I'm nervous. I actually have a cute story to tell. We've only been married for 20 plus years, so it takes a while to get comfortable. You have a story? I have a cute, violent story that you might want to hear. Let's hear it. Okay, well, I was driving the kids to school this morning. I was feeling nervous about doing this, and I said to Violet, I'm nervous about my interview with Daddy today. I said, do you have any advice?
And she said, well, I don't know what you do in interviews. How could I give you advice for an interview? And I said, yeah, but you know me. Like, could you give me advice, you know, because I feel nervous. And she said, well, don't cry. I'll try not to cry.
Well, feel free to cry. Okay. Well, you have an amazing audiobook series. It's really, it's an audio documentary, but it's being framed as an audiobook. It's available on Audible and elsewhere, which just dropped this week. Normally, we would have recorded this earlier, but I've been sick for 10 days. But now we're free to talk about the contents of what you've done here and
And we're also going to release one of the chapters on the podcast and on waking up.
It's about 11 hours of content for the whole series? Mm-hmm. And you did how many interviews of scientists for this? How many hours of interviews? I did about 35, but I believe 15 made it into the documentary. Right. I could be wrong about those numbers, but about 35 and 15. So you had something like 60 or 70 hours of content? Yeah, at least more. Yeah. And you spoke to some fascinating people. Who did you speak with?
I talked to physicists like Brian Green and Jan Eleven and Adam Frank, Sean Carroll, and then I spoke to many neuroscientists, Anil Seth and David Eagleman and others. I think the list is actually 18. I spoke to people who specialize in consciousness like Sue Blackmore, Christophe Koch. Yeah, the list was long. And the whole thing is organized around a
single question really, which is what if consciousness is fundamental? Yeah, it is. I mean, it started with a less extreme question. I think the first question I went into it with was really, is it possible that consciousness goes deeper in nature than the sciences have assumed? And kind of how deep does it go? But I became convinced over the course of years of having these conversations that if it does go
go deeper than we have assumed and much deeper than we have assumed, then I have an argument that it has to really go all the way down. And so then, yes, the question became, is consciousness fundamental? So we might want to review the starting point here, which is inevitably the hard problem as David Chalmers described it. We've talked about this before. I've talked about it many times and you cover it in depth in your book, Conscious, and you also start the series.
reviewing it but i just think any conversation here needs at least touch on why it's a difficult intellectual problem to situate consciousness in the order of things yeah it's a problem i didn't get for a long time actually but really what it comes down to is the way in which consciousness and by consciousness i mean in the most fundamental sense the fact that there is
something that it's like the fact that there's any felt experience internal felt experience at all to any system really and the question is you know because consciousness is different from everything else we study in science and that it can never be directly observed from the outside you can communicate a lot about conscious experiences we can talk about them we can talk about how
We think they're generated, but to actually know my experience right now of looking at a brown wood table, there is nowhere else from the universe that that direct experience can be talked about or felt except from the experience itself. And so the question that I finally understood to be mysterious is if the universe is made of non-conscious matter...
and why is it, how really is it, that some non-conscious matter gets configured in a way that suddenly there's this other property of there being something that it's like to be that matter. Which is what we mean by consciousness. Yes. We have that formulation, that something that it's like to be a system or a creature is the explicit framing of the philosopher Thomas Nagel in his famous essay, What Is It Like to Be a Bat?,
Right. And it's interesting because a couple of the, more than a couple of the scientists I spoke with feel about consciousness the way I did for most of my life and most of my career, which is that it seems mysterious now, as life did at some point in our history. And eventually the sciences and neuroscience in particular will understand enough about the workings of the brain that we will, you know, it will no longer seem mysterious once we understand it.
And it's funny, actually, I don't even know if you remember this, but so you were one of the first people to help me actually understand that the hard problem is a hard problem. And we, when we first met, were arguing about it. And I was arguing for the physicalist side. And I said, you know, it seems mysterious that...
That when you flip a switch, a room fills with light, a previously dark room fills with light. But once you understand the physics, it doesn't seem magical in the same way. And so I use that analogy of the lights coming on, which is where this title came from.
Which I don't know if you know or remember. I don't think we even said it, that the title of the series is Lights On. So, yes. So I think I'm a good proponent of this argument because I really came from the other side of it. And so I speak to a lot of physicists in particular who...
Either don't think there really is a hard problem or thinks we'll resolve it soon. But I was surprised at how many of them, in particular Brian Green, seemed to really understand how it could be different from other problems we faced. Well, let me pull out a few points here because I think it could still be unclear why the hard problem is hard. Mm-hmm.
Because the analogies to things like life or to the mind in general make it seem like consciousness must be reducible to what some properties of the physical world are accomplishing, right? Right.
There should be no mystery there. Life is no longer mysterious. But the crucial difference is that intelligence and life and virtually any other thing you can name that science explains can be defined by virtue of its extrinsic properties. But what it does to other things in the universe, its behavior, its covert internal behavior. And
And it's completely explained by the behavior, by the external observations. Yeah, once you explain all the input-output characteristics of life, nothing has been left out except, obviously, consciousness, if you're talking about conscious life. Right. And so it is with the mind. A visual system can function perfectly in a robot, and the only residual mystery, once you've explained everything about its input-output characteristics, is
If there's something that it's like to be that system intrinsically, if there's a visual experience, then you have to confront the mystery of consciousness. So consciousness is intrinsically defined. If there's nothing on the inside, then there's nothing to explain. If there is something on the inside,
It is just a fact that there is the only evidence for its existence is on the inside. It's not on the outside. You can't see a brain do anything which announces that there's something that it's like to be that brain or part of it. And so it will be with a perfectly functioning robot that
Unless we know how consciousness arises or that it does arise based on information processing, we'll have robots that seem conscious to us, but we won't know whether they're conscious. Yeah, this actually points to an example I've been using a lot lately that I think also helps highlight why the hard problem is hard. And also why I think our intuitions have been misleading us about what consciousness is. But, you know, we're so used to it. Yeah.
I mean, it's in some sense, it's everything that we are. We don't know how to know anything or talk about anything that happens out of our conscious awareness. It's all playing out for us in consciousness. And so we kind of, in a sense, we take it for granted and it kind of, we don't think about it too much. It seems, yes, you know, so if you think of something like sight, if I see the color yellow, it seems like, oh yeah, there's this advantageous evolution.
evolutionary system that gets put in place where we understand that there are light waves and there are wavelengths that appear red to us, appear yellow. There's a spectrum of light. We don't perceive the whole spectrum, but there's one that we refer to as yellow because when it hits our retina and gets processed by the brain, an experience, a felt experience of seeing yellow materializes in the universe. This is something that comes into existence is this experience of seeing yellow.
And we know that yellow isn't something that exists out there in the world. It's, you know, it exists as a light wavelength. But in terms of the felt experience of it, and, you know, scientists and everyone else used to think that, yes, yellow does exist out there. We used to think we kind of had this perfect window onto reality. And it turns out that the brain is actually generating this experience of seeing yellow.
And so that kind of all seems natural to us until you realize that cameras and computers also process light waves and can distinguish between different wavelengths of light.
There's a whole category of fascinating plant research that I get into in my documentary also, which talks about how plants process light waves and how their subsequent behavior is based on how they process those light waves. But we can easily imagine that computers and cameras and plants do all of this without, we don't think they're seeing yellow. We don't think they're having an experience from the inside. But for some reason, it seems natural to us that we do.
But the more you kind of interrogate these intuitions we have about what consciousness is doing, what it's there for, what function it serves, and why we think it comes out of complexity,
our reasons for it really do start to fall apart. And I think that's incredibly interesting. And so you realize that you actually, it is completely mysterious why a brain produces an experience of seeing yellow and other systems in the universe that process yellow light waves do not, and whether we're right about that or not.
Right, right. So that's the hard problem. No matter how much you explain about the behavior of a system or its input-output characteristics, there seems to be this remaining mystery as to why it should be like something to be associated with any part of that behavior. And the hard problem is really based on what I think you call...
in the series, a primary assumption. The strong assumption is what I've termed it. The strong assumption. So what is the strong assumption? So the strong assumption is the assumption that the sciences have made and that I include myself in until somewhat recently, that consciousness arises out of some sort of complex processing, namely in brains, probably doesn't exist outside of brains and central nervous systems that those are required.
But that we've kind of come to this assumption because we are conscious creatures and the only evidence we can really get is in the form of communication. And we can only communicate with systems that are similar to us. So, you know, I look at all your behavior, even, you know, the behavior of my cat, and there's enough communicated to me that they are a similar system to myself. You think that I'm at least as conscious as our cat? Yeah.
And so we've made this assumption that because we are the most complex things we know of in the universe, the human brain is the most complex thing we know of in the universe. We do all of these complicated things and we have this high level of intelligence that because we only seem to get evidence from other systems like ourselves that they're conscious, we have no way of communicating with other types of systems. We've assumed that consciousness arises out of complexity.
And we have a lot of assumptions about where we're likely to find it in the universe. And so that is what I call the strong assumption. And that what I discovered was we actually have no good reason to begin with that assumption. And that the science is when we don't know something, and in this case, when we don't know how consciousness arises in the universe, we're actually, when it comes down to it, we're faced with starting with two assumptions. So we have to start with the starting point. We look out at the universe and all these collections of
of atoms and say, okay, which of these systems are conscious or might be conscious? And the simple answer is either all or some. We know the answer isn't none because we at least have direct experience of our own. We know the conscious, I know the conscious experiences I'm having, whatever the cause of them is, whatever kind of crazy situation I'm in, I could be a brain in a vat, who knows what reality is.
But these experiences are arising in the universe. I'm experiencing them directly. Something is happening and it's being experienced. And so the sciences have assumed that only some things in the universe are conscious, which is a totally natural starting place. They're all liquid reasons we have for starting there. I think we've made a ton of progress in neuroscience with that starting assumption. But what I realized is we don't actually have strong evidence for assuming that.
And where might the science lead if we started with the other assumption? It doesn't even make sense how it sounds completely crazy even to me, but sometimes interesting science comes out of ideas that at first sound crazy. And I found more and more evidence in my conversations to support that.
the fact that this is actually a legitimate starting position, at least, you know, to leave as a question mark, but to say, what if we assume consciousness is fundamental? And then how do we analyze the data that we find? And how do we interpret the phenomena we find in, you know, in all of the sciences? And where might that lead us? Or do we hit all kinds of roadblocks and it actually doesn't make sense? Yeah. So then, then you take it in a slightly different direction, um,
where the focus is still on consciousness, but rather than simply hurl yourself at the hard problem, you come at it somewhat more obliquely by asking the question, what are the implications for physics of all this? So could treating consciousness as a fundamental property of the universe help us make progress on any current theories in physics? And sort of the flip side of that or another facet of that is,
do any of the established understandings in physics rule out the possibility that consciousness is fundamental? Right. And I actually expected that I might find answers there in my searching. But yeah, I mean, what became obvious to me pretty quickly when I thought, okay, let's do this, let's do this thought experiment and just start thinking, you know, I was just doing this on my own and then I was doing it in conversation with the scientists and philosophers. But
If consciousness is fundamental, what does that mean? And what implications does that have for everything we understand, everything we don't understand? And I realized almost immediately that this is a question for physics. The science of the fundamental is physics. And that was where I needed to go. And it was pretty early on. It was, I think, the second conversation I had was with Adam Frank. And that led to many more conversations with physicists.
