The Jordan B. Peterson Podcast - 486. The Intersection of Science and Meaning | Dr. Brian Greene

Episode Date: October 3, 2024

Dr. Jordan B. Peterson sits down with physicist and author, Dr. Brian Greene. They discuss the strange conceptualization of “before” the Big Bang, how time might be a microscopic phenomenon, how o...rder existed at the point of the universe's creation, what would happen if you fell into a black hole, and the process of going from understanding to harnessing new insights. Dr. Brian Greene is an American physicist known for his research on string theory. He is a professor of physics and mathematics at Columbia University and the chairman of the World Science Festival, which he co-founded in 2008. Dr. Greene has worked on mirror symmetry, relating two different Calabi–Yau manifolds (concretely relating the conifold to one of its orbifolds). He also described the flop transition, a mild form of topology change, showing that topology in string theory can change at the conifold point. This episode was recorded on September 9th, 2024  - Links - For Brian Greene: On X https://x.com/bgreene?lang=en Website https://www.briangreene.org/ "Until the End of Time: Mind, Matter, and Our Search for Meaning in an Evolving Universe" (Book) https://www.amazon.com/Until-End-Time-Evolving-Universe/dp/1524731676 "The Elegant Universe: Superstrings, Hidden Dimensions, and the Quest for the Ultimate Theory" (Book) https://www.amazon.com/Elegant-Universe-Superstrings-Dimensions-Ultimate/dp/039333810X 

Transcript
Discussion (0)
Starting point is 00:00:00 Hello everybody. I had the opportunity and privilege today to speak with Dr. Brian Green, who's a physicist and an author of a number of books. The book we delved into most deeply today was The Elegant Universe, Super Strings, Hidden Dimensions and the Quest for the Ultimate Theory that was originally published in 1999, but he's offering an updated version as of 2024. And so we had a chance to delve into the mysteries of quantum mechanics, special relativity, and string theory. And string theory is a branch of physics that was designed or emerged to deal with the contradictions that exist between general relativity and quantum mechanics.
Starting point is 00:00:56 And so what did we do in our discussion? Well, we talked about quantum mechanics and what it means and signifies. We talked about the theory of general relativity. We talked about the nature of time and the nature of entropy, which are concepts that are quite tightly related. We talked about the infamous double-slit experiment, which is a mind twister to say the least. We talked about the potential testing of string theory. We talked about what it has to offer
Starting point is 00:01:31 and what we talked about consciousness and the perception of time and the relationship between the perception of time and entropy and the expansion between the perception of time and entropy and the expansion of the universe. And we talked about situating that more narrow pursuit of the truths of physics in a, what, in a more broadly humanistic approach to the world at large. And so if you're interested in the mysteries of physics
Starting point is 00:02:06 and the relationship between the various deep theories of physics to one another, and trying to develop some understanding of cutting edge inquiry in that regard, particularly in relationship to string theory, let's say, then this is the conversation for you. Thanks to Dr. Brian Green for agreeing to put up with my questions and for sharing his deep knowledge
Starting point is 00:02:35 with me and my viewers. So Dr. Green, you've written a number of books. I think I'll just list them. And if I miss any, I don't think I will, but if I do let me know Until the end of time that was 2020 light falls 2016 the hidden reality 2011 Icarus at the edge of time
Starting point is 00:02:59 2008 the fabric of the cosmos 2004 and the elegant universe, superstrings, hidden dimensions, and the quest for the ultimate theory. That was published originally in 1999, but it's been updated for 2024. And I guess that's part of the occasion for our discussion.
Starting point is 00:03:17 And so you've been investigating and popularizing advanced physics for a very long time. And I guess we'll have an opportunity to delve into that today. So I wanna go through the elegant universe in some detail, but if you don't mind, I'd like to take this opportunity to ask you some questions
Starting point is 00:03:40 that I've been wanting to ask a theoretical physicist for a long time. And that'll help me rectify some holes in my knowledge. So the first, I wanted to ask you about two things that are related to begin with. One has to do with time and its relationship to entropy. And I just wanna see if I understand that relationship. I have some specific reasons for that
Starting point is 00:04:08 because there are attempts in the neuroscience literature to tie emotional processing, both on the positive and negative side, to the concept of entropy. And I did some work on that topic, especially with negative emotion in my lab, and I want to make sure that I actually understand the underlying concept. And it should be of some interest to the people who are watching and listening.
Starting point is 00:04:33 So the first question I have is whether or not it's reasonable to, is there a distinction between time and change? My sense is that, and this ties us into the entropy discussion, I guess, to some degree, my sense is that our perception of time, which is difficult to distinguishable from time itself as a phenomenon, our perception of time is something like our abstraction of average rates of change. And it also seems to me that in a system where there's no change, like a closed system where there's no change, there's also no time.
Starting point is 00:05:18 And that time is something like the walk through the multiple states that a complex system can be in and that that's essentially associated with something with entropy. Now is there anything wrong with this? I mean it's very close. Not really at all. Okay. I say that the real challenge to give a precise answer to your question, which is a good one. The challenge is nobody has a real definition
Starting point is 00:05:48 of what the word time actually means, what it is. The best that we can do in physics is posit that there is some access, there is some quality that we can measure change by invoking, much as you just described. We say that time is elapsed because the system has changed. But is that a real definition of time? Not really, it's a very pragmatic approach.
Starting point is 00:06:19 In our equations, we have a little variable called T. It's introduced in basically all the dynamical equations of physics. And yet we are still struggling to figure out, is it something we impose from the outside because it's a useful way of organizing experience to have a temporal order to things? Is it fundamentally written into the laws of reality
Starting point is 00:06:42 that there is this thing called time? Might there be realms of reality where there is no time, and yet there's still something there that we would call in existence? So these are the big tough questions that we've yet to fully been able to grapple with. Well, I saw Richard Dawkins recently being interviewed by Pierce Morgan and Pierce was struggling with the idea that there was no time before the Big Bang and that obviously violates our embodied intuitions, right, which are strongly tilted in the direction of presuming time as a constant and but. But I would even say the framing of that question is an interesting one, because to talk about
Starting point is 00:07:27 before the Big Bang is to assume that the notion of before is applicable in that extraordinarily different realm of existence in everyday life. Of course, the word before makes sense. But when you get right back to the Big Bang, it could be that this conception of time emerges with that event and the very concept of before may be meaningless. It's like, you know, Stephen Hawking had a great analogy here, which was if you're walking on planet Earth and you
Starting point is 00:07:58 pass somebody, you tell, ask them which way is north, they point you northward, you keep on walking, you ask somebody else, how do we go further north? They point you northward. You keep on walking. You ask somebody else, how do I go further north? They point you further north as well. When you get to the North Pole and you say to somebody there, how do I go further north than the North Pole? They look at you quizzically because it doesn't make any sense. You've reached the location on earth where north begins. The Big Bang could in principle be the location in reality where time begins
Starting point is 00:08:25 and going further back in time maybe as nonsensical as going further north than the North Pole. This is exactly the difficulty of conceptualization that Pierce was struggling with. To me, it's a lot easier to understand that if you understand that there is no fundamental distinction between time and change. And so if time, if the existence of time is predicated, let's say on the existence not only of matter, but of matter that's changing, and you have a state where there's either no matter
Starting point is 00:08:58 or the matter that is there is not changing in any manner, the whole notion of time vanishes is there is not changing in any manner, the whole notion of time vanishes because the phenomenon itself doesn't exist. And okay, so all right, so then let me ask you about the idea of entropy a little bit. So it's very difficult for me to understand entropy except in relationship to something like a goal. So let me lay out how this might work psychologically.
