Lex Fridman Podcast - #403 – Lisa Randall: Dark Matter, Theoretical Physics, and Extinction Events

Episode Date: December 3, 2023

Lisa Randall is a theoretical physicist at Harvard. Please support this podcast by checking out our sponsors: - Babbel: https://babbel.com/lexpod and use code Lexpod to get 55% off - Notion: https://n...otion.com - SimpliSafe: https://simplisafe.com/lex to get free security camera plus 20% off - LMNT: https://drinkLMNT.com/lex to get free sample pack - InsideTracker: https://insidetracker.com/lex to get 20% off EPISODE LINKS: Lisa's Twitter: https://twitter.com/lirarandall Lisa's Instagram: https://instagram.com/proflisarandall Lisa's Website: https://www.physics.harvard.edu/people/facpages/randall Books: Dark Matter and the Dinosaurs: https://amzn.to/417cKZJ Knocking on Heaven's Door: https://amzn.to/3R4LjLC Warped Passages: https://amzn.to/49Xcr85 Higgs Discovery: https://amzn.to/4a6sfWe PODCAST INFO: Podcast website: https://lexfridman.com/podcast Apple Podcasts: https://apple.co/2lwqZIr Spotify: https://spoti.fi/2nEwCF8 RSS: https://lexfridman.com/feed/podcast/ YouTube Full Episodes: https://youtube.com/lexfridman YouTube Clips: https://youtube.com/lexclips SUPPORT & CONNECT: - Check out the sponsors above, it's the best way to support this podcast - Support on Patreon: https://www.patreon.com/lexfridman - Twitter: https://twitter.com/lexfridman - Instagram: https://www.instagram.com/lexfridman - LinkedIn: https://www.linkedin.com/in/lexfridman - Facebook: https://www.facebook.com/lexfridman - Medium: https://medium.com/@lexfridman OUTLINE: Here's the timestamps for the episode. On some podcast players you should be able to click the timestamp to jump to that time. (00:00) - Introduction (11:11) - Dark matter (30:02) - Extinction events (41:02) - Particle physics (56:16) - Physics vs mathematics

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Starting point is 00:00:00 The following is a conversation with Lisa Randell, a theoretical physicist and cosmologist at Harvard. Her work involves improving our understanding of particle physics, supersymmetry, barriogenesis, cosmological inflation, and dark matter. And now a quick few second mention of the sponsor. Check them out in the description. It's the best way to support this podcast. We got a babble for learning new languages,
Starting point is 00:00:25 notion, for note-taking and team collaboration, simply safe for keeping your home safe, element, for keeping your body feeling good with deliciousness, and inside tracker for getting biological data and giving you life advice. Choose who I is in my friends. Also, if you want to work with our team, we're always hiring go to lexfreedman.com slash hiring, or get in touch with me by going to lexfreedman.com slash contact. And now onto the full ad reads. As always, no ads in the middle.
Starting point is 00:00:56 I try to make these interesting, but if you must skip them friends, please do check out our sponsors. I enjoy their stuff. Maybe you will too. This show is brought to you by Babel, an app and website I use to learn new languages, and you can too. They have all the languages you need.