And actually, I should say that I think this line of thinking really needs to be heavily informed by neuroscience. But the question itself, is consciousness fundamental or fundamental property of the universe? It truly is a question for physics. And you spoke to some neuroscientists who have a fairly deep connection to physics, people like Christophe Koch. I think Arnold Seth actually studied physics as well before he became a neuroscientist. That rings a bell. Yeah.
And those conversations are great. Christoph has some mystical experience he likes to talk about, which is fascinating. One of my favorite parts of the series. Yeah. Okay, so let's just
Let's linger on this claim that consciousness might be fundamental. What are the implications of that or what are you visualizing or imagining could be true if consciousness goes all the way down in some sense? Are there different versions of that claim?
What's the picture of reality that you're? Yeah, no, I think there are. And I think if more people get on board with believing that this is a legitimate path forward, I think we're, you know, we're just at the very beginning of what the implications are. And I think this will go in directions that no one can yet imagine, really, which is kind of how science works.
It will be the next paradigm shift, I think. If we become as convinced that consciousness could be fundamental as we are convinced at this point that it emerges, because then that will lead all of the new questions.
Before I answer that, though, I'm aware I've been talking about this so much that I'm aware that I've made my case in many other contexts, but I'm certainly aware of how insane. No, to you I am, but to your audience, this may be the first time they're hearing about this, and I don't want to sound too crazy. And so I just wonder if we should backtrack a little bit or if I should just say that I spend— Meet my crazy wife.
That I spend much of the documentary and have spent much of my work explaining and making an argument for how I have come to the belief that this is a legitimate and important scientific question to ask. And my argument is based in neuroscience. It was working with neuroscientists for 20 years and learning more and more about how the brain works that convinced me that our assumptions about what we think consciousness is, how it's causal, all the rest, actually many of them have already been proven
proven to be illusions of sorts. And so we don't need to get into the details there, but if anyone has read my book, Conscious, there are two questions that I raise in that book that I think are interesting, intuition-shattering questions once you start to look closely at the details of how we try to answer them, because they feel like questions we know we have the answer to and we feel confrontational
confident that our answers are right. And the first question is, can you find evidence of consciousness from outside a system? And we feel the answer is obviously yes. We know when you see it. If I see my friend coming toward me with her arms outstretched, I have a very strong belief that she is conscious and feeling love and excitement. And I think we're very likely right about that.
But the idea that we can always be sure that the behavior of a system or that we could list behavior in a system that is conclusive evidence that consciousness is present. I think one, we're starting to already get confused with the advancements in AI because as you mentioned, there could soon be a system that looks like my friend running toward me with its arms outstretched and we won't know whether there's a conscious experience on the other side of that.
So it turns out the answer to that question, is there conclusive evidence we can find from outside a system? The answer there is, you know, at the very least, maybe, but very likely no. I would say that if your friend has a credit card reader on her face. I could see the joke brewing. Anywhere on her face. If the credit card can be scanned, she's probably not conscious yet.
And the second question is, is consciousness causal? Is it behind many of our behaviors? And this is where a lot of the neuroscience disproves our strong intuitions that consciousness, that our felt experience of certain brain processing is the thing that causes us to then act. And there's now a ton of research. I'm sure you've talked to many neuroscientists on the podcast about binding processes and
Almost every process in the brain actually kind of is a clue that our feeling, our conscious feeling of making a decision is.
of trying to think of another example. - Being the actual authors of our thoughts and actions. - Right, as if there's kind of this conscious lever. - The consciousness initiates the thing that happens. - And the truth is that most processes in the brain that we know about, the conscious experience, at least the one that we can report on, is at the tail end of all of that, and that all of the processing kind of happens.
But doesn't the second point cut the other way? Because if you knew that about the mind, which in fact we do, or it certainly seems to be the case that much of what's going on is going on in the dark, then what is the motivation to imagine that consciousness might go all the way down if it seems like even mental processing is going on in the dark? Well, if consciousness is fundamental, then whatever seems to be in the dark to us
is just other conscious experiences arising that don't enter our stream of memory. And so, yes, there's another way to talk about all of that if we're assuming that consciousness is fundamental, but speaking straight from the neuroscience. So there's a lot of self-contradiction here in the neuroscience in terms of assuming that consciousness is causal and assuming it evolved.
But then all of the research showing that it isn't consciousness actually that is behind all of these things. So there are two ways to talk about it here. Another point I was going to make about that, because I think it's interesting that if, again, if we shift our perspective and we start looking at these things and we ask the question, if consciousness is fundamental, what does it mean that a person seems to be unconscious when they're under anesthesia or when we're in deep sleep?
Or that there are all these unconscious brain processes that go on that we are completely unaware of or seem to be unaware of. You know, what does that mean if consciousness is fundamental? And so I've been thinking a lot about this. And one of the last chapters where I talked to Sarah Walker, the astrophysicist, really focuses on this. She really is willing to go there with me on this idea of, you know, what does it mean to be a human mind and consciousness?
have a self and how much memory comes into play. And so the truth is,
There could be countless conscious experiences happening in my brain and maybe elsewhere in my body that don't enter the stream of memory that I call me, right? And so the split brain research is really interesting to look at here. I think just kind of to break open your creativity to think about other things that might be happening besides if I report on it, if I can feel it and talk about it, that means it's conscious. And if I don't remember it or don't feel it, it means it's not conscious, even
Even a simple example of a pregnant woman, which I thought a lot about when I was pregnant.
Even conjoined twins is another example. Split brain research gives the best, the cleanest examples. But I'll just go back to pregnant woman. We don't know when human babies become conscious, but it's not that hard to imagine that it happens at some point in utero in some late stage. And so babies could be experiencing sound and light and very minimal experiences of consciousness. They would never expect the mother to be feeling, right? It's a separate system.
And so there are many ways we might imagine that there are countless systems within the human brain and the human body that just don't get shared with what I'm calling me. You know, in the case of a split brain patient,
It really seems that you've basically just split these streams of memory that you would call I, that we're always referring to as I. And there's a whole half of the brain that the left hemisphere, which is the speaking hemisphere in a split brain patient who can report about things, will not be aware of or doesn't seem to be aware of and can't answer questions that have been posed to the other hemisphere. And so that, you know, there's already evidence.
that there can be many different streams of consciousness. And I actually think that's probably the wrong way to think about it. I think it's more useful to think about memory and how different experiences get tied through time in the form of memory. Lately, I've been thinking about the fact that, you know, even my own memories of...
A week ago, 10 years ago, each moment is a new moment. And so I have this memory and I have this kind of false sense that I'm this concrete entity that moves through time and kind of touches on all these conscious experiences. But the truth is this new conscious experience is being generated anew now. And it's been affected by previous experiences through memory.
So I have some relationship to, you know, even though I was a completely different person with a very different brain when I was four years old, there's some continuity there. There's some way that this conscious experience in this moment,
is being affected by a conscious experience that happened in that my four-year-old self. And there's a way in which I've been thinking more about how conscious experiences affect one another in time and in space. And so there's a way in which also everything in this room with me, especially you, is affecting my conscious experience right now. So you're having conscious experiences.
And the look on your face or the sounds that you make are in those ways, they shape the conscious experiences that are arising over here. And so conscious experiences kind of affect each other through space in the moment and through time, through memory. Yeah. So, and all of this deconstructs a standard notion of a self, which I guess we can leave aside. That's something that I've spent a lot of time talking about. Yeah. And there's a whole chapter devoted to it. Yeah.
Yeah. And you also talk about the split brain research, which is interesting. Yeah. I should also say just for listeners who want to go deep, I also have chapter notes for every chapter. So on my website, yeah, it's clear when you're listening, but all of this research, people can, yeah, people can go deep if they want to. Although, so your reference to...
A few of these phenomena, split brain, conjoined twins, pregnant mother, invites discussion of what is called in this literature the combination problem. If consciousness goes deeper than most people think, if it goes down to the level of cells or even further still, if there's an interior experiential dimension to everything, including electrons, it
It still leaves it mysterious how any of these parts combine to produce specific, seemingly independent islands of consciousness. So that, you know, there's something that it's like to be some considerable portion of your cerebral cortex functioning properly.
but it doesn't seem like there's something that is like to be your liver, but maybe every cell in your liver has some conscious or proto-conscious quality to it. So why doesn't the liver have an independent point of view on the universe, et cetera? And so how physical structures that are wherein the lights are on in some sense combine the
to create a more hierarchical, more complex point of view that is the result of those structures combining? Yeah. First, I think it's more useful to think of conscious experiences arising and passing away in the universe. And some of those conscious experiences contain much more content than others. I will also say that, you know, I still consider myself to be a physicalist and I actually
I actually haven't even landed on, you know, believing that consciousness is fundamental. All I believe is that it's a legitimate question and I'm interested in exploring the possibility that that's the case. But if consciousness is fundamental, I think the physics and math that we have discovered and developed so far explains the structure of consciousness. And
I'm very curious to know more about what that means. But clearly, there are more complicated structures than others. You've mentioned the liver. I think, you know, the human brain and the types of processing that goes on between neurons, the firing between neurons. I think my liver is probably about as conscious as our cats. Right. I think, yeah, less. So I think just because we see a liver as a single system, you know, and actually the
The truth is, as we were talking about, I don't think the brain is even a single system. I think if consciousness is fundamental, there are maybe hundreds, if not thousands of conscious experiences coming in and out of existence right now that I, my stream of memory, doesn't have access to. And so I'm not calling that me, but they're coming into being in the universe.
So if consciousness is fundamental, I would expect a liver to, you know, in that point in space and time where the liver exists, I would expect there to be an incredibly minimal form of experience and nothing that implies memory. You know, as much as far as we understand memory, there's almost no system that has any sort of hint at memory. I mean, you know, Venus flytrap
shows us a system of memory. And so I would expect a Venus flytrap, even though I don't think that a Venus flytrap feels like a self, if it feels like anything. But wherever there's more memory, there is more chance of an experience of being a self. There's this continuity through time. And so a liver doesn't
show any signs of having that. And so whatever the types of experiences are that get generated by that type of matter, I would expect them to be very, very minimal and very fleeting. And so there's no sense of being a liver because there's actually... It's not thinking, God, this guy really likes margaritas. No more margaritas.
There's a great, fascinating, and sad documentary that is in the notes, I forget which chapter, but of a man, I believe it was a PBS documentary. It was a man who had the shortest memory based on brain damage. Clive something. I forget which episode that was, but it was crazy. And it's so fascinating to hear him talk about his experience. So he, I think his short-term memory is like three seconds long or something. So he's just constant, his experience is...
of just constantly kind of waking up over and over. Just being annihilated, yeah. But he seems to have some, I mean, he seems to have some awareness of this, but he will talk about how much he has been, how long he's been unconscious for. And he sees the way he experiences it is as going in and out of consciousness because he experiences himself waking up even though in the last second he was talking. For him, that goes black. So I think, I think...
I think it takes a lot of intuition shattering for us to get creative enough to think about what conscious experience means without memory, possibly even without time, but certainly to be very unlike a human being, which I actually think is why psychedelics can be so helpful for these types of insights because it makes you, I see another joke brewing.
