Quantum physics powerless to explain consciousness – Nobel Prize physicist (1/2)
Theoretical and particle physics continues to be mysterious, almost an occult science, and the more you try to figure out our reality, the more confusing and counterintuitive it gets. We talk to Nobel Prize-winning physicist Professor Gerard ‘t Hooft.
Sophie Shevardnadze: Professor ‘t Hooft, thank you very much for agreeing to talk to us.
Gerard ‘t Hooft: That's my pleasure.
SS: We did an interview but we couldn't see each other because it was over the satellite. So I'm very glad that we're able to do this live and in person. Last time, we were speaking about black holes. This time, since we're meeting face to face, I thought I would ask you all the big questions –
SS: – because I don't know when I'm gonna see you next. So let's start with this. Your Nobel Prize is for studying electroweak interactions, the four great interactions that govern the universe of which gravity is the most basic one. So gravity for us is this thing that helps us stay grounded so we don't soar somewhere in the universe. But do we have any idea of how gravity actually came to what it is? Can there be a universe without gravity?
GH: Well, gravity didn't just come and go, it is not a force you can switch on and off or something like that. Gravity has always been there. The question is, of course, to understand how to describe it. That's always the kind of questions we physicists ask, we don't ask an explanation as to why is it there and how did it come. We have to ask, how does it work? How does it fit in with the rest we know of science? And the ultimate goal is to have all scientific phenomena, whatever they are, described by the same basic equations, by the same basic theory that covers everything. And the theory that we have and that works very, very well, is the three other forces: electromagnetic, weak and strong forces among the fundamental particles, the particles of which everything is built. We understand those forces much better. So we have a fairly complete description of that. When we try to put in gravity we see how difficult it is, as if we are missing out on something. And how to do it very precisely, we simply don't know. But we do realise that gravity has very similarities, it looks very much like the other forces, the way it acts on particles and objects is very similar, but there are very important elementary differences. Gravity acts on mass, why is that? And already Einstein noted that the fact that gravity just acts on mass makes it very, very special. And you can regard gravity as a property of space and time themselves. Since he believed that gravity actually is related to the other forces as well, you might think, perhaps, also the other forces have to do with space and time themselves. But we're not that far yet to understand all forces as we do to one particular phenomenon, even though there are very many theories around that suggest how this could happen, we simply don't have a new clue as to what the actual correct answer is.
SS: So you're saying in your words that gravity has always been and it relatesto space and time. And here, I want to ask you about where we’re all coming from because a lot of scientists agree that the Big Bang was like the thing that actually gave birth to our universe. But then the theoriesy s differ very much about what was before the Big Bang. Some say that it was another universe that gave birth to our universe. Others say there was nothing, not even time. What do you think?
GH: Our favourite last view is that time just begins at the Big Bang literally. So we call it ‘the moment that all clocks are set to zero’. And there was nothing before that. So it looks as if the whole universe was in its simplest possible form when everything got started. And all that needed to be done was someone to pull the switch, not literally but metaphorically, and then the universe starts expanding. So where do those equations come from and who pulled the switch – that is not the kind of question that science can answer. Nor can we answer the question as to what happened before that. As far as we know, there was nothing before that. So I would rather abstain from answering that. As far as I can tell, there was nothing before “moment zero” when the switch was pulled.
SS: But, you know, I mean, I know that science and religion, they're like completely separate. But then a lot of people would say, ‘Okay, if you're saying that science cannot explain what was before the switch or the Big Bang that's because it's God.’ Would you say that it's possible? Maybe it is God that switched it on?
GH: Those are just beliefs without any basis. And the idea of science is we only accept beliefs if they have some basis and truth, if you can check them experimentally. And the notion of God doesn't help us because nobody can check that.
SS: Alright, so let's talk specifics. So we have the micro-world, that is something that we cannot see, that's not tangible for me, and the macro-world – this is where we humans operate and, you know, we can grasp things, the celestial bodies, etc. Both worlds are ruled by completely radically different laws, I would say. Where is it that the micro-world ends and the macro-universe begins? Where is this verge?