Starting point is 00:09:34 Carl Friston has been working on this. He's the world's most cited neuroscientist. And I interviewed him relatively recently. And he has a notion of positive emotion that's associated with entropy reduction. And our work is run parallel with regards to the idea that anxiety is a signal of entropy. So imagine that you have a state of mind in mind,
Starting point is 00:10:02 that's a goal. You just want to cross the street. That's a good simple example. Now, imagine that what you're doing is comparing the state that you're in now, you're on one side of the street, to the state that you want to be in, which is for your body to be on the other side
Starting point is 00:10:24 of the street. And then you calculate the transformations that are necessary, the energy expenditure and the actions that are necessary to transpose the one condition into the state of the other condition. Then you could imagine there's path length between that, right, which would be the number of operations necessary to undertake the transformation. Then you could imagine that you could assign to each of those transformations something approximating an energy and materials expenditure cost. And then you could determine whether the advantage of being across the street, maybe it's closer to the grocery store, let's say, whether the advantages outweigh the disadvantages. Okay, now, if you observe yourself successfully taking steps that shorten the path length across the street, that produces positive emotion. And that seems to be technically true.
Starting point is 00:11:19 And then if something gets in your way, an obstacle emerges or something unexpected happens, then that increases the path length and costs you more energy and resources and that produces anxiety. Now the problem with that from an entropy perspective is it seems to make what constitutes entropy dependent on the psychological nature of the target. Like I don't exactly know how to define one state as say, more entropic and maybe it doesn't make sense, more entropic than another, except in relationship to like like a perceived end point.
Starting point is 00:12:08 I mean, otherwise, I mean, I guess you associate entropy with a random walk through all the different configurations that a body of material might take at a certain temperature. It's something like that. And I would say it analogous to that, but a little bit different. So what we do is we look at the space of all possible configurations of a system, whether it's a psychological system or whether it's air molecules in a box.
Starting point is 00:12:35 It doesn't really matter to us the way we humans interpret that system. We simply look at the particles that make up the system and we divide up the space of all possible configurations into regions that from a macroscopic perspective are largely indistinguishable, right? The air in this room, it doesn't matter to me whether that oxygen molecule is in that corner or that corner, it would be indistinguishable.
Starting point is 00:13:02 But if all the air was in a little functionally equivalent. But if all the air was in a little ball right over here and none was left for me to breathe, then I would certainly know the difference between that configuration of the gas and the one that I'm actually inhabiting at the moment. So they would belong to different regions of this configuration space, which I divide up into blobs that macroscopically are indistinguishable. And we simply define the entropy in some sense to be the volume of that region. So high entropy means there are a lot of states that more or less look the same, like the gas in this room right now.
Starting point is 00:13:41 But if the gas was in a little ball, it would have lower entropy because there are far fewer rearrangements of those constituents that look the same as the ball of gas. So it's a very straightforward mathematical exercise to enumerate the entropy of a configuration by figuring out which of the regions it belongs to. But none of that involves the psychological states that you make reference to. So now there may be interesting analogies, interesting poetic resonances, interesting rhyming between the things that one is interested in from a psychological perspective and from a physics perspective, but the beauty or the downfall, depending how you look at it, of
Starting point is 00:14:21 the way we define things in physics, we kind of strip away the psychological, we strip away the observer dependent qualities, we strip away the interpretive aspects in order to just have a numerical value of entropy that we can associate to a given configuration. Right, well, what you're trying to do when you control a situation psychologically is to specify the, I suppose it's something like specifying the entropy,
Starting point is 00:14:48 right? Because you're trying to calculate the number of states that the situation that you're in now could conceivably occupy if you undertook an appropriate, what would you say, an appropriate course of action. And as long as while you're specifying that course of action, the system maintains its desired behavior, then it's not, for example, it's not anxiety provoking and you can presume that your course of action is functional. And I'm saying if that proves to be a valuable definition
Starting point is 00:15:19 to acquire insight into perhaps human behavior or the psychological reasons for crossing that street, as you were describing before, then that may be valuable within that environment. The reason why we find entropy valuable as physicists is we like to be able to figure out the general way in which systems evolve over time. And when the systems are very complicated,
Starting point is 00:15:45 again, be it gas in this room or the molecules inside of our heads, it's simply too complicated for us to actually do the molecule-by-molecule calculation of how the particles are going to move from today until tomorrow. Instead, we have learned from the work of people like Boltzmann and Gibbs and people of that nature a long time ago, we have learned from the work of people like Boltzmann and Gibbs and people
Starting point is 00:16:05 of that nature a long time ago, we've learned that if you take a step back and view the system as a statistical ensemble, as an average, it's much easier to figure out on average how the system will evolve over time. Systems tend to go from low entropy to high entropy from order toward disorder. And we can make that quite precise in the mathematical articulation. And that allows us to understand overall how systems will change through time without having to get into the detailed microscopic calculations. Okay.
Starting point is 00:16:42 So there's some implications from that, as far as I can tell. One is that time itself is a macroscopic phenomena. And then the other, see, there's times when it seems to me, and correct me if I'm wrong, that you're moving something like a psychological frame of reference into the physical conceptualizations.
Starting point is 00:17:11 Because, for example, you described a situation where if there was a room full of air, one of the potential configurations is that all the air molecules are clustered in one corner. And at least it's denser there. Now, it's going to be the case that on average, the vast majority of possible configurations of molecules in, of air molecules in a room, are going to be characterized by something approximating random disbursement. And so that fraction of potential configurations where there's, what would you say?
Starting point is 00:17:51 There's differences in average density are going to be rare. But what you did say that you use the term ordered and I guess I'm wondering if there is a physical definition for order. Because the configuration where there's density differences is, has a certain probability. It's very low, but it has a certain probability. There isn't anything necessary that marks it out as distinct from the rest of the configurations except its comparative rarity. But you can't define any given configuration as differentially rare because every single configuration is equally rare.
Starting point is 00:18:38 So how does the concept of order, how do you clarify the concept of order from the perspective of pure physics? Yes, and so you're absolutely right. When you begin to delineate configurations that you describe as ordered or disordered, low entropy or high entropy, it is by virtue of seeing the group to which they belong, as opposed to analyzing them as individuals on their own terms. And when we invoke words like order and disorder, obviously those are human psychologically developed terms. And where does it come from? It comes from the following basic fact, which is if you have a situation
Starting point is 00:19:24 that typically we humans would call ordered, for instance, if you have books on a shelf that are all alphabetical, there are very few ways that the books can meet that criterion. In fact, if you're talking about making them alphabetical, there's only one configuration that will meet that very stringent definition of order. You could have other definitions of order, like all the blue ones are here and all the red covers are here. Then there's a few. You can mix up the blues, you can mix up the reds, but you can't mix them together.
Starting point is 00:19:55 So again, you have a definition of ordered. Disordered is when you can have any of those configurations at all. So clearly, an ordered configuration is one that's harder to achieve. It's more special. It differs from the random configuration that would arise in its own right if you weren't imposing any other restrictions. And so that's why we use those words, but you're absolutely right. Those words are of human origin and they do require. It's partly improbability and rarity. And then the emotional component seems to come in in that it's not only rare and unlikely,
Starting point is 00:20:39 but it also has some degree of functional significance. I mean, the reason that you alphabetize your books is so that you can find them. And so it's a rare configuration that has functional utility. And that's, and that's not a bad definition of order. But the problem with that from a purely physical perspective is a definition that involves some subjective element of analysis. So that's, that's fine. It does.
Starting point is 00:21:04 And this is by, but I should say this has bothered physicists for a very long time, that when you invoke the notion of entropy, unlike most other laws in physics, like, you know, Einstein's equations of general relativity or Newton's equations for the motion of objects, you can write down the symbols, everybody knows exactly what they mean, and you can simply apply them and start with a given configuration and figure out definitively what it will look like later. Entropy and thermodynamics and statistical mechanics,
Starting point is 00:21:35 which is the area of physics that we're talking about here, is of a different character. Because for instance, the second law of thermodynamics that speaks about the increase of entropy, going from order to disorder, you know, your books are nice and alphabetized, but you pull them out, you start to put them back and you're gonna lose the alphabetical order
Starting point is 00:21:53 unless you're very careful about putting the books back in. It's more likely that you get to this disordered state where they're no longer alphabetized in the future. But that's not a law, That's a statistical tendency. It is absolutely possible for systems to violate the second law of thermodynamics. It's just highly improbable. If I take a handful of sand and I drop it on the beach, most of the time it's just going to splatter and move those sand particles all over the surface. But on occasion, is it possible that I drop that handful of sand and it lands in a beautiful sandcastle?
