#403 – Lisa Randall: Dark Matter, Theoretical Physics, and Extinction Events

27:46It wasn't just one country and how it was, it was also impressive in that it was a long -term project that people committed to and made it happen. So it is a demonstration that when people set their mind just to things and they commit to it that they can do something amazing. But also in the United States, maybe a lesson that bureaucracy can slow things down to work with you. Eurocracy and politics and economics many, many things can make them faster and make them slower. So science is the way to make progress politics is the way to slow that progress down. Well, I don't want to overstate that because without politics, you know, the like to end up in either.

28:30So, but you need broccoli. But sometimes I do think what I mean, you're not asking this question, but sometimes I do think when I, you know, think about some of these conflicts, you know, sometimes it's just good to have a project that people work on together. And there were some efforts to do that in science too, to have Palestinians and Israelis work together. Project called Sesame. I think it's not a bad idea when you can do that. When you can get sort of forget the politics and just focus on some particular project. Sometimes that can work. Some kind of forcing function, some kind of deadline that gets people sitting in the room together and you're working on a thing, but as part of that, you realize the common humanity that you all have the same concerns, the same hopes, the same fears, the same that you are all human.

29:27And that's an accidental side effect of working together on a thing. That's absolutely true. And it's one of the reasons Cern was formed, actually. It was post -World War II and love European physicists had actually left Europe. And they wanted to see Europeans work together and serve rebuild. And it worked. I mean, they did. And it's true. I often think that one of the major problems is we just don't meet enough people so everyone thinks it seems like when they seem like the other, it's more easy to forget their humanity. So I think it is important to have these connections. Given the complexity, all cosmological scales involved here, the lead to the extension of the dinosaurs.

30:09When you look out at the future of Earth, do you worry about future extinction events? I do think that we might be in the middle of an extinction right now. If you define it by the number of species that are getting killed off, and it's subtle, but you know, it's a complex system. The way things respond to events is sometimes things evolve, sometimes animals just move to another place. And the way we've developed the Earth, it's very hard for species just to move somewhere else. And we're seeing that with people now too, I mean, I know people are worried just about AI taking over and that's a totally different story.

30:48We just don't think about the future very much. We think about what we're doing now. And we certainly don't think enough about all the animals that we're destroying, all the things that are precursors to humans that we sort of reliant. It's interesting just to think whether the the things that threaten us is the stuff we see that's happening gradually or the stuff we don't really see that's going to happen all of a sudden. And sometimes like think about what is what should be more worried about because it seems like like with the asteroids or nuclear war, it could be stuff that just happens one day.

31:24You know, when I say one day, me over a span of a few days or a few months, but not in a scale of decades and centuries. Because we sometimes mostly talk about stuff that's happening gradually, but you can be really surprised. It's actually really interesting, and that was actually one of the reasons it took a while to determine what it was that it caused the last extinction. Because people did think at the time, how many people thought that things were more gradual. and the idea of extinction was a very, was actually a novel concept at some point. I mean, these aren't predictable events necessarily.

32:03They're only predictable in a grand scale. But sometimes they are. And I think people were pretty aware that nuclear weapons were dangerous. I'm not sure people are aware now as they were, you know, say 20 or 30 years ago. And that certainly worries me. I have to say I was not as worried about AI as other people, but now I understand. And it's not, I mean, it's more that as soon as you create things that we lose control over, it's scary. And the other thing that we're learning from the events today is that it takes a few bad actors. It takes everyone to sort of make things work well. It takes not that many things to make things go wrong.

32:47It's the issue with disease. You know, we can find out what causes a disease, but to make things better is not necessarily that simple. Sometimes it is, but things to be healthy, a lot of things have to work for things to go wrong. Only one thing has to go wrong. And so it's amazing that we do it. And the same is true for democracy. For democracy to work, a lot of people have to believe in it. A few bad actors can destroy things sometimes. times. So a lot of the things that we really rely on are delicate, equilibrium situation. Some of you know, and there is some robustness in the systems we try to build in robustness, but a few extreme events can sometimes alter things.

