Carlo Rovelli Love And Quantum Physics Are The Same The Futurology Podcast

TITLE: Carlo Rovelli: Love and Quantum Physics are the Same | The Futurology Podcast CHANNEL: Futurology DATE: 2026-06-23 ---TRANSCRIPT--- Hi and welcome to Futurology. I’m your host Don Nakagawa. In this interview between Claire Webb and Carlo Ralli, we span the universe and explore the nature of reality. Carlo is a proponent of relational quantum mechanics. His bold claim is that the universe from the smallest to the largest cannot be understood by studying its objects. But rather we can only understand it through its connections, its interactions and its relationships. From particles to people, from physics to philosophy, nothing stands alone. This interview covers his work, his theory of reality, and how Buddhist cosmology may reveal the secrets of the universe. And now, let’s go to the interview with Claire and Carlo on Futurology. Carlo Ralli, welcome to Futurology.

Thank you very much, Claire. It’s a joy doing this with you. I’ve joined you in taking off my shoes. Um because this is your habit during interviews and I do feel more loose and comfortable. It’s my habit in life. I hate shoes. Um Carlo, uh behind us is this beautiful background of of Venice. Um you’re Italian, uh from Verona. uh tell us about growing up here and and how it’s informed your philosophy and your physics. Verona is 100 miles from Venice. So this is still home in a little bit a little bit for me. Um so I grew up in this region uh uh in a comfortable rich postwar Italy uh much loved by my family in a in a rich country. Um and uh I think the privilege of growing this way was also that is a country that gave a very wide education to to kids based on history, on art, on philosophy um on everything. It was very useful for me for later my my scientific uh career and also I grew up during the cold war where the world was divided in two two parts that were hating one hating one another and describing one another as horrors both of them and uh to some extent Italy was in between was not the only country in between but was a country in between because it was a major communist party here which also was good because it gave a double perspective on on the world. But then I left Italy pretty soon. I traveled a lot. I lived US, France, Canada, now Spain, many places. This doubleness that you talk about or the desire to to be in the middle of two things very much resonates with your chosen field of interest. um quantum mechanics. So, why don’t you tell us about um what first got you interested in theoretical physics and how uh how you’ve been curious about the very small world. It happened quite late. Um I went to university. I studied in Bologna. Um oldest university in Europe. Um and uh I enrol enrolled in physics uh I took physics as a major uh not really because I was particularly attracted by physics but because I didn’t know what to do and uh my university years were years of uh exploration of the world a lot of reading a lot of traveling a lot of friends a lot of experiences a lot of uh trying different things were the 70s in which part of the young generation was very exploratory in terms of behavior and uh and also ideas. Uh a lot of discussion about ideas, a lot of reading of philosophy, a lot of reading of intellectuals. Um so science was I felt that science was sort of the the new knowledge of the new century and so I needed to know something about it but I I didn’t go into it thinking I would become a scientist. Then I stumbled about quantum mechanics in a funny way because um of course there are classes courses in quantum mechanics in the university when you study physics but that’s not how I studied quantum mechanics. stud quantum mechanics because of a misunderstanding because my mathematical teacher um sort of gave us pieces of mathematics to study gave me group theory and I said okay what should I do and he said the applications to quantum mechanics and I said but I don’t know quantum mechanics yet and he said well study it and he was joking but I didn’t understand he was joking so I went home and spent two months total immersion in learning in quantum mechanics and it was best two months of my life. for me to five or six books and uh studied this fabulous theory and uh more or less the same time I got in love with general relativity, Einstein theory and that changed my life the two things because uh now I found a problem a a a kind of knowledge that uh uh completely captured me and fascinated me because it was profoundly Um, let me use this word revolutionary. And that’s what I wanted somehow. I wanted something else. Not the world that I had around me. I wanted something else. And there was something else there. There was a a discovery scientific so in some sense reliable that the world is not the way we look at it. It’s profoundly different. I was extremely fascinated by that. I started doing less and less of all the rest and just naturally spending more and more of my time uh reading about science and then I realized that these two major steps ahead in the knowledge of of the world uh were not yet combined. So the problem of quantum gravity was still open and I I said okay this has to be done. tell us what quantum gravity is and how Einstein’s equations of general relativity describe spacetime on um cosmological scales. Yes. Um ice and relativity um was born as a gravity. Gravity is you know things falling down and the moon going around the earth kept by gravity. Um I realized that all the Newton theory was insufficient the light of what was had been understood. So uh changed it and gave us this fabulous theory which is general relativity which understands gravity in terms of um uh a different way of thinking about space and time with respect to Newton. So space and time becomes dynamical fields become things themselves that can bend and stretch and uh it’s a it’s a marvelous theory. It really changes your understanding of reality. Um and uh it’s 100 years old now 110 now. Uh but in the last decades it has obtained spectacular confirmations. So basically everything Einstein predicted black holes gravitational waves expansion of universe turned out to be true true and then the other half is quantum mechanics. Quantum mechanics is a it’s a theory about things um which uh shows that things don’t behave the way we we we thought before. Um they have curious properties. First of all um they behave with probabilistic. We cannot predict it with certainty. Uh second there’s a sort of granularity discretetness at short scale. So light for instance made by photons which are little particle of light quanta that’s the name quantum mechanics and third which is the most interesting thing that things cannot be understood just by themsel they don’t have just properties by themsel the properties of things and this is you said small things but in reality everything just this is more evident for small things things um have properties when they interact with something else. So we understand an electron as in terms of the way it affects something else and in fact we understand everything in terms of how it relate to something else. Which means that to understand the world we have to think in terms of relations rather than in terms of individuals having properties. Um this is very deep. it took long to be digested but I think is the core message of uh uh the new physics but that’s what we’re asking um what is quantum gravity u the problem of um understanding