Starting point is 00:22:31 Statistically unlikely, probabilistically unlikely, but could it happen? Yes. And if it did, that would be going from a disorder to an ordered state, violating the second law of thermodynamics. So that's why this law is of a different character than what we are used to in physics. Yeah, well, that's what we've been trying to wrestle with to some degree on the neuroscience.
Starting point is 00:22:51 And so, okay, so let me ask you another question. It's probably obvious to you, but I just also want to make sure that I've got it right, is that there is a widespread consensus, let's say, that the universe is expanding. And is there any difference between that proclivity for the universe to expand and time itself, and also more specifically the forward direction of time. Like is the expansion of the universe the macro equivalent of the arrow of time at the more micro and subjective
Starting point is 00:23:33 level? Some people have thought so. There was a time even when Stephen Hawking a while ago made a claim of a similar sounding sort. Currently we do not believe so. We have theoretical models in which the universe can expand and even then contract, even though the direction of time has not reversed when the rate or direction of expansion has changed. And so the idea that the way in which the universe expands is intrinsically tied to the arrow of time
Starting point is 00:24:06 is not one that is currently at all in favor. In fact, the issue of the arrow of time is one of the big perplexing questions, which we can only at the moment give the following answer to when you're talking cosmologically. If entropy is meant to increase toward the future, then just running it backward, you'd think that entropy must have been lower in the past. And if you take that directive and you push it to its limits, it would suggest that at the Big Bang, entropy was in a really low value,
Starting point is 00:24:44 really ordered state. Now that's confusing because A, we don't really know how the universe came into existence, but B, if it's so ordered, you ask yourself, how did it get so ordered? I mean, when the books on the shelf are alphabetized, we know how they got ordered. Some intelligent being came along, you or me or my kid, and put the books in alphabetical
Starting point is 00:25:07 order. But if the moment of creation was so highly ordered, the question is, who did that or what did that or what's the origin of this order? And this is a vital question. Because if the Big Bang was not highly ordered, if it was disordered, if it had high entropy, there'd be no opportunity for ordered structures like stars and planets and life forms to ever exist. So we owe our existence to the apparent fact that the Big Bang was highly ordered, giving the opportunity for ordered structures to then emerge as the unfolding and change.
Starting point is 00:25:45 What's the relationship? Okay, I have two questions on that front then. What's the relationship between the ordered state at the hypothetical Big Bang and the emergence of order on the cosmological and galactic level following the Big Bang? I don't understand that relationship. And then, so that's one question. The other question is, you know, I read a brief history of time, a long time ago. So I have, I want to ask a couple of questions about that. So when the universe is contracting within Hawking's model, there is this proclivity, as you just pointed out, for everything to move from a state of relative disorder and dispersal to a state of relative order.
Starting point is 00:26:27 And Hawking seemed to imply in that book that that meant that the arrow of time was running backwards. But that puzzled me in two ways, and one would be that there could still be all sorts of random perturbations in systems that were collapsing. And the other is that it seems to me that the notion of quantum uncertainty also disproves the idea that the time, the arrow of time would run backwards in some deterministic way, because there's no, so okay. So that's the question on the Hawking side. So.
Starting point is 00:26:59 Yep. So let me answer those in reverse order because it's worthwhile noting that Hawking himself changed his mind on this point regarding the reversal of the arrow of time upon contraction. So much of your concern with that is actually borne out by our views as well. So nobody really takes seriously this idea anymore that the arrow of time would reverse. But the first question of how do you get the ordered structures like stars and galaxies from this Big Bang beginning is a deep one.
Starting point is 00:27:31 And I believe that we have some insight into that, which more or less goes like this. The Big Bang happens, the universe starts swelling rapidly, and the energy that drove that expansion then disintegrates into a bath of particles that fill space. Now you might think a bath of particles filling space, that sounds disordered, that sounds really high entropy, like the gas in this room, the particles are filled out through the room. Perhaps things would just stay that way and there would never be clumps of particles.
Starting point is 00:28:11 And what changes is when gravity matters, and it does on cosmological scales, it doesn't matter in this room. Gravity is irrelevant to the air molecules in this room. But gravity does matter if you have enough particles filling space, and that certainly happens with the universe as a whole. And what that means is gravity starts to pull. Little inhomogeneities, a little denser knot of particles here, a little less dense over here, the denser one starts to pull in more particles. It gets denser still. And because it's denser, its gravitational pull is yet stronger and it pulls in more particles.
Starting point is 00:28:41 And ultimately you get these locations where particles begin to implode in on themselves, getting hotter and denser, ultimately igniting nuclear processes and a star is born. And the beautiful thing about this, and this is incredibly subtle, but the beautiful thing is this formation of the star is indeed a drop in entropy. A star is more ordered than the original configurations, but in the formation of the star, the star gives off heat and light that emits entropy to the wider environment.
Starting point is 00:29:18 I like to call this the entropic two-step. Entropy goes down in the formation of the star, but it goes up in the wider environment. And overall, the entropic balance works. The overall entropy goes up, even though you get a pocket of order in the wake of that entropic increase. Okay, when human beings do that too. Exactly. That's what we do, right? So, you know, we eat food, we take in these orderly sources of energy, we burn that fuel to allow biological processes to take place, keeping our entropy low. But in the process, we go off heat, we expel waste. And if you take account of that, then the
Starting point is 00:29:58 overall entropy of us and the environment does go up. But our entropy is able to kind of thumb its nose at the second law of thermodynamics, at least while up, but our entropy is able to kind of thumb its nose at the second law of thermodynamics, at least while we're living, and are able to keep our entropy stable. So let me ask you a question about that initial clumping. It occurred to me, I'm sure this isn't an original idea, that so if that initial state,
Starting point is 00:30:27 that initial state immediately after the Big Bang can't be homogeneous, perfectly homogeneous, because quantum uncertainty with regards to the positioning of the particles would mean that there would be some lack of homogeneity. And the explanation you gave seems to imply that even minor deviations of homogeneity. And the explanation you gave seems to imply that even minor deviations in homogeneity would start a clumping process, would begin the clumping process. And then once it starts, it's going to,
Starting point is 00:30:56 it's going to capitalize on itself. And so is it, is the lack of homogeneity after the Big Bang a direct consequence of quantum uncertainty with regards to the position of the particles? It is, it is. That's exactly right. And it's even more than just an interesting idea. What we've been able to do,
Starting point is 00:31:18 and these are calculations that go back to the 1980s, we've been able to model the early universe mathematically using quantum physics, using Einstein's general relativity, and we've been able to calculate how the uncertainty in the positions and the energies and the speeds of the particles should affect the environment. And we've been able to calculate that it should cause tiny inhomogeneities as well in the temperature of the night sky and the temperature of space. Which means that if you could measure the temperature of the night sky to adequate precision, you should be able to test the prediction.
Starting point is 00:31:55 And this is what we have been able to do with the so-called cosmic microwave background radiation. This is heat left over from the Big Bang. And starting in the 1990s with ever greater precision, we've used space telescopes and other devices to measure the temperature of space. And the agreement between the theoretical predictions and the observations is so incredibly accurate
Starting point is 00:32:21 that to see the error bars in the measurements, you have to magnify them by like a factor of 500 so that the naked eye can even see them on the graph. That's how tightly there is an agreement between the mathematical calculations that we humans do, these little biological systems crawling around this planet, barely coming of age in the Milky Way galaxy, been able to calculate conditions billions of years ago and compare them to observations and they agreed to spectacular precision. This is one of the great triumphs of modern science. I see. So you could detect lack of homogeneity
Starting point is 00:32:56 in the background temperature. And that was also indicative of lack of homogeneity in terms of dispersal of particle density. Exactly. Oh wow, okay, that's very cool. All right, so that is so interesting because that implies as well that or indicates that quantum uncertainty makes it impossible for there to be a homogenous distribution of particles. There's going to be asymmetries emerge. And those asymmetries... There have to be. Right, and then the asymmetries expand up
Starting point is 00:33:29 until they manifest themselves at a cosmological level with stars and galaxies and those large filaments that the galaxies appear to congregate in. Wow, okay, so that's how that comes about. We are the progeny, we are the progeny of quantum uncertainty writ large across the universe. Right, right, right. Okay, okay.
