# 2025-11-06 - Philosophy For Our Times - In Search of Nothing [Apple Podcasts](https://podcasts.apple.com/us/podcast/in-search-of-nothing-david-deutsch-amanda-gefter-lee-smolin/id1151965239?i=1000735543705) Duration: 01:00:18 ## Transcript ### Amanda Gefter 00:00:00 - 00:00:19 What I've come to believe in a sense is the opposite of the suggestion that's in your question, that maybe nothing is the only possibility. And because of that, it's the appearance of something that is inevitable. ### Avi and Ali 00:00:19 - 00:01:29 Hello and welcome to Philosophy for Our Times, bringing you the world's leading thinkers on today's biggest ideas. I'm Avi. And I'm Ali. And today we have In Search of Nothing, an exploration of the philosophical and scientific idea of nothingness. On the panel, David Deutsch, a theoretical physicist known as the founding father of quantum computing. Lee Smolin, a theoretical physicist. And finally, Amanda Gefter, a renowned science writer specializing in fundamental physics, cognitive science and philosophy. While this sounds very sciencey, it's actually really delving into the philosophy of nothing, which is a fascinating topic. So without any further ado, we're going to hand over to the host, Matt O'Dowd. ### Matt O'Dowd 00:01:29 - 00:03:59 Hello, my name is Matt O'Dowd and you've tuned into the Institute of Art and Ideas debate In Search of Nothing. At first sight, the idea of nothing appears as a straightforward concept, being simply the absence of anything. However, for centuries, philosophers and scientists have grappled with this unexpectedly perplexing idea. Nothing is an absence so absolute that even defining it becomes problematic. We might imagine nothing as the void, the empty vacuum of space. But to be true nothingness, our possible candidate would need to lack time, space, matter, energy and relation to the rest of the universe. Meanwhile in philosophy, from Hegel to Sartre, many have placed nothing at the center of their philosophical accounts of the world. Do so in part by maintaining the picture of nothing as an unfathomable mystery. So should we conclude that nothing is an impossibility and if so, that something is inevitable? Can the paradoxes surrounding nothing be written off as a logical mistake as Bertrand Russell maintained or can we uncover the true nature of nothing and with it, other mysteries of the universe as well? So today we have three eminent scholars who have thought long and deeply about nothing. Let me rephrase that. They've thought long and deeply about a great many things and one of those things is the concept of nothing and so today to help us understand nothing we have David Deutsch, a pioneering theoretical physicist best known as the founding father of quantum computation and as a key figure and advocate for the many worlds interpretation of quantum mechanics. We have Amanda Gefter, a celebrated science writer specializing in fundamental physics, cosmology, cognitive science and philosophy. She is also the author of Trespassing on Einstein's Lawn, the story of her quest with her father to figure out the nature of ultimate reality and finally Lee Smolin, a renowned theoretical physicist known for his work on loop quantum gravity and more broadly in the philosophy of physics. He challenges mainstream ideas in physics such as the idea that time is an illusion and that the laws of physics are fixed. So let's get started with our opening question. Is nothing an impossibility and if so is something inevitable? David we'll start with you then go to Amanda and Lee. ### David Deutsch 00:03:59 - 00:07:41 Okay, well I think it's important not to lapse into essentialism here trying to extract the essence of things like you know Plato and that kind of person because that leads to thinking that this is a non-issue that anyone who tries to ask what nothing is is just talking nonsense and but it does come up in terms of real problems. So for example 13.8 billion years ago time began at the big bang and is that a paradox? Well if something began then it can't have existed at an earlier time and if time began there were no earlier times whatever brought about the transition from time not existing to existing must have happened before time existed which seems like a contradiction but it could make sense. For example it could be that there was no moment of the big bang just moments after it just like there's no smallest positive fraction and thus there would be no moment before which the universe did not yet exist. So that would make sense. Is it true? I don't know but here's a case where we're really talking about nothing. Suppose you're standing at the North Pole and you ask what is north of here? You've been trudging all the way there you can get more and more north is it possible to get more north than the North Pole? Is there a barrier there preventing you from going further or is it just that all directions are south and we'll just call one of them north arbitrarily? That is a question of terminology but a very similar question about the universe is not a matter of terminology. That is suppose that the universe were a torus so that if you went far enough in that direction you'd come back from that direction then is that the same as there being an infinite number of universes all identical and you go from one to the other. Is identifying two sides which you can go through the same thing as having an infinite number? Well there I don't think it's just a matter of terminology I think there's a real question there and it shows you that there has to be a broader theory of what the universe is and what space is that would tell you whether the real thing is just an