GH: These are not totally different worlds. In fact, they're all just one world. So all those stars and planets that are roaming around our universe, they are built with the same particles that we study in our laboratories — the smallest units of matter. So the smallest units of matter, make up everything. So if in principle, if you would know exactly what the laws are that move these particles around, then we can understand how stars and planets are made, how galaxies are made of stars and so on, and in fact, how our universe is made. So there's no fundamental boundary between those worlds. It's just one world. And this is certainly the way we prefer to see things that there's just one world, this world is made out of particles that first form planets and stars and galaxies, and then together these form the entire universe. But there's no boundary anywhere.
SS: But do you think we can ever come up with a precise formula that would explain how these quantum particles influence and transform the macro-reality that we live in?
GH: Well, science actually has gone a long way to say, “Yes, we do have a very precise view about how this goes about”. We understand the forces that act between particles, we understand how to describe them. We don't know where they come from, but we do understand how to describe them. And we know how the motion of these particles has been described, how they come together, how they interact, and how they can form substances that ultimately give shape to planets and stars and why stars or planets behave the way they do because of these particles. For instance, in the sun, one of the stars, there are nuclear reactions taking place. Those nuclear reactions are described by the physics, that we know about, concerning these elementary building blocks. So it already all hangs together, there's much more known than many people realise, but our science is a huge topic. So although I'm saying there’s a lot we know there was a lot we don't know.
SS: So you’re saying there cannot be one formula, there needs to be many formulas? Some of them we have already that explained this mechanism…
GH: Well, it's almost one formula that already fits on a coffee jar. Or on one piece of paper you can write down the formula, which basically symbolises all forces that exist. And we've reached that stage already. The only thing not put there or put there only in somewhat harder, obscure form is gravity itself. So we can add gravity to the laws of particles. Basically, it's very simple, particles move, not in straight lines anymore, but they move in lines and they slightly bent because of the gravitational force. And if that's all you say, you can say okay, we also understand how gravity acts in the whole system. So what's the problem? The problem is that high domains where we want to describe the particles where the gravitational force explodes, that's when particles come too close together, and where space and time get too much curved, and then our understanding stops. And we want to have a better, complete view of what equations are that govern that domain. So there we realise there's something missing in our fundamental understanding of gravity, something extremely important. If you could answer those questions, we will suddenly put the whole thing in a different perspective. This far we understand that to make all the questions fit together properly, we haven’t quite succeeded in doing that. But we've gone a long way. But that's not good enough because something’s missing.
SS: I’m so far from physics or quantum physics, you know, I'm just someone who's interested in things, but to me, it's mind-boggling that you're saying, we've gone so far, but yet, we're missing the understanding of the most basic fundamental thing that is gravity.
GH: Right. Well, gravity itself – We have Einstein's theory, and it works extremely well for stars and planets. So Einstein noted that if you are more precise than what Newton did a couple of centuries ago, you get a slightly different shape of the orbits of particles, although, we managed to reproduce what Newton said by 99,9%. So basically, Newton was right, there's no question about that. But it can be done more precisely – that’s what Einstein found.
SS: Professor, because you're saying, you know, if we find out exactly what is gravity, then things could turn out to be completely different from what we thought, do you feel like someday we'll come to a point where Newton's physics and Einstein's relativity could turn out to work in a completely different way?