Starting point is 00:33:49 So, all right, let me, if you don't mind, I have one other specific question before I turn to maybe the more particular details of your work, especially with regards to string theory. So, you know, I've been perplexed like so many people with the double slit experiment. And the fact that if you, I'll just review it for people very briefly. If you shine light through a, say a cardboard sheet that has slits in it,
Starting point is 00:34:17 and you put a photographic plate behind it, you can produce interference patterns that you can capture with the photographic emulsion. And the hypothesis is that when the light beams go through the slits, they interfere with one another. And so you get these variegated zebra-like patterns on the photographic emulsion. But the peculiar thing about that setup
Starting point is 00:34:45 is that if you slow the transmission of the light through the slits down to one photon per unit of time, so that there's only one photon being admitted, you still get the interference patterns. Okay, so I had a thought about that and I want you to correct it if it's wrong or indicate if it's right. So my understanding is that at the speed of light,
Starting point is 00:35:14 the universe is flat, perpendicular to the direction of the travel of the light beam and that there is no time. And so is it not fair to say that from the perspective of the photons, like from our perspective we're firing one photon at a time, but from the perspective of the light beam, the light beams, there's no difference between the one photon at a time state and the shining a light beam that's composed of an indefinite number of photons at the same time.
Starting point is 00:35:47 If there's no time from the perspective of the light beam, then it's all the same to the light, whether it's one photon at a time or a plethora of light. Now, so I don't exactly understand what that means because I can't understand the difference between the time-free frame of reference that the light beam has and our expansion of that. But is there something wrong in my reckoning with regards to the idea that time has collapsed and so it's irrelevant from the perspective of the light? Well, what I would say there is that from a poetic sensibility, if you apply Einstein's special theory of relativity to the frame of reference of a photon, then the things that you say are correct.
Starting point is 00:36:37 But I always caution my students against taking that perspective, because what you're ultimately doing is you're infusing the photon with the very things that we care about, such as time and space and interference patterns. But the photon doesn't have any capacity to care about those things. The photon doesn't have any conscious experience. What we want to do is explain our experiences
Starting point is 00:37:04 in our frame of reference. experiences in our frame of reference. And in our frame of reference, photon upon photon upon photon do have temporal separations. So while it's kind of mind-slapping to imagine yourself in the perspective of a photon, it's not a perspective that any material object can ever have. The special thing about a photon is that it's massless, and only massless objects can ever achieve the speed of light. And that's why us and material objects will never have that perspective. So if we want to explain the things that we encounter,
Starting point is 00:37:40 the things that we experience, we have to use a frame of reference that is not moving at the speed of light in the manner that you described. And so if it offers some sort of poetic insight to imagine that there's no time from the point of view of a photon, there's no space, it's all been Lorentz contracted infinitely far, these are actually pushing Einstein's ideas a little too far. Poetically, you can do it, but Einstein's derivation of time dilation and Lorentz contraction, it all was from the perspective of a massive body that was not itself traveling at light speed. Right, well I guess that the reason I was thinking along those lines wasn't so much,
Starting point is 00:38:16 at least as far as I was concerned, for poetic reasons, but to explain the fact that the interference actually still happens if the reality, and not merely subjective reality, if the reality that the photon is operating in lacks the temporal dimension because it's contracted, then of course it's going to, the interference, the interference phenomenon is still going to make itself manifest. And that seems to me, maybe I'm misunderstanding you,
Starting point is 00:38:45 but that seems to me to be more than merely poetic. It seems to me to be an explanation for why the interference phenomena still makes itself manifest. It's all happening at the same time, as far as the, from the, I don't mean the subjective perspective of the light beam, because as you pointed out, that's preposterous, because it doesn't have a perspective but it still is interacting with its
Starting point is 00:39:09 other with the with the other photons in that in that setup because the temporal dimension is collapsed and that seems to be an explanation. Go ahead. But again it's pushing Einstein's special relativity to a place that it doesn't technically apply. So when Einstein derived all of the ideas that you're implicitly making use of, that there's this thing called time dilation, which becomes infinitely big at light speed, or this thing called Lorentz contraction that becomes infinitely small at light speed. Einstein's derivation only worked for speeds
Starting point is 00:39:45 that were less than the speed of light, not equal to the speed of light. So there's a technical glitch in trying to actually push that idea through. And so what we have been forced to do is stick with the perspective that we actually have in the laboratory and try to explain what we see,
Starting point is 00:40:04 which is utterly bizarre as you set it up, that individual photons that are encountering this barrier with the two openings somehow still produce this interference pattern that is a wave-like phenomenon, but what does it mean to have a wave when you've got one particle, right? That's the big puzzle. And the solution that we've come to
Starting point is 00:40:24 is that individual particles do themselves have a wave-like quality, an unexpected one. It's a quantum wave that was introduced by the great thinkers in the early part of the 20th century, beginning with Einstein, and then Niels Bohr and Werner Heisenberg and Erwin Schrödinger and Max Born and Paul Dirac and all the people who developed these ideas. But the bottom line is, individual particles have a spread out wave-like quality and that wave is not an electromagnetic wave. It's not a wave of light, if it's a photon, say. Rather, it's a probability wave. It's a wave that no one had ever anticipated arising in our understanding of the physical world. The idea of being the best you can ever do is predict the likelihood or the probability of a particle being here or here or there. Unlike what Newton would have said, Newton would have
Starting point is 00:41:17 said, just tell me where the particle is and how fast it's moving right now and I'll use my math to tell you exactly where it will be later on. And quantum physics had to turn to Newton and say, you're asking for an impossibility. You can't tell where a particle is and how fast it's moving. There's quantum uncertainty and the best you can do because of that is predict probabilities of a particle being one place or another. Right. Okay.
Starting point is 00:41:43 So, let me delve into that a little bit. I know that's like impossibly incomprehensible in a way, but the wave that you're describing as a probability wave, that's the possibility that a given phenomena, let's say speed and location, might make itself manifest, but it's indeterminate. There's some circumstances under which it's indeterminate. There's some circumstances under which it's indeterminate. And I don't exactly understand the circumstances under which it's indeterminate. In conventional quantum mechanics, it would be all situations.
Starting point is 00:42:17 Conventional quantum mechanics would say, you physicists or you human beings, you're asking for too much. Your intuition based on everyday experience has misled you into thinking that you can talk about the position and the speed of objects. You can't. You can talk about one or the other, or you can talk approximately about each, but you can't delineate both simultaneous
Starting point is 00:42:40 with total precision. It simply can't be done. You've been misled by common experience. Macroscopic experience. Macroscopic experience is a completely misleading guide to how the microscopic world works. And, you know, we really shouldn't be too surprised by that. Why should it be the case that the things that we experience in everyday life also govern the incredibly small or the incredibly big, and it turns out that they don't.