Starting point is 00:01:14 Spanish for example, I've been learning a bit of Spanish for several reasons, one of which, in case you're curious, this very podcast is getting translated and overdubbed regularly into Spanish on Spotify by the brilliant Spotify AI team. You can actually find it. There's a few episodes now that are fully overdubbed in Spanish. It's really quite incredible. You can also learn a bunch of different other languages, Turkish, German, Italian, French, Portuguese. I definitely need that because
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Starting point is 00:02:31 The light of the sky will be a third of the alley, and the heart will be like a star. Translation is you will hear thunder and remember me, and think she wanted storms. The rain of the sky with the color of heart crimson in your heart as it was then will be on fire. She's one of the great Soviet poets in history, and I of course have trouble finding the right words to translate. I'm long overdue by the way. On a podcast conversation with the Dusty Eskian Tolstoy translators. That was planned a long time ago, but it requires quite a bit of travel and quite a bit of preparation on my side to read several of the
Starting point is 00:03:18 Dusty Eskian novels in both Russian and English. come up with great questions that address some of the intricate complexities involved in the translation. That really, really requires a lot of preparation, but it also reveals the power of language. Anyway, get 55% off your babble subscription about with a Com slash Lex pod spelled BABBL.com slash Lex pod rules and restrictions apply. This show is also brought to you by Notion. First, a note-taking app, but also a team collaboration tool. Both. All the cool people use it for note-taking and all the cool teams use it for collaboration. The thing they've added recently and have been continuously developing is a notion AI. It's the best, I would say, integration of large language models into the note taking
Starting point is 00:04:15 process. If you like interacting with chat you're BITI or like I've gotten a chance to recently with GROC but want to bring the power of that to the note taking process, to the collaboration process. Then no shanei is really, really great. You can ask no shanei to rewrite the thing you've written, to summarize the thing, to shorten it, to lengthen it. You do all kinds of stuff, Q&A. I like it because it gets me going on an idea, like it generates text as I'm taking the notes and kind of gets through the natural
Starting point is 00:04:50 process of a writer's block. It just gets your brain going and all the ideas flowing and sometimes just having stuff in the page is a really, really huge help. You can of course translate, you can also change the tone and the voice of the thing you've written. Like you can make yourself more confident, more clear, more friendly, all that kind of stuff. There's a million other things, but really the point here is that it's really nicely integrated into the whole note-taking process, which is really the crucial part.
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Starting point is 00:05:45 power of notion AI today. This shows also brought to you by SimplySafe, a home security company designed to be simple and effective. They have something called the Fast Protect Monitoring, which allows SimplySafe Monitoring agents to see, speak to and deter intruders to the smart, alarm, indoor camera. For me, it's one of the many layers of security, physical, cyber, emotional, all of it that take very seriously. This one in particular is super easy to set up, super easy to customize, and it just works and everything is being monitored. You don't have to worry about anything. And like I said, there's now monitoring agents that can speak to the intruders, which
Starting point is 00:06:34 is kind of epic. This world is full of dangers, sadly. So you have to do the basic, low- low hanging fruit steps to keep yourself protected. I highly recommend simplicity because it just works. The solutions in your life should be simple and resilient and also inexpensive. So simply save is perfect. Anyway, go to simplesafe.com slash likes to get 50% off any simply safe system when you sign up for fast protect monitoring that's simply safe.com slash Lex. This episode is also brought to you by Element Electrally Drink Mix, the thing that I am currently
Starting point is 00:07:20 drinking and I drink many many many times a day. It brings me happiness and joy. It prevents me for having any kind of headaches or issues associated with fasting for 24 hours, 48 hours. Eating only meat, which I do often, you have to make sure that your electrolytes are right. Sodium, potassium, magnesium, element has it in perfect proportions and is delicious. My favorite flavor is watermelon salt. They've recently sent me different flavors of chocolate. I don't know if they've always had this or just, they've recently sent me several flavors of chocolate. I think it's chocolate several flavors of chocolate. I think it's chocolate chai, chocolate raspberry
Starting point is 00:08:10 and chocolate mint. I also think it's a limited time thing. I'm guessing for the holidays. I don't know what holidays, who knows? But you make it hot and it's delicious hot. It like blew my mind. It's basically like hot cocoa. that's what it tastes like. And once again, you get all the electrolytes.
Starting point is 00:08:33 I was skeptical at first on the chocolate and the hot chocolate, but it turned out to be incredible. Anyway, I still probably go to watermelon salt most of the time, but sometimes on a, He's still probably going to water my own salt most of the time, but sometimes in a, but sometimes in a chilly Texas evening, and by that I mean, when it gets into 50 degrees, I'll make myself a chocolate chai element drink. I'll make myself a chocolate chai element drink and think about all the beautiful things I'm grateful for in this world.