I was just going to ask, are you on psychedelics now? No, I would not be speaking this well. Sorry, you had a point you wanted to come back to. It was just a question about.
combination problem, but then when you talked about the brain potentially having many islands of conscious experience, which you, the reporting witness who I'm talking to, don't have access to, that sounds really far-fetched on some level until you realize what if there simply is a bottleneck where there's only one system of processing in the brain that
That is what we mean is, in fact, what constitutes memory and reportability. Right. So it's like, you know, in order for there to be many different verbose islands of consciousness, it would need to be memory and reportability and all these other islands. Right. You'd be talking to multiple people.
you know, not selves, but points of view. Yes. But if there were only one in an intact brain, which seems to be the case, I mean, this is what's so unique about the split brain case is that when you divide the corpus callosum and all the other commissures, you have partitioned the brain in such a way that if there is language ability on both sides, which in some cases there is, you can talk to two, effectively two different people.
Yeah. And, you know, or at least communicate with them. Different opinions and different answers to the same question. There are these famous cases that where, you know, the left hemisphere is talking with the mouth and the right hemisphere is spelling something out, an alternate answer out with letter cards. But it just so happens that in most people, language is heavily segregated in one hemisphere, usually the left. And so when each of us introspects,
and tries to take the measure of what could possibly be the totality of consciousness in our own case, all we have is some version of this memory buffer that's allowing us to integrate our perception and sensation and thought and emotion over a narrow time window. Right.
And without that, I mean, just imagine, take the case you just referred to, and just imagine not remembering anything that preceded two seconds ago, right? Like, what a punctate, you know, slice of conscious reality that would be. All that other stuff that happened would be in the dark, right? Like, it is memory that makes this sense of psychological continuity available to us. Yeah, and then reportability and communication. Right, right.
So if we had multiple versions of that, well, then we would have a sense that, okay, there's a congress of selves in here that you can pass the mic around and they can talk. The fact that there's a single common pathway of reportability and short-term memory puts us in a situation where, by definition, it's going to seem like there's only one of it, right? Whatever else is going on. Exactly. Yeah. All right. We figured it out. So where's the Nobel Prize? Yeah.
And you see this, I mean, it's really intuition shaking to see the interviews with split brain patients. I have one that I play in one of the chapters. But to see a question asked of a split brain patient's right hemisphere, which is the non-speaking hemisphere, which apart from these ways that the neuroscientists found to interrogate, you would have no idea these opinions and feelings were there at all. Right.
You know, they ask the participant who answers with his left hemisphere, what did you just see on the screen? And they flashed it to the right hemisphere. So he thinks he didn't see. He'll say, I didn't see anything.
So his conscious experience is nothing was seen. They realize that they can have the right hemisphere answer either by writing with their right hand or by pointing to cards, as you said, and they point to the right object. They saw it. And the fact that's already something we know happens. And so, yeah, the question is, how often is that happening in our own minds? And then throughout the universe, I got
very interested in plant behavior at some point. I still do not have an intuition that plants are conscious, but some of the behaviors that they exhibit are quite complex and actually new things that have just been discovered as early as 2014 about plants' ability to, vision is not the right word because they don't have eyes, but their ability to
perform all kinds of tasks based on detecting light in a way that seems very much like vision. And why we would assume that our experience of vision includes a felt experience, again, of seeing yellow and other processing in nature that in many ways is more complex. They have many more photoreceptors than we do.
Why do we assume that that doesn't require consciousness? And, you know, I don't have the answer, but I think it's very interesting that we don't have an answer for why we need it and plants don't.
And we don't have an answer as to whether conscious experience even arises out of complexity at all. Okay. So how does the possible fundamental nature of consciousness affect physics? Yeah. I mean, I think if enough scientists are willing to move forward with the assumption, not knowing either way, but rather than the assumption that consciousness emerges at any level or at a
complex level, that it's actually part of the fundamental story or is in fact the most fundamental thing. I'm aware that human beings are generally very bad at predicting where new science will take us and what the future will look like. But I did for this series spend a lot of time doing my best to imagine
what scientists might be exploring and the types of things we might be able to discover. And there are kind of three general areas. And so the first is actually connected to work that's already being done, which is called sensory analysis.
and sensory addition. I talked to David Eagleman about this work. And so this started as something called sensory substitution, which were devices to help blind and deaf people. They're devices that they wear that helps them process light waves, you know, in the case of a blind person. And very interesting and very successful work, actually, these tools. The brain learns to use these other signals, electro-tactile signals, usually, that come in through a camera. And the people...
People who are blind are then able to do things like shoot hoops and walk through mazes and incredible things once their brains adapt to this new way of getting visual information. And so the science then naturally led to something called sensory addition, where we realized there are all these things that we don't perceive in the world, one of them being the Earth's magnetic field.
And I talked to a participant in a study where they tried to give participants an experience of feeling magnetic north.
And so I explained the whole study in the series, but essentially these participants were given a new sense. And David Eagleman talks about all of the possible potential for this type of thing. And so one way I imagine is that we already, a lot of our science is done because we perceive. We perceive gravity, we perceive color, we perceive all these things, and we actually have good intuitions for a lot of them.
And so we have to do science to enhance our understanding of these things that we perceive and feel. But it really always begins with a perception of them. We can now understand the microscopic world, but it helps to be able to use a microscope to see the microscopic world. And we gain intuitions when we can actually experience the things. So I think there's incredible potential. And so I call this whole realm experiential sciences.
I think there is potential for learning a lot more about the way the world works by directly experiencing other systems and forces. This actually got me thinking after I spoke with Sarah Walker. She writes in her book about
Einstein's intuition that space-time is space-time, that they're not two separate things, and that actually the fabric of reality is space-time, and gravity is not what we thought it was. It's not a force, but it's this warping of the fabric of reality. It's a warping of space-time, and that explains the things that we see gravity affecting. And it took him
a good decade and longer to really express this initial intuition he had through mathematics, through language. And so
There's something very interesting I learned along the way that communication is so central to this conversation about consciousness because we can't really talk about anything that we don't share an experience of. So in the same way that you can't explain to a blind person what it's like to see, you can give analogies. There's a lot of information you can give.
especially if you share other senses, but there's no way you're ever going to give them the experience of seeing red. There's nothing you can say about it. And so communication relies on a shared felt experience. And actually the man I spoke with, Sasha Fink, who did the study for Magnetic North,
He talked about this kinship he felt with the other participants because they were the only people in the world who had experience, who had this feeling of magnetic north and could talk about what it felt like and share their experiences with each other. So in terms of scientific advancements, I think about, you know, what if Einstein had been able to share the intuition directly?
Because language and mathematics, while extremely useful, can take a very long time, especially if it's something new that no one else has thought of before. Well, the point you're making now actually subsumes this whole conversation on some level because the fact that we're constrained to talk about, think about, try to resolve the contradiction between reality being this two-faced object, the mental and the physical, that on some level could be a...
constraint that's artificially imposed based on our perceptual systems, the way our neurology just sections reality or seems to, and the linguistic concepts we have available to talk about it. We're constrained to talk about the mental and physical and then to try to reconcile them. Unless we find a way to share experience through memory. So I think, as I was talking before about my memories of when I was younger, I have this sense that I have access
to another point in time and space, which is true, but it's more that those points in time and space are informing this moment in time and space. And so the idea is that the same way that I have that information available and that that information is available in this moment,
If Einstein's intuition, that felt experience, whatever created that, if that or at least enough of that could be in my stream of memory so that it's an intuition I can refer back to, right? Suddenly, I mean, yes, this has all kinds of implications. For me, I think about the scientific implications, but
it naturally dissolves the sense of self. I think it gives us a better felt experience of how the universe is actually structured. The separateness we feel in the experience of being a self, I think would start to dissolve if not only would the experiences I had when I was 10 affect the experiences I have now, but the experiences you had yesterday could affect the experiences I have now. And so I don't know what the
the future technology looks like. And it gets scary if you try to imagine it. They do, because I always complain about that. But there's no reason, there's no real reason why I could have an experience now of a memory of being myself yesterday making breakfast and not have a memory of being you yesterday making breakfast. And so that's kind of the second area that I think is interesting and likely to be explored.
And then the other thing is a little harder to explain, or maybe a little harder to explain the usefulness of, but I was thinking about this idea of being able to experience other systems. Is there some way in which we might be able to feel, I'm trying to think of a good example of a plant or a tree, feel an oak tree.
And what does that even mean? And of course, even if we found some way to connect my neurology to an oak tree and I had some very interesting experience, there'd be no reason to believe that that's what the oak tree feels, right? But what I realized in these crazy thought experiments is that we use our conscious experiences as intuition tools.
Already for so much science and for our guesses about what other systems are conscious. And so I have all of the evidence from you that you are conscious, but that's so much of that is based on the shared experiences we're able to communicate to each other.
my cat to a lesser degree, but it's the way in which I notice the cat behaving in ways that I expect it feels something similar to the things I feel when I behave in similar ways. There's pain, there's pleasure, there's hunger, there are all these things that I can relate to. I imagine there's some version of that happening.
If we were able to start to experience other systems in the way that David Eagleman talks about, he gives this crazy but fascinating example of astronauts being connected to the workings of the International Space Station so that they wouldn't have to be reading numbers all the time, but they could actually intuitively feel, you know, the health of the space station or the things that need to be attended to. If there were some version of that and we were able to connect to other systems,
would we gain intuitions that would maybe not be full evidence, but maybe as much evidence as I have that my cat is conscious based on the things that are able to get communicated through that? Is there some sense in which we might be able to experience other systems that would give us new intuitions for one, how they work, which is just interesting scientifically, but then two, whether they're conscious? Well, it's fascinating terrain. I think we should
just introduce the episode here because there's no, there's nothing we're going to say here that's a surrogate for just actually listening to what you've produced here. Yeah, so this is chapter eight called Space and Time. And I spoke to two physicists, Lee Smolin and Carlo Rovelli, and a science writer, George Messer, to try to get as clear of a sense as I could about
the different interpretations of quantum mechanics and the new theories of quantum gravity and how they might relate to this possibility that consciousness is fundamental and how these physicists would react to that suggestion. I also, at that point in my journey and in the series, became very interested in whether time
is a fundamental property of the universe or not. Physicists are generally in agreement that space is emergent and not fundamental. And I talk a lot about that and how actually I think that makes sense at the level of the brain as well and what we're perceiving as space not being out there in the way that green is not out there, but more of a mapping of structure of the universe that we have some access to.
And so Lee Smolin believes that time is fundamental and his new theory of quantum gravity places time at a fundamental level. And Carlo Rovelli does not believe time is fundamental in his theory. Talks a lot about how time, he wouldn't say time is an illusion. It's something that emerges, but that essentially it's not something that is part of the fabric of the universe. Lights on chapter eight, space and time.
When I first began to wonder if my and others' experiences in meditation were providing any hints of deeper truths about the nature of reality, the fact that I was even contemplating this question came as a complete surprise to me. I had always considered any type of personal, subjective experience to be more or less useless as a tool for probing scientific truths.
Maybe not for psychology and neuroscience, but certainly for fundamental physics. Through my work with neuroscientists over the years, I had learned just how indirectly we're in contact with the outside world. In fact, many of the things that seem like the most direct channels to reality, as we've seen, turn out to be what Anil Seth rightly refers to as controlled hallucinations. But there's a hitch.
Strangely, when you place careful attention on your moment-to-moment experience in a very disciplined way, some of our perceptions, including those of space, time, and self, actually begin to shift or drop out altogether. And surprisingly, our window onto reality can be transformed into a more accurate one, at least in some cases.