Starting point is 00:43:12 But I will say one thing just on the side, there are alternative ways of talking about quantum physics and articulating it mathematically that have not achieved the kind of widespread acceptance as the version that I'm relying upon in our conversation here. And in some of those alternative versions, which are perfectly good, they make the same predictions, you have a situation where you can delineate a particle's speed and position. They are determinate. The indeterminacy comes into the equations in a different manner. So this is an approach that was developed by David Bohm. It was developed by Louis de Broglie, it got completely ignored in the
Starting point is 00:43:50 history of quantum physics for the most part. There are some people who think about it today, but I only raise this to say even with a subject like quantum physics, which we can now use to make predictions that agree with experiments to nine or ten decimal places, That's how precise these ideas are. They're still an interpretive quality. They're still struggling to make sense of what it is that it's really telling us about reality. And there are alternate versions
Starting point is 00:44:15 that are out there right now that in principle are each as good as the other in the minds of their different proponents. Right, right. So it's useful to keep in mind the fact that those interpretive, that there's a variety of opinions with regards to the plethora of interpretive frameworks that might be appropriate. So yeah, there is a dominant, there's a dominant one. I don't want to give an incorrect view. Most physicists who you talk to will speak in the manner that we were a moment ago,
Starting point is 00:44:42 but I always feel that it's worthwhile pointing out that that's not the only way that you can talk about quantum physics. This is a very ill-formed question. And it sort of pushes me to the edge of my understanding. I've spent a lot of time studying mythology and the ordering effect of consciousness is something that's represented in deep narratives universally. And the story is something like an ordering agent encountering a field of possibility
Starting point is 00:45:21 and casting it into a determinant and somewhat fixed order. So for example, in the Genesis account, the waste and chaos that the Spirit of God encounters is the Tohu Vabohu. And it's something like a field of potential. And I've been curious about that, about the relationship between that and these ideas at a quantum level, that the ground of reality
Starting point is 00:45:53 at the most fundamental material level starts to become something other than the determinant particles of dust that we're familiar with from our day-to-day experience, that it's something like a realm of, determinant particles of dust that we're familiar with from our day-to-day experience, that it's something like a realm of, realm isn't precisely the right word, but I'll use it because I don't have a better one, a realm of possibility that can be cast into the actuality of the present and the past.
Starting point is 00:46:20 And so I'm wondering how you understand that wave. You know, you were careful to distinguish it from the electromagnetic wave form. And you're talking about it as, I understand it correctly, as a field of possibility, a field of actualizable possibility that exists in potential, whatever that means, before it's actualized into an actual event. And so
Starting point is 00:46:47 how do you or do you understand that field of possibility and what existential or phenomenological significance might that have? Do you have any sense of what that might mean? Yeah, it's a deep and very difficult question. And let me just give you a little bit of insight as to why it's so difficult that may not be obvious from what we've discussed so far. If we have a single particle, a photon or electron, we can talk about its probability wave as existing in ordinary three dimensions, because after all, it's telling us the possible, the potential locations that that particle might occupy. And of course, those locations exist in three dimensions.
Starting point is 00:47:32 But if you have two particles, that wave doesn't now exist in three dimensions. It exists in six dimensions, because there are three locations where the first particle might be, and there are three coordinates, I should say, that would delineate the location of the second part. So three coordinates for the first, three coordinates for the second. If you have three particles, that wave lives in nine dimensions, four particles, it lives in 12 dimensions. If you have a trillion particles, that wave lives in three trillion dimensions.
Starting point is 00:48:04 How do you think about that wave lives in three trillion demeri- how do you think about that wave? So that wave as something that for one particle is at least, it's tricky, but at least you can envision it as, you know, some gossamer substance that's filling space and where that gossamer substance has a little bit, you know, more opaque, high probability, where it's thinner, low, you can think about, you can cogitate on that. I don't know how to cogitate on the version that describes many particles because it's beyond my capacity to envision the arena within which that wave exists. So it's a tough, tough question.
Starting point is 00:48:43 And sort of the way it relates, at least the way I try to make it relate to the kinds of topics that you were speaking of, be it the Bible, be it mythology, I sort of see reality as striated, stratified into different layers that all relate to each other. And you need to choose the right language, the right story, if you will, to gain insight into whatever layer you're interested in. And if you're interested in the rock bottom reality, quantum physics is where you should absolutely go.
Starting point is 00:49:13 If you're interested in the layer where particles come together into molecules, well, that's more chemistry, how they come together into cells, more biology, how they come together into living systems, you know, then you get into the self-consciousness, neurology, psychology. So you see all these nested stories, are they reliant upon quantum physics? In the rock bottom reality, they are, but the language that's more useful at the higher levels, of course, is the higher level language that we invoke. And so, you know, to me, mythology is this wonderful realm where we human beings have struggled to find coherence at the societal level to try to understand our own mortality, to try to understand where we came from and where we're going, not from general relativity,
Starting point is 00:49:59 but from a more human standpoint. And so that's where I see those stories interfacing with the cosmological and quantum mechanical story. Okay, so you talked about the difficulty of mapping that three trillion dimension space, let's say, that emerges as a consequence of the interaction of a plethora of particles. I mean, it seems to me that that's actually, and this is a huge leap, and I'm not claiming it's correct, but there's something to it, because of course, I'll lay it out first.
Starting point is 00:50:37 I mean, we use imaginative projection to envision alternative potential futures, right? And we seem to concentrate on the ones that are relatively statistically likely. Like when you're, I've been thinking a lot about how consciousness operates. And you know, you can think of us as deterministic creatures who are driven by mechanical algorithms
Starting point is 00:51:01 to move forward robotically lockstep as we're driven by material causality. But you can also think about us as imaginative visionaries who flesh out realms of possibility and then implement processes to bring those about. And I think the latter conceptualization is much more accurate with regards to the contents of our consciousness, because what consciousness focuses on isn't constants. Consciousness focuses on variability. So for example, if something unexpected happened
Starting point is 00:51:42 in your sensory field right at the moment, you would orient towards it and you do that implicitly, but your consciousness would focus on the uncertainty and the variability. And so we seem to use consciousness to shape variability. And so I guess the first thing I'm wondering is, is it reasonable to suppose that the purpose of the imagination is to map out that dimensional,
Starting point is 00:52:07 multi-dimensional space with regards to its most likely configurations? And the second question is, this is a more oblique question, is that is it reasonable to assume that the possibility that consciousness appears to be contending to, like the field of possibility that opens up to be contending to, like the field of possibility that opens up to your imagination,
Starting point is 00:52:28 let's say when you wake up in the morning and start to apprehend the possibilities of the day, is that a manifestation of the, what? Is that a manifestation of that? Is it a higher level manifestation of that field of possibility that characterizes the micro realm? You know what I mean?
Starting point is 00:52:50 There's possibility at the quantum level. Does that possibility make itself manifest all the way up to the level of macro experience? Because we seem to be dealing with something like possibility rather than deterministic algorithmic actuality. And so... There definitely is a rhyming between the two kinds of ideas, for sure.
Starting point is 00:53:14 But how is it that quantum physics at that rock bottom story bubbles up and influences conscious experience? I don't know and nobody does. It's too complex a problem right now, but what I would say is there are things about consciousness that the rock bottom story does give insight into. And one of the big ones is free will, right? I mean, there have been arguments about free will going on for thousands of years. And to me, it's quite clear that when you recognize, if you believe that the physical is all that there is, and I don't know that that is the case, but let's
Starting point is 00:53:51 just take that as an assumption for the moment, that there's no consciousness field that's out there in the world that we somehow are tapping into, that there's no greater power that's somehow beyond the laws of physics. If all we are are bags of particles governed by physical law, and our brains are nothing but gl all we are are bags of particles governed by physical law and our brains are nothing but gloppy three pound collections of particles that are organized sufficiently to somehow yield the information processing that we call conscious awareness. If that's all that it is, and I think that is all that it is, then there's no opportunity for us to have any freedom of the will because our particles are going to do what they're going to
Starting point is 00:54:26 do governed by the quantum laws and there's no opportunity for an eye to intercede in that lawful if probabilistic projection. So that's just the way things work. And so the view that we can somehow cause our particles perhaps to hold still for a moment, wait for Brian to make a decision, and once Brian makes a decision then carry on with whatever motion that you were going to do by the laws of physics, that's incoherent. That's ludicrous. And so however much we may feel that we are the ultimate authors of our actions, I don't see any opportunity for that because we can't intercede in the lawful progression of the particles that govern
Starting point is 00:55:08 whether I move my arm, whether I say this or I say that. It's all just the motion of particles that are instantiated in my biological form. Do you feel that, what's your opinion about okay, you can make causally determinate arguments very far, very high up the resolution spectrum. So the more macro the system, the more deterministic processes seem to be at play. But when you push all the way down to the micro level, you have this fundamental
Starting point is 00:55:48 indeterminacy. And so why would you presume that the deterministic argument holds true given that at its most fundamental basis there's indeterminacy? You know, isn't it the case that if you wanted to make an algorithmic case that you'd need
Starting point is 00:56:08 like predictable algorithmic causality all the way from the most micro levels all the way up, or are you making the case that once you get to the macro level, the determinacy takes over to the point where there is no possibility for such a thing as free will? No, I think that the indeterminacy of quantum physics turns out to be irrelevant to the particular story
Starting point is 00:56:31 that I'm telling in the following sense. So what I'm not saying that we are determinate in the sense that I can't predict what you're going to do next because you are ultimately a quantum system. Let me look right down at the level of your particles. Imagine I could zoom in on you and see your individual particles.