33:27And I think that's what people are scared of today in many ways. They're scared of it for democracy, they're scared of it for peace, they're scared of it for AI. I think they're not as scared as they should be about nuclear weapons to be honest. I think that's a more serious danger than people realize. I think people are a little bit more scared about pandemics than they were before, but I still say they're not super scared about it. So you're right. There are these major events that can happen and we are setting things up so that they might happen. And we should be thinking about them. The question is who should be thinking about them?

34:04How should we be thinking about them? How do you make things happen on a global scale? Because that's really what we need. It certainly shouldn't be a source of division. It should be a source of grand collaboration, probably. Wouldn't that be nice? Yeah. I just want to be like to be a dinosaur. It must have been beautiful to like look at that asteroid just enter the atmosphere. Until like everything, just, man, would I, that would be one of the things I would travel back in time too. you. You know, that's also one of the things that I think you probably could do with virtual reality. I don't think you have to be there and get.

34:40I think there's something, you know, it's an event you're just watching. You're not doing anything. You're just looking at it. So maybe you could just recreate it. I actually heard that there's a nuclear weapon explosion experience in virtual reality. That's good to remind you about like what it would feel. I have to I just say, you know, so I got a, I got an award from the Museum of Nuclear History and Technology in the Southwest. And I went to visit the museum, which turned out to be mostly a museum of nuclear weapons. And the scary thing is that they look really cool, you know. It's true that you have that, yes, this is scary, but you also have this, this is cool feeling.

35:21And I think we have to get around that because, you know, I kind of think that, yes, you can be in that but I'm not sure that's going to make people scared. Have they actually asked afterwards or are you more or less scared? That's a good point. I mean that's a good summary of just humanity in general. We're attracted to creating cool stuff even though it can be dangerous. And actually that was the really interesting thing about visiting that museum actually. It was very nice because I had a tour from people who had been working there on the Cold War and actually one or two people from Manhattan Project, it was a very cool tour.

35:58And you just realize just how just the thing itself gets you so excited. I think that's something that sometimes these movies miss. Just the thing itself, you're not thinking about the overall consequences. And it was kind of like in some ways it was like the early Silicon Valley, you know, people were just thinking like, what if we did this? What if we did that? And you know, not keeping track of like what the peripheral consequences are. And you definitely see that happening with AI now. I mean, I think that was the moral of the battle that just happened that you know, it's just full speed ahead Which gives me a really great transition to another quote in your book So you you're right about it the experience of facing the sublime in physics and you quote Ryan Arroke Quote for beauty is nothing but the beginning of terror Which we are still just able to endure and we're so odd because it's serenely disdainst to annihilize us.

36:55It's pretty intense. I think applies to nuclear weapons. But it also, I mean, at a more mundane perhaps level, I think it applies, you know, it's really interesting. One of the things I found whenever I wrote these books is, you know, some people love certainty. You know, scientists kind of many revel in uncertainty. It's not that you want to be uncertain. You want to solve it. But you're at this edge where it's really frustrating because you don't really want to not know the answer, but of course if you knew the answer, that would be done. So you're always at this edge where you're trying to sort things out, and there is something scary.

37:33You don't know if there's going to be a solution. You don't know if you're going to find it. So it's not something that can destroy the earth. It's just something that you do on your individual level. But then of course there are much bigger things like the ones you're talking about where they could actually be dangerous. The stuff I do, I just want to be I'm doing theoretical physics, not very dangerous. But sometimes things end up having mirror consequences, anything. Yeah, but dangerous in a very pragmatic sense, but isn't it still in part terrifying when you think of just the size of things?

38:08Like the size of the power of this thing in terms of its potential gravitational effects, just the cosmological objects and a black hole at the center of our galaxy. This might be where I am if it's just a wide different from other people. Because I'm not such a big fan of humanity in some ways, some ways I am. But the idea that we were everything would be really boring to me. I love the idea that there's so much more out there that there's a bigger universe and there's lots to discover and that we're not all there is.