infinitely repeated finite segment of space or whether it is just one of them identified. So I would say don't get sucked into the nihilist position that the problem is not a problem. Usually a problem is a problem and unless people are mischievously citing just words which some philosophers do then the problem has to be addressed. Let's hope we can at least define our terms better if not solve the problem today. ### Matt O'Dowd 00:07:42 - 00:07:52 Thank you David. So Amanda would you like to address the pitch? Is nothing an impossibility and if so is something inevitable? ### Amanda Gefter 00:07:53 - 00:10:29 This question of what is nothing is extremely close to my heart. It's actually the singular question that has driven my entire career. It's what got me interested in physics in the first place. It's how I ended up as a journalist and I mean it's truly shaped my life. I've spent the last 30 years thinking about nothing and that's because when I was 15 years old my father who is this sort of Zen guru, former hippie turned radiologist took me out to dinner at our favorite Chinese restaurant and asked me how would you define nothing. This question was like this spark that set off this crazy journey that led us deep into cutting edge physics. It led us to crash a physics conference in 2002 that was being held in honor of the great physicist John Wheeler. Wheeler was about where I met Lee Smolin for the first time and Wheeler was this brilliant physicist who had these very radical ideas about the nature of reality and my dad and I showed up posing as journalists and I said I was from Manhattan magazine which you know didn't exist and we met Wheeler at this meeting and we asked him several questions but one of them was is everything from nothing and Wheeler nodded and said I like to say the boundary of a boundary is zero. So it was like Yoda answering a physics question and we had no idea what it meant and um so for the next few decades well for one thing my fake journalism career sort of morphed into a real journalism career and but more importantly I kept chasing this question about nothing and what I've come to believe you know after reading through all of Wheeler's personal journals trying to get it like what did what was he really trying to say what did he think about nothing after speaking to so many amazing physicists and like immersing myself in today's cutting-edge physics and cosmology what I've come to believe in a sense is the opposite of the suggestion that's in your question that maybe nothing is the only possibility and because of that it's the appearance of something that is inevitable. ### Matt O'Dowd 00:10:29 - 00:10:35 So now we should move on to Lee. Lee? ### Lee Smolin 00:10:37 - 00:13:13 I've built several theories of physics, incomplete but some that get us some insight into what the world might be and none of them had a concept of nothing or required a concept of nothing. I think that you're wrong-headed to start at the beginning with that question because I think the question we should start with is time and if you get the meaning of time the construction of the world in time correctly I'll say what I mean by that in a minute you don't have to ever encounter the idea of nothing in a physics concept and I'm going to talk about my Zen Buddhist friends and so forth who are justly on their own path. So I believe that all that exists, first of all nothing exists, things only happen, and things that happen do so according to some rules which are developed in time and change in time so there's nothing that we call time which is real which is really what a Platonist would call time that is I don't believe there's any thing that is stationary and unchanging I think everything changes and our job as physicists is to find out what are the rules under which things might change and if you go about that seems to me correctly you don't have to encounter the idea of nothing so that's where I would start I don't want to go on and on with that but that's where I would start with the notion of time and if you like with time being the distinction between something unchanging and something changing and when we have something which changes we want it to change according to some rules or some happenings and then we're talking about changes of changes and that's what I think is interesting and I think Johnny Wheeler thought that way and he was very confusing certainly but I think that what he was searching for was an understanding of how change could change. Thank you. ### Matt O'Dowd 00:13:13 - 00:13:52 Wonderful. I really hope we can pick apart some of the potential conflicts here but for now we're going to move into what we're calling theme one where we build our definitions and make sure we're speaking in the same language and so theme one is what is nothing which we can expand on our earlier statements and I again want to start with David. David I invite you to expand and to even address the positions of your fellow speakers if you so wish. ### David Deutsch 00:13:52 - 00:15:42 Yeah I too don't think that what is questions are a good place to start because you only find out what something is when you have a theory of it. What is a dog? Well the only people that can really answer that question are zoologists or veterinarians who deal with dogs and they can answer such questions. So coming to what Lee was saying okay I don't mind things just happening and not primarily existing so things happen if they happen they happen according to rules I'm with you that far the rules can change I'm with you that far but I would draw the line at well the question is do the rules which change according to a rule and if