So as I followed the advancements in quantum physics, reading about newer theories that suggest space and time are emergent rather than fundamental, I was reminded of some of my and others' meditative experiences of a timeless, spaceless experience of consciousness. And much like the experience of self, the suggestion that space-time is not fundamental, though mind-blowing on one level, actually made some intuitive sense to me.
And this was the beginning of a sort of merging of two areas of interest of mine that I had never dreamed would intersect. I had already witnessed the convergence of my interest in meditation with neuroscience earlier in my career, even developing into some fascinating scientific studies in which they scanned experienced meditators' brains in fMRI machines. But experiences in meditation more naturally lend themselves to neuroscientific interests as a phenomenon for obvious reasons.
And I was still fairly skeptical that there was any useful connection to be made between meditative insights and fundamental physics. Hmm. Okay, so where to start?
I just want to say that I've been immersed in this conversation with you for quite a while now, and I'm never really sure how jarring some of these arguments are for newcomers. But this is Chapter 8, so hopefully by now the listener hearing a casual suggestion that space and time might not be fundamental is not that crazy anymore. I know. Sometimes I have to remind myself of what it's like to come across these topics for the first time. Yeah. Yeah.
And it's also surely clear by now that language really does fail us here. Language, it's naturally bound up in the assumptions of time and space. In fact, the most commonly used noun in the English language is time. Year and day also rank in the top five, I'm pretty sure. But I think it would be helpful before we jump into the conversation to just have you quickly lay out a distinction in your own words.
What's the difference between something being fundamental versus something being real? Or do you not see a difference there? Yeah, this is an important distinction. And these are terms that people use in different ways, so there's a linguistic element as well. But when I say fundamental, I'm trying to get at the deepest understanding of reality, the place where explanation essentially stops. So there are plenty of things that are real that aren't fundamental.
We can have the experience of seeing the sunrise, for example. And that's not only a real experience, but it's connected to something real that's happening outside my brain as well. And just with that sight of the sun rising, with that limited window onto reality, we're definitely getting some information about the underlying reality.
But there's a deeper explanation there, a more complete picture of our solar system and the Earth's rotation, etc. So it's possible to grasp something more fundamental beyond our immediate perception, and then we can go a step beyond that through an understanding of the force of gravity and so on. And when we're including the human brain, it gets even more layered than that. For example, I can dream about the sun rising or hallucinate that I'm seeing it.
Then, in order to explain the experience, we need to get into not just the mechanics of the solar system, but the understanding of what's going on at the level of the brain to produce an experience in the absence of the usual circumstance. So when we're talking about the brain and the experiences it generates, there are the external inputs and the activity of the brain itself. And the sciences have really helped us shed light on where the inputs end and the brain processing begins.
And of course, science has also shed a ton of light on our understanding of what those inputs are, of what the outside world consists of. We still have a long way to go in terms of a complete understanding of any of these things. But generally, the more we understand, the more fundamental a layer or explanation we've exposed.
In the case of space and time, we're talking about needing to understand both the inputs and the universe outside the brain, as well as the brain processing itself. So let's start with space, because physicists are basically in agreement about space being emergent and not fundamental. Time is in a different category because we don't yet have scientific consensus one way or the other.
So when talking about space, is it possible that just like the color green doesn't exist out there in the universe, but it's how our brains represent a light wavelength in our experience, is it possible there isn't space, at least in the form that we perceive it to be, out there either? That the three-dimensional space we experience is yet another way our brains create a map of something out there we're perceiving.
And that's on the side of the experience of space, how it's generated by the brain. And the question for physics is, if space isn't a fundamental aspect of the universe, what is it that's giving rise to this domain we call space in the first place?
And there, the holographic principle is one promising way to explain it. We won't get into those details now, but if space can be explained through physics as emerging out of some other process, space is not fundamental. It's not part of the fabric of reality as we had always assumed.
So to go back to your question about my use of the word fundamental, at the very least, we know we've been able to probe deeper and deeper into the nature of reality through scientific investigation. And we arrive at a fuller, more complete picture every time we reach a more fundamental level. And wherever that explanation stops is where we'll find the true fabric of reality, the true fundamentals.
Now, whether or not that's possible even in theory, we don't know, but that's the idea, that at least we can keep moving in that direction. And so that's a very long answer to how I and physicists in this domain are using the word fundamental, something that's not dependent on the presence or activity of anything else, where explanation stops. Okay, got it.
And that was just about space. Just wait until we start asking those questions about time. Right. And that's where I get completely stuck and start spinning in circles, trying to understand what it could possibly mean for time to be emergent out of something more fundamental. The statement itself sounds paradoxical because for something even to emerge, you need time, or at least it seems that way. I don't know.
But luckily, I knew the perfect person to help me think through these questions about space and time. George Musser. Hi. Hi. Tell me about your project, though. It's so exciting. I mean, it's... It's been really wonderful, and I've learned a lot, and I still have so many questions. And I'm also just...
excited to find out how many physicists are interested in consciousness and interested in having this conversation. Each of them, however, is kind of wedded to their own theory and very invested in the work they're doing. And there's still kind of a limit on how much we can brainstorm together or just play around with ideas.
And so while I was reading your book, I just thought, oh, George has come along at the perfect time because he understands so much more than I do. You can help me understand all of this, but also there's an openness because you're not attached to any theory that you're working on. That sounds great. I mean, I also, when I read your book, I felt a certain kinship with the craft there as well. I think both of us are very synthetic writers that we take vast advantages.
quantities of information and knowledge and try to distill what is the most essential from it. George Musser is a science journalist and the author of two of my favorite books for a general audience. One is titled "Spooky Action at a Distance" about quantum mechanics, and the second is called "Putting Ourselves Back in the Equation," which addresses the very question I'm most interested in: how does consciousness relate to fundamental physics?
When I spoke to him, I started our conversation by reading a passage from his book, Spooky Action at a Distance. So I wanted to start with space and non-locality. I am going to read an excerpt from your book on page 135. You write...
The velocity and position of a particle are not independent quantities. If you know the spread of possible velocities, you can calculate the spread of possible positions using the Heisenberg uncertainty principle and vice versa.
Relativity theory spoils this conversion by requiring that the uncertainty principle be observer independent. Now when you translate velocity to position, you find that the different positions are no longer mutually exclusive. You might find the same particle in two different places at once, or the particle in one place and its energy somewhere else.
The combination of quantum mechanics with relativity violates locality in what was for Einstein its most basic sense, the stipulation that all things have a location.
Okay. It seems that there's now a consensus among physicists that space is not part of the fundamental story, that space emerges, and perhaps space and time, but it seems like there's really a consensus at this point that space must emerge out of something more fundamental. So I should first just say that
My intuition has, this is in line with my intuition. It has always seemed to me that space is not fundamental and that kind of the fundamental nature of things. So one thing I just want to make clear at the outset is that
Because I have a lot of questions about string theory and higher dimensions of space, more dimensions beyond the three that we experience. And to just be clear that when we're speaking about those other dimensions of space, possible dimensions of space, that I'm always assuming those are reflecting or representing something at a deeper level that is not space. Does that make sense? Right, right. Yes, absolutely. Okay. Yeah, I mean, it seems that whatever...
space is representing at a more fundamental level, it can still be a good map for us of the underlying reality, especially because we can't seem to think in any other terms. It's almost everything we experience we kind of put into these three spatial categories. Yes, yes. Science always progresses. Physics is no different in a stair-step kind of way. So we go from, yes, we see three dimensions of space in string theory,
There seem to be additional spatial dimensions that are associated. We can't see them directly, but they're associated with the properties of different particles. And then, you know, the next climbing up the stairs or descending the stairs, whichever you want to think of it, would be, oh, let's dissolve the space altogether and think about space as coming from these more fundamental dimensions.
ingredients physicists call degrees of freedom to kind of avoid prejudicing whether they're particles or something else. Degrees of freedom is the kind of abstract word for that. Actually, that's one question I do have is whether most physicists working on string theory at this point believe that these other dimensions of space are still pointing to something more fundamental, that space is not the ultimate story.
Or do they really have some picture of a universe that has nine or ten or more dimensions of space and that that space is kind of the fundamental reality rather than it being a sign or signal of a deeper structure? Yeah, well, I think physicists and string theorists in this case in general think on a different kind of
layers of description, levels of description. So for some problems, they'll think in terms of 3D space plus time. I'm going to put time on the side for now. In some cases, they may think of nine dimensions of space, six on top of the ones that we know. In some cases, even they go to 10. And in some cases, they go back down to zero again. It just depends on kind of what they're trying to do with that particular dimension.
moment, what they're trying to accomplish at that level of description. And that's what's fun about physics is that you can kind of plumb these different depths. Yeah. But do you think most of them are kind of on board with assuming that however many dimensions space has, ultimately space is not
is not really the story, is not really the underlying reality? Yeah. I mean, I've never done a proper opinion poll, but that is certainly my reading. And the individuals will come to that from different arguments and directions. But one thing that's interesting about string theory is to the extent to which it's actually not about strings anymore. String theory is kind of a historical term that describes a general direction in fundamental physics, but that
It doesn't mean that day in, day out they're actually thinking of literally, oh, there's little strings. So right now, the predominant direction is indeed to think of spatial dimensions as being emergent, that you can have, again, these degrees of freedom, these fundamental ingredients that organize and behave in certain ways, out of which space pops like a figure in a pop-up book. And that goes on.
Under the rubric of what's known as dualities or the holographic principle. And these dualities relate space times or universes of different spatial temporal dimensionality. So you might have a four dimensional universe that is equivalent to a five dimensional one or three dimensional one.
And as soon as you start kind of doing this cross over, you're saying that four dimensions is really no different from five. That's tantamount to saying that at least that fifth dimension isn't fundamental. So they at least get one to straight off the math, one dimension difference.
Is this pop-up dimension. Interesting. That isn't real, isn't, I mean, it's there in a sense, but it's reflects the steeper physics. And then they'll usually then go to say, well, one can pop up. I guess they all do. So that's kind of usually how thinking like go. Interesting. Okay.
So one thing that just always resonated with me and has been part of my thinking since I was probably 9 or 10 years old is the story of Flatland and this analogy. Love that. And my father had explained this to me, and I've just never stopped thinking about it, this idea of…
And imagining what it would be like to be in a two-dimensional plane, you know, in this three-dimensional world and how much information you don't have access to and how mysterious certain things would seem, whereas if you could jump out into three dimensions, they're not mysterious at all. You can see the whole picture. Yeah.
And so when I started learning about string theory, however many 20 or so years ago, I really gravitated towards it because the first time I heard an explanation of quantum mechanics that fit with the way I had been thinking about it all those years that
having more dimensions of space could potentially really help explain these things that seem so mysterious to us. So the idea that the types of things we witness like non-locality and entanglement
if we were perceiving four dimensions or five dimensions, the structure of that would make perfect sense. But we're missing so much of the information that, you know, we're in our little 3D plane or 3D sphere. Right.
without access to the fuller picture, to the larger reality. And I just wonder, does that analogy hold at all? I mean, does anyone actually think in those terms? You mean in the terms of by elevating to a higher dimensionality, you see the world as it truly is? Yes. Well, in that it
could potentially explain the types of things we see in three dimensions, where if they're explained in four or five dimensions, there is much more logic to them? Yeah. So, yes. Well, the answer is basically yes, and it's a great question. In fact, and this is why dimensions even come up in these foundational discussions of physics, why they play such a role in string theory and certain other theories as well. People seek
And remember, what physicists are trying to do here is they're trying to unify. So they see there are nuclear forces. There are electromagnetic forces. And already electromagnetic is a unification of electrical and magnetic. They see gravitational forces. All these forces that seem quite different. And they ask, are they unified or are they really the same but seen from different sides in a way? And the dimensionality of space helps with that.