38:43I want to be diversity of other stuff. It's pretty interesting. You know, we have no idea how much there is. You know, we know what we can observe so far. So the idea that this other stuff out there that we yet have to figure out, it's exciting. Let me ask you out there a question. Okay. So if you think of like humans on earth, life on earth as this pocket of complexity that emerged, you know, and there's a bunch of conditions that came to be and there's Darwinian evolution and however life originated. Do you think it's possible there's some pockets of complexity of that sort inside dark matter?

39:27Well, so that's possible. I can't be streamed biology evolving in different ways. And that's one of the reasons we suggest. I mean, it's not the reason, but it would be true if there were the type of interactions we suggest, I mean it would need more complex ones. And we don't know. I will say that the conditions that could rise to life and complexity, they're complex, they're unlikely. So it's not like there's great odds that would happen, but there's no reason to know that it doesn't happen. It's worth investigating, are there other forces that exist in the dark matter sector? It's exactly. So the dark matter sector doesn't have all the forces of the standard model of physics.

40:12Right. As far as we know, it doesn't have any. It might have it at some low level, but it could have its own forces, just like the dark matter might not experience our light. Maybe it has its light that we don't experience. So there could be other kinds of forces? I mean, there could be other kinds of forces even within our sector that are two weeks for us to have discovered so far, or that exist at different scales that we know about. I mean, we detect what interacts strongly enough with higher detectors to detect. So it's worth asking. And that's one of the reasons we build big colliders to see are there other forces, other particles that exist say at higher energy, that shorter distance scales than we've explored so far.

40:55So it's not just in the dark matter sector, even in our sector, there could be a whole bunch of stuff we don't yet know. So maybe let's zoom out and look at the standard model of particle physics. How does dark matter fit into it? First off, what is it? Can you explain what the standard model is? So the standard model of particle physics is basically tells us about nature's most basic elements and their interactions and so it's the substructure as far as we understand it So if you look at atoms, we know they have nuclei and electrons nuclei have protons and neutrons in them protons and neutrons have particles called quarks that are held together by something called the strong force.

41:40They interact through the strong force, the strong nuclear force, something called the weak nuclear force and electromagnetism. So basically all those particles and their interactions describe many many things we understand. That's the standard model. We now know about the Higgs boson, which is associated with how elementary particles get their mass. So that piece of the puzzle has also been completed. We also know that there are kind of a weird array of masses of elementary particles. There's not just the up and down quirk, but there are heavier versions of the up and down quirk. Charm and strange top and bottom.

42:18There's not just the electron. There's a muon and a towel. There are particles called neutrinos, which are under intense study now, which are partnered with the leptons through the weak interactions. So we really do know these basic elements. And we know the forces. We know... I mean, when we're doing particle physics experiments, we can usually even ignore gravity, except in exceptional cases that we can talk about. So those are the basic elements in their interactions. Dark matter stands outside that. It's not interacting through those forces. So when we look at the world around us, we don't usually see the effects of dark matter.

42:54It's because there's so much of it that we do, and it doesn't have those forces that we know about. But the standard model has worked spectacularly well, it's been tested to a high degree of precision. People are still testing it. And one of the things we do as physicists is we actually wanted to break down in some of it. We're looking for the precision measurement or the energy or whatever it will take, where the where the stand -in -mell is no longer working. Like not that it's not working approximately, but we're looking for the deviations and those deviations are critical because they can tell us what underlies the stand -in -mell, which is what we really want to see now.

43:31Next. Where can you find the places where the stand model breaks down? What are the places you can see those tiny little deviations? So we don't know, yeah, but we know the kinds of things you wouldn't want to look for. So one obvious place to look is that higher energy. We're looking at the large hydrangellator, but we'd love to go beyond that. Higher energy means shorter distances, and it means things that we just couldn't produce before. I mean, E equals mc squared. So if you have a heavy particle and you don't have enough energy to make it, you'll never see it. So that's one place. The other place is precision measurements.