Starting point is 00:09:04 Anyway, get a simple pack for free with any purchase. Think about all the beautiful things I'm grateful for in this world. Anyway, get a simple pack for free with any purchase, try to drink element.com slash flex. This shows also brought to you by Inside Tracker, a service I use to track biological data from my body. That take that data from the blood DNA data, fitness tracker data, all that kind of stuff and makes diet and lifestyle recommendations. Just imagine where all of this is headed with a very rapid development of larger language models where you can integrate all the scientific knowledge from the various papers that are being
Starting point is 00:09:42 actively published thousands of papers published every month. Integrating all of that together with the data that comes from your own body and making recommendation. That's what it's headed. And inside trackers taking the early steps on that. As far as I know, they're not integrating large language models yet, but it seems obvious to me that this is where there's going to be a lot of benefit.
Starting point is 00:10:08 At least in the step of it, having a conversation about the interpretation of the data in as far as it applies to what kind of diet and lifestyle decisions you need to make. I suppose one way to think about LLMs is you can have a natural language conversation with data, as long as that data is collected and processed properly. I mean, this is just a fascinating feature. So I'm a big supporter of InsideTrack for pushing that future forward. Get special savings for a limited time and you go to insidetracker.com slash Lex. This is the Lex Friedman podcast to support it. Please check out our sponsors in the description.
Starting point is 00:10:51 And now, dear friends, here's Lisa and I'll end out. One of the things you work on and write about is dark matter. We can't see it, but there's a lot of it in the universe. You also end one of your books with a Beatles song, quote, got to be good looking because you're so hard to see. What is dark matter? How should we think about it given that we can't see it? How should we visualize it in our minds, I? I think one of the really important things that physics teaches you is just our limitations, but also our abilities. So the fact that we can deduce the existence of something that we don't directly see is really a tribute to people that we can deduce the existence of something that we don't directly see is really
Starting point is 00:11:46 attribute to people that we can do that. But it's also something that tells you you can't overly rely on your direct senses. If you just relied on just what you see directly, you would miss so much of what's happening in the world. And we can generalize this, but we're just for now to focus on dark matter. It's something we know is there. And it's not just one way we know it's there. In my book, Dark Matter and the dinosaurs, I talk about the many different ways, you know, this eight or nine, that we deduce not just the existence of dark matter, but how much is there? And they all agree.
Starting point is 00:12:22 Now, how do we know it's there? Because of its gravitational force. And individually a particle doesn't have such a big gravitational force. In fact, gravity is an extremely weak force compared to other forces we know about in nature, but there's a lot of dark matter out there. It carries a lot of energy, five times the amount of energy, as the matter we know that's in atoms, et cetera. So you can ask how should we think about it? Well, it's just another form of matter that doesn't interact with light,
Starting point is 00:12:52 or at least as far as we know. So it interacts gravitationally, it clumps, it forms galaxies, but it doesn't interact with light, which means we just don't see it. And most of our detection, before gravitational wave detectors, we only saw things because of their interactions with light in some sense. So in theory, it behaves just like any other matter. It just doesn't interact with light.
Starting point is 00:13:17 So when we say it interacts just like any other form of matter, we have to be careful because gravitationally, it interacts like other forms of matter but it doesn't experience electromagnetic system which is why it has a different distribution. So in our galaxy it's roughly spherical unless it has its own interactions that's another story but we know that it's roughly spherical whereas ordinary matter can radiate and clumps into a desk. And that's why we see the Milky Way desk. So on large scales in some sense, yes, all the matter is similar in some sense. In fact, dark matter is in some sense more important because it can collapse more readily than ordinary matter
Starting point is 00:14:01 because ordinary matter has has radiative forces which makes it hard to collapse on small scales. So actually it's dark matter that sort of drives galaxy formation and then ordinary matter kind of comes along with it. And there's also just more of it and because there's more of it it can start collapsing sooner. That is to say the energy density in dark matter dominates over radiation earlier than you would if you just hadn't ordinary matter. So it's part of the story of the origin of a galaxy, part of the story of the end of the galaxy and part of the story of all the various interactions.
