving us a. Some kind of structure that we can process and understand and, you know, navigate? But I mean, yeah, and to your point, do you think we can ever know reality in some sort of evolutionary sense? As in we get better and better over millennia or centuries? I mean, how?
- [31:48]
C
There's no question that our approximation to reality gets better over time. Okay, but it might be, and this is a question which can't be answered, it might be that all those approximations are so far from what is actually out there that there's almost no difference from a Neanderthal looking at the stars to modern physics from a different perspective. We just can't know. It's, you know, I think with that sort of question, Kant had it right and he just said, you cannot talk about what the noumenal is. All we've ever got is a phenomenal. We just cannot know and it's not even worth talking about it.
- [32:28]
B
Yeah, it seems like again, another area like consciousness, where we're just really have very little understanding of it. But like I said, it forces you to think, you know, how are we processing and what is reality? I want to. You have another great quote on emergence. You said emergence, if it exists in a meaningful way, must be a property of physical systems. But the map is not the territory. What do you mean by that?
- [32:54]
C
Yeah, so this is something really addressed directly at physicists. So many models that physicists use have properties which look emergent. Remember when we talked about strong emergent, I said the real characteristic is there's a discontinuity. You've got a few atoms and you can't see this property. You've got lots of atoms and it suddenly discontinuous, discontinuously pops into existence. Lots of models look like that. Let's talk about that a bit more. So when modeling systems, it's often useful to assume the systems are infinite in size. This makes the maths a whole lot easier. It means you can ignore boundary conditions, etc. To take a more concrete example, think about phase transitions. So water boiling, that's some infinitesimal fraction of a degree under 100 degrees centigrade, water's liquid a tiny bit the other side, it's a gas. This looks radically different, discontinuous. So to think about phase transitions, physicists use the icing model. Now, the icing model is this lovely model which has loads of applications. Basically you have a grid, a two dimensional grid. And on each point of the grid is a little magnetic spin. This. Think of it as just this little magnet. It can either point up or down. Now, these magnets tend to align. They tend to all point towards the north or all point towards the south. Heat tends to randomize them. So if you plot the magnetization of this grid against temperature, at low temperatures, all the spins align, so the magnetic field is on. At high temperatures, the spin's being bounced around so the average magnetization is zero. Somewhere in between high and low temperatures, you get a transition. If, as most physicists do, for their simple models, you make the reasonable assumption that the grid is infinite, the transition is discontinuous. It looks like you've got an emergent property. And this happens at precise critical temperature, which there's a very neat mathematical definition of. However, the map is not the territory. There are no infinite systems in nature. And you can prove for the icing model and in general that all finite systems are continuous. One physicist said more is the same, infinitely more is different and is right. Now, going back to the boiling water example, it's not a sharp transition. There are loads of interesting complex phenomena which happens just below boiling point and just above boiling point. So instead of a sharp transition, you've got a finite range. And I discuss a paper which, a really neat paper which does this, which observes water really closely and sees all the fascinating things which go on around boiling points.
- [35:42]
B
But again, to your point, it's continuous, those phase transitions. It's not.
- [35:47]
C
You can prove that every finite physical system is continuous.
- [35:51]
B
Yeah, yeah. Again, I want to ask you about another quote here. Emergence may be no more than an assertion that there are interesting questions at every scale. To understand the world, emergent concepts are essential. You would say that. Or we think that again, does that go back to how our brains evolved and we need this sort of, this nomenclature or this crutch to help us absorb reality or process it?
- [36:18]
C
Yeah, I mean, I like the word crutch, that's spot on. But I think you can be much more positive about. So back at the beginning I said that everywhere I looked I came across the term emergence. So I think it's interesting to ask, what do people mean when they use the term emergence? And it can of course simply mean approximate. That we're ignoring the microscopic details and focusing on the big picture, the concept that you were talking about. But when you see the term emergence, it often means that we just don't properly understand the underlying physics. So if you want an interesting research topic, find a phenomena which people label as emergent, build a simulation of it based on elements close to physics as you can, and hey presto, you've got a paper. You know, in the book I have a whole load of examples of this being done for so called emergent phenomena. The bacteria is one example. Convection cells, back to boiling water, flocks of starlings, quasi particles. There are loads of cases where systems have been described as emergent and then people have written papers explaining the physics of them.