that cannot change so then that's the only thing that can't change this rule that can't change or if everything can change then it's not true that everything that changes changes according to a rule. Right and that's a that's a paradox and I wrote a book with Roberto Mangabeira Unger who is a rather a very deep philosopher he thinks about many things and I certainly admire him and he that's a paradox according to him we've walked into it it's a paradox and he would argue that bringing oneself into a deep paradox is progress and that's that's what you've accomplished. And out we won't be able to come out of a deep paradox as well. Well that's that's what we can call it progress seriously that's that's how he thinks. ### Matt O'Dowd 00:15:43 - 00:15:50 Amanda do you have any comments on the pictures or things to expand on right now? ### Amanda Gefter 00:15:51 - 00:17:27 Sure I mean I guess in terms of just defining nothing I mean one of the things that that my dad and I talked about back in that conversation in the Chinese restaurant was you know is it seems like a lot of the problems that we run into at least semantically with nothing is you know it's defined as a negative right and so then you know if you say nothing is no thing it's the absence of everything and then you ask you know how does something come from nothing you've sort of set yourself up to fail and I think it was William James said something like you know from nothing to being there's no logical bridge like you've just sort of set it up logically so that it's impossible and so the thing that you know my my dad was interested in that started that whole conversation was is there a way to define nothing in the positive like if you could just describe its features like what is nothing I mean it sounds paradoxical to say features but he said well what if you had a state of infinite boundless sameness I mean that would really be indistinguishable from a void right and so that would be the sort of like the unchangingness against which any kind of change could happen and so I think you know still to this day I find that like a useful way to think about nothing as kind of this completely invariant unchanging sameness and then anything that we want to say about the universe and what we observe can be sort of set against that. ### Matt O'Dowd 00:17:28 - 00:18:00 Right and you know I think when physicists talk about nothing they mean something a little bit different often to the philosopher which rather than just being the absence of anything physicists often use what to them is a more useful term the idea of the vacuum the idea of empty space but such a nothing is a pretty active place is there anyone who would care to elaborate on the physicist nothing versus the philosopher's nothing? ### Lee Smolin 00:18:02 - 00:20:02 Well you can go cheap and talk about the vacuum by which we physicists mean the quantum state which is lowest in energy and if you get there are questions about how does the vacuum get chosen and why this vacuum not the other vacuum and if you go in that further you go into what Roberto and I call the meta-law dilemma and that is a paradox there is a paradox of the meta-law dilemma and I think we have to face it because well one place to start is Peirce who is a great philosopher as you know first said that if we want to understand nature we have to understand evolution and we have to understand the kind of natural selection of laws of physics and then and then we're in the paradox that David pointed out and I think we are and I don't know the way out of it and certainly I have a different instinct perhaps than David I think that it's real progress to have arrived at that and arrives at a place in physics where we can talk about a version of the meta-law dilemma counts in what the laws of physics might how they might be chosen because it's not even not giving up here saying in biology we don't give up when we state the meta-law dilemma we say that but we need to make more progress still is to understand why the laws of nature would change as we see them do and I think that's just where we are. ### Matt O'Dowd 00:20:03 - 00:20:49 So this idea of the vacuum as a thing on which the laws of nature are operating and in the case of our universe that means quantum mechanics which means fluctuations due to the uncertainty principle and particles appearing and disappearing from which much presumably can happen that this isn't quite nothing this is a first of all you do have space and time and you do have the laws of physics and the laws of physics themselves if thought of as something that needs to be explained and where do the laws of physics even if they do evolve afterwards as your cosmological natural selection suggests how do laws of physics spring from nothing? Maybe David you have ideas? ### David Deutsch 00:20:49 - 00:23:54 Yeah I think that quantum field theory and so on make this problem of nothing easier much easier philosophically it's a much more severe problem to think about the vacuum as it appeared in classical physics and I think that I'm very sympathetic to Amanda's idea of sameness because and you mentioned explanation a moment ago which I think is a key that opens many philosophical problems when something is the same then it doesn't require any more explanation like if there's more of it then if it's just an infinite amount of sameness then it requires no explanation so if you say when the universe came into existence was that something new? Was there novelty there? And that's an interesting question and I think that if you pursue that question you're led to the answer it starts being something when there's something new to be