And there's a whole program going back to Cluesa Klein and two mathematicians in the early 20th century that basically takes gravity and imagines just the ordinary force of gravity operating not just in three dimensions, but in four and five and so forth. And they find that when you start piling on these dimensions, what is gravitational in, say, the fifth dimension looks to us.
Unable to see that fifth dimension directly as electromagnetic force. So they take two forces in that case and unify them into one by saying that there's this hidden it hidden to us. It's not hidden to the universe, of course.
We're trapped on this three-dimensional space, and we can't even put our arm, can't look out of it. But if we could, in a flatland kind of way, like, you could see that, aha, this electrical force, which seems so different from gravity, is actually is gravity. Yeah. Yeah, you know, this reminds me of another train of thought I often get on, which is, you know, wondering...
what the difference is between actually physically being confined to a three-dimensional space and whether...
It has more to do with the human mind and the human brain and what we're perceiving so that it's only possible for us to perceive in three dimensions. But there are, you know, right there in front of us, if only we could perceive them, we would have access. It seems to me that whatever the number of dimensions are that exist in the universe,
that those are always there and we exist within that. It's all part of the same thing. We're limited in terms of what we have access to through our perceptions. But there's obviously the other way to look at it, and I assume it's the way most physicists look at it, is that there are actually different
structures that can physically be described as three-dimensional and they're not in a four-dimensional or five- or six-dimensional space. Is that right? Yeah. So the way the physicist who works on this would think of it is
They basically would do what you've just done. They would pose the question, if space were multidimensional beyond our three dimensions, and if there were, it could explain aspects of physics that reflects us today. But then why don't we see those other dimensions? It's something about us. It's something about the universe, about both. And there's a range of thinking on that. And
There does seem to be a connection to us in the sense that it might in fact be impossible for us to be higher dimensional. There are certain aspects of three-dimensional space mathematically that are special. It isn't just an arbitrary number three. We can do more than two. If, for instance, in two, any...
line divides the plane. And so a body couldn't have cavities in it because that would actually create then two bodies always. There couldn't be a unified body. The kind of complexity of our body is not really possible in two dimensions. The complexity of some of the gravitational effects we see are not possible in two dimensions. Gravity still operates in two and even one dimension, but it's just not the same as the kind of rich,
fabric of gravity we have in three. And then if you start going up, if you ask four dimensions, five, six, also problems start to occur there that seem to, in other words, we sit at a kind of sweet spot in the complexity, ability of complex structures to form. So there's probably no accident that if there were more dimensions, we'd
That we would still be three-dimensional creatures. Interesting. So when I started learning about string theory about 20 years ago, it always kind of bumped me and just I couldn't ever get my mind around the idea that these larger dimensions would be smaller.
And I've now, you know, read so much on the topic that I realize this isn't a consensus. But at some point early on, it seemed like that's where it was all headed, was that it was these like, you know, tiny wrapped up dimensions and small in scale.
in some sense, which is the opposite of this flatland analogy, right, where it's just bigger and we have this small view on it. And then in your book, you quote Fontini-Marcopolo. She says, if quantum gravity is as fundamental as we think it is, if it's something that's about the very structure of spacetime, it's just not obvious to me that the signature of that thing has to be something very small.
And I wasn't sure if that related to this other issue I was having or not, but I kind of held on to that as something that was interesting. I just wondered if you could elaborate on what she meant by that. Yeah. So a couple of things here. First, regarding the extra dimensions and then about quantum gravity. Again, string theory has gone through a lot of evolution. So the early thinking, which is still around today, but
modulated is that those dimensions have to be small. And there's a few reasons for that. One is if they were large, we could see them. So we could move in them. Our arm could stretch out and accidentally go into one. So to eliminate that kind of eventuality, which would be bad, A, and B, we don't see
It was postulated – a strength theorist postulated that the dimensions must be extremely small. The other thing is that the kinds of forces they're trying to explain with this, electromagnetic forces, nuclear forces, seem to require, I mean, beyond microscopic, minuscule, minuscule dimensions. And it's not just, by the way, that they're small.
It's that they're finite. Right. And that they are circular. They kind of have a closed topology to them. If you could walk into one, you would come back to where you started. Whereas our dimensions are not only big, but they're infinite probably, at least to our knowledge. And they're not circles. They're lines, essentially. So if you start walking out into the universe, you will never –
And there's some debate about that, but the kind of default view is that they're the topology of a line and you start going and you'll never come back to where you were.
Now, things are a lot more flexible, even starting 15, 20 years ago. Actually, by the time Brian Greene came out with his book, it was already starting to turn then. You can see the evolution in Brian's books, actually. He starts off with this all-dimensions idea, but in the elegant universe, but his subsequent books really flesh out that the dimensions could actually be quite big and that we don't see them for some other reason, that we're stuck. Yeah.
on our dimensions or the dimensions are highly curved. So they're strong gravity and then I'm basically, and so we're kind of trapped in them. And one of the hopes for the large Hadron collider was maybe those dimensions would manifest or somehow the, we would basically lose particles. It'd be like, what, where did the particle go? And you would say, ah, the particle must have gone to the other dimension, but that didn't happen. So probably, uh,
The dimensions aren't accessible to us. Anyway, so that's point number one is these dimensions could in fact be large, infinite even, and restricted in some other way besides size. Then there's Fortuny's point, which I think is really, really important. And I'm glad you picked up on it. That quantum gravity is conventionally thought to be an extremely, extremely tiny object.
as in physical size effect. So you'd have to take your mice group and dial it up and go through atoms, through protons, all the way down to what's known as the Planck scale. And then you'd see space-time kind of foamy or some other weird thing would happen to our ideas of space at that level. And the other, this is just think in terms of scales, not just of size, but of energy. So the small
tiny, tiny distance also corresponds to a very high energy. So you'd have to dial up your particle accelerator or your x-ray gun or whatever in order to access those very fine scale effects, these kind of deep effects. And there's a lot of thinking to support that as well. But as she points out, you can't really... Physics is interconnected. The nature is interconnected. You can't just...
change one part of it and not expect some other part of it to to remain the same so if you're going to this deep level and you are saying for example that new forces could materialize then you need to ask maybe we can see them in addition if you start and this is something closer to my heart with with my book if you start mucking around with the nature of space and time
Then you might ask whether if space and time breaks down at that fine scale, whether there could be a residue of those effects at our scale. And this is something Lee Smolin has argued as well. I was really, when I talked about this in my book, I was really responding to him a bit that maybe these non-local effects are,
that are seen in quantum physics, quantum field theory, general relativity, other areas could be somehow a residue of this space-time emergence or this deep breakdown. Yeah, no, and that makes a lot of sense to me. There's also just kind of part B of that is there's kind of this misconception that physicists themselves have promulgated since the early days of quantum physics that quantum physics is a theory of the small. Mm-hmm.
So quantum physics was developed for atoms, electrons, particles, you know, small things. And the experiments are usually done on atoms, electrons, photons, small things, because they're easy to control. But there is no limit in quantum physics. Quantum physics is a theory of everything, period. Big, small, the universe is quantum. You and I, you know, everything is quantum. We may not notice it.
we don't notice a lot of things. I mean, the vast majority, we can't see radio waves, for example, directly. We don't see a lot of things in the world. I think this table is solid, but I know it's mostly empty space. So it is with quantum physics. It's there if we know how to look. It is just in line with this very strong intuition that drives a lot of my interest and that seems to be confirmed as I've worked in the sciences that
There is so much kind of right here with us. It's all, it's all right here. We just are very limited in our ability to, to perceive it and access it just, you know, based on the limits of the human brain and what we evolved to be able to perceive. Exactly. But we, we've also have a brain, which is, you know, a step up there so we can translate
This is what science does. It gives these microscopes of the mind, whether they're really microscopes or other techniques that kind of bend the world into a place we can see it. So we take radio waves, translate it into sound waves or into light, a visible light. And so it is with these gravitational effects. We take things that are so impossibly distant from us and we can see.
find situations like black holes. This is why black holes come up so much in these discussions is that they're a kind of canary in a coal mine for our current physics. They're the place where our current physics dies. And we have to figure out why. And I'm very much in the program of like, I love exotic physics, don't get me wrong, but I'm also in
and the idea of take the simple things and ask yourself, do you really know what's going on? How many people can explain how a toilet works, for example, or why the table is solid or why the universe doesn't implode? I mean, these little things around us that seem so basic. Why is the night sky dark is something I talk about in my book. It's a very, very deep question.
that no one or very few people stopped to think about. And yet if they did, they would be like, whoa, I can't believe this. This is amazing. That's great. This is all where I wanted to go. I think you can now probably understand why I would recommend George Musser to anyone who is looking for a quantum physics tour guide. He and I ended up talking for almost two hours and I loved every minute of it.
And I want to play a bit more from another part of our conversation, where George describes what is known as the holographic principle, which helps illustrate how space as we perceive it and how we usually think of it may be distorting the true picture of fundamental reality. The first time I truly felt like I could begin to grasp what the holographic principle describes was when I was watching a lecture at Harvard given by Nima Arkani-Hamed,
a theoretical physicist at the Institute for Advanced Study at Princeton. And we'll link to the video of his lecture in the notes. The title of the course is "Space-Time and Quantum Mechanics: Total Positivity and Motives." As you can see, the first part of the title is all about physics, the second part of the title... In the lecture, Nima explains something called ADS-CFT correspondence, which is an example of the holographic principle.
And to describe anti-de Sitter space, the ADS of ADS-CFT correspondence, he draws a picture of a hypothetical universe on the blackboard. But it's the sort of simplest example of a world in a box. You can think of the geometry as like the inside of a tin can. There's a warping, a negative curvature inside the space.
which means that the distance from a point on the inside to the boundary is indeed infinity. It has some resemblance to our universe, but with one very important difference: it has an outside boundary. So the blackboard sketch looks like a tin can, and the interior is filled with stars and other matter, but it is enveloped in a cylindrical two-dimensional surface, like the metal of a can.
All those stars and matter represent a vast amount of information: where the atoms are placed, how they are moving, and so on. And here's what's amazing: the math shows that the very same information exists on the interior surface of the can. Which is strange because inside the can is a three-dimensional volume, but the cylindrical surface is only two-dimensional.
So how can a two-dimensional surface hold as much information as the three-dimensional volume? How can two very different geometries be mathematically equivalent? And what ensures that information is replicated in both places? These puzzles have haunted Nieme and his fellow theoretical physicists ever since they realized this correspondence in the 90s.
And many have come to think that it's the surface of the interior of the can that's actually fundamental. And the volume is a kind of mirage or illusion.
So this is an example of something and people have been exploring it actively for 20 years and I'm sure explore it for another 20, 30 years. It's a vast, rich, deep, every superlative you want subject. But it's an example of quantum mechanics is king and space emerges from quantum mechanics.
I know all of this is still very hard to fathom, but hopefully it will be a little clearer after you hear the wonderful analogy to music that George comes up with. Let's listen to the second part of our conversation now. Let me just read this one excerpt of yours. This is page 165.