Starting point is 00:14:36 Exactly. I mean, in my book, I make kind of sort of jokes about, you know, it's like when we think about a building, we think about the architect, we think about, you know, the high level, but we forget about all the workers that did all the grant work And in fact dark matter was really important in the formation of our universe and we forget that sometimes That's a metaphor on top of a metaphor. Okay The the unheard voices that do the actual work Okay, no, but it is a metaphor
Starting point is 00:15:04 But it also captures something because the fact is we don't directly see it. So we forget it's there or we don't understand it's there or we think it's not. The fact that we don't see it makes it no less legitimate. It just means that we have challenges in order to find out exactly what it is. Yeah, but the things we cannot see that nevertheless have gravitational interaction with the things we can see at the layman level is just mind-blowing, you know? It isn't because I think what is teaching us is that we're human, the universe is what it is, and we're trying to interact with that universe
Starting point is 00:15:46 and discover what it is. We've discovered amazing things. In fact, I would say it's more surprising that the matter that we know about is constitutes as big a fraction of the universe as it does. I mean, we're limited, we're human. And the fact that we see 5% of the energy density in the universe, you know, about 1, 6 of the energy
Starting point is 00:16:07 density and matter, that's kind of remarkable. I mean, why should that be? There could be anything out, anything could be out there. Yet the universe that we see is a significant fraction. Yeah, but a lot of our intuition, I think, operates using visualizations in the mind. That's absolutely true. And it's certainly writing books I realized. Also, how many of our words are based on how we see the world. And that's true. And that's actually one of the fantastic things about physics is that it teaches you how
Starting point is 00:16:36 to go beyond your median intuition to develop intuitions that apply at different distances, different scales, different ways of thinking about things. Yeah, how do you anthropomorphize dark matter? I just did, I think. I made it to grant work, workers. Oh yeah, that's good. And you did.
Starting point is 00:16:52 That's why I can get paid the big bucks with the great and write the great books. Okay, so you also write in that book about dark matter having to do something with the extinction events, the extinction of the dinosaurs, which is kind of a fascinating presentation of how everything is connected. So I guess the disturbances from the dark matter, they create gravitational disturbances in the orcloud at the edge of our solar system. And then that increases the rate of
Starting point is 00:17:26 asteroids hitting Earth. So I want to be really clear. This was a speculative theory. I love it though. I mean, I like to too. And and we still don't know for sure, but we can what we liked about it. So let me take a step back.
Starting point is 00:17:43 So we usually assume that dark matter is what we being physicists. That's just one thing. It's just basically not interacting, aside from gravity, or very weakly interacting matter. But again, we have to get outside this mindset of just humans and ask, what else could be there? And so what we suggested is that there's a fraction of dark matter, not all the dark matter,
Starting point is 00:18:08 but some of the dark matter, maybe it has interactions of its own. Just the same way in our universe, we have lots of different types of matter. We have nuclei, we have electrons, we have forces. We have lots of, it's not a simple model, the standard model, but it does have some basic ingredients.
Starting point is 00:18:26 So maybe dark matter also has some interesting structure to it. So maybe there's some small fraction. And the interesting thing is that if some of the dark matter does radiate, and I like to call it dark light, because it's light that we don't see, but dark matter would see, it could radiate that, and then it could perhaps collapse into a disk the same way, ordinary matter collapsed into the Milky Way disk. So it's not all the dark matter, it's a fraction, but it could considerably be a very thin disk of dark matter, thin dense disk of dark matter.
Starting point is 00:19:00 And so then the question is, do they success? And people have done studies now to think about whether they can find them. I mean it's an interesting target. It's something you can measure by measuring the positions and velocities of stars. You can find out what the structure of the Milky Way is. But the fun proposal was that the solar system orbits around the galaxy. And as it does so, it goes a little bit up and down, kind of like horses on a carousel. And the suggestion was every time it goes through,
Starting point is 00:19:29 you have an enhanced probability that you would dislodge something from the edge of the solar system in something called the word cloud. So the idea was that at those times, you're more likely to have these cataclysmic events, such as the amazing one that actually caused the last extinction that we know, for sure.