Starting point is 00:56:49 The best I can do is predict the likelihood or the probability that those particles are going to evolve from one configuration to another through time. But that probabilistic prediction, that uncertainty, that's not freedom of your will. You aren't controlling which outcome happens. prediction, that uncertainty, that's not freedom of your will. You aren't controlling which outcome happens.
Starting point is 00:57:08 You aren't determining which outcome is more likely or less likely. You still are just going along for this probabilistic ride. And so whether physics is probabilistic, as quantum mechanics says, or in the classical determinant view that Isaac Newton would have said, we know it's the former, not the latter, but even in the former, you aren't controlling that uncertainty and therefore you aren't controlling how things are unfolding. You aren't controlling what you do or what you say at that fundamental level. So you are nothing but this collection of particles still fully governed by laws, which I should say the quantum laws as mathematical equations, they are as deterministic as the classical laws,
Starting point is 00:57:52 but what they determine are likelihoods, probabilities. And so once those probabilities are determined by mathematics, you are out of the equation. And that's the way in which you don't have the freedom of will that you feel that you do. Okay, yeah, I understand the argument. I guess, of course, the classic, what would you say, rejoinder to that is that, you know, we structure, and I don't know how to reconcile the two, you know, I'm not claiming that I do in the least, but you know, we structure our societies on the presumption of something approximating responsible free will. And in so far as we do that,
Starting point is 00:58:32 we seem to be able to hold people responsible, help them govern their behaviors, integrate them psychologically and produce stable communities. And so it's a very strange situation that the presumption of free will seems to be a pragmatic and metaphysical necessity, but it's hard to square with the kind of modeling that emerges, well, in your argument, either from a more Newtonian deterministic view of physics,
Starting point is 00:58:57 or even from the quantum view. You know, it's a gap that's very- But I think I have an answer. I think I have an answer to that, but these are difficult issues. So I don't by any means think it's all settled. But I still think that in a world of the sort that I've described, which I think is our world, I think you still bear responsibility for your actions. It's of a slightly different nature than the responsibility in a world that does have freedom of the will. But if you are the causal actor that results in a certain effect, if you are part of the
Starting point is 00:59:31 causal chain that results in certain things happening, then you are responsible for the things happen because you are linking the causal chain. And the closer your link is to the outcome, the more responsibility you bear. So what does that mean for punishment? Right, right, I see. Exactly. And so my view on punishment from a societal perspective is it can't be from the standpoint of retribution.
Starting point is 00:59:58 That would seem to require free will if you're going to actually take a punitive stance on someone's behavior. But rather, I think punishment should be viewed as shaping future behaviors based upon current actions. I mean, the example that I like to use to sort of take this out of the emotional realm of human beings, imagine you have a Roomba, many of us do, that cleans your floor, right? That Roomba doesn't have free will, that's not controversial. And yet when that Roomba bounces or bangs into furniture, it's internal, if it's a high-end version,
Starting point is 01:00:32 it modifies its internal map of the space in order that subsequently it doesn't bump into things, it doesn't do the wrong thing in the future. And so you can update your program, you can update your behavior, you can update your behavior based upon getting feedback. And so if punishment is viewed as feedback in order to shape future behavior,
Starting point is 01:00:52 then yes, we should punish people that are responsible in the manner that I just described for things that we view as transgressing the rules that we collectively have brought into existence for society to be able to function. We're not punishing them because we're coming from a standpoint of retribution. We're coming from a standpoint of shaping future behavior.
Starting point is 01:01:12 Right, right, right. So yeah, so that's a more behaviorist conceptualization of the utility of punishment, the necessity of punishment. All right. Well, I think I'll leave that. I think what we'll do now, if it's okay with you, is turn to string theory. And I mean, I'm so ignorant about string theory that it's kind of miracle.
Starting point is 01:01:33 And I guess so I'm gonna start by asking you some basic questions. I guess the first question, you know, you touch upon this in the second edition of your 1999 book, which is The Elegant Universe, Super Strings, Hidden Dimensions, and the Quest for Ultimate Theory. You've just updated that. And you open the book by explaining, I suppose, at least part of the problem that string theory
Starting point is 01:02:01 is hypothetically poised to solve. And at least to some degree, that's the lack of unity between the theories of general relativity and the theories of the quantum physicists. And so maybe you could explain to us first what it means that those theories aren't unified, like what that means in the scientific realm, but also what it means practically. And then walk us through what string theory is and how it constitutes a potential solution to that conundrum. Yeah. So, the two big discoveries of the 20th century are Einstein's general theory of relativity,
Starting point is 01:02:45 which describes the force of gravity. And as we discussed before, the force of gravity matters when things are big, stars and galaxies and the whole universe. And in that domain, Einstein's ideas have been tested and they do an incredible job of explaining things that we see in the heavens. The other big development, which we've spent some time already talking about, is quantum physics, which describes the small things, molecules, atoms, subatomic particles. And in that domain, quantum physics has itself been tested to incredible precision, and it works. The crazy thing is, in any situation where you need to put quantum physics and general
Starting point is 01:03:21 relativity together, when you need to use the equations in tandem, you get nonsensical results. You get results like infinity is the only answer that you ever get for any question that you pose. Now you might say, well, do you ever need to put them together? Quantum mechanics are small, general relativity is big. Those seem pretty separate, but there are extreme realms like the center of a black hole where a lot of mass is then crushed to a very small size. Big mass, general relativity, small size quantum physics or the Big Bang. The entire observable universe crushed to a very small size. A lot of mass energy, small size. Again again you need general relativity and quantum mechanics.
Starting point is 01:04:05 And so in those extreme realms, you find that the equations simply fall apart. The laws of general relativity, the laws of quantum physics, they do not play well together. They are ferocious antagonists, and that's the problem that we've been trying to fix. And that produces these mathematical absurdities that you've been describing and interferes with our understanding. I guess there's the aesthetic problem too, which is that we're possessed by the strong intimation that all forms of descriptive knowledge should unify, at least not exist in contradiction to one another.
Starting point is 01:04:39 That seems, while it seems to violate, I don't know our understanding of what understanding itself is. And so that's okay. Okay, and so, well, so can you give us a maybe a more tangible indication of what sort of absurdities might emerge in the conceptual realm when you're dealing
Starting point is 01:04:59 with something like the situation that obtains in a black hole? And you said that the equations will produce references to infinity continually, which seemed to be non-helpful, but that's still pretty abstract for people who aren't mathematically oriented. Is there a way of simplifying that so that it's more graspable?
Starting point is 01:05:17 Yeah, so for imagine, imagine you jump into a black hole, inadvisable, but imagine you do it. We know that as you get closer and closer to the center of the black hole. Inadvisable, but imagine you do it. We know that as you get closer and closer to the center of the black hole, things will start to feel uncomfortable. If you jumped in feet first, your feet are going to be pulled more strongly than your head, so your body's going to stretch, it's going to spaghettify, we call it, ultimately it's going to be pulled apart into its constituents. And those constituents are then going to fall toward the center. And the deep question is, what finally happens when you actually reach the center?
Starting point is 01:05:51 And if you ask any physicist today for the answer, they would be forced to tell you, if they're honest, we don't know. We just don't know what happens at the center of the black hole. Some ideas are it's a portal to another universe. That's a wild sci-fi sounding idea. It'd be wonderful it's the case, but we just don't know. Some people think it's a location where time comes to an end. It's just where there's no notion of time any further.