On the downside, what the heck does the holographic principle actually mean? How could the universe around us be a holographic projection? What's the projector? The key, I think, is not to get caught up in the minutia of the metaphor. The point is just that the space we observe could be a product of some underlying structure. When we walk across a room, we are not gliding passively through a pre-existing expanse. Something is happening. There is a machinery at work, a
A grinding of gears deep within nature to produce the experience of being here and being there. When you stretch an arm to grasp a pencil and it's just outside your reach, something is acting to thwart you, creating what you perceive as distance. And when we ask what that machinery could be, we have arrived at the outermost frontier of modern physics. I'm very interested...
in this idea. And it's very, it matches my intuitions very well. And so there's a lot more I want to understand about it. Oh, wow. So this is, this is basically all of modern string theory now. When I was finishing, actually, I think I had just finished the book. This is 2015. I thought to myself, the holographic principle, what does it have to do with holograms, actual holograms you can buy or have in the back of your credit card?
or whatever. And I've always loved holograms. When I was a student, I did a spring break in San Francisco and I went to the hate and bought a hologram that was nails. This would be a white light hologram. You'd show the hologram under just a lamp and the nails would pop out at you and it's creepy. And it was always stuck in my mind how incredible it is that a two-dimensional sheet of film could conjure up
a third dimension of space, a sense of depth. And the holographic principle is very similar to that, but at a deeper level of science. So anyway, so basically, the physicist normally thinks of it as you have a ball, a big sphere, and inside of that is the universe. And so they think of the universe basically as an enclosed space. Right.
And inside of it are galaxies, stars, and everything else. But there's this outer surface. It's interesting to think of what that actually means if it isn't space. Just what that means to have any kind of boundary at all.
Ah, yeah, you brought up a very, very important question here, which I think we can bracket, but let's acknowledge. And so we know, come back to it. What does it mean to have a bounded space? Because in these theories of holography, space does have to have a boundary to it. And that already seems to be a bit of a regression in our cosmology because we're taught to think of, well, Copernicus dethroned the bounded space, the universe in a nutshell kind of idea.
And now we seem to be thrown back into that picture, which is important. But let's come back to that because it's kind of cool story in its own right. But just for now, except that the universe could be a big ball with a boundary to it. In fact, it's an infinite ball with a boundary to it. But that's neither here nor there. It's a ball with a boundary to it. The boundary.
It's if you think of as a three dimensional ball with a two dimensional sphere as its bounding surface, the boundary space is two dimensional space, but it's as good a space as any. It's like a map as a representation of the earth. It's, you know, it's it's a world in its own right. So you can talk about physics on the boundary, ignoring the fact that it is a boundary. Just think of it as any old two dimensional plane, let's say, or sphere in this case.
And it has particles, fields, quantum processes going on it. So the first thing the holographic principle tells you and this idea of duality, which is kind of they're paired. Those two ideas are paired, is that the two are equivalent. So the interior is.
And the exterior don't look the same, but they actually, in a deeper sense, are the same. Right. So, for example, if you have something in the middle, like a planet, there is something acting as a planet, even if it doesn't look like one, there's something acting as a planet on the boundary. Right. If you have a hand on the boundary, there's something with the same properties somehow in the middle.
Now, that's kind of weird to think of it that way, but this is where the hologram now starts to come in. So something similar happens with the hologram. You've got something that looks like nails appearing before you if you illuminate the hologram, but you know that it's equivalent to what in fact is generated by what's on the sheet of film. So there's kind of a matching of the two sides that in the space above the hologram are nails on the film is hologram.
If you look at it after you see a wave pattern and the waves interfere in a way, they kind of combine in a way that leads to the appearance of nails. So the quantum fields combine and interfere in a way that leads to a planet. And this is the essence of holographic principle. And actually, it's a very, very deep, more than just a metaphor. It's kind of really kind of a good way to think of it. In my view, it does lend itself to...
losing this notion of space also. Exactly, exactly, exactly what it does. And actually, I have a quote here under this. You say, locations that seem far apart can lie right on top of each other. What appears to be spatial distance is in fact a difference in energy. Exactly. So for example, suppose you're moving along the radius of that sphere. Suppose you and I are standing, you know, 100 feet apart
But along that radius. So our avatars, our kind of corresponding entities on the boundary, let's call them avatars, are co-located on the boundary. So if you imagine drawing a line that starts at the center of the sphere, goes out, keeps going out, hits the edge of the sphere. So it's like a radius line. You are maybe in the middle and I'm a little bit further out. Where that radius line hits the boundary at the outer edge
perimeter, both of us are actually both there. We're actually, even though we look a hundred feet apart, we are actually zero feet apart on the boundary. And what is accounting for our distance is something else. So what does distance mean? This is why we have to kind of dissect concepts of space and of physics. Distance means that I can't reach you. You're a hundred feet from me, I can only reach a couple of feet away. It takes a certain amount of time, you know,
whatever number, 300 nanoseconds for light to get from one to the other. There's a delay. So all these kinds of features of our spatial position and location have to be translated into something not spatial. So for instance, that when I can't touch each other, that means, okay, what does that mean? It means we can't interact. And indeed, there's a way of structures of different energy
don't interact. And examples of this, we just know from music. So if you play a chord, let's say, or just two people are singing in a room and one sings C, one sings C sharp, that would be terrible, but if they sing a third apart, then it's more harmonious. Those waves of your voice are, you're hearing as a listener, both notes
because both waves are passing through the room. Sound waves just pass through one another. And that can be thought of as something similar in this holographic principle, that different effects can pass through each other. But you and I, 100 feet apart to our eye, what's really happening is that our energy is just passing through each other in a way. I'm
It's big here, but there's a different effect. And then when we do touch, suppose we were to walk toward each other and then we just be outstretched at arm's length. And finally, we can touch our fingertips. That would be like the energy is converging. So it would be like the two singers bringing their harmony down to their singing in unison. That would be like touching. That would be like touching.
The discoveries of entanglement and non-locality in physics are both good clues that space is not fundamental. And the very last phrase George landed on of it being like touching when energies interact is so interesting to contemplate. I often wonder when we consider space to be a kind of projection or translation of the fundamental physics, if our conscious experience reveals anything even comparable to it.
Or does the conscious experience of, say, a lamp being on the other side of the room, represent something entirely unlike the picture at a deeper level? As George masterfully points out, something is clearly obstructing my ability to interact with the lamp on the other side of the room, even if it's totally unlike the space we experience.
In the case of the lamp, we're still close enough to interact with it at some level by perceiving it through sight. But there are of course countless objects we can't have any interaction with at all, like a pebble on a moon on the other side of the universe, or a million other things. But if space is not fundamental, it seems like there's a sense in which everything, at least the stuff that we can potentially interact with, is actually right here in a sense.
Because there is no space, and the space we perceive between everything is just a hint of some more fundamental structure or force or laws of nature. The space could even theoretically be bridged if we only understood what it represents, with the use of some future technology that was built on that understanding. If you're having trouble picturing how everything could be right here, I don't blame you, but it's fun to think about.
And strangely, it's actually another type of experience that's regularly described by people in meditation and on psychedelics.
I'm the first to be quite skeptical that any human experience could be a true window onto the ultimate nature of reality. But I think it's incredibly interesting that when scientists probe the physical world deeper and deeper, we're left without space. And when we interrogate our conscious experience with greater and greater concentration and skill, many people arrive at the same conclusion.
So first, through our investigations in neuroscience, we understand that there really is nowhere for a self to dwell in the brain. And when we look directly at our own conscious experience, we find no self there either. And then through physics, we've discovered that space is not fundamental, and perhaps time isn't either. And when we interrogate our first-person experience deeply, all sense of space and time can slip away as well.
even though conscious awareness remains perfectly intact and as present as ever. Here's where I continue to find myself stuck, because I've had these experiences myself, both in meditation and under the influence of psychedelics, and I'm of course not alone here. The philosopher Thomas Metzinger is very interested in these states, and he refers to them as Minimal Phenomenal Experiences, or MPEs.
He has studied this phenomenon and published his results in scientific journals. We'll link to a talk he gave presenting his research in the notes. And I'll play some readings now of anonymous first-hand accounts from his research. The body felt like it dissolved. What was left was my awareness being aware of itself. I felt like I just was, and my awareness just observed. It was just experience happening. I didn't feel a contracted version of a self, but rather an openness.
Boundless space. The perception of space, infinite, unseparated, without inside and outside, weightless in the space of infinite possibilities. On a few occasions, I have entered the state of deep, dreamless sleep consciously. It is in this state where my experiences have occurred, whereby I am a simple, unified awareness, seemingly without the daytime qualities of ego.
I have experienced vast, non-centered, timeless space, and sometimes light and sometimes pure black or color, but can really only put inadequate words to the experiences in retrospect. I was everywhere at the same time. Attention floated freely in space between the different mind objects. I felt completely empty. It was a clear awareness, but with no thoughts.
I was not quite sure about or did not feel time or space or thought or body. But I knew that something, I take it as me, exists. It's that background awareness behind any thoughts and perceptions, and it knows itself. Even though these experiences pique my curiosity tremendously, when it comes to the subject of time, my skepticism really prevents me from taking these experiences as real data.
For one, the idea that time is not fundamental is a complete roadblock to any further reflections about anything really, at least for me. I don't know how to attempt to make sense of anything, even consciousness, without time, even though I have a vague recollection of having had an experience of it myself, which is somewhat comical. But most importantly, when I turn to the scientists, there aren't any conclusive answers about the status of time either.
There are some physicists, such as Nima Arkani-Hamed and Carlo Rovelli, who are convinced that time isn't fundamental. But there are many more who believe it is, and even more who just don't yet come down on one side or the other. So in an effort to get a little more clarity, I decided to reach out to two physicists, one who has convinced time is fundamental, Lee Smolin, and one who believes it's emergent, Carlo Rovelli. Hmm. Okay.
But before we listen to those conversations, there's an important distinction emerging here between consciousness and perception that often trips me up and that I think is important to spell out. So let me see if I can get this right. The perception of space is our way of mapping whatever is really out there onto some kind of familiar, understandable world in order to navigate it.
something that's distinct from a true illusion or mere hallucination, right? But consciousness is not necessarily perception, even though it includes our perceptions as content.
consciousness, in the way you're using the term, is just the fact of felt experience, no matter what content is being experienced, whether it's perceptions, thoughts, hallucinations, or even sort of timeless, spaceless awareness. Am I splitting perception and consciousness correctly there? Yes, that's such a necessary distinction. And you reference the phenomenon of an illusion, which I think is also important to clarify a bit further here.
So when I suppose that space is a perception of a deeper fundamental reality or just a small window onto it, I'm not at all saying that our experience of space is an illusion in the way we typically think of illusions. And I often make a distinction between illusion with a capital I and illusion with a lowercase i as I see them. So a typical visual illusion, which falls into the category of what I'm calling illusion with a lowercase i,
A typical visual illusion takes place when our visual system, which works well at mapping the world for us in most circumstances, fails us under an unusual condition. So we've all been exposed to the fact that we can be tricked into seeing two arcs of identical length as having different lengths.
I'm sure everyone listening to this audio documentary has seen this illusion and knows that when we're presented with the illusion, no matter how hard we look or how well we understand why it's happening, we will still always see these two identical arcs as having different lengths in this particular setup.