Starting point is 00:19:47 It wasn't so amazing for the dinosaurs. Or for two thirds of the species on the planet. Yeah, but it gets amazing for humans, wouldn't be amazing. What really is amazing, I mean, I do, I mean, I talk about this in dark men and dinosaurs, it's just an amazing scientific story because it really is one of the real stories that combine together
Starting point is 00:20:05 different fields of science. Geologists at the time, or you know, people thought that things happened slowly and this would be a cataclysmic event. And also, I have to say, you know, if you think about it, it sounds like a story, like a five-year-old would make up. Maybe the dinosaurs were killed by some big rock that came and hit the earth, But then there really was a scientific story behind it. And that's also why I like the dark disk because there's a scientific story behind it. So as far fished as in my zone, you could actually go and look for the experimental consequences for the observational consequences to test whether it's true. I wish we could know like high resolution details of where that asteroid came from.
Starting point is 00:20:44 Like we're in the or cloud, why it happened, is it in fact because of dark matter, sick to full tracing back to the origin of the universe. Is it humans seem to be somewhat special, but it just seems like so many fascinating events at all scales of physics had to happen for a couple of years. So I'm really, really glad you mentioned that because actually that was one of the main
Starting point is 00:21:06 points of my book, Dark Matter and the Dinosaur. One of the reasons I wrote it was because I really think we are abusing the planet, we're changing the planet way too quickly. And just like anything else, when you alter things, it's good to think about the history of what it took to get here. And as you point out, it took many operations on many different scales. You know, we had to have the formation of structure, the formation of galaxies, the formation of the solar system, the formation of our planet, the formation of humans.
Starting point is 00:21:32 I mean, there's so many steps that go into this. And humans, in some part, were the result of the fact that this big object hit the Earth, made the dinosaurs go extinct and mammals developed. I mean, it is an incredible story, and yes, something else might come of it, but it won't be us if we mess with it too much. But it is, and a grand scale earth is a pretty resilient system. Can you just clarify, just fascinating, the shape of things, So the shape of the Milky Way is of the observable stuff is mostly flat.
Starting point is 00:22:10 And you said, dark matter tends to be spherical, but a subset of that might be a flat disk. So you want to hear about the shape of things. Yes, please. So structure formed early on, and now our structure that we live in is So we know about the Milky Way galaxy. So the Milky Way galaxy has The disc you can see in a dry dark place. That's where stars and light is
Starting point is 00:22:37 but you can also Measure in some ways that dark matter And we believe that dark matter is more or less verically distributed. And like we said, there's a lot of it, not necessarily in the disk, but just because it's the sphere, there's a lot of it sitting there. And the reason it doesn't collapse,
Starting point is 00:22:59 as far as we know, is that it doesn't really, it can't radiate the same way. So because it can radiate ordinary matter collapses. And it's actually because of conservation of angular momentum, it stays at desk and it doesn't just collapse to the center. So our suggestion was that maybe there are some components of dark matter that also radiate. Like I said, that's far from proven. People have such for desk. They see some evidence of some desk of certain densities. But these are all questions that are worth asking. Basically, if we can figure it out from existing measurements,
Starting point is 00:23:29 why not try? Okay, so there's not all dark matters made the same. Well, that's a possibility. We actually don't know what dark matter is. In the first place, we don't know what most of it is, we don't know what a fraction is. I mean, it's hard to measure. Why is it hard to measure for exactly the reason you said earlier? We don't see it. So we want to think of possibilities for what a fraction is. I mean, it's hard to measure. Why is it hard to measure for exactly the reason you said earlier? We don't see it. So we want to think of possibilities for what it can be, especially if those give rise to some of observational consequences.
Starting point is 00:23:54 I mean, it's a tough game because it's not something that's just there for the taking. You have to think about what it could be and how you might find up. And the way you detect it is gravitational effects on things we can see. That would be the way you detect the type of dark matter I've been talking about. People have suggestions for other forms of dark matter. They could be particles called axions.
Starting point is 00:24:16 They could be other types of particles. And then there are different ways of detecting it. I mean, the most popular candidate for dark matter, probably until pretty recently because they haven't found it, or something called WIMPS, weekly interacting mass of particles, particles that have mass about the same as the Higgs boson mass, and turns out that you would get about the right density of dark matter. But then people really like that, of course, because it is connected to the standard model, the particles that we know about.