- [37:28]
B
Liam, how much do you think is just, you know, vernacular or nomenclature? What you say is interaction to others may Say emergent. And I was struck by the graph and the description you have of. I'm going to mispronounce it. Convectiture. I have to go back and get that. Right. But, I mean, it was very cool the way it was. Almost perfect symmetry. How would you, you know, if somebody said, listen, this looks like an emergent property, what would you just say? That's the basic physics. Basic physical. Yeah.
- [38:00]
C
I don't want to make a. I'm not making a point about terminology here. I'm making a philosophical point about causation. If people want to call things emergent, I don't care whether people call them emergent or not. I mean, who am I to tell people what language to use? But the point for me is that all this term emergence means is arising from interactions. There's no contradiction between physics and emergence. That's the point I'm making. It's not a point about language. It's a point about where the causation happens, and the causation happens at the level of physics, which describes both the particles and their interactions and hence everything in the universe.
- [38:39]
B
Yeah, I was referring to figure 210, Bernard. Convection. Yeah. Very, very cool. I. I do got to hit you because you address it in the book. I think it's one of the last, really, paragraphs or sections. The Meaning of life. Liam, what do you think the meaning of life is?
- [38:59]
C
I've always wanted to finish a book with a section the Meaning of life. So this has dropped in a bit gratuitously. You know, if you take austere physicalism seriously, there is no escape. We are just physical systems like any other. We're like the hurricane, just a bit fancier. Now, you can say a bit more than that, but if you. There's an interesting graph you can draw which plots the age of the universe against the rate of entropy, creation of the systems in it. So entropy, let's call it disorder for the moment, Even though the person who wrote my first book would be very unhappy with that.
- [39:40]
B
Microstates.
- [39:41]
C
Yeah, exactly. Yeah, we should count the microstates. Exactly. But for the moment, let's talk about disorder or we're going to be here all night. It seems that as the universe gets older, it finds systems which dissipate entropy faster. And this means that it finds systems which hasten its own end, because the universe will. Well, it won't end, but it will run down to heat death, to the big freeze when entropy is maximum. Now, think of a really good way to increase entropy. It's evolution spend loads of energy building complex systems, complex living systems and then have them eat each other. Fantastic way to increase entropy. Even better than that is to have some of these systems, that is us, build technology which dissipates energy even faster. So we by existing are hastening the universe to its end.
- [40:41]
B
Yeah.
- [40:42]
C
Does that sound bleak? If you want an external meaning of life, that's all I can give you.
- [40:48]
B
I have to say you are brutally honest and consistent. You know, I sometimes wonder if people use emergence as sort of another term for spiritualism or some sort of vague cosmic meaning. And what I love about your book, and this is what I'm trying to say earlier, man, you call it the way you see it and you know, you call it very well and you know, you're not afraid to go to the inevitable conclusion no matter where that may lead. And I think most would agree the picture you paint is a bit bleak. You know, on our day to day existence noticing or suggesting that whatever we do is we become more efficient as we evolve, as we build and you know, continue to, I guess, evolve and expand as humans, we are hastening our demise. You know, it's almost like it's embedded within our DNA. But I have to say your book is just so brutally honest and I mean that absolutely as a compliment. It was like, you know, let's just drill down and figure out where we are here. Last question. Maybe a little more upbeat. Is there anything that would convince you of an emergent property?