Starting point is 01:06:17 So these are the things that we just don't know how to answer. So I have a question about that too. Well, correct me if I'm wrong about this, but my understanding is that as something falls into a black hole, and this is from the perspective of an external observer, as it falls, it's transforming more and more slowly and that that transformation decreases in speed until it's really at a standstill. And so I'm wondering if that's the case and that there's that time deletion that's accompanied by descent into a black hole. I'm trying to put like vague imaginations here, imaginings together. You have something that's very, very dense at the center of that.
Starting point is 01:07:11 And you also have this time dilation process. Is it, and you have the idea that at some distant point in the future, everything is going to come back together in a big crunch. At least that's one of the hypothesis. Is there any difference between the destination point when a given body is falling into a given black hole and the big crunch itself? Like, is that destination point the same destination point?
Starting point is 01:07:41 And that would account to some degree for the kind of infinite density at the center of the black hole and it seems to make sense if if time is dilating to that degree That's the best I can do the question and certainly you're right from the standpoint of an outside observer Watching say you jump into a black hole. They will see you move slower and slower as you reach the jump into a black hole, they will see you move slower and slower as you reach the event horizon, the edge of the black hole. And in fact, they will see you ultimately come to a standstill right at the event horizon itself.
Starting point is 01:08:13 But the amazing thing is from your perspective, you will fall right through that event horizon. You will go right to the center and it will happen in finite time. It will not happen in some long cosmological time. It will happen in finite time. It will not happen in some long cosmological time. It will happen in finite time. And so it's not as though the center of the black hole is the big crunch, if there is such a thing for the universe, but it is the case that we believe
Starting point is 01:08:34 that if we could answer the question of what happens at the center of a black hole, we would then be able to answer the question of what happens at the big crunch or what happens at the big bang, because we face exactly the same issue. If you weren't so interested in black holes, but you're interested in how the universe got started, again, ask any physicist what really happened at the moment of the Big Bang
Starting point is 01:08:56 times zero itself. If the physicist is straightforward, honest, they'll say, we don't know for exactly the same reason. That's a realm where the density is so high that you need general relativity, where quantum physics is vital because it's so small and the equations break down and the equations are the only tool that we have to gain insight into realms that we can't literally visit. And that's the issue that we're trying to fix. Okay. So why does it matter that from your perspective you would continue falling at a finite time with regard to the question of whether what's at the bottom of the black
Starting point is 01:09:32 hole is the eventual aggregation of all matter? Because looking at it from the outside as that falling entity grinds to a halt, there's an infinite duration of time that's now involved in the process. And in that infinite duration of time, if the big crunch models are correct, that big crunch is eventually going to occur. So I don't understand why they don't necessarily dovetail, let's say, or converge. So, our goal is to be able to explain the happenings in the universe from any and all perspectives.
Starting point is 01:10:14 The one interesting thing that Einstein taught us is that different perspectives can tell very different stories about the universe, but our goal is to be able to understand all those stories. We want to chronological all the narratives, if you will, that could be told about the universe. And so you're right, from the standpoint of the outside observer, the chronicle you're telling is correct. Okay, okay.
Starting point is 01:10:34 Infinite time. Yeah. Okay. But we also want to know the chronicle from the person that could fall in as well. Yeah, right, right, right. Fair enough. Fair enough. Okay.
Starting point is 01:10:43 So let's go back to string theory. So you made the case that the equations that govern general relativity and quantum mechanics don't dovetail well, and that poses certain interpretive problems, and you outlined what they might be. And I don't remember if we did try to nail that down so that it was more comprehensible if we got out of the realm of mathematical infinity
Starting point is 01:11:08 to point out some of the, maybe that's where we went into the discussion of the black hole. But okay, so okay, fine. So let's talk about, you know, how string theory in principle reconciles that. I'm also curious, you know, there's a lot of physicists who are very skeptical about string theory in principle reconciles that. I'm also curious, you know, there's a lot of physicists who are very skeptical about string theory as an enterprise.
Starting point is 01:11:30 And so I guess I'm also wondering, has the, have the proponents of this theory come up with an explanation that adds additional predictive validity to the combined use of the theories of general relativity and of quantum mechanics. So what is string theory and then why should we believe that the suppositions of the string theorists have any validity? Yeah.
Starting point is 01:11:56 So they're both good questions. Start with the first one. So the basic conventional way of talking about string theory, the way I spoke about it even in the elegant universe back in 1999, is a slight shift in how we envision the fundamental ingredients of matter. The old view that we've been talking about in quantum mechanics are these little particles, they are described by probability waves, but the particle itself is a little infinitesimal dot, the electron or the photon. String theory says that you need to update that picture. Think now of the electron as a little tiny vibrating filament, a little tiny vibrating string-like filament. Think of the photon
Starting point is 01:12:38 as a little tiny vibrating string-like filament. And the different vibrations of the string, just like the string in a violin produces different musical tones, the different vibrational patterns of these little strings don't produce different music, they produce the different particles. So a photon is a string vibrating in one pattern, an electron is string vibrating in a different pattern
Starting point is 01:12:59 and so forth. That's the basic idea. Now, why do we invoke that idea? Amazing. And what does vibration mean? Amazing, yeah. I mean, in that situation, what does vibration mean and what's vibrating? Maybe those are nonsensical questions like the color. They're not nonsensical.
Starting point is 01:13:14 Okay, good. They're tough questions. So what is the string made of? The best answer I can give, it's made of string stuff. It's made of energy. If I could delineate something yet more fine from which the string was built, our focus would be on that finer constituent. It may be, if these ideas are correct, that this is the finest ingredient, period, end
Starting point is 01:13:34 of story. We don't know that, of course, but that is one way of thinking about the theory. And so the remarkable thing, and this is not obvious and a little difficult to explain in words, but I will say that mathematically mathematically when you make the move from a point particle to a filament, the problems between general relativity and quantum mechanics, they go away. All of a sudden these two theories can play well together. The infinities that we were talking about from the conventional formulation are quelled. They're tamped down.
Starting point is 01:14:05 You can make sensible calculations, at least in principle. And that's why this idea took off in the 1980s. I see. Now is that, okay, so one of the problems that non-physicists have, and I presume physicists as well, is that as we peer more and more deeply into the micro realm, we get farther and farther away from our embodied axiomatic presuppositions, right? I mean, we're accustomed to dealing with objects
Starting point is 01:14:34 in the macro world that operate like macro world objects. And then as we increase our resolution, the things we're looking at increasingly don't act like that. And so they escape from our, really our axiomatic or a priori understanding, which is very deeply embodied. And so you already have that problem at the level of the electron and the photon.
Starting point is 01:14:58 And it seems to me not improbable that that problem would be multiplied if you increase the level of resolution past that. So is there any possibility whatsoever of the non mathematically inclined observer of even understanding what it means further to be filaments or further to be vibrations or are those like second-order castings of things that have to essentially be mathematical. Well, they are ultimately mathematical. The imagery that we paint in words is a reasonable approximation to what we believe the mathematics is telling us.
Starting point is 01:15:35 So it's not far from a reasonable poetic description of what's happening down there. But you're absolutely right. It's so far from common experience. We're talking about distance scales that make the atomic seem large by comparison. So we're way, way down at a distance scale of like 10 to the minus 33 centimeters. You know, an atom is like, you know, 10 to the minus 10 centimeters or something. So we're talking 20 orders of magnitude smaller than an atomic ingredient.
Starting point is 01:16:07 So we're far, far from the familiar things that we used to base our understanding of the world upon. But the question then you ask is how do you test this? And why should one believe? And what practical use is it? Yeah, well, quantum mechanics is obviously insanely practically useful. I mean, it's produced technologies
Starting point is 01:16:24 that are world transforming. So but let me just point out on that because that's a very vital realization. If you would have asked the people who develop quantum mechanics like Niels Bohr and and Schrodinger, if you ask them way back in the 1920s, what's the practical utility of what you're working on? I'm pretty sure they would have said, not much, we're just trying to understand. And so then it's 80 years later, we go from understanding to harnessing. So I always find it dangerous to talk about practical utility of ideas when they're being formulated, because it may be a century more before they're actually put in practice. But you still need to ask the question, why should you believe any of this stuff?