GH: The thing that we all expect, actually, is that the language will have to be modified. We use a certain language to describe the particles, we talk about particles being here, moving to there, about a planet being here, moving to there, a planet consisting of particles, we use all those words. And those words work very well under ordinary circumstances. But the suspicion is they will fail when we want to describe gravity at a very, very short distance range, much tinier distances, even in the size of the particles, then things go wrong in our description. And we want equations that do not want go wrong anywhere. And this we did not succeed in. But the belief is, we’ll have to modify our language to get this right. And that is quite normal. That's actually where Einstein differs from Newton. Einstein discovered a different language to say the same things as Newton. So what Newton said was not wrong, but you have to say it in a different language. And then you discover you can do more precisely the equations that Newton ever did. In particular, Einstein found that the fact that light only goes to the finite speed, it's the same everywhere – that fact was not properly incorporated in Newton’s theory. To do that right, you need a different language. Einstein found that language. And this happens again and again. Quantum mechanics is the fundamental theory that describes how particles have forces on each other and how they move. It's a totally different language from what we were used to before. And that language helped us to get a better description, it’s fundamentally better. Now we understand how atoms move, how chemical reactions work. You know, an atom is a relatively simple thing, an atom just consists of a nucleus with electrons going around it, like a solar system, what's so complicated about it? But then we find that quantum mechanics makes that complicated and generates things that we call chemistry, atoms attract or repel each other. Those forces are quite complex, yet basically understood by quantum mechanics, provided we use this new language, which is a very mysterious language, we won't understand better why this language is there. And I fear that we will have to change the language again.
SS: Okay, so let's try to do it right now. For instance, if we take the quantum entanglement theory, for me, a mortal, who is far from physics, the way I understand it, is that you have two particles, no matter how far away they're from each other, and somehow they react at the same time to the changes that are done to both of those particles, or many particles, I don't know. So what is it exactly? Does information travel faster than light? What's going on here?
GH: Well, I'm convinced that those words you are not inventing because you heard them many times.
GH: Those words are actually the wrong kind of language, it is not true that information travels faster than light. We know that pretty for sure because Einstein’s theories work extremely well. And they tell your information never goes faster than light. And in all our quantum theories, also, information does not go faster than light. So when they say it does go faster, it means that they're using the wrong language. Indeed, entanglement is a very special phenomenon that you only encounter in quantum physics, and it has to do with this information we have about those particles. If you know how one particle is oriented, you can sometimes know how other particles are oriented because particles spin and they have an orientation that way. But they spin in a very special way that you can only understand in the quantum language. If you use the quantum language only, nothing goes faster than light. And this is the way we have learned to describe the fundamental particles. But people want to understand what they're doing. They want to understand, ‘This quantum language is fine but there's something fishy about it, something we don't believe, we want to go deeper, we dig deeper.’ When they dig deeper, they find there may be other ways of describing what's going on. And in this other language, it looks as if information goes faster light. I think personally, that's a lie. Because those people think they have found a better language, but they have not. They’ve found a worse language. The best language you can use with quantum mechanics is only the language that helped us forward in the past. And don't try to think what that really means. That's good for the moment. But many people say, ‘No, no, we can't have that. We can't have this crazy language.’ This language doesn't tell you exactly where a particle is. It only tells you where the particle is with some probability. And we don't want that probability language. We don't want to say, ‘Well, you if you throw dice, you never know where dice will go because of the laws of probability.’ No, if you hold the dice very carefully, you know how to make two sixes, right? I mean, a very agile magician might be able to throw dice in such a way that he always gets two sixes if he knows exactly how the dice work. Very hard, but possible. So that's what we want in quantum mechanics as well, we think there's something underneath that says, there's no statistics at all, quantum mechanics is just a bad language of something that's much better, but we don't understand what it is.
SS: But for an ordinary person, the more I delve into this whole quantum mechanics, and I'm listening to you, it still seems pretty random to me. You know, like Einstein said, ‘God doesn't play dice,’ you're saying there is no dice. But then, at the same time, you're saying it's impossible to predict exactly, right? So to me, it sounds like quantum physics is more of an esoteric discipline rather than a precise science, because it's all probabilities that we're talking about. No?