the the quantum aspect the quantum properties of space and time is is still open we have theories I my me and my friends and and my colleagues uh have been working on this um uh theory of quantum gravity uh for decades. It’s called loop quantum gravity. It might be right but we don’t know because it has not been tested yet. So in one sense it’s very conservative as a way of thinking because it’s it’s based on the idea let’s we have discovered something about the universe quantum mechanics let’s take it seriously we have discovered something about the universe generative TV let’s take this seriously what does this imply together and it’s very it’s very conservative but then it becomes very radical because uh it means that space has quantum properties and time has quantum properties It is. So it means that space is made by quanta as this granularity and so is time. Uh but not only that that space and time themselves have this relational property. They’re not things by themsel. They’re ways in which various things affect one another. So it’s a it’s a really new way of thinking about the world. Um a lot of contemporary theoretical physics is different. It’s sort of based on the same old conceptual scheme trying to guess something new. What about these equation can be changed? What about the new particles? What about the world is made by strings? What about the many dimensions? What about the other words? It’s a I don’t think it’s good way of going ahead understanding the world. We understand the world either because we have new data or because we take it seriously what I have learned so far and we try to work out the consequences and this is a conceptual work. It’s a theoretical work but it’s also a philosophical work. Um so I think that the physics of the 20th century it’s truly pushing us into a new philosophy a new way of thinking. It’s not completely new. I mean it’s ideas which were around um but it forces us towards certain way of think about the world and away from other ways of thinking about the world. The world is not made by things. It’s not entities out there. There’s not the being. The world made is is a flow of things related to one another that make sense by the fact that they’re related to one another and uh that we understand by realizing not by looking for the outside but realizing we are part of this uh sort of network of relations which is reality. And it seems to me though that there’s something different about making a measurement of a particle. Uh freezing it in time, let’s say, uh is an electron spin up or spin down. Um your relationship to that particle and knowing about that particle is mediated by uh really sophisticated um technologies of perception. That seems to me to be really different than being in love. So, how do you think about different kinds of relationality? Or is every kind of relation made out of the same stuff built on the same principles? Um, that’s a fabulous question. It’s a great question. Um, thank you, Claire. Um, it’s both in my opinion. First of all, I don’t think there is any gap in the world. Um, title of my next book is going to be on the equality of all things. So, I think that measuring an electron um it’s a complic complex operation that um involves the electron itself. Poor poor guy is there and it’s real. It’s it’s something there. uh but it interacts with an apparatus. It’s a complicated apparatus. There’s a lot of technology. We read it in terms of our theoretical ideas. So what we’re really doing is applying theory to some phenomena which are out there and that that’s reality. We’re describing reality. Um it’s complex relation of things. Now when when we when we get in love uh it’s completely different uh set of relations which are around but it’s also a complex relations of things and like electron it can be described in different manners. Um I can be a poet and express or try to express uh the unique feeling of um happiness, excitement, absoluteness, total change which is to get in love. I can be a medical doctor and describing what happened in my body. I can be a um a person studying the the the the neuro neurological aspect of that or the chemical aspect of that. I’m not I’m always describing the same phenomenon. It’s not one is right, one is wrong. There are level of descriptions. Some are more appropriate, some are less appropriate. Uh some work well, some do not work well. Um but it’s always the same thing happening. It’s just reality happening. And reality happening is just reality happening. Whether it’s a moon going around the earth, a ball falling on the ground, or me getting in love with a person, that’s my view of the world. There’s a deep equality of levels between between all the things. And there are many languages we have to describe um reality which are coherent with one another even if they are distinct. Can you talk about this relationality uh from the perspective of your new work on uh consciousness? What you’re describing to me, Carlo, is you’re you’re a physicist. The world is real. The world is material. Love isn’t just um oxytocin and serotonin and and endorphins um dopamine flooding the brain in particular ways. So, it’s not just chemistry, but it’s an entanglement of relationships that include hormones and chemistry. How does that all link up to the conscious experience of knowing you’re in love or enjoying poetry? Is that all materialist, but it’s just different layers together? Yes and no. Once again um to say that if some complex situation obey certain simple uh laws doesn’t mean that we understand it because uh the the simple laws are just a some regularities that reduce the the infinite possibility of just logical facts. So saying if I get in love with chemistry, it’s just silly because also a a glass of water is just chemistry. That’s not interesting. What is interesting is that chemistry of the glass of water is very different than the chemistry of of a person in love. Okay. Now, do we know the language for describing specifically the chemistry of a person in love? No. Only a little bit. Only some bit little chunks. You’ve mentioned some of them. But the complexity of going on far um goes beyond what can be said in chemical terms and even more what can be said in uh physical terms. So to say that everything is when we get in love everything is chemistry or our consciousness everything is chemistry. First of all why chemistry I mean why not physics then or why not basic biology? I mean all all these levels are good but all these levels are completely insufficient. So no they do not describe what happens when we are in love. We cannot uh we have we need another language. We need another set of concepts. But we make a mistake if we think that um there is a metaphysical gap which is uh sort of breaking the sort of underlying description. And now I come to your question about consciousness. This brilliant um American philosopher, Australian philosopher is David Chalmer who has separated the famously two problem of consciousness. The easy problem he called the easy problem and what he called the hard problem and the easy problem is everything can be in principle said about the phenomena of consciousness if we could understand all possible signs uh about it. all possible physical, all possible psychology, all possible all everything that could be that and then he says suppose we could have um solved all that there would remain an open problem which is what he called the hard problem of consciousness and the hard