44:05If you, you know, the standard model has been tested exquisitely. So if it's been tested one percent, you want to look at a tenth of a percent. And there are some processes that we know shouldn't even happen at all in the standard model or happen at very suppressed level. And those are other things that we look for. So all of those things could indicate there's something beyond what we know about, which of course will be very exciting. when you just step back and look at the standard model the quirks and all the different particles and treasins isn't it while how this like little system came came to being quates is underpins everything we see absolutely and that's why we'd like to understand it better we want to know is it part of some bigger sector why are these particles why did they have the masses they do yeah why is the exposed and so like compared to the Master Cudipad, which we might have even expected based on the principles of special relativity and quantum mechanics.

45:03So that's a really big question. Why are they what they are? And they originate, there's like some mechanism that created the whole thing. That's one of the things we're trying to study. Why is it what it is? I mean, even just like, the mechanism that creates stuff, like the way a human being is created from a single cell, I'd say, I'm pure Genesis. The whole thing, you build up this thing. All of it, this whole thing comes to be from just like a... I'm not sure. I'm not sure. I'm not sure. Okay, right. It's not. It's not. Well that's a really good question is how much of it is the environment?

45:42Is it just the environment acting on a set of constraints? and like how much of it is just the information in the DNA or any information, how much is it in the initial conditions of the universe versus the some other thing acting on it? These are big questions. These are big questions in pretty much every field. You know, we, for the universe, we do consider it, you know, it's everything there is by definition. But people now think about it as it wanted many universes. Of course, it's a misnomer, but could there be other places where there are self -contained gravitational systems that we don't even interact with?

46:23So, but those are really important questions. And the only way we're going to answer them is, you know, we go back as far as we can. We try to think theoretically and we try to think about observational consequences. That's all we can do. One interesting way to explore the standard models to look at your fun, nuanced disagreement with Carlo Revelli. When you talked about him writing in his book, Electrons Don't Always Exists, they exist when they interact. They materialize in a place when they collide with something else. And you wrote that, well, I'll just read the whole thing because it's kind of interesting.

46:59Stocks may not achieve a precise value until they're traded, but that doesn't mean we can't approximate their worth until they change hands. Similarly, electrons might not have definite properties, but they do exist. It's true that the electron doesn't exist as a classical object with definite position until the position is measured, but something was there which physicists used a wave function to describe. It's a fascinating, nuanced disagreement. So do electrons always exist or not? Does the tree fall in the forest if nobody's there to see it? So I like to think of the universe as being out there, whether or not.

47:37I mean, it would be really weird if the only time things came into existence was when I saw them or I measured them. There's a lot of weird stuff. I mean, I could believe that the Middle East doesn't exist because I'm not there now. I mean, that would be kind of ridiculous. I think we would all agree on that. So I think there's only so much that we can contribute to our own powers of seeing. So and the whole system doesn't come into being because I'm measuring it. And so what is weird, and this isn't even a, just giving me about the standard model, this is a agreement on how you interpret quantum mechanics.

48:08I mean, I would say that those wave functions are real. I mean, one of the things that don't forget that particle physics does that quantum field theory says is that electrons can be created and destroyed. It's not that every electron has to be in the universe. I mean, that can be, I mean, that's what happens at colliders. Particles get created and destroyed. But that doesn't mean that if I have an electron in an atom, it's not there. It's really there. And we know about it. It's charge is there. So physics is a kind of way to see the world. So what would the bottom, what's the bottom turtle? Do you have a sense that there's a bottom reality that we're trying to approximate with physics?

48:47I think we always have in our head maybe that we'd like to find that but I have to I mean I might not seem so but I think I'm kind of more humble than a lot of physicists I'm not sure that we're going to get to that bottom level But I do think we're going to keep penetrating different layers and get further. I just wonder how far away we are You know, we all wonder that And it's not even like what's even the measure of how far away we are I mean one way you can measure it is just by our everyday lives in terms of our everyday lives we've measured everything. In terms of what underlies it, there's a lot more to see.