GH: Well, you have to understand that this world consists of particles, which interact with each other. But just imagine how many particles there are! How many particles are there in your body, that's more than you can count in a computer. So you very easily land in a world that's infinitely complex… Well, not really infinitely, but very, very complex, so complex that it is hopeless to predict exactly where every particle is going. That doesn't mean these particles don't know where they're going. They do know, they are exactly prescribed by laws of nature. But we don't understand those laws of nature well enough to be able to foresee where a particle will be going. So we use the laws of statistics, there's actually a very smart move that scientists made in the beginning of the previous century to say, well, we don't know for sure where particles are going, but we know where they go on average. And that has been extremely helpful. And basically, that's all you need, because in practice it's never possible to control all the particles that are running around somewhere. It's hopeless. So don't even try, don't even dream about it. Just say, ‘Okay, we know where they move on average, that's good enough for us. If we can get the maximum amount of information about that, that's what we want.’ That's the present state of affairs. That's how we understand how particle physics works, how quantum physics works. But it doesn't tell us what those underlying rules exactly are. So what I want to know is what tells a particle exactly where to go, even though it's impossible for us to reproduce it. You will not be able to use that knowledge to make better predictions than quantum physics itself, it’s always probability distributions. Think of an insurance company that wants to fix the premium for someone who's insured. In principle, what they could try to do is calculate exactly in advance what the lifetime of a person will be, and whether he'll make an accident or not and exactly estimate the premium for that. But that's hopeless, no insurance company can do that. They don't want to do that. They say, ‘Okay, this is the general probabilities. This is what we choose as a basis for how much you pay for your insurance.’ So that's the same way quantum mechanics works today. We don't even try to make a better prediction than what we can do. It doesn't make any sense because the equations we do have work extremely well. So little exactly what chemistry is, and so on.
SS: When I listen to you speak about the nature of this whole quantum mechanics, it reminds me how great neuroscientists speak of human brain, because they're saying ‘No, no, it's not that the neurons there are infinite. There’s a certain number, but there's just so many of them and the connections between them, it's hopeless to try and figure out each one of them. So the laws that we have so far, works somewhat ok.’ Would you say there's a connection? Does our consciousness, our brain have a quantum nature as well?
GH: I personally don't think that's the case. So quantum mechanics determines exactly how all chemical reactions take place. And these chemical reactions are extremely complex, and obviously, they are of great importance for the way our neural systems work. So in that sense, quantum mechanics is very important for understanding how the brain functions. But the memory cells themselves, I don't believe they’re based on quantum mechanics. Many people think so but I disagree. I don't believe that. I think the memory cells just contain certain chemical particles sitting somewhere, or sitting not somewhere, or sitting somewhere else, that terms the state a neuron is in, and that's the way we memorise things. And that's quite enough for all practical purposes. So I think our brain will be able to do very, very well, without using quantum mechanics to explain how the memory cells in our brains work. We only need quantum mechanics to explain how the chemistry works. But once you know that, you can just close the quantum mechanics book, now open up your chemistry book, then you know how those neurons will transmit information to one another. Then you close that chemistry book again, and you say, ‘Now I only need my computer books, my computer manual.’ The manual says that if you know all the hardware, this is the software you can produce. And the most miraculous features in our brain is the software. How does our brain work? And how are we able to think? And that includes the concept that we call ‘consciousness’. So some of my colleagues attach some mystic value to the notion of consciousness, but I don't. I think consciousness is just a question of information, and in particular information about yourself and information about your environment, all information. So to be able to investigate all information that comes to you and to make use of that, all that together is consciousness and is intelligence. So the next step, of course, is to understand intelligence, human intelligence. But all that is basically a question of software. It’s my conviction.
SS: I mean, we can't see it, we can't see intelligence and we can’t see consciousness when you open a skull.
SS: You see neurons, but you don't see consciousness.
SS: That's why we think of it as something mystic.
GH: But if you open a computer, what do you see?
SS: A lot of…
GH: You see a lot of wires,
GH: you don't understand what's the information inside that computer. I don't at least, I just see all these little things there.
SS: So this is just the first half of our in-depth talk with Nobel Prize winner Professor Gerard ‘t Hooft about the way the universe works. Stay tuned for the second part.