problem is understanding what according to David Chalmer’s what qualia are that um that that calculating the distance um between you and me would be very straightforward with a physics well with a ruler but figuring out what is red. Figuring out what is red or the taste of chocolate or the feeling of being being in love. These qualia are irreducible phenomena in the world that somehow within Talmer’s framework elude quantification, understanding, parsibility. Exactly. And I think that um the distinction is brilliant. So what could be understood so to say scientifically from what would the problem will remain open after all that. But I think David Chalmer completely misnamed these two problem because what we call the easy problem is nothing easy there. It’s enormously complicated. It’s extremely complicated to understand what happens when I taste chocolate or even more when I uh when I’m in love or when I have a emotion one kind of the other. So the easy problem is hard but what he calls the hard problem namely whatever remain open after I have uh understood that that’s easy in my opinion that’s extremely easy because that’s a false problem the answer to that problem is the answer that vikstein vidkstein um gave to the question about what is the great riddle the answer of the riddle is that there is no riddle there’s no problem. What is the qualia of me tasting chocolate? Well, it’s whatever happen in me when I taste chocolate. It’s nothing else than that to which I give a name which is chocolate. And if you say well but that particular feeling well that particular feeling is a particular thing that happens in me. We do acquire capacity of distinguishing qualia as we uh live right. I mean you I don’t know you drink wine it tastes like wine and then you you drink more wine and you realize that Keianti tastes different barolo and then you start distinguishing different kind of Keiantes. Uh is this a plug for Keianti? Uh yes. Yes. I I prefer barolos but I I love this. Okay, great. Oh that’s a subtle discussion. But Carlo, can you tell me why measuring the distance between the two of us with a ruler is harder than you knowing what chocolate tastes like? Well, you’re saying that they’re saying that they’re more immediate to us. Um, there are many things which are more immediate to us because uh um the easy problem is complicated. Namely, um when we say consciousness, which by the way, it’s a very modern uh notion. Um nobody talked about consciousness a few a few centuries ago. Um if not in moral terms, which is not what we mean together. Consciousness doesn’t even have good translation in Italian. There’s no word for that. The problem with consciousness is that everybody means something else. Okay, for some people to be conscious is like to be awake versus to be asleep. For other is to have to perceive. For other is to have a self idea of oneself. To other is just a awareness. Um just being aware I’m I’m aware that you’re there. I know that you are there. So I have some awareness. So therefore I’m conscious. To others is even something more generic. Is a vague sense of distinction of me from the rest. It’s for others is the capacity of using the noun I okay or me. So people talk us this were the same things but these are completely different things right my my cat certainly has awareness of a lot of things and has a a rich emotional life a sensory life which is compared to mine but I don’t think spend time reflect self-reflecting about its own identity it doesn’t care it cares about mice and and and me and and and and being pet and sitting in the sun so The consciousness is extremely confused and vague term and we are making a big deal of it. We shouldn’t we should just break it apart in a variety of different notions which are all interest to study. For instance uh in our own life we have the experience of being awake or asleep and sleep with dreams sleep without dreams. Oh that’s super interesting. What’s the difference between this? what different is going on in our brain, in our body, in our relation with the outside um in these cases. That’s a good question. Okay. But do you think there’s something uniting um when you break out these questions of consciousness? Is there a a through line? Um for instance the cat not having uh consciousness you were saying is about self awareness. So the cat doesn’t reflect about itself have self-reflection. I imagine it doesn’t. Yeah. So is this quality of self-reflection essential to the quality of consciousness no matter how we might study it? It’s a matter of definition. It’s like is having a cover essential for a book? Well, yeah. Do you want to call book book without cover? You want to call it book is up to you. It’s not there’s no the essentialism. It’s a wrong idea to ask what is the essence of something. There’s no essence of something. There are names we give to classes of phenomena. These names are completely arbitrary. We’re interested studying how these phenomena are, how relate to one another, what we can say about them. Not to ask what is to be a book. There’s no what is to be a book. I mean there is a You know somebody wrote stuff on paper and printed it and we call them book. Now a notebook is a book. Well yes and no. I mean it’s not that’s a bad question. So where where do we want to put the label consciousness is totally arbitrary. There’s no the essence of consciousness. There are many phenomena. All of this can be understood. There is no mystery. There is no riddle. So consciousness as a category is laden with a particular historical meaning. um also a particular uh social meaning now. Um so while it’s a academic category now that intellectuals can can talk about and have conferences about it wasn’t really something that Buddhists were naming as such uh thousands of years ago. So can you talk about the history of consciousness and how you see the category of consciousness now amidst that history? Yes, you touched many things. Um one aspect of this and let me just fall back to books for a moment. Um is that when we think about our own conscious there’s a deep linguistic aspect of it. So one thing I find fascinating it’s a question not what consciousness is but how much uh this extremely developed language that our species has developed as a species not as a recent civilization we don’t even know since when this is we’re very confused about the origin of language how much this has changed um our perception of ourself so the question what’s the difference between me and a cat it’s some extent connected to language and so um how much giving a linguistic uh account of reality uh changes the way of perceiving reality that’s that’s a that’s a great question for me um and staying still on the on the long term sort of humankind um time scales um no doubt we are social animals um erh uh like our cousins a great apes uh but much more so because we make a much larger uh structure. So no doubt uh the language and uh uh our brain function have developed also in in relation to this um to this complicated social relations we have. So I think a lot of my sense of self is social. I personally think that when I mean when I think about me, what I’m really referring to is how my friends, my mom, my lover, my all the people, my enemies look at me. And this um and is the way I look at them. I know how they look at me. And this back and forth between images that construct our social identities. So the self it’s it’s very much a social build up in in some sense. Okay. Um