And there's a whole world of fun examples like this, where we can essentially trick our brains into hallucinating an inaccurate map of the outside world rather than an accurate one. So again, I call this more commonplace type of illusion an illusion with a lowercase i. But an illusion with an uppercase I is an experience that gives us a more or less accurate map of the world and does its job of helping us to navigate it very well.
But it tricks us into believing we have a perfectly clear window onto exactly what the world is, rather than a map or an interface, as Donald Hoffman likes to call it.
I also want to make one last point and be very clear that I'm not saying the concept of space has no meaning in physics either, nor are any physicists saying that. Every physicist I know would say that space is certainly real even though it's not fundamental. So a phenomenon can be emergent and as real as anything else, yet still not be a clear view of the underlying reality. Okay. So let's move on to your conversations with Smolin and Ravelli.
I'm hoping they're not only informative for the listener, of course, but that they might also shake up intuitions about space and time like they did for me. In addition to resources about the relevant physics, we've put some links in the notes to different meditation traditions and techniques for those who are interested in engaging in their own experiential science here.
When I spoke to Lee Smolin, he had begun to develop symptoms of Parkinson's disease, so you'll hear his voice is a bit shaky in our recording. But he was, of course, still as brilliant, sharp, and fascinating as ever.
At the time of our conversation, Lee was working on a theory of quantum gravity in which time is fundamental. And at that time I had been leaning towards the assumption that time is emergent along with space, as I had been heavily influenced by the work of both Nima Arkani-Hamed and Carlo Rovelli and others. But I knew that I was extremely limited in my understanding of the physics and had no business taking sides.
I had just finished reading Lee's brilliant book, Einstein's Unfinished Revolution, and I was beyond honored and a bit overwhelmed at this opportunity to interview such a renowned scientist. I jumped into the conversation by reading a passage from his book in which he paints a compelling image of causality and what he terms views.
This is from your chapter 15. Okay. "Your view of the world is like a film projected on a two-dimensional sphere which we call the sky. The view of an event in a model with three emergent dimensions of space will then be represented as a two-dimensional sphere that we call the event sky. What an event sees on its sky is the events directly in its causal past. More precisely, it sees the energy and momentum coming from each of its parent events.
And then you go on to say, the next step is simple. Hypothesize that all the universe consists of is these skies, each one the view from some event. Rather than construct the views from the causal relations, reverse things and derive the causal relations and everything else from the views.
So I think this is so interesting and fantastic. And it's the closest thing I have seen on those of, you know, the scientists I know who are working on these types of things.
that leave room in a way that makes sense to me for consciousness at a fundamental level. But the thing I really am interested in discussing today, I'm interested in what your theory is telling us if it turns out that time is emergent and not part of the fundamental story. I want to talk about all the ways in which
I see your theory completely holding together, yeah, without time. So to me, it's about how we look at causality and also about how we look at space. It seems to me that there's a way in which we can still talk about or preserve causality even if time isn't fundamental.
But what we would mean by causality is more like connections in what are represented as more than three dimensions of space, but not causality as an act of bringing something fundamentally new into being. And so if causal relations and causal structure are actually a deeper structure that's more fundamental than time, then
and is actually expressed fully in more than three dimensions of space. Like time is the perception, but the causal structure itself,
could be the fabric of which these larger spatial dimensions are made. And, you know, and our, so our experience of the fundamental is through three dimensions of space and then this perception of time. Let me first read something to you. Okay. And you have to guess who the author is. Oh my goodness. Okay. If you've never heard this. It's also a paragraph. It's not me. Okay. Just as the same city views
viewed from different directions, appears entirely different and, as it were, multiplied perspectively. In just the same way, it happens that, because of the infinite multitude of simple substances, there are, as it were, just as many universes which aren't nevertheless only perspectives on a single one. Hmm. Interesting. I have no idea.
Leibniz. Oh, mm-hmm. From the monadology. This is the founding document of relationalism. And the difference is striking. People who don't take this kind of thing seriously end up interpreting the evidence as if we were in a large number of different universes. And it's exactly the opposite. Right. There are many different partial views.
which stitched together gives you a view of one universe, one city. And it requires complexity and variety to work. Now, let me respond in two stages. Something like the causal theory of views, it could be part of a timeless picture. It could be part of what we say a black universe picture. And all I have to do is erase...
where it says the world consists of the present events and their views. And I just have to say all past, future, present. And the views are just different perspectives. Okay. And there are perspectives from the past to present.
and the future. So you get to be both a person who appreciates the centrality of time and not to believe in it. Okay, great. I'm so happy to hear that. So you can, it's unfortunately apparently coherent to believe that. I think it's much deeper to believe the version of
That I've been talking about. That you put forth, yeah. Which is, we can call it, it's something like the presentist or stripped-down presentist. And the little manuscript with Collelio Verdi is the furthest I've got towards kind of lyrically, at least, saying what we're trying to do. Because we're trying to get rid of the past and the future and just have the present and the present.
The idea, which was Kallia's idea, which has gotten me, it's just changed how I think of this recently, is that what an event is, what a moment is, is a transition from indefiniteness to definiteness. I actually just had a question, which is, when you say views, is there any sense of conscious experience being part of these views, or is it just kind of an unknown at this point, or...?
I guess I have a hard time understanding what a view or perspective would refer to without a conscious experience. Are you talking about the possibility of affecting or how is a view even a single thing that you can talk about? Yeah.
Well, you know, there's this funny thing in which you don't have to find your most fundamental quantities. Right, yes. So the image that I'm trying to evoke is the sphere of directions around an event. And there might be photons or other particles coming at you from the past, crossing that sphere. And you make a little triple dot when it crosses. I don't know why.
And that is a physical quantity. I am just going to assert that those are the fundamental vehicles, if I can use John Bell's term, things that are real. And I'm going to assert that the universe knows how to measure the difference between two views, the notion of difference. And I can write a mathematical formula
for that, and I do in the work, but I just have to assume that that's fundamental. So what I'm looking for is the answer to the following question. First of all, I don't want to believe in a cheap version of panpsychism where it has no cause at work, things being, quote, conscious of
or having sensations or qualia has no causal consequences. Well, no, I think it obviously does. I mean, the causal consequences...
throughout the universe. And so if consciousness is part of the fundamental story, it's part of the causal story as well. My question is just, is the causal story how it appears to us? Are we anthropomorphizing what causation actually is? And my deep sense is that causation is about a kind of fundamental structure by which different things in the universe are connected and come to be.
And therefore, I mean, so if consciousness is at a fundamental level, it's not a separate thing that's causing things to happen. It's just part of the causal story. It's part of the structure. It's part of... Good, good. So now I have a few proposals which are very tentative. One of them is that the consciousness is an aspect of these views, right?
That gives me a vocabulary. Second, not most views, but some special views. And I want to say or hypothesize, it could be wrong, it's a scientific hypothesis, that it's important for the laws that I've been playing with at this level that we can distinguish between
new views from precedented views. A precedented view is one that there are the same views in the past. It's a view that has precedents. And sometimes there are views, most of the time views have precedents. And that's why they know how to evolve. And every once in a while there's a view without precedent. And those are the ones that
that somehow consciousness is associated with. That is, the view has not existed in the history of the universe. Yes, that I think, I think a lot about that. Even though I have no way of assessing the science myself, of course, I still have a hard time getting on board with the idea that the future does not exist by definition, as Lee describes.
But I love this image of the universe being made up of views. And much of what he described was more or less something I could grasp and accept. And what I really appreciate is the emphasis he places on what he calls relationalism. And this is a theme I see popping up in so many theories at the cutting edge of fundamental physics, both in theories in which time plays a fundamental role and those in which it doesn't.
I often try to imagine analogies for an innately relational universe, like a web or a loom. I described a version of my web analogy in an article I wrote for Nautilus in 2022, titled "What is Time?" And I'll read an excerpt from it here: "In my efforts to understand what it would mean for the flow of time to be an illusion,
The closest visualization I've been able to create is that of a web of nodes in which we experience only one node at a time. At each locus, all the other nodes become inaccessible to us, as if a spotlight were continually traveling across this web of time, inch by inch, painting our reality. If you were to experience a structure on this web, such as node A, node A, node F,
you might interpret the experience as two node A's cause a node F, when in fact the whole web of nodes already exists in its entirety. The implicit causality would not apply at a deeper level. Causality through time would still illuminate connections. It's just that the underlying reality of these connections would reveal a structure vastly different from the one we intuit.
That is a universe with a flow of time where the past is set in stone, the future is undetermined, and the present is the only true reality. But this analogy is certainly far from perfect and not always appreciated. And that's completely fair because it can never really be accurate to talk about a web that somehow exists outside of space and time.
But the picture I'm always attempting to paint is essentially a modern version of what has been referred to as the block universe view in physics, where the past, present, and future all exist in some complete way. Though not static in the way the image of a block universe implies, but dynamic. Whatever dynamic means without time. We're clearly going to need new language as the science progresses here.
Anyway, Carlo Rovelli is a physicist who believes the flow of time is an illusion and should be challenged. So I began by asking him to distinguish his view of time from that of Lee Smolin's. What I think about space and time, we get confused because we make a mistake.
We have an intuition about time or about space, and we ask, is it like that or not? And the answer is, of course, it's not like that. I mean, we know for sure it's not like that, right? For instance, we know for sure that space is curved. If you take a triangle and you make a right angle, it's not true that it's three, four, five. It doesn't work because in reality, space is curved. So space is definitely not the way it looks.
The point is that when we say space, we pile into the notion of space all sorts of aspects of it, which in our language, in our intuition, in our perceptions, in our culture, go together with that idea. Now, some of them are wrong, are just approximation. Some of them are useful to some extent. Some of them are useful to a more extent.
So there is a complexity in the notion of space and even more in the notion of time. I work in a theory of quantum gravity where there is no time variable. There is no T in which things evolve.
So is this dramatic? Well, not so much. I mean, things happen. We describe things happen. There's just no clock ticking the entire world. And the interval between two events can be a quantum superposition of two different values, so on and so forth. So time has a different feature.
Does this mean that time is emerging? Yeah, of course it's emerging. I mean, what we call time in our experience, it's emerging from all sort of levels. For instance, for me, time is my memory, my expectation, the sense of flowing, the sense of urgency, all this. This, of course, has to do with physics. It's just neuroscience. It's just psychology. What happened to my brain, okay?
From that to say, okay, so time is just created by my brain. No, no, wait a moment. It's not true. Because I can understand my brain as a structure that changes in time. So there is a clock time, which has nothing to do with my brain. I can describe my clock using a notion of time, and my clock has no expectation, no memory, no distinction between past and future, and so on. So it's less timey than my perception, but it's still some time.
But the description of my clock is not relativistic in this regard, relativity. So if I fold in relativity, I lose another piece. And if I fold in quantum gravity, I lose another piece. So I think that space and time are layers of concepts which are born in different approximations. And if you want to understand them, we have to open them up and say, aha, this comes from that, this comes from that, this comes from that.