explained if there was just a whole bunch of sameness then that wouldn't need it might need one explanation for why it was the same but after that bits of it wouldn't need any further explanation and I think that this idea that reality is about the distinction between sameness and novelty comes into all sorts of other philosophical issues like for example what is free will? What is consciousness? Consciousness is the ability to create something that needs additional explanation so if I have an AGI or something and it says a thing which doesn't require any more explanation then it hasn't really been a GI but if it says something where you have to say well, he or she is not the same as another instance of that, it needs more explanation, like he is sad but not the same sadness as someone else has that person has a different sadness which we have to distinguish from the earlier sadness from the other person's sadness by an explanation so yeah I'll stop there. ### Matt O'Dowd 00:23:57 - 00:24:13 So Lee of course respond but at one thing I'd like you if at some point so I know that you've talked about the idea of nothingness as that which is outside the universe so if you can also add I'm curious whether that agrees with your the notion of the idea of nothingness sameness. ### Lee Smolin 00:24:14 - 00:25:17 Let me quote I often think about this time and it's by Werner Heisenberg who said that this formulation makes it clear that the uncertainty relation does not refer to the past and I think it's very important to separate the past in the future in order to think about these things clearly. I disagree I don't think that I've thought about the outside of the universe what are the assumptions that I use when I study the cosmology of quantum cosmology is that there is nothing outside the universe and that's further the definition of what a universe is is it's something which has nothing outside of it there's no cause to it that comes from outside of it etc there's no law which comes from outside of it the law must be understood endogenously as coming from the inside. Perhaps this is a helpful definition of nothing if the universe is all that ... ### Matt O'Dowd 00:25:17 - 00:25:40 Is then that which is not the universe is nothing which I know that's a useful move in a discussion about quantum cosmology. But Amanda this seems to conflict with the notion of nothingness I'm not sure it does I ### Amanda Gefter 00:25:44 - 00:28:14 How do I put this I mean I think I thought a lot about Lee's you know he said like the first principle of cosmology must be there's nothing outside the universe and I guess to cut to like the conclusion I think it's almost like if you could see if you could take the sort of God's-eye view from outside of reality I think then what you would see is that sameness you would see the nothing but like by definition you can't be outside of that because if it's true like infinite sameness then you're swallowed up in this in the sameness as well which makes it sort of unobservable which is why I think the appearance of something becomes inevitable. But maybe I'll just say one quick thing which is like you know when we talk about the vacuum something that I find so interesting in physics you know you're talking about the vacuum and these particles appearing and all the activity and everything but one of the really deep results in quantum gravity and I think I first learned this from Lee as well is that the vacuum state is observer dependent so when we look at you know there's things like the Unruh effect and Hawking radiation and whenever you have quantum fields like in a curved space time in a in a universe with gravity which our universe has or a universe of dark energy anything where you end up with a horizon a black hole it becomes impossible to say in any absolute way like what the vacuum is the vacuum for an inertial observer is different from a vacuum for an accelerated observer and there's no it's not like one observer is right another observer is wrong there's just it's not something that's definable in like an absolute way and I think that's a really deep thing that that we've learned from quantum gravity which is I mean if you want to say like oh the vacuum like that's the nothing and that's you know we're going to base our understanding the universe on that you have to ask you know from whose perspective according to who and again that comes back to like you can't take this kind of God's eye view from nowhere you have to be an observer inside the universe that has a particular perspective and then the very notion of a vacuum is going to change depending on which perspective you take ### David Deutsch 00:28:15 - 00:29:45 You've just you've just taken the God's eye view you you've talked about all sorts of different people's perspective and the set of all those perspectives is what you think is the real reality just like with the statue you know the set of all the perspectives all the perspectives that there could be on that statue is all we can say about the statue not that I shouldn't be defining reality in terms of all we can say because there's plenty of morality plenty of reality that we can't say anything about by the way there's also abstract reality we say that a second even prime doesn't exist it doesn't exist anywhere so it exists nowhere where is that nowhere in order to avoid paradoxes like that we have to say that all the numbers exist even the ones that we can't see but the ones that we can define that can't exist they don't exist they're in some other like then we can add them we can say the square root of minus one is a new thing that we shall say exists abstractly so I think we