- [41:55]
C
Absolutely. And here's, here's if you want to do it, here's how to do it. Take a finite physical system of your choice, write down the many body description of it in maths if you can, or build a simulation if you can't and show it's discontinuous. Explain how your emergent property or an emergent property in this system springs into existence when it gets to a certain size that will be strongly emergent. And that is a perfectly plausible hypothesis. So yeah, Liam, what do you think.
- [42:28]
B
The odds of us finding that in our lifetime?
- [42:32]
C
I mean, I've no idea, but I'd love for it to happen. That would be very, very, very exciting.
- [42:37]
B
Yeah, yeah, no, I'd love to see your reaction to that. You know, one thing I was going to ask you about is heuristics. For example, what role does fast and frugal heuristics play? And I guess our perception of thinking.
- [42:54]
C
Yeah, so the idea of fast and frugal heuristics is that our brain's got limited capacity and lots of stuff to do. So evolution has given us useful rules of thumb to deal with the world. And my favorite example of this is catching a ball. So imagine someone throws a ball, we play cricket, you play baseball or whatever. So you've got someone whacks a ball and you've got it coming towards you. How do you work out where to run to to catch it? Now, to solve that in terms of physics, you need a big computer and lots of sensors. You can do it. There are lots of sort of automatic refereeing systems that can do it now, but they've only really been developed over the last 20 years or so. But actually your eye can do it pretty well and dogs can do it even better. How do they do it? They have a really simple rule. You keep your eye on the ball and you run. So the angle between you and the ball is constant. If you do that, the ball will just plop into your hands. We do that without knowing it. That is a faster, frugal heuristic. So we talked earlier about the importance of simple concepts, approximations for us to deal with the world. Fast and frugal heuristics are the ones that evolution gave us.
- [44:15]
B
Liam, if you've got a few minutes, I want to ask you. I was going to ask you about the quote from Robert Laughlin and I should say I just purchased his book. By the way, after reading your book, the Von Clipping discovery is when physics stepped out of the age of reductionism into the age of emergence. Would you want to comment on that or give a view on that?
- [44:34]
C
I mean, this guy's got an. Is a absolutely titanic physicist. And has got a Nobel Prize. And has got a Nobel Prize. Lalin's work is just amazing. Any physicist can't. Can't but respect it. But I don't agree with anything he says about emergence. I'll be interested to see what you think of his book. I mean, part of the reason I wrote my book is because of his book. Actually, when I was working on the first book, Molecular Storms, I read a bit about emergence and I read his book and I disagreed with everything in it. I should send him a copy of Physics Fixes all the Facts. I didn't think of that. I should. I will.
- [45:13]
B
Hey, Liam, I really found the discussion in your book about the renormalization group transformation interesting. Could you briefly talk about what that is? Yeah.
- [45:21]
C
The renormalization group is a mathematical transformation used by physicists across the spectrum from particle physics up to condensed matter physics. Now, we haven't really got time to go into it in any detail and I suggest Wikipedia if anyone's interested in what it is. But for me it falls into the category we talked about earlier, that it's a model physicists use to explain the world, and most times it's used. It involves an assumption, possibly two assumptions of infinity in there. So the renormalization group is an example where the map is not the territory. The product of applying the transformation looks like emergence. But that's a property of a model physicists use. There's no renormalization group in reality, it's a model with assumptions of infinity.
- [46:15]
B
Yeah, you have a wonderful description in the book and similar to what you just said, it's like a series of steps, coarse graining or averaging over small scale details to eliminate them and then rescaling the system to observe large scale behavior on that process. Just fascinating, isn't it? Yeah. I think that concludes our interview. As always, it was fascinating. Again, the book is Physics Fixes all the Facts by Liam Graham. Sounds like this is the latest but not the last, and thankfully that's a good thing. Liam, as always, thank you so much for your time and thanks for producing a really thought provoking book. I think a lot of people are going to be challenged by it in a good way.
- [46:54]
C
Yeah. Greg, thanks very much for your time and for asking some great questions which really got down to the essence of what I'm interested in.
- [47:00]
B
Thank you, Liam.