Starting point is 01:17:06 Are there any experimental tests? Yes, yes. Well, the same was true of Maxwell when he discovered electricity, right? Electromagnetism, yep, so. And I'm always in the elegant universe back in 1999, and today I am forthright in saying, there are no experimental observations.
Starting point is 01:17:26 There are no definitive predictions that we can test with today's technology. So we have not been able to bridge the gap between the theory and the observation. They say, what the heck are you guys doing? Why are you still thinking about something? And the answer is we have made such stunning, and I am saying this from the perspective of someone who's lived the life of mathematics, we've made stunning mathematical advances in this field that are beyond anything that most of us would have thought remotely possible to have occurred by today.
Starting point is 01:18:00 We've understood the equations. We've been able to gain insight into the nature of black holes, not answering that fundamental singularity question, but we understand the horizon of a black hole, the entropy of a black hole. We've made progress in understanding the way in which this mathematics paints a vastly new picture of reality. Some of the developments just in the last few years are absolutely mind blowing. So if you are like me and many of my colleagues
Starting point is 01:18:25 willing to defer observation and experiment for now, not forever, but defer it now, develop the mathematics in the hope that this risk that we are taking, that this math may not be relevant to the world, but if it is it will give us the deepest explanation of how the world came to be and how it came into existence and the fundamental ingredients and how they behave. That makes the risk for some of us worth taking. It's not a risk worth taking for everybody. This is where human nature comes into science.
Starting point is 01:18:57 Some scientists, God bless them, they're vital, need to have an ongoing dialogue with experiment and observation for them to feel that what they're vital, need to have an ongoing dialogue with experiment and observation for them to feel that what they're doing matters. Other scientists are willing to defer that dialogue, develop the mathematics for however long it will take if you feel that the math is progressing at a rate that's sufficiently gratifying and satisfying to make you feel that you're en route toward truth. And that's the kind of person that works on strength theory. There's no right or wrong here.
Starting point is 01:19:27 It's a matter of scientific taste. So science, you can imagine, has two poles. And one would be hypothesis generation, which is a relatively mysterious pole. And the other would be verification and testing. And it's always the case that the hypothesis generation horizon exceeds the testing horizon because otherwise the hypothesis would be trivial. Now and then the question would be well to what degree are you temperamentally capable of what would you say appreciating that gap and there's going
Starting point is 01:19:59 to be wide individual differences in that they're probably related to something like trait openness but the notion that the hypothesis should exceed the data is that's a truism in some regard. Now that does open up a very complex question, which is how do you, in the absence of experimental verification, how do you determine which hypotheses aren't dead ends? And that seems to have something to do with it's something like pattern recognition. You know, I mean one of the ways that we determine that something is real is by quintangulating, I suppose, with our senses and if we can detect something in five dimensions, in the five sensory dimensions, then we assume that it's real, sometimes after talking to other people
Starting point is 01:20:45 who are doing the same thing. But the great pattern recognizers who are the hypothesis generators in science seem to do something approximately the same in the absence of experimental proof, right? They're using a vast variety of information sources to determine whether their hypotheses are valid as opposed to say, you know, delusional conspiracy theories
Starting point is 01:21:07 or their approximation. So, and you think the string theorists are, okay, so what is it? And I think we'll delve into this more particularly on the daily wire side. I think maybe actually we'll turn to that because we are coming to the end of our discussion. So I think what I'm going to do on the daily wire side
Starting point is 01:21:24 for everybody who's watching and listening is to continue talking to Brian about the development of his interest in the microcosmic realm and why in particular he was attracted to investigation of string theory per se. There's lots of potential places that someone with an interest in physics might go. And so I'm always interested in the
Starting point is 01:21:45 biographical element. So I think we'll pursue that on the daily wire side. And so is there anything else that you can tell people that would flesh out their understanding of string theory in relatively short order? I mean, I know that's a tall order, but I'm still, we talked about these filaments and their vibrations. I mean, what's the nature of that vibration? I mean, we know that light waves vary in their quality and because of different frequency of vibration, let's say. And so that plays a fundamental role
Starting point is 01:22:26 in the phenomenology of everyday being. And so it's obviously the case that difference in vibrations can be of crucial importance. Like, is there an analogy between electromagnetic frequency in the case of photons and the vibrations of the filaments? And then how do you understand the nature of the filament? Because filament sounds material,
Starting point is 01:22:47 like it sounds like it's something that should be made of other things, you know, like an ordinary object. Well, our everyday experience certainly teaches us that any extended object, which is all objects we encounter in the real world, can be cut up into smaller things. And experience has taught us that if you cut fine enough, you may find new ingredients that were not visible or available or something that you would have recognized on the macroscopic
Starting point is 01:23:15 scale. If you take that idea and you bring it into the micro world, you would think that a string itself could be cut up into finer things and maybe you'll find ultimate constituents. But again, we don't know if that macroscopic notion applies in the microscopic realm. So you have to be very careful taking things that you're familiar with in the macro world and just porting them into the micro world.
Starting point is 01:23:39 So again, it might be that we, and there've been some studies that have suggested the possibility that strings made themselves be made up of smaller ingredients, but there's also a whole literature that suggests that they may be the fundamental entity in a certain domain of the theory and there isn't something finer within them. But let me give one, if you don't mind, because you were saying we're going to slightly wrapping up this part. I want to leave one idea, which is one of the more spectacular ones.
Starting point is 01:24:07 It'll just take me a moment to describe of recent insight in string theory. Many of your viewers and listeners may be familiar with the idea of quantum entanglement, which is the idea that two distant particles can have kind of an invisible quantum link between them, where what you do in one particle instantaneously affects the other particle. The particles are said to be quantum entangled, a mind blowing idea that comes from the work of Albert Einstein in 1935.
Starting point is 01:24:36 Your viewers, listeners may also be familiar with the notion of a wormhole, a completely different idea, that in general relativity, you can have a tunnel through the fabric of space linking one location and the other. completely different idea. That in general relativity you can have a tunnel through the fabric of space linking one location and the other. Einstein developed that idea too in 1935, just two months apart from quantum entanglement. For 90 years nobody thought there was any connection between these two ideas.
Starting point is 01:24:58 String theory has recently revealed that it's very likely that these two ideas are the same idea described in different languages. That when you have two particles that are quantum entangled in some sense there is a tunnel through the fabric of space, a wormhole that is connecting them together. And if this idea holds up it shows that a general relativistic idea, a tunnel through the fabric of space, and a quantum idea, quantum entanglement across space, are the same idea, which would suggest that general relativity and quantum mechanics are deeply connected from the get-go.
Starting point is 01:25:36 It's not so much that we need to find a way of bringing them into union. They may already be in union, and what we need to do with string theory or whatever approach is understand that intrinsic relationship more fully. This is the new perspective that has emerged in the last decade and it's a thrilling one. All right, sir. Well, I think that's a good place to end. That's a nice ending.
Starting point is 01:25:58 And so I think we will in fact do that. And so for everybody who is watching and listening, well, thank you for your time and attention. Thank you to the Daily Wire people for making the public distribution of this podcast possible. Thank you very much, sir, for spending the time today delineating out your ideas. That's much appreciated. And- My pleasure. Thank you. Yeah. Yeah, my pleasure. And good luck on the second edition of your book. When did it come out?
Starting point is 01:26:27 I think last week. Oh yeah, and how's it doing? It just came out. I have no idea, I've not been tracking it. Okay, okay, well that's an exciting thing to, that'll be an exciting thing to encounter with any luck. And so, yeah, well thanks again for talking to us today. And then reminder for everybody who's watching and listening,
Starting point is 01:26:47 we're gonna delve into the origin of Dr. Green's interests and how they developed across time. It's very useful to talk to people who've been successful in their field of endeavor to find how that pathway made itself manifest to them across the ups and downs of their life and why they stuck with it and what made them successful. Everybody has to find out what compels them
Starting point is 01:27:14 and interests them in their life if they're going to adjust to the difficulties of their existence successfully and gaining some insight into that process is always useful. So that's what we'll delve into on the Daily Wire side so everybody can join us for that if they're so inclined. All right, sir, thank you very much. Much appreciate the discussion today. Thank you.

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