shouldn't leave out abstractions by the way the laws of physics are such an abstraction this is a great time for us to move on to theme two now ### Matt O'Dowd 00:29:45 - 00:30:31 That we're getting to more of our philosophical definition and so I'm going to start by badly misquoting the great philosopher lewis carroll who wrote I see nothing on the road said alice I only wish I had such eyes the king remarked in a fretful tone to be able to see nothing and at such a distance too so an even greater philosopher Bertrand Russell warned about treating nothing as an object of study as being a logical mistake so theme two centers around the question of whether the paradoxes surrounding nothing can be dismissed so handily and I think we all have a lot to say but I'd like to move to lee for your thoughts on that well I think a lot of the simple questions ### Lee Smolin 00:30:31 - 00:31:21 That Russell and similar language philosophers argued for that there when it comes to nothing you're just using a bad grammar when you say nothing is nothing or nothing exists but ultimately you solve the problem by improving your grammar and I think that Russell is right about many questions in philosophy turn out to be decidable by improving your language and I don't particularly like where that leaves us but I think it is a similar rule we haven't applied yet oh I don't know if that helped you I felt it was helpful so David you were talking ### David Deutsch 00:31:21 - 00:33:30 About the paradoxes of nothing and the reality of nothing, what's your thought? I think it's always dangerous to define away a problem. If someone has a problem, if someone is wondering what, like I said, happened before the big bang or what is north of the north pole, that kind of thing, that arises from some kind of real conflict between ideas which were originally proposed for some purpose and which seem to serve that purpose. And so to just throw away that whole situation and say it's only a matter of words, I think, is a mistake. People can say things that are nonsense and are only a matter of words, but it's not always the case. And in particular in regard to nothing, I think behind the apparently nonsensical or the apparently just purely verbal conflicts there are often real conflicts that have real solutions. And I mentioned also that Immanuel Kant was perturbed by things like that, that there can't be a beginning of the universe, because and so on. And in fact, that was just resolved later by a better understanding of continua, so that there can be an infinite sequence of earlier times without the limit of that sequence really existing. Now whether that's how the universe really is, that's a matter for physics. But whether that makes sense, I think it does, and one needs a good theory of how things like that can make sense, which is a matter of mathematics. So we shouldn't just throw away problems. ### Matt O'Dowd 00:33:30 - 00:33:42 David you've left out one entire field which is the philosophers well I don't want to interrupt Lee but I'm curious if you have an idea of whether philosophers have a role to play in helping us define these? ### Lee Smolin 00:33:42 - 00:35:14 Well I think my response is the same as it was before I think there are questions which were just not that interesting when you have a proper language I think if you have a proper language for physics you start with time and with you start with a universe in which the world consists of nothing but events and events happen there is a world before an event and a world after the actual event and they're different and that's a way that you make progress I think that physics must make progress by focusing on what happened rather than what is and sure when you do that sometimes you would make great discoveries but sometimes you just reorient what direction your boat is going in so to speak and go somewhere where there's more where to learn and I certainly would never rule something out as a direction to go in but I would rule things in and I do worry when there is not enough variety in our searches because I don't think we know what the right direction is to go in now. ### Matt O'Dowd 00:35:16 - 00:35:42 Totally agree with that yeah. So Amanda it seems that you don't just think that nothing is a reasonable thing to study but rather an essential thing to study would you like to elaborate on that and on you know the context of nothing that should be studied? Yeah I mean I think one way into it is to ask what is ... ### Amanda Gefter 00:35:42 - 00:38:26 Something right like what are we what's the other side of that coin that we're trying to talk about and I think one definition that I've come to from speaking to physicists is you can think of something being like a real thing like an ultimately real piece of furniture of the real stuff of the universe is that which is invariant in every reference frame. So if you have something that like from some perspective doesn't exist then you know think of like a mirage or a rainbow or something you know that's not like you know it's not imaginary but it's not like the real real stuff of the universe and you know you can go back to Einstein you know taking space and time which were thought to be these absolute you know the absolute scaffolding of the universe and then he said well wait actually space and time are relative to your perspective and it's this combined four-dimensional space time that's like the invariant thing and so the idea was well if you can find these invariants the things that aren't observer dependent then you have the something and then that's what you have to account for coming from the nothing right and so what I think has