At the bottom level, well, at the bottom level, as far as we know, there is a quantum theory of gravity of which we have hypothesis, tentative theories, where there is no time in the Newtonian sense. There's no direct time. Yeah. But there are events that happen. Yeah. Okay. So, yeah. So we're very much on the same page there. Yeah. And the way I sometimes think about it is that
Our experience of time is kind of this very limited window onto a structure for which we have very little understanding. But there is a structure there, and time gives us a sense of that structure, but it is a very, very small window onto it. So in my work, I'm always kind of trying to play both games at once, which sometimes doesn't make sense. But to
wrap my mind around what we understand about the, you know, as much as we can understand about the fundamental nature of reality and then what that means in terms of our experience and what parts of our experience are useful and are, you know, telling us something about the structure because it's
the innate curiosity that we, that you and I both have, you know, the answers that we want to arrive at, whether or not, you know, human beings can actually arrive at them. Yeah, okay. I think in my work that often we make the mistake, even scientists make the mistake, of being aware that reality is different from what it looks at first sight. But nevertheless,
sort of using introspection, of using intuition and being very attached and say, okay, that has to be like that because I feel it is like that. I perceive it like that. And that, I think, is a mistake. And I think it's very common. I think at least morning is making this mistake about time. And when I talk with some colleagues, there are technical discussions, there are mathematical discussions, there are discussions about experiments, but often,
There are conceptual dyslexia in which I find exactly this difficult. I wish to say, come on, how do you know things are like that? Why do you trust your intuition so much? Allow the possibility that things are not the way you think they are. That's basically where I spend all of my time. My thought time is in that place. That's right. So I think this is important to be able to recognize the things we give for obvious and
And question them because that's what blocks us in going ahead in understanding. Yeah. Okay. So I've spent some time just thinking about what it means that time has the character that we now understand.
And that we, like, what does that mean about our experience? And so the only way I could get my, I'm always trying to visualize things. And so I started visualizing like this web or loom. Because one of the interesting things to me about losing time as we generally think of it is that we also lose causality in the way we think of it. And so I imagine causality and time being about connections between things and not about the way we think of it.
the way we experience them moving in one direction where this thing happens and then the next thing happens. One big disagreement I had with Lee was,
is the way he describes reality kind of unfolding through time so that there is all of this potential future and it is not part of the description of reality until it happens and time somehow is magically bringing things into being. And I just don't think that's the right way to think about it. But I was trying to imagine...
what this structure is. I know you don't like that phrasing, but what this structure is, what our experience of time and causality are telling us about the structure and how different is it from our experience. And so I started imagining this web or loom that is kind of the structure of reality and our experience being
very limited to, you know, one location isn't quite the right word, but one location at a time and kind of wherever we are, the rest disappears for us. It doesn't exist for us.
even though that structure is clearly there and is the reason why things are the way they are. But I was thinking about causality and thinking that if, you know, if I were on some sort of web that had a structure and I make it very simple, you know, it's like a sort of weaving on a loom where there's a right stitch, right stitch, left stitch, and there's this pattern. But the only thing that exists for me is each individual moment that I have access to. And so it's
It makes sense that it would seem to me that, you know, right stitch, right stitch causes left stitch, right? That those things don't come into being and that one thing being makes the other thing come into being and that that's kind of a false way of seeing things, but that the structure itself is always there.
Yeah, I think the key to this puzzle here is traces. So we happen to live in a corner of the universe, right? We happen to be here in a corner of the universe. This is just because we're here. I mean, we could be elsewhere. I mean, that's the contingency of...
It's specific of reality around us that there is a difference between the set of events that we call the past and the set of events that we call the future. And the difference is that in the present, there are many traces of the past events and little traces of future events. It's a contingent fact, I think, of nature. So in your mental game, if you were on this web,
and you happen to have next to you a lot of pictures, photographs of things far away from you but on the same side, and nothing at all of the other side, you would naturally consider one side a fix and the other side of open. And I think that's what happened to us. I think so too. Yeah. So it's the abundance of traces of the past. And the abundance of traces of the past by itself is not a mental phenomenon. It's a thermodynamical phenomenon. So it is a fact that...
that we only connect with macroscopic variables and not microscopic variables. So we describe things in terms of macroscopic variables thermodynamically. And macroscopically, because we are in an entropy gradient, because entropy would lower the past and higher in the future, this implies that there are traces of the past, namely that looking around us, we know the past easily and the future in a more difficult way.
So the future looks more mysterious to us because we don't have information about it. While nature is arranged so that we have a lot of information about the past and therefore we consider the past. That's what we mean by the past being fixed and the future be open. That's a meaning of that. So we shouldn't, in my opinion, think of this mysteriously, potentially becoming reality. That's
confusing because that doesn't mean anything, in my opinion. We should think that there are events. I think we should think about nature as events. But these events are connected, they're connected to one another probabilistically in such a way that microscopically we have information about the past. Microscopically, we have equal information about the past and the future, right? If we know the microscopic picture state of the world today,
The past and the future are exactly the same. There's no difference, both classically and quantum mechanically. Classically, it's uniquely determinate. Quantum mechanics is equally undeterminate, the past and future. So in this sense, I think this flowing of time ahead is illusory. Yeah, I do too. That's interesting. Okay. So let's see. I was going to have you read this beautiful section from your book. Which one? Page 182.
If the world consists of relations. If the world consists of relations, then no description is from outside it. The descriptions of the world are, in ultimate analysis, all from the inside. They are all in the first person. Our perspective on the world, our point of view, being situated inside the world, our situated self, as Janani Smile Beautiful puts it,
is not special. It rests on the same logic on which quantum physics, hence all physics, is based. If we imagine the totality of things, we are imagining being outside the universe, looking at it from out there. But there is no outside to the totality of things. The external point of view is a point of view that does not exist.
Every description of the world is from inside it. The externally observed world does not exist. What exists are only internal perspectives on the world, which are partial and reflect one another. The world is this reciprocal reflection of perspectives. So this is so wonderful. And this is something I'm going to spend hours and days and weeks and months thinking about because...
It's a way of describing something that I already had read about and understood. I don't know. It somehow opens my mind to thinking in new ways. I think that we used to think the world in the following way, that we can make sense of the world. That's what we used to think. By thinking that there are objects, we can sort of break the world apart in objects, right? There's this object, this pen, this computer, this lamp or this tree.
All these things. And each one has properties. Okay, so this plane is black, it's here, it's not moving or whatever. And I think what quantum mechanics is ultimately telling us that this doesn't work. This doesn't work well. It works to some approximation, it works to our microscopic classical picture, but it doesn't work in the details. What the properties of a thing are...
is the way in which these things affect other things. So therefore, they're those things by themselves. Do you have a sense of what that means without time and without causality? I mean, it almost seems impossible to talk about. Well, because if we think about time and causality, we should not talk about things. We should talk about processes.
So I think what the thing is, it's a long sequence of processes. Like Goodman said, an object is a monotonous process, the process repeats itself. So something that happens in some location of space or in some time, some other time, that's a process. Or this pen during one second is a process. And the way this process affects other processes is
is everything there is to say about this process. But how can we think about process without time? You think it's just impossible for us to... No, time is just our... What is that? Time is our way when there is a set of processes. But a process... Isn't a process kind of defined by time? Like a process seems to me one thing happening and then another thing happens and another thing happens. No?
No, no, no. Time is the counting of processes. Yeah, okay. One, two, three, four, five. Processes come before time, not the other way around. Yeah, no, I agree with you. It's just so hard for me to get my mind around to understand what that means. It's not, because look, well, you like experience. Our experience is day, night, day, night, day, night. And then we give a name to that, day one, day two, day three, day four, day five, and then say, oh, let's give a name to this sequence.
Let's call it time. Time is a game we give to set of processes that are next to one another. So there is no time, just processes. Do you see, I don't want to use the word fixed, but do you see the universe as a stable structure, which kind of just is what it is? Absolutely.
Absolutely not. Okay. Because we use stable. Yeah. I know. It's the wrong word. It's not quite what I mean. So what is something stable? This house is stable, meaning last year it was like that. This year it's still like that. We're talking about something outside of time. It's a structure of processes outside of time. Is that right? I think, yeah. I don't even know how to think about structure without space and time. I mean, I completely agree with you. And I do think...
I do think this is right. I mean, I'm completely convinced by your arguments and other people's arguments like you. Strangely, it also matches the experience. I wasn't going to talk much about this, but it's kind of just coming up for me naturally, but
There's something very interesting to me about the way all of this matches the insights one tends to have in meditation. I've spent many, many hours and have sat silent meditation retreats. I don't know if you've had any experience in meditation. And I don't think it necessarily would have to match. I wouldn't be surprised if all my experiences in meditation give me no insight into the way things are at all. I don't think it necessarily should match. But it's very interesting to me
That it does and that it's so close to when you pay close attention to your moment-to-moment experience, you know, in these micro moments for hours and days at a time. It just becomes so obvious that our experience is just dynamic to the core, that it is these processes in this way and that there's truly nothing to hold on to.
It's hard to even pinpoint what the present moment means when you start paying close attention to it. You know, some Buddhist teachers talk about it as the passing moment, which is a better way to describe what it is. But there's this really kind of strong insight that nothing is stable or static or isolated. It's such a stark difference from the way we normally go about our daily lives and feel that the world is.
Okay, so no self, no space, and no time. You're really taking a whole lot away from my world over here, Annika. Yeah, sorry.
But I think that shifting our experience of these things that we tend to take at face value and that we think of as the canvas on which everything else plays out, that we tend to look right past. And viewing them with fresh eyes gives us a new exciting dimension to the deeply mysterious nature of reality and to the mystery of consciousness.
And you aren't going to take that away. No, I promise. Okay. Consciousness is the one thing I won't take away. Okay. So let's check in with your timeline as you were preparing your presentation for Philip Goff's consciousness conference. Had you figured out what you wanted to say at this point? Yeah, my thoughts were finally starting to take shape through all these conversations.
And I was getting clearer about which scientists and philosophers' efforts I thought held the most promise, as well as the questions that seemed most important to address regarding consciousness being fundamental. I was also beginning to take note of which theories in the field strongly stem from and rely on the assumption of self.
and a lack of understanding of its illusory nature in one way or another, making them likely hopeless paths forward for that reason, in my mind. But there were two more people I wanted to have conversations with before I finalized my talk.
The first was Donald Hoffman, a scientist working on a theory of consciousness who I had actually been meeting regularly with for years, ever since I reached out to him after seeing his TED Talk in 2015 called Do We See Reality As It Is?
He was the first person who introduced me to ADS-CFT duality and how it relates to the holographic principle, and the work being done by the physicists Juan Maldacena and Nima Arkani-Hamed, who I've mentioned, at the Institute for Advanced Study, which concludes, as Nima often puts it, that space-time is doomed. In space and time, we've had this useful notion of causality, but it
It's apparently just a useful fiction and not a deep insight into reality. There is a reality beyond, and it may just be consciousness, and interaction with that reality leads to certain experiences that are triggered by a much more complicated realm that I'm interacting with.
You'll hear more of my conversation with Donald Hoffman, as well as my exchange with the physicist and astrobiologist Sarah Imari Walker about her collaborative effort with the chemist Lee Cronin and what is called assembly theory in Chapter 9 of Lights On, Consciousness as Fundamental. Okay, well...
I guess there's nothing left to say but congratulations. I'm very happy to see this work finally in the world. You've spent a long time on this, and it's got to feel good to have it finally out there. Yeah, it does. It's great to share it. Yeah, yeah. Well, now people get to enjoy it. I can tell Violet I didn't cry.
It feels weird to thank you for having me on. No, no, don't do that. Thank you for marrying me. Maybe that's it. I can thank you for marrying me. Thank you for marrying me.