49:19And so part of it has to do with how far we think we can go. I mean, it might be that the nature of reality changes so much that even these terms are different. Maybe we'll measure the notion of distance itself might break down at some point. But also to push back on that we've measured everything. Maybe there's stuff we haven't consider as measurable. For example, consciousness, or there might be stuff just like you said, forces unseen, undetected. So it's an interesting thing. So one, and this is often a confusion that happens. So there's sort of the fundamental stuff underlying it. And then there's sort of the higher levels, what you know, what we'll call like an effective theory at some level.

50:01You know, so we're not always working. I mean, when I throw a ball, I don't tell you where every atom is. I tell you this ball. And so there might be different layers of reality that are built on terms, on terms of the matter that we know about, in terms of the stuff we know about. And when I say we've measured everything, I say that with a grain of salt. I mean, I measure of course, everything about the stand -in -mom. So, so there's lots of phenomena that we don't understand that we, but often there are complex phenomena that will be given in terms of the fundamental ingredients that we know about.

50:34But that is an interesting question because yes, there's phenomena that are at the higher level of abstractions that emerge, but maybe with consciousness, there's far out people that think that consciousness is pan -psychos, right? There's going to be almost like a fundamental force of physics that's consciousness that permeates all that, right? So, usually when you have a crazy, sorry, okay, when you have a far out theory, the thing you do is you test all the possibilities within the constructs that exist. So you don't just jump to the most far out possibility. I mean, you can do that, but then to see if it's true, you either have to find evidence of it, or you have to show that it's not possible without that.

51:16And we're very far from that. I think one of the criticisms of your theory on dinosaurs was that it requires, if I remember correctly, for dark matter to be weirder than it already is. And then I think you had a clever response to that. Can you remind? I'm not sure I'll be the boy I said then, but I mean, we have no idea how weird dark matter is. I mean, it's based on everyone thinking they know what dark matter is. I mean, so weirder than already is. I mean, it's not already anything. We don't know what it is. So there's no normalization here. So dark matter, do we know that if dark matter varies in density?

51:51It definitely does in the universe, just like, I mean, so for example, there's more dark matter in galaxies, and there's between galaxies. So it clumps. I mean, so it's matter. So it's distributed like matter. It is matter. It does clump. But the full details of how it clumps. And again, the complexity of the clumping. It's interesting. I'm pretty well. People do simulations. Where people are always looking for things including us as particles, it's sort of at small skills are the deviations on small skills so that indicating other interactions or other processes or interactions with barriands that is to say normal matter that we don't understand.

52:32But on large scales we have a pretty good understanding of dark matter distribution. You were part of a recent debate on quote, concise and cover reality. Let me ask you this question then. What are things the limits of science? I'm smart enough to know I have no idea. And also, it's not even clear what science means, right? Because there's the science that we do, which is particle physics, we try to find fundamental things and figure out what their effects are. There's science like biology where, you know, at a higher level, the kind of questions you ask are different, the kind of measurements are different.

53:07The kind of science that's going to happen in the sort of more numerical age, I mean, or even AI. or like what does it mean to answer a question? Does it mean that we can predict it? Does it mean that we can reproduce it? So I think we're coming up against sort of the definition of what we mean by science as human beings. So in terms of the science that we can do, I don't think we'll know it until we get there. I'm, you know, we're trying to solve hard problems and, you know, we've made progress. I mean, if you think of how much science has advanced in the last century or a century and a half, it's incredible.

53:41I mean, you know, we didn't even know the universe was expanding at the beginning of the 20th century. We didn't know about quantum mechanics of the beginning of century. We didn't know about special relativity. That's a lot in a relatively short time on depending on how you think of time. So I think it would be premature to say we know limitations. And at various points throughout the history, we thought we solved everything or declared or at least various people were we was various people exactly declared that we've solved everything. So this is also a good place to maybe could you describe the difference between top down and bottom of approaches to theoretical physics that you talked about in the book.