been really fascinating is if you look at sort of the progress of physics from Einstein forward one by one these things that seemed in classical physics to be absolute invariant you know perspective independent things have turned out to be observer dependent have turned out to somehow depend on your perspective and that progression and this was something that Wheeler thought a lot about seems to open up the possibility that eventually what you're going to find is that the only real thing is nothing and so I mean so that's a way in that's not purely philosophical you can say let's look at these things and say what is actually invariant what is not and you know so like the vacuum I was saying earlier seems like something that should be invariant but it's not you know space time when you get into like the holographic principle it seems not invariant in the way that Einstein thought so yeah. May I finally disagree? Please. ### Lee Smolin 00:38:26 - 00:41:06 What we've learned is that there are no absolute frames of reference to this. There are no Lorentz frames. There is no geometry of Lorentz frames and when we look for those things we find we have to throw them away and just go back to the only observables are in the universe and then you're only as I agree invariant under certain operations but then we find when we try to discover those invariants we find that there is, as you say, nothing there is no invariant of string theory that can stand in the place of you know search for nothing and the holographic principle I think is a near miss and there's some truth in it but I think it really doesn't work in the end and general relativity where you face a theorem there's no Killing field on the space of solutions of general relativity and Killing fields are connected to symmetries and the statement that there are no symmetries in the solution space of general relativity is very important it tells us there are no such things as we're looking for um to guide our way and I think it's a very important thing to learn and I think that theorem that there are no Killing fields on the space of solutions for a closed universe is it shuts down a whole thing that many friends of mine and yours and so forth try to construct and then end up failing to construct and let's remember that the holographic principle although it's not nice to talk against it only works for systems which have negative cosmological constant and negative vacuum energy and we know from observation that our universe is not one of those so again though there is this appearance of triumph actually that's that whole direction of thinking leading to what people call AdS/CFT is actually failed if you would just look at it exactly. So look Amanda I'm so compelled by the very loose idea ### Matt O'Dowd 00:41:06 - 00:42:02 That that you started to present but you did mention John Wheeler a couple of times and you know I guess alluding in part to his participatory universe in which he described reality as a self-exciting circuit that can you know bootstrap itself from nothing I guess in a sense. So I'm curious about your view is this also your sense of how reality can come from nothing and also if such a thing can come from nothing why couldn't there just have been straight up nothing at all why necessarily have a universe of some things that emerges from you know this I guess cooperation of agents. Yeah so I mean Wheeler I certainly can't do justice to his ideas ### Amanda Gefter 00:42:02 - 00:45:06 In a quick summary but he you know he went through these different stages in his career of trying to build the universe out of different material essentially and so early on he said you know everything is particles then that didn't work out because particles are not observer independent enough they're not invariant enough then he tried everything is space time he wanted to sort of use the topology of space time to kind of bootstrap you know charge and mass and all of these things and eventually he thought space time can't be the fundamental ingredient like that's that that's not solid enough and then he came to everything is information which you know had a huge impact on the field of quantum information theory but in his journals what he kept agonizing over is whose information is my information the same as your information that can't be guaranteed what happens when we disagree how do we piece that together into a shared universe and so yeah he came to this idea that the universe he believed is participatory in a fundamental way but he, you know, that wasn't fully resolved these questions about whose information how do we piece together my information your information but he had this quote in his journals where he said this is very Wheeler phrasing there is many a game we cannot play until we draw with chalk a line across the empty courtyard it doesn't matter where we draw it but only that we draw it and so right this is the idea you can think of the empty courtyard as nothing the little line creates a boundary that creates something and what it creates is something you can call observer something you can call observed and now you can define everything relative to everything else but the whole mystery there which is sort of what you're asking is like is the drawing of the line right is that chalk line I mean it's not meant to be something deeply real because you know it's chalk it can be erased it can be moved but yet everything that we see seems to depend upon it in some way and so you know I think the idea that he was groping toward was somehow everything seems to be defined relative to observers to observers asking a question right it's participatory it's not passive