Starting point is 00:24:44 And if it's connected to that, we have a better chance of actually seeing it. Fortunately, it's also a better chance that you can rule it out because you can look for it. And so far, no one has found it. We're still looking for it. Is that one of the hopes of the large Hadron Collider? That was originally one of the hopes of large Hadron Collider. I'd say at this point, it would be very unlikely given what they've already
Starting point is 00:25:06 accomplished. But there are these underground detectors, xenon detectors that look for dark matter coming in. And they are going to try to achieve a much stronger bound than it exists today. Just take that tangent. Looking back now, what's the biggest do you insight to humanity that the LHC has been able to provide? It's interesting. It's both a major victory. The Higgs bosom was proposed 50 years ago and it was discovered. The Higgs mechanism seemed to be the only way to explain the elementary particle masses and it was right. So in the one hand it was a major victory. On the other hand, I've been in physics long enough to know it was also a cautionary tale in some sense because at the time I started out in physics, we had some proposed something in the
Starting point is 00:25:58 United States called the superconducting super collider. A lot of physicists, I'll say particularly in Europe, but I'd say a lot of physicists were saying when that the large hedgeon collider. A lot of physicists, I'll say particularly in Europe, but I'd say a lot of physicists were saying when that the large hedgeon collider would have the energy reached necessary to discover what underlies the standard model. We don't want to just discover the standard model, we want to know what the next step is. And I think here, people were more cautious about that. They want to have a more comprehensive search that could get to higher energies, more events, so that we could really more definitively rule it out. But in that case, many people thought they knew it would be there. It happened to be a theory called supersymmetry. So a lot of physicists
Starting point is 00:26:35 thought it would be supersymmetry. I mean, it's one of the many factors, I think, that went into the fact that the large hydrogen collider became the only machine in town. And the superconducting super collider would have just been a much, if it really had achieved what it was supposed to, would have been a much more robust test of the space. So, so I'd say for humanity, it's both a tribute to the ability to discover it and the ability of really believing in things so they have the confidence to go look for them. But it's also a cautionary tale that you don't want to, you know, assume things before they've been actually found. So you want to do things in, you know, you want to believe in your theories, but you also want to question them at the same time in ways that you're more likely to discover the truth. But it's also an
Starting point is 00:27:19 illustration of grand engineering efforts that humanity can take on and maybe a lesson that you could go you in bigger. I'm really glad you said that though too because that's absolutely true. I mean, it really is an impressive. It's impressive in so many ways. It's impressive technologically, it's impressive at engineering level. It's also impressive that so many countries work together to do this. It wasn't just one country and how it was, it was also impressive in that it was a long-term
Starting point is 00:27:51 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 for you. You are for C 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. And here we are.
Starting point is 00:28:25 Well, I don't want to overstate that because without politics, the, you know, they like to move up and either. So, um, but, you need broccoli. Um, 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 with 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 you know
Starting point is 00:29:07 It's 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 to sit 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. And 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.
Starting point is 00:29:34 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 that led to the extension of the dinosaurs, when you look out at the future of Earth, do you
Starting point is 00:30:13 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 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,
Starting point is 00:30:43 I mean, I know people are worried just about AI taking over and that's a totally different story. We 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 rely on. It's interesting just to think whether 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 we be more worried about?
Starting point is 00:31:18 Because it seems like like with the asteroids or nuclear war, it could be stuff that just happens one day. You know, when I say one day, I mean 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.
Starting point is 00:31:55 And the idea of extinction was a very, was actually a novel concept at some point, you know. I mean, these aren't predictable events necessarily. They'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, say, 20 or 30 years ago.
Starting point is 00:32:20 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 actors. It takes everyone to sort of make things work well. It takes not that many things to make things go wrong. It's the issue with disease.
Starting point is 00:32:49 We can find out what causes a disease, but to make things better is, this is why that's simple, sometimes it is, but for 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.
Starting point is 00:33:05 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. 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 and I Think that's what people are scared of today in many ways. They're scared of it for democracy
Starting point is 00:33:33 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? How should we be thinking about them? How do you make things happen on a global scale? Because that's really what we need.
Starting point is 00:34:09 It certainly should be a source of division. It should be a source of grand collaboration. Probably. Wouldn't that be nice? Yeah. I just wonder what it would 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. 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 extinct.