54:18So you could try to jump in and say I have a theory that I think is so perfect that I can predict everything from it or at least predict some facility and features from it. Let's top down. That would be a top down. Bottom up is more like, You know, like the questions we just asked, why are masses what they are? We measure things, we want to put them together. And usually a good approach is to combine the two. If you ask a very specific question, but combine it with the methods of knowing that there could be a fundamental theory underlying it. Sometimes you make progress. I mean, the community tends to get segmented or fragmented into people who do one or the other.

55:00But there are definitely times, I mean, some of my best collaborations have with both people who were more top down than I am so that we come up with interesting ideas that we went to thought of if either one of us was working individually. Would you say the truly big leaps happen top down like Einstein? Einstein was not a top down person in the beginning. He was um special relativity was very much him thinking about you know they were thought experiments but he was very much you know the original theory about relativity is something like on the nature of electromagnicism. He was trying to understand how Maxwell's laws could make sense when they were, you know, seem to have different symmetries than what we had thought there were.

55:40So he was very much a bottom -up person. And in fact, he resisted top -down for a long time. Then when he tried to do the theory of general relativity or the general theory of relativity, whichever you want to call it, incorporating gravity into the system where you need some feedback, then he was held by a mathematician who had developed some differential geometry and helped him figure out how to write down that. And after that, he thought top -down was the way to go, but he actually didn't make that much progress. But certainly, so I think it's naive to think it was just one of the other. In fact, a lot of people who made real progress were rooted in actual measurements.

56:17Well, speaking of mathematicians, what to use a difference because you've had a bit of foot in both between physics and mathematics in the way it helps us understand the world? Well, to be frank, there's a lot more overlap in physics and math, I think that has been, I mean, well, maybe not more, but there's certainly a lot. But I think, again, the kinds of questions you're asking are usually different. Mathematicians like the structure itself, physicists are trying to concentrate on, to some extent, on the consequences for the world. But there is a lot of overlap. The string theory is an example.

56:52There's certain theories where there's a certain kind of mathematical beauty to it. There's also some really cool ideas that you get in particle physics where you can describe what's going on and connect it to other ideas. That's also really beautiful. I think basically insights can be beautiful. They might seem simple, but sometimes they genuinely are. Sometimes they're built on a whole system that you have to understand before. If you actually saw Einstein's equations written out in components, you wouldn't think it's so beautiful. You write it in a compact way, it looks nice. What do you think about the successes and the failures of strength theory?

57:34To what degree do you think it succeeded to what degrees it not succeeded yet or has failed? I think to talk about any science in terms of success and failure often misses the point because there's not some absolute thing. I think, do you think that strength theorists were a bit overly ambitious? It's not overly ambitious, but a little bit overly arrogant. In the beginning, thinking they could solve many problems that they weren't going to solve. That's not to say the methods and advances in strength or you don't exist. And, but they certainly weren't able to immediately solve all the problems I thought they could solve.

58:10But it has given us tools. It has given us some insights. But it becomes almost a sociological question of like how much it should be one or the other. I do think that you can get caught up in the problems themselves and Sometimes you can get caught up in the methods and just sort of do other examples So the real physics insights often come from people who are thinking about physics as well as the math Because you mentioned AI is there hope that AI might be able to help Find some interesting insights. I mean another question another way to ask this question is how special are humans? that we're able to discover novel insights about the world.

58:55That's a great question. It depends on what kind of insights and what we're going to find that out. It's because it's hard to think about something that doesn't quite exist yet. I could just think about something. Take a step back. It's a little bit like, to understand four dimensions, you go back to three dimensions. To go to something you can imagine. So you can sort of say that a lot of the things in a very different level about the internet, you could say, you know, has the internet helped do things. And that's, you know, it definitely took on a life of its own in some sense. But it's also something that we're able to tame.

59:32You know, I know that I, myself, wouldn't have been able to write books as the internet didn't exist because I went to have the time to go to the library and look everything up. And it helped me enormously. And in some sense, AI could be that in a very nice world. It could be a tool that helps us go a step further than we would and a lot more efficiently. And it's already done that to some extent. Or it could be like the parts of the internet that we can control that are ruining politics or whatever. So, and there's certainly a lot of indications that can do that. then there are even bigger things that people speculate about AI being able to do with their own things.

1:00:13But in terms of actually figuring things out, we're in the early stages. Yeah, there's several directions here. One is on the theorem -proversize, so Wolfram Alpha, where everything is much more precise, and we have large language model type of stuff. One of the limitations of those is it seems to come up with convincing looking things which we don't know if it's true or not. That's a big problem for physics. Large language models are more or less like generalizations of stuff that we have. The question is, they're still breakthroughs in AI waiting to happen and maybe they are happening and maybe they'll be good and maybe not.

1:00:54That's not quite the same. Maybe just in some cases, it's just pattern recognition that leads to important things, but sometimes it could be something more insightful than that that I can't even put my finger on. So it forces us to, I mean, we don't really understand how smart we are. We don't understand how we think about things all that well, actually. But one thing is true though, we are a lot more efficient right now than computers and coming up with things. We require a lot less energy to do that. So if computers figure out how to different ballgame. So, and so, there are clearly kinds of connections that we don't know how we're making, but we are making them.

1:01:33And so, that's going to be interesting. So, you know, I say we're in early stages, but this is changing very rapidly. But right now, I don't think that it's actually, you know, discovered like new laws of physics, but could it in the future? Maybe I can. It will raise big questions about what is special about humans that we don't quite appreciate. You know, there could be things that are like that leap of insight that happens, truly novel ideas. That could potentially be very difficult to do. So there are sort of abstract questions like that. There's also questions of how is it that we can address to some extent, you know, how How will AI be used in the context of the world we live in, which is based on, at least our country is based on capitalism in a certain political system, and how will global politics deal with it, how will our capitalist system deal with it?

1:02:34What will be the things that we focus on doing with it? How much will researchers get control of it to be able to ask different sorts of questions? I mean, while it was starting out, people were doing these kind of toy problems, but what will it actually be applied to and what will be optimized to do this? There's a lot of questions out there that it's really important we started dressing. What to you is the most beautiful and solved problem in physics and cosmology? What to use really exciting if we can unlock the mystery of in the next few decades? leads. So is it what's the most beautiful and self -problem or what is the most beautiful and self -problem?

1:03:19I think we can make progress on. Oh boy. We make progress on in the next few centuries. Most of the questions, the big questions have to do with what underlies things, how things started at the base of it. There's also just basic questions that you asked earlier, how far will science take us? How much can we understand? There are questions like how we got here, what underlies it? Are there, you know, but also, I mean there's really deep questions like, you know, what fraction are we actually seeing? If there are these other forces, if there is another way of seeing the world, are there galaxies, you know, universes beyond their own?

1:04:00If there's so totally different, how do we even comprehend them? I mean, how do we detect, like, what would we even think about them. So there's a lot about trying to get beyond, it's always just getting beyond our limited vision and limited experience and trying to see what underlies it both the small scales and at large scales. We just don't know the answers. I mean, I'd like to think that we understand more about dark matter, about dark energy, about are there extra dimensions, things that we actually work on? Because there's probably a lot beyond what we work on that's yet to be discovered.

1:04:35Yeah, understanding the answer to dimensions piece will be really interesting. Totally. I mean, if it is, you know, how the universe went from higher dimensions to what we see, you know, are the extra dimensions present everywhere? I mean, you know, one of the really interesting pieces of physics we did that I talk about my first book, War of Proustages is finding out that But there can be a higher dimension, but only locally do you think there's a gravity of a lower dimension. So it could be like only locally do we think we live in three dimensions. It could be higher dimensions. It's different.