the observer asks the question the universe answers and yet if you sort of take that line away you're back to the nothing so I yeah in brief I think that was his thought ### Matt O'Dowd 00:45:07 - 00:45:27 It's a beautiful image and it is you know the idea that the universe is information but whose uh makes me think david of your work um in quantum information I'm curious whether your notions of information are similar to Amanda's and John Wheeler's uh like you can say more ### David Deutsch 00:45:27 - 00:49:28 No, they're not the same. So John Wheeler was thinking of classical information in his attempt to understand. He understood that ultimately it has to be quantum, but all his attempts to, how can I put this, 80 percent of Wheeler's agonizing was about trying to construct a single world in which Everett's multiple universes were not the true description of reality and he got this compulsion from his, what do you call it, mentor Niels Bohr, who was a brilliant innovative thinker who contributed to the foundations of quantum theory when other people were still trying to hark back to classical physics. But he had a supernatural streak, a streak of sympathy for the supernatural and for obscurantism, which apparently infected all his mentees including Wheeler and including Heisenberg. See, you mentioned something earlier, or Lee mentioned Heisenberg. I've forgotten what it was, but whatever it was, it was because of Bohr. And so Bohr then attached himself to the stream of bad philosophy that was happening anyway in the 20th century and gave it the apparent imprimatur of fundamental physics and that whole thing was a mistake. The whole participatory universe and it-from-bit universe, information and observer-participator, and the lines across the courtyard, those are all copes for not wanting to accept Everett's quantum theory. Fortunately the remaining 20 percent of Wheeler's musings were incredibly fruitful. So, yes, information in the universe is fundamental. Information making the universe, information being the thing that makes the universe or is somehow outside the universe or before the universe or logically prior to the universe, that's wrong. That's just all this supernatural stuff. It's very important that the physical universe is such that information can exist in it, that is, information can be physically instantiated in it, never perfectly, and it's never the ultimate structure. We have computers that have got terabytes of information in them, but the physical structure is still silicon, and it was silicon even when our computers had only a few k of memory. Well, actually even before that it was probably vacuum tubes. So there you had some kind of nothing that was bearing information. So in a serious sense, when we're talking about what the substrate is, whether the physical is the substrate to information or information is the thing from which the physical emerges, either way, both of them are not nothing. There's something first, and ... ### Matt O'Dowd 00:49:29 - 00:49:54 Uh so I want to move to theme three now in which we try to think about whether thinking about nothing helps with this biggest question of the bottom layer of the universe and so on so I'll articulate it will the possibility of nothing help us understand the mysteries of the universe or should we look to the universe to tell us what nothing is and perhaps we can move to Lee now. ### Lee Smolin 00:49:54 - 00:51:07 Well, I just wanted to insert into the last discussion that I had the privilege once of being in a meeting with John Wheeler and Carlo Rovelli this is years and years ago and Carlo got John perfectly excited enormously excited by reading to him from his books of Heidegger and John had never heard of Heidegger before this but he certainly took off on what he understood Heidegger to be meaning and that's that's I would agree with you 99 percent I'd agree with you David but I should say that I have a one percent that wonders whether there is something in the in the European style of philosophy that there is something for us to learn there we shouldn't rule anything out one shouldn't rule anything out so I agree you know I keep the one percent it might be useful even if it's false. ### Matt O'Dowd 00:51:07 - 00:51:13 Lee, could you elaborate on what particular European style of philosophy or Heidegger's statement? ### Lee Smolin 00:51:13 - 00:54:35 Um, it's been it's been very hard for me to understand I am better telling stories about my failures to understand it like um I had a very good friend um who was a feminist philosopher in New York Drusilla Cornell and she um she read my first really philosophical book the book that became a joint book with Roberto Unger and she said there's somebody in our community who says the same things you say and it was Roberto Unger and as a result I met Roberto and we wrote this joint book together which consists of a just a kind of exploration of our disagreements which turned out to be an interesting thing to do I don't know if anybody reads it that way but that's the way you should read it um I'm caught between um between wonder at trying to understand time in the sense of a creation of the world a continuous creation of the world I wrote my first book I and I began with a introduction in which I um in which I quoted from Leibniz and I quoted from Leibniz this beautiful passage in which he says basically that the scientist trying to understand the world in all this in all this enormous variety is just like somebody in a city trying to understand the city that they live in terms of the enormous variety of ways that you can be a deserve and be what um what Amanda was calling who is observer who's observer and Leibniz was celebrating the variety of observers in a city as a metaphor for what there may be in the world and I think that there's an enormous there's something enormous enormously celebratory about the idea that the world is infinite variety has infinite capacity to teach us and surprise us and I think that's that's very promising especially at the moment but it may be that our you know friends Galileo and so forth Kepler all these figures are tremendously paradoxical if you read if you really read into them because they are both celebrants of variety and explorers of a world with simple laws ### Matt O'Dowd 00:54:38 - 00:54:58 Amanda nothing is central it seems to um the way that you talked about the universe and physics can nothing tell us about the universe or can the universe tell us about nothing and how do we study nothing at all? ### Amanda Gefter 00:54:58 - 00:57:43 I honestly think it can go both ways. Um, I think getting like a good grip on what nothing is can help us understand the universe but I also think things in the universe can help us understand nothing I mean an example that comes to mind um I remember having a conversation with Alan Guth the cosmologist about um conserved quantities in nature right so one of the really fundamental things in physics is to look at um at what's conserved the conservation laws is like very that's sort of the architecture of things and um and what Guth was pointing out is first there were a lot of things in physics that people thought were conserved for a long time like things like baryon number of people thought were conserved and then it turned out they're not conserved um but if you look at the things that are so like electric charge is conserved energy is conserved angular momentum is conserved and then so imagine you know you have a ton of angular momentum in the universe or a ton of charge or a ton of energy if that's really conserved then that had to have been there from the very beginning and that can't come out of nothing so that impacts our understanding of like what are we trying to get out of nothing and how do you do it and what Guth pointed out was actually when you add up all take angular momentum you know the galaxies are spinning in different directions you add all of it up it all cancels out to zero electric charge the universe seems to be electrically neutral it all adds up to zero energy there seems like there's all this energy mass in the universe but you know he gave this whole explanation of how gravity actually has like a negative uh contribution to that and so it all perfectly balances out to zero and so all of the conserved quantities turn out to the value is zero. That didn't have to be a fact that's like an empirical thing the universe is telling us um and so I said to Guth well so are you saying as long as everything all these conserved values are zero that means we can get something from nothing and he said maybe a better way of saying it is that something is nothing um and I think like when Wheeler said that very cryptic thing to me about the boundary of a boundary is zero I think he was trying to get at something very similar that like when you look at the gauge theories and physics you know all the forces in physics he believed seemed to suggest like that they're trying to conserve nothing um And so I think you can go both ways I think you can look at facts in the universe and say well wait a minute maybe in some sense everything is nothing I think you can start with the nothing and try to tell the story from there and I think it's helpful to like sort of bounce between the two. ### Matt O'Dowd 00:57:44 - 00:58:05 Wonderful, plus something minus something equals nothing got it. David it's to you to bring us home today if you can a minute or two respond or give your last words on the matter. ### David Deutsch 00:58:05 - 00:59:24 Yeah, well as I said uh there's this ancient mistake of trying to find the bedrock on which everything can be built and from which everything can be understood and I agree with as always as usual with uh Karl Popper who said that that that's not where thinking should begin we should always start with the problem and the problem is never what the foundation is because then there would still be the problem of why that foundation and not another foundation and what does it really mean and so on and that leads nowhere or to nothing um so we need we have to start with the problem and what we're looking for when we're trying to solve a problem is again not the final answer it is an explanation that tells us why the conflicts that we thought that we saw aren't really there why some of the ideas that we thought were incontrovertible are not incontrovertible and what can replace them not because they are the final answer but because they are a better answer than the one we had before and that's all we can ever do but that is a good thing because that is the doorway the open window to an infinite progress. ### Matt O'Dowd 00:59:24 - 00:59:39 And I think on that note, now that we have hope for infinite progress, I'm going to call the official part of the debate here. Thank you all. Thank you for listening to Philosophy for Our Times. ### Avi and Ali 00:59:39 - 01:00:18 This episode and don't say nothing shout out to Eric, Manny and Matt who reached out over the last couple of weeks about our Kehinde Andrews and Adam Phillips episodes your feedback was much appreciated and if you want more talks videos and articles from the world's leading thinkers don't hesitate to go to iai.tv for thousands more talks we'll be back next week with more groundbreaking philosophy so see you then bye bye