Starting point is 00:34:40 I think there is 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 say, you know, so I got a, I got a 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. It's true that you have that, yes, this is scary, but you also have this, this is cool
Starting point is 00:35:20 feeling, and I think we have to get around that. Because I kind of think that, yes, you can can be in that but I'm not sure that's going to make people scared Has it have they actually asked afterwards? Are you more or less scared? Yeah, that's good It's a really good point. I mean that's a good summary of just humanity in general where Attracted to creating cool stuff were 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 the Manhattan Project. It was a very cool tour.
Starting point is 00:35:58 And you just realized 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, people were just thinking like, what if we did this? What if we did that? And not keeping track of what the peripheral consequences are.
Starting point is 00:36:21 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 write 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 serenely disdains to annihilize us. That'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,
Starting point is 00:37:06 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. You don't know if there's
Starting point is 00:37:34 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 clear, I'm doing theoretical physics, not very dangerous, but sometimes things end up having bigger consequences than you think. 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? Like the size of dark, like the power of this thing in terms of its potential gravitational effects, just the cosmological objects of a black hole at the
Starting point is 00:38:20 center of our galaxy. So this might be where, why I'm a physicist or why I differ 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. It's going to be disappointing if we were all there is. Wouldn't it be disappointing if we were all there is? Yeah, and the full diversity of other stuff is pretty interesting. We have no idea how much there is. 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.
Starting point is 00:38:59 Let me ask you out there a question. 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 a Darwinian evolution and however life originated, Doing as possible, there's some pockets of complexity of that sort inside dark matter. Well, so that's possible. I can't be streaming 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
Starting point is 00:39:40 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 give 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.
Starting point is 00:40:02 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 Santa model of physics. Right, 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
Starting point is 00:40:30 two weeks for us to have discovered so far, or that existed at different scales that we know about. I mean, we detect what interacts strongly enough with our 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. So it's not just in the dark matter sector, even in our sector, there could be a whole bunch of stuff we don't
Starting point is 00:41:01 yet know. So maybe let's zoom out and look at the standard model of physical, 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.
Starting point is 00:41:27 So if you look at atoms, we know they have nuclei in electrons. Nuclear, I have protons and neutrons. And then protons and neutrons have particles called corks that are held together by something called the strong force. They interact through the strong force, the strong nuclear force, something called the weak nuclear force and electromagnetism.
Starting point is 00:41:48 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,
Starting point is 00:42:16 charm and strange top and bottom. There'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.
Starting point is 00:42:54 It'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.
Starting point is 00:43:12 We're looking for the precision measurement or the energy or whatever it will take where the where the stand model 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 standard model, which is what we really want to see next Working fine the places where the standard model breaks down like What are the where the place you can see those tiny little deviations? So we don't know yet, 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 Hadron Collider,
Starting point is 00:43:48 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.
Starting point is 00:44:03 The other place is precision measurements. If 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 treasurls and... Isn't it wild how this little system came to being quates, is underpins
Starting point is 00:44:43 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? Why is the exposed and so light compared to the mass it could have had, which we might have even expected, based on the principles of special relativity and quantum mechanics? So that's a really big question. Why are they what they are?
Starting point is 00:45:07 And they originate, there's 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, it's like, shh, shh, shh, embryogenesis, like the whole thing,
Starting point is 00:45:27 you build up this thing. All of it, this whole thing comes to be from just like a, I'm not gonna forget, it is interacting with the environment. For sure. Okay, right, right, right. It's not, it's not, it's not, it's not, it's not, it's not, it's not, it's not, it's not, it's not, it's not, it's not,
Starting point is 00:45:39 well that's a really good question is how much of it is the environment, is it just the environment acting on a set of constraints? Like how much of it is just the information, the DNA or the information? How much is it in the initial conditions of the universe versus the other thing acting on it? These are big questions. These are big questions in pretty much every field. For the universe, we do consider it, it's everything there is by definition. But people now think about it as one of many universes. Of course, it's a misnomer, but could there be other places where
Starting point is 00:46:19 there are self-contained gravitational systems that we don't even interact with? 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
Starting point is 00:46:37 to look at your fun, nuanced disagreement with Carlo Revelli. When you talked about him writing in his book, Electrons don't always exist. 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. Stocks 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
Starting point is 00:47:17 position until the position is measured, but something was there, which physicists use 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. I 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.