1:05:11That's not actually the gravity we have. But there's all sorts of phenomena that might be out there that we don't know about. All sorts of evolution things, time depends that we don't know about. And of course, that's from the point of view of particle physics, from the point of view of other kinds of physics, we're just beginning. So who knows? You have to physics changes throughout. It's not homogeneous throughout the universe. That's, that'll be weird. I mean, you know, for the observable universe, it's the same, but beyond the observable universe, who knows? What advice would you give? You've had an exceptional career.

1:05:46What advice would you give to young people? Maybe high school, college, and how to have a career that can be proud of and a life that can be proud of? I think the weird thing about being a scientist or an academic in general is you have to believe really strongly what you do while questioning it all the time. You can't, you know, and that's a hard balance to have. Sometimes it helps to collaborate with people, but to really believe that you could have good ideas at the same time knowing they could all be wrong. That's a tough type of up to walk sometimes, but to really test them out. The other thing is sometimes, you know, if you get too far buried, you look out and you think, oh, there's so much out there.

1:06:26And sometimes it's just good to bring it back home and just think, okay, can I have as good ideas as the person next to me rather than, you know, the greatest physicists who ever lived. But right now, like you said, I think there's lots of big issues out there and it's hard to balance that. And sometimes it's hard to forget the role of physics. But I think Wilson said it really well when he said, you know, when they were building Fermilab, it was like, this won't defend the country, but it'll make it worth defending. You know, there's just the idea that, you know, in all this chaos, it's still important that we still make progress in these things.

1:06:59And sometimes, you know, when major world events are happening, it's easy to forget that. And I think those are important too. You don't want to forget those. But to try to keep that balance because we don't want to lose what it is that makes humans special. So that's the big picture. Would you also lose yourself in the simple joy of puzzle solving? Yeah. Yeah. I mean, that's what we all like solving puzzles. And actually one of the things that drives me in my research is the inconsistencies. When things don't make sense, it really bugs me. And it just will go in different directions to see how could these things fit together.

1:07:32So bugs you, but that motivates you? Yeah, totally. Until it doesn't. Because I think, because I had this underlying belief that it should make sense, even though the world comes at you in many ways and tells you nothing should make sense. But if you believe that it makes sense and you look for underlying logic. And I think that's just good advice for everything to try to find like why this is the way it is. I think, you know, we talk, I talk about effective theory in my second book now, and it happens to a lot. You know, it's sort of rather than ask the big questions. Sometimes we just ask the questions about the immediate things that we can measure.

1:08:04And we can, like I said, we can sometimes tell one that we'll fail, but we can have these effective theories. And sometimes I think, you know, when we approach these big questions, it's good to do a effective theory point. You know, why do I find this as? Why is the world we have the way it is? We think things are beautiful that we live in. I mean, you know, I'm not sure if we had different senses or different ways of looking at things, we wouldn't necessarily find it beautiful. But I have to say, you know, it is kind of fantastic that, number of how many times I see a sunset, I will always find it beautiful.

1:08:33It's like, I don't think I've ever seen a sunset, I'd say, uh, whatever. You know, it's just always beautiful. You'll always, you know, and so there's, There are things as humans, you know, clearly resonate with us, but you know, we were maybe evolved that way. That's about us. But in terms of figuring out the universe, it's kind of amazing how far we've gone in, you know, we have discovered many, many wonderful things. But there's a lot more out there. And I hope we have the opportunity to keep going. And with effective theories, one small step at a time, just keep unraveling the mystery. But also having in mind the big questions, but doing one small step at a time, exactly.

1:09:09Yeah, looking out to the stars you said the sunset for me. It's the sunset the sunrise and just looking at the stars It's wondering what's all out there and having a lot of hope that humans will figure it out Right, I like it Lisa, well thank you for being one of the humans In the world here for uh, that are pushing it forward and uh, figuring out this beautiful puzzle of ours and thank you for talking today. This is amazing. Thank you. Thanks for listening to this conversation, Melissa Randell. To support this podcast, please check out our sponsors in the description. And now let me leave you with some words from Albert Einstein.

1:09:51The important thing is to not stop questioning. Curiosity has its own reason for existence. Thank you for listening and hope to see you next time.