which doesn’t change the fact that animals which are not social have some sort of self different different kind but but very different I think for for this re reason. Now historically uh we know I learn that the the way different civilization described um the inner working of a person has changed a lot. Um we know famously that in Homer at in the early Greek civilization there are no words that correspond to a person directly thinking meditating um deliberating having ideas taking decisions in the Iliad when when describes somebody having an idea it’s always a god that comes and and and gives the person an idea so it’s a different language for describing what happens and the modern uh um the modern western notion of self and conscious is really modern. Uh maybe it has a root in St. Augustine. So there are some root in late antiquity. Um but there’s nothing like that in in antiquity even if it is extremely developed cultural and intellectual tradition of course around the Mediterranean. China and India as far as I know are different and different among themselves. India is closer to uh to the west to the Mediterranean. It had more relations of course back to millennia ago. Um and Buddhism had a long reflection about the self which interesting got in two different directions. One is um a lot of attention about the self. there’s a large very developed Buddhist psychologist psychology traditionally um but also in the opposite direction there is the idea that the self is illusurary that there’s no self um which an idea I like a lot and I think I like a lot because it heals us from this illusion of essentiality I am this um cartisian or better hideer idea that we have a direct intuition about being because we are um I think there is something deeply wrong there in the sense that it gives a priority uh to to to consciousness the first person which is illusion silly right when when when we put put ourself in the center we know we’re making a mistake right we’re little things in the huge cosmos there are billions of galaxies and galaxies billions of stars and then there’s earth and the earth is a it’s very big and we know don’t even know what happening in its center and there’s a sky. There’s a s teeny teeny layer which is the the biosphere at the surface of of the earth where there’s this complex phenomena happening like complex phenomena happening all over the universe. The little waves on the sea and one of these is us. That’s what we are nothing more than that. We make a big deal about that you know we we get angry we make wars with all the stupid things when we are just uh little ripples on the floor. That’s how I I I think and I hope that thanks to modern science, thanks to modern reflection, thanks to cross-cultural dialogue, we could use this uh sense of irrelevance of ourself to uh give less importance and go away from this essentiality, this absolutism which I think is devastating in our lives and uh accept the lightness of a view of the world in which we’re just part of this network of interactions. How’s relationality uh meaningful make meaning in in the quantum world in quantum mechanics? Yes. um this this large angle view of reality I was uh referring to uh for me to a large extent emerged by think about quantum mechanics specifically and since the ‘9s I’ve developed a um a way of thinking about quantum mechanics which is called relational quantum mechanics um which today is more and more this part of the main discussion about interpretation of quantum mechanics Quantum mechanics is a strange theory, right? Because it’s super effective. It’s used in technology all over and yet it’s very strange. It’s very It was developed um in the 1920s in particular and really caused a major shift in in how physicists saw the world. Yeah. Yes. And in fact, now we are exactly 100 years from the the group of papers that established it. Um quantum mechanic was born in uh four or five papers uh that came out within a within a year. Uh the first one was by Heisenberg and then by born and Jordan B Jordan and Heisb and Iraq and uh it’s quite astonishing because five papers in um in a short time that’s it that’s quantum mechanic then it was developed applied to everything except gravity. So the point is that uh the questions are clear the application are clear but what exactly the theory says about the world is very confused and the discussion is going on. There are conferences with physicists, philosophers, mathematicians um having different opinions of how to think about that and there are a number of possibilities on the table which are all good. And what and what is so confusing? What what kind of existential confusion did uh quantum mechanics first give rise to? Because it doesn’t describe what happens. It describe what you see when you look. Okay? And if you look at some moment, it gives you the probability of what you’re going to see if you look after some time. And if you try to fill in a story, it doesn’t fit. So in Newtonian mechanics, in classical mechanics, it is completely knowable where a ball would land. Um if I threw a if if I threw a football through the air, um I could calculate the time, the distance, the arc. Uh things would be certain. quantum mechanics. One of the foundational paradoxes of of quantum mechanics um is the more you know about momentum of a particle, the less you know about its about its position. And there’s something deeply odd about this that goes against what we see every day and can describe every day in the day-to-day world. Absolutely there is. And it’s not just the fact we cannot predict things with certainty that okay, that’s our life. Of course we cannot predict things with certainty. We do not have enough data. It’s more than that. Is that if we see a particle in a point and then after 10 seconds we see another particle in another point and we say okay the particle has gone through this path in between. This does not work. If we work this out we find contradictions. So it’s more complicated. The particle doesn’t go from here to here. So disappears and reappears there in some sense. So the theory is not about how things are at some time at every time but they’re only how things affect something else. Now at the beginning people were saying oh how they are observed but of course it’s not because we human observe them. We humans are just stuff like anything else from a physicist perspective. The point is that how things affect other things, it’s a crucial part of the story, not how things are. So the theories about how things affect one another and how what what’s what because of that um what things can know about one another because they can have records of what happened before. And this is very different than saying how things are. It takes away the R. It takes away the being. It reduces the being to relationality. Now people try to make sense of this in different manners and uh let me mention two or three which are not wrong but I think they’re not good different thing they’re not useful one is to say oh well there are things that happen we just is in they’re invisible to us is a big complicated world of hidden variables that are in principle hidden you can always add pieces of reality to make sense of it even if there’s not access a Second one is to imagine that there’s multiple world. We you and I are just in one branch of a immense universe in which the copies of yours eyes and this for some technical reason make things more sort of metaphysically clear but to my opinion in my opinion absurd. I you and I are here now they’re not doesn’t make sense think about other copies of us. A third possibility is to think that quantum mechanics is just wrong. Oh, perhaps it’s wrong, but it’s wrong in a way that it’s going to be replaced by a theory is not so strange. But I don’t think so because usually when science goes ahead, theories are replaced by thing theories which are more strange, not less strange. So where does it leave us? I think it leads us to relational quantum mechanics which is to the idea let’s not try to fill to add to quantum mechanics an ontology a story how things really are because the question how things really are is a meaningless question what does really mean I can ask how can I understand better I can say look this is a table but if I study better it’s made by atoms true that’s a better understanding but I cannot say yes but what is the ultimate description the ultimate description the ultimate doesn’t mean anything the most fundamental way what does fundamental means okay fundamental is a is a relative term there’s something which is fundamental for one perspective something fundamental for a different perspective so I think what quantum mechanic this is relation quantum mechanics what quantum mechanics is telling us is that we can give a description about the world but it’s our perspective ive and it doesn’t necessarily match with some other person or another object description of the world. So phenomena relative phenomena relative to one system and the same set of phenomena relative to a different system might be different. Now these perspectives talk to one another because I can ask you what have you seen? So they’re not um they’re not we don’t live in islands that don’t talk. We talk all the time because the perspective themselves are of physical just the way I am. Okay. But the idea of having a description of the world which is a absolute final universal the god view of the world doesn’t play any role for us. It’s not accessible. It it doesn’t make sense. It’s a it’s an open riddle whose uh answer is that there’s no riddle. Forget about that. Let’s talk about the perspective. Let’s talk about the information the system have about one another. We are physical system like any other. And that’s a way of understanding quantum mechanics. And that’s of course that’s the relation of quantum mechanics. It’s a way of understanding quantum mechanics which inspires and resonates with this general view of the world as perspectival um a non foundational view of the world. um which I mentioned before which uh if I have to find traditional thoughts in philosophy uh it’s not totally new of course you can find in philosophy some bits in western philosophy but remarkably clear expressed in some chapters of eastern philosophy um in particular in some aspect of Buddhist philosophy I was particularly struck by Nagajuna who was a very very similar suggestion. So discard any questions about the ultimate reality. Uh just talk about the the apparent reality things make sense um in relative to other to other things. So I want to get to that um very soon. But one could say an example of relational uh ways of being in the world which quantum mechanics is one description. Um if you take this table from a quantum perspective uh things are so far apart nothing is touching each other. If you take it from um a geological perspective you could describe this table in terms of um marble that was probably quarried around here. If you’re taking it from a um like a molecular perspective you could describe the molecules of of that rock. Um, if you’re a functionalist, this table is something that is holding our water glasses uh and and our books. Um, so these are different descriptions of reality from different perspectives that rely on at least two objects in the universe. Um, and perspective is very important um in understanding what that relationship is. You always have to have a perspective. Yes, your example of the table is very good because uh all these perspectives on the table are um meaningful and interesting for us. Each one give us a a good story about the table and the point I want to stress about the table still are two. One is that some of this perspective more obviously and some less obviously you’re never really talking only about the table. Okay. Uh you can talk about this function of the table which of course is to hold the glasses there and to put sang which of course is a very good account of what the table is but not by the table itself. The table in in full immers immersion in a civilization of ours where it plays this role. Okay. Uh you can talk about the color of the table but the color of the table is not a property of the table. Of course it’s the space of color is threedimensional. We know it very well how to describe it. But why is threedimensional? Because we have three receptor in our eyes. So you talk about the color, but you’re also talking implicitly about our eyes and also about the social context of what this color is. Going back to uh Homer, your example of Homer describing the wine dark sea. Uh, we presumably had the same um well, we did have the same number of cones and and the the physical and the optics of our eyes are exactly the same as as people um more than two millennia ago, but descriptions of colors are socially based. Homer did not say that the ocean is blue. He described the wine dark sea over and over and over again. Yes. So it’s um you you to describe a single object you you’re implicitly referring to other things around it. But the interesting thing is that when you go down to a physical description also okay because when you do a quantum mechanical description of the table you cannot talk about the table by itself. You’re talking about the measure quantum measurement of the table which are interactions of the table with an apparatus. So in a sense we always knew then in take talk about the table we’re talking about also something else but we were hoping that down there there’s an ultimate table which is physical and it’s not true. So there’s no ultimate table table there’s just table from all possible perspective and uh our best knowledge of this table is not one of these it’s as many as possible of this. Now let’s go to Nagajuna. Najuna um I met him um not long ago maybe 10 years ago um it’s considered a major philosopher in his in in in Buddhist philosophy classical uh couple of millennia ago a bit less um and uh he has a book um in which he uh describes in detail what you call emptiness the empty nature of um um of things in which um a lot of things are going on. But from from my perspective, one of the central ideas is going on is precisely the impossibility of um um accounting for one thing whether it is an object, whether it’s a time, whether is knowledge, whether it’s whatever idea you have just by itself. and understand that if you try to isolate one thing you’re you’re do he’s a logician you’re you’re doing something contradictory you always understand things in terms of something else so but why is that um emptiness emptiness is a is a technical term for najuna it doesn’t mean non-existing it means um uh absence of autonomous independent existence okay so naju never says something doesn’t exist It says it it it it only exists depending of something else. Okay. And then this leaves a strange uh circularity, right? Because if something depend on something else where you hang on. Okay. And this is the key point I this the first key point he says uh and and I think it leads us to thinking that there’s nothing wrong with the circularity. Um he talks about like everybody he talks about um the apparent world and the ultimate world. Okay. The apparent reality, the ultimate reality and the apparent reality is no. This is a book. It’s white hole blah blah blah because of I read it this way the way what is the ultimate reality. Well, there isn’t. That’s the point. There’s no ultimate reality. But then he call emptiness this quality this property if you want of things of not of of not existing if not independence of something else. But then the point where the book really got me is uh toward the end there’s a chapter in which in the slogan can be introduced to the emptiness of uh emptiness uh emptiness is empty. So he warns the reader very clearly that if you take this story as the ultimate description of reality, you’re making the same mistake as if you take something as the ultimate description of reality. Right. So there’s no ultimate description of reality and this is um again this is a spectacular idea. It resonate with the best of Vietkashan in my in my opinion. The answer to some questions is that the question is just wrong. Um asking what is the ultimate structure of reality? It’s a confusion is our language that tricks us or our mind or whatever that tricks in that. So uh the self the mind is not the ultimate part of reality. Matter is not the ultimate part of reality. Information is not the ultimate aspect of reality. Computation is not the ultimate aspect of reality. Um uh perceptions, phenomenology is not everything is not wherever you we can organize reality in structures of course and put something at the bottom of each structure. But then there’s always a blind spot that bottom which you sometimes very easily understand that in terms of something else. So you’re in these circles. But the circles is the best we can say about the world. And is this because uh oh there is an unknown mysterious reality alanton which is unaccessible. No there’s a better way of thinking about that. It’s because it doesn’t mean anything to ask what is ultimate reality. That’s what I what’s fascinated me in the garden. It strikes me, Carlo, that the emptiness of emptiness is a beautiful description of a pre big bang universe. We don’t know anything about the pre- Big bang. I think, you know, this is another thing we we’re afraid of saying, I don’t know. I mean, both personally and uh and and culturally and and as a knowledge, so many things are so easy, right? What happened before the big bang? But we don’t know. Okay, maybe nothing, maybe something, maybe a bounce. We can study it. It’s not that we we know that we cannot know. We don’t know if we will know or don’t know. Um for specifically about the big bang, there is in loop quantum gravity a lot of calculations that suggest um there was something. So we can tell a story of the other side of the big bang. Um but this is science and the scientific way of trying to get better understanding you you make you make hypothesis but then you have to test them. So my my my my work in science is not just to make hypothesis about quantum gravity and from quantum gravity how the world could be but also try to find ways to test them. In a Gargna’s framework within this emptiness, you need a relationality. Um, you need an observer. Uh, but the self, a soul, we might say, uh, he thinks about that in a really different way than, um, modern scientists usually do. A codified self. I have a sense of self. What I did yesterday, what I’m doing tomorrow. Um so within your framework of relationality that’s very much inspired by um Nagarjuna’s what is the self? Yeah I would I would try to answer um using a terms but also a little bit using charmer terms if you ask what is the ultimate nature of the self. Okay so what is the self in itself? Um I think I I find today a clear answer clear convincing answer answer there isn’t there’s nothing like that. Okay. Uh which again is a comedy. Ern uh used to say there’s no self there’s no I. Okay. Um one could say using bad words it’s an illusion. Okay. Uh and one can tell stories about how this illusion could make up. For instance, um I and let me by I mean my body here in a in a in in a simple sense. Okay, I need to have information about the external and make models of the external to be able to predict what’s going to happen. So I do that for for the bird, for the rain, for the water, and for you. Okay. So I and since we’re social animals, we build strong internal models of other human beings. So I know what I do because I I I see you smiling. I see you sitting. I want to predict what you’re going to do next. I want to interact with you and so on. But then of course I realize that you know in this social interaction there isn’t just you and him and her blah blah. There’s also another guy. It’s me. Okay. So it’s me. It’s me. I mean what is it self is just the self in the most trivial sense. I mean this piece of flesh which is thinking and doing stuff with all its internal. That’s what the self is. Is me. Nothing else. There’s nothing mysterious in that. There are philosophies, there are traditions in which enormous importance is given by this uh uh centrality of the self. I I find them badly misleading for understanding the world. Me is just what happened in my brain. That is a name I give to what happened in my brain which has a remarkable way of thinking about itself and unity for structural reasons because bodies I cannot split my body if I if we were animals which I can split in two and go in different things I would have very different sense of self of course so it’s just a reflection of the unity of my body but also I think a reflection of the need of the enormous amount of activity that is in our brain to have a centralized the system of processing for arbitrating between different needs that come from the body from from outside. So it’s not strange if I had to uh you know um program a computer that needs to go around and do stuff. Uh I I would put a special routine that says here think about yourself and what you’re doing and just focus on one thing so you take the non-contradictory decisions so you will have a self. That’s what the self is. So fundamentally I think the best answer to what is the self is nothing at all. Uh in the apparent reality in the in the in in the part of reality that can be described then we can say plenty of things about our sense of self which I just did how they come socially how they come neurologically. So that’s would be my answer in terms of um the simple problem easy problem the self we can say a lot of things how we develop this idea if we ask a question about the a fundamental entity metaphysically fundamental entity about the self I think we are misguided so Carla what is your theory of consciousness I don’t have a theory of consciousness but I have a number of ideas um that I think could be part of the puzzle not of the hard problem of consciousness of the easy problem of consciousness. Um the first uh remember I’m a physicist. So what I would love it’s a way of connecting the levels the physics with the languages the the description that we have in terms of higher level knowledge. And the first key idea that separates these two worlds uh these two ways we have to describe the world is meaning right it seems that in physics there’s no meaning right things are are there while when we talk about our mental activity our conscious activity things of meaning of in in all possible senses so what is meaning where does meaning come from um there is an idea widespread is that meaning is incompatible with physics cannot come out with physics and I think is wrong because uh there are two remarkable discoveries of science in the last centuries I’m talking about couple of centuries which together um tell us what is meaning um and one is uh the realization that um information is a key tool for talking about reality and that information can be described in pure purely uh physical terms information is correlation. So um if you correlation is when you you know that by looking at one thing you know something about the other and what’s information it’s just correlation so far just okay by by information I mean correlation okay um suppose you have uh two balls and are connected by a chain and you see one ball there and you know the chain is is is short so you know that the other ball is nearby so this ball has information about the other one. Okay? Because they’re correlated. If one is here, the other can only be here and not elsewhere. So the two positions are not independent. Or suppose you have a coin and one side of the coin could be head or how do you say in English? Yeah, tails. Head or tail. And the other side also can be head or tail. So this can be two-way. This can be two way. 2 * 2 makes four. No, it’s not four. Because if one is tail, the other is head. Okay? So one has information about the the other one. If you see on the table, you look at one, you know about the other. So one has information about the other. They’re correlated. Correlation is all over. The world is full of correlations. Okay? The things know about each other in this trivial way, physical way. Okay? But now um we know that uh life can come about um and and and happens and we know the biological systems and biological system are systems even cells systems that have the capacity of reproducing and surviving and because they have the capacity of reproducing and surviving they survive and and there are many of them and that’s Darvin major idea so system have an sort of intrinsic builtin purpose not because uh somebody put purpose into them but is a feature of them such that they allow them to reproduce. So everything that contribute to reproduction or survival it looks like a purpose because it justify know we have eyes to see. Okay. So on so now when you mix put the two things together something magic happens and very beautiful. Namely some information that a biological system some correlation between the biological system and the exterior are just random correlations nothing meaningful. But some information can be meaningful if it contributes to survival and reproduction. Right? For instance, um if I uh I’m walking the mountain, there’s a fall a stone coming down, I see the I I move. Okay. So when I see the stone coming down, in my head there is something correlated to the position of the stone. Okay. Now imagine you take the same situation and you think there’s no correlation. Then I don’t move and I get crushed. So that co that particular correlation is a huge survival value for me. It increases my possibility of survival. That’s what is meaningful. So it’s correlation that has survival and reproductive value. So this is purely physics. You can you can just build a you know balls that bounce and construct systems that reproduce which we think is possible. chemistry that does that and suddenly there’s information which is meaningful. So correlation which is meaningful which is meaningful information relation let’s build meaning okay and I think that this sort of construction step by step um can be allows us to connect the levels and so that nowhere there is magic nowhere there is a gap um the second key ingredient um that seems to differentiate different um level of reality is agency. Right? So we talk about agency, different meaning, different senses, but often we have the idea that agency is something spontaneous that allows us to work in a non in a way that incompatible with the with way with the ways of of physics, right? And I think that’s an illusion because we can make a sense of what is happening when we say that some system is an agent in purely physical terms and I think that what a physicist can contribute to dispel the illusion of some gap in in reality. So one of the things I’ve developed is thermodynamical theories um in which you can account of what happens in a system when we call it an agent and to show that this is uh not only consistent with with the laws of nature but is also uh makes sense um thanks to the law of nature in particular to thermodynamics that that sort of drives the the the the biosphere. To to back up a little bit, um what do you see as the relationship between um agency and instinct? Um if you put your hand on a hot griddle, um you have this embodied response, pain. Um and perhaps you learn as an agent not to do that again. Um when you’re seeing an avalanche coming towards you, uh you run. But how conscious is that decision to run? And how much are you acting as an agent versus how much are you acting on instinct? Do you see the the two concepts as identical? I see a degree a degree of complexity in our own reactions. So um if you if you tell me are you do you want to come to Beijing next year? What happened in me is not the same thing as I touch something a hot what happened in me is a much more complicated thing because this information goes to my memory stored is compared is a complex deliberation process it’s a long deliberation process at the end of which I decide who else but I decide it means a deliberation in me decides and when we when what we do depend on a complicated process happening in us like a deliberation and you spend the night saying should I do that should I not do that should I take this job should I not the night a week should I take this job should I not um that we call deliberation that we call our agency and the subtle confusion here is that people say oh it’s not you to decide because there’s a process happening in you but I am those process so when I when I say I decide I am that process process and all the other processes. So of course I decide I think that there’s a misuse of language is very common people tend to say uh if you understand something then it becomes illusurary which is completely silly right if you understand what happened when you take a decision it doesn’t mean that you’re taking decision illusory it means you understanding what happened when you take a decision if you if we understand what we call free will it doesn’t mean that we don’t have free will if we understand what it is that we call consciousness. It doesn’t mean that consciousness is an illusion. It’s just a name. Okay? When um Copernicus discovered that the earth does not the sun does not move in the sky. Okay? He didn’t show that sunsets are illusions, right? Because sunset is a sun setting. So sun moving down, but the sun isn’t moving down. So is is sunset an illusion? No. Sunset is still sunset. just is not what we thought it was. So I think we use the right word for describing the world. There’s nothing illusion in the world. Consciousness is not an illusion. Uh free will is not an illusion. Agents is not an illusion. But each of these things we can understand them better in terms of other things. And to wrap it up with the beginning, we understand things in terms of other things and not in terms of ultimate things. Carla, you’ve been talking about information as correlation. What about causation and your explanation of agency uh with regards to the second law of thermodynamics? Um this is a topic on which I’ve I’ve worked a lot in recent years um in the following sense. There are a number of phenomena uh which are very important for us which are time oriented very much time oriented. uh agency is one right so we decide the future we don’t decide the past okay we can decide where to have dinner tomorrow we cannot decide where to have dinner yesterday so there’s a profound orientation in agency and also we talk about causes and effect uh meaning that the cause come first in time the effects come later okay uh I can say oh there was a I don’t know there was a earthquake And then the that’s why that house is destroyed. None of us would say uh oh look um that house is destroyed and and that caused the earthquake. Everybody will say no come on that’s silly. So the effect comes after the cause. Um our decision affect the future and not the past. Now where does this kind time orientation come from? uh because uh as I claimed uh there’s no gap in nature and so everything should be consistent with the laws of physics and the laws of physics notoriously uh don’t distinguish the past from the future. So where does it why is is is why there are this orientation in this phenomena. Well, the answer it’s uh it’s uh not immediate. Um but there is an answer and it goes through the general orientation that we saw we see in nature which is described by the second law of thermodynamics the the growth of entropy. Um the laws of the fundamental mechanical quantum mechanical generativistic laws of of physics are um time reversal invariant. They don’t distinguish past from the future. But this does not mean that the solution okay are time reversal invariant. We live in a solution somehow the world is described by a solution of these equations in which the past is different for the future. Okay. And it is different for the future in a very specific way which is this constant growth of entropy. Okay. Entropy. Entropy. So the the state of the universe in the past was very low entropy. We understand that very well. We don’t understand why it was low entropy. But if you just accept the idea that it was low entropy, it follows that entropy glows as things happen. Some phenomena happen in one direction and not in other. It’s easy to break an egg. Um but it is statistically extremely unlikely um for the universe to put back the molecules in the same way that before the egg was broken. Exactly. So statistically it makes sense that things go where there more possibility of being. is very intuitive. It’s very clear. What’s not completely clear is why things were in the past in a special state. But let’s accept that for in the past were in a special state and so therefore you know X breaks they don’t go together. Um but now the once this is given the question is how it comes that given the second law of thermodynamics you know which is simple gas expands things break and don’t go together. Uh it’s very intuitive. How do you go from here to I can decide where to go to dinner tomorrow and not yesterday? Okay. Or how do you go from here to um a cause affects the future and not the past? That’s not direct. Okay? You need a story for that. You need to understand the physics of agency and the physics of causation. And this can be done. I’m not going here in the detail of of equations of formula can be done. Uh there is a story one can tell. So one can show in which precise sense um given an approximate description of reality the second law of thermodynamics implies that um position goes in one direction or the other. However, in doing that, um something subtle uh comes out which is that we need to fold into the story um our own time orientation. Okay. And that’s a beautiful part of this uh of this. I wish I had more time to describe it a little bit more in detail. Namely, it is true that we live in a time oriented world. in a world where uh eggs break and and uh glasses break if they fall down and vice versa. But it’s also true that we are time oriented things. Uh all biological things are dramatically time oriented. Uh not for a strange reason just because we are born on the surface of the earth which is near this burning star which so we get all this um high energy photons from the from the um from the sun and then we radiate but the the the energy we get is much more low entropy than the radiation that we give out. So we we live in this flu of entropy. We are entropy creators. Um living being is an entropy creator is a burning of stuff. A candle is an entropy creator. So the biosphere is time oriented. It’s time oriented by by its very nature. Okay. The the the metabolism is raising entropy. So it’s is a and so are we. And our thinking is time oriented. We cannot think backward in time. Okay. Why? Because we are a process which is time oriented. Our when we think when you think hard your head become hot and this is basic physics because you’re raising entropy. It’s just like like friction there’s the same thing transforming free energy into okay. So since our head is an entropy raising thing, our thoughts are time oriented and because of that we read a lot of time orientation in the world. So the time orientation of a lot of phenomena high level phenomena like causation like agency is double. It’s because the world itself is oriented and also because ourself are oriented and that’s created a lot of confusion about the nature of time because people usually don’t see this double source of time orientation and for instance people say um imagine that in the future in the distant future the the universe termalizes. So now you’re at maximum entropy. Everything is uh uh is in equilibrium. So no phenomenon would distinguish the past from the future. Okay? And people say, “Yeah, but if I was there, I could still feel the time passing.” Okay? So therefore, time exists even at equilibrium. Where is the mistake? The mistake is that if you were there and you’re thinking that you were thinking there, you’re still thinking that there is a raise of entropy in your brain. If you were there and you also were in equilibrium, you couldn’t think, you couldn’t record anything, you couldn’t have thought, you couldn’t exist, the neurons wouldn’t be firing. So there would be no time at all, not only in the phenomena, but also in your thinking because you would not be thinking. So um the the beauty of this story in my opinion is that careful complete analysis of what is going on shows that uh if you want to understand complex phenomena you have to regard them in their physical basic description. But also keeping into account that we use some way of describing them that depends on ourself. Not ourself as metaphysical non non non-physical beings but ourself as being in the world um like any other thing. So we are burning candles like the rest of the biosphere the rest like the sun. So um this you know this beautiful Chinese philosophy which is daoism um with this foundational book is swansi swansi in which uh it’s all about this uh uh similarity of all things. We are part of nature. We are not something outside nature and we understand things why not by trying to understand how why we’re different from nature. imagine that there is some deep fundamental gap just part of the flow. Thank you very much Carlo for this wonderful conversation. Thank you Cliff.