Starting point is 00:47:44 I mean, I could believe that the Middle East doesn't exist because I'm not there now. Yeah. 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 attribute to our own powers we've seen. 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 disagreement about the standard model, this is a disagreement on how you interpret quantum mechanics.
Starting point is 00:48:08 I 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 that collider as 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, it's charge is
Starting point is 00:48:32 there. So physics is a kind of way to see the world. So what, what, what, at the bottom, what's the bottom turtle? Like, what, do you have a sense that there's a bottom reality that we're trying to approximate with physics? I think we always have in our head maybe that we'd like to find that. But I mean, I might not seem so, but I think I'm kind of more humble than a lot of physicists.
Starting point is 00:48:55 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
Starting point is 00:49:12 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. And 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 even considered as measurable. For example, consciousness, or there might be stuff just like you said, forces unseen, undetected.
Starting point is 00:49:49 So it's an interesting thing. 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 we'll call an effective theory at some level. 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.
Starting point is 00:50:16 That, 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 they're complex phenomena that will be given in terms of the fundamental ingredients that we know about. But that is an interesting question because yes, there's phenomena that are at the higher level of abstractions that emerge, but maybe like with consciousness, there's far out people that think that consciousness is Pants like this, right? That there's going to be almost like a Fundamental force of physics that's consciousness that permeates all that right? I mean usually when you have a crazy sorry, okay, when you have a far out theory
Starting point is 00:51:00 Yes, the thing you do is you test all the possibilities within the constructs that exist Yeah, 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 And we're very far from that. I think one of the criticisms of your theory on the 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 if the boy said them, but I mean, we have no idea how we are dark matter is. I mean, it's based on everyone thinking they know what dark matter is. I mean, so we are
Starting point is 00:51:40 to then 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? It definitely does in the universe, just like, I mean, so for example, there's more dark matter in galaxies than there is between galaxies. So it clumps, I mean, it's matter. So it's distributed like matter, it is matter.
Starting point is 00:52:04 It does clump, but the the full details of how it clumps and the complexity of the clumping. It's under a student of pretty well. People do simulations They're I mean where people are we're always looking for things including us as particles It's sort of at small scales are the deviations on small scales so that indicating other interactions or other processes or interactions with barrions that is to say normal matter that we don't understand. But on large scales we have a pretty good understanding of dark matter distribution. You were part of a recent debate on quote, can science uncover reality? Let me ask you this question then.
Starting point is 00:52:44 What do you think is 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, it's at a higher level, the kind of questions you ask go different the kind of measurements are different
Starting point is 00:53:07 The kind of science is 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. We're trying to solve hard problems. We've made progress.
Starting point is 00:53:36 If you think of how much science has advanced in the last century or a century and a half, it's incredible. We didn't even know the universe was expanding at the beginning of the 20th century. We didn't know about quantum mechanics in 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 declared. Where we was various people exactly the history, we thought we solved everything or declared or at least various people We were we was various people exactly. Yeah declared that we've solved everything
Starting point is 00:54:09 So this also good place to maybe could you describe the difference you top down and bottom-up approaches to theoretical physics that you talked about in the book so You could try to jump in and say I have a theory that I think is so perfect 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 of the cellular features from it. Let's stop down. That would be a top down. Bottom up is more like, you know, like the questions we just asked, like, 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,
Starting point is 00:54:55 some, you know, the community tends to get segmented or fragmented into people who do one or the other. But there are definitely times, I mean, some of my best collaborations have with 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 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
Starting point is 00:55:29 the nature of electromagnetism. 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. So he was very much a bottom-up person. 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,
Starting point is 00:55:55 then he was helped 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 or the other. In fact, a lot of people who made real progress were rooted in actual measurements.
Starting point is 00:56:17 Well, speaking of math and 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, than 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.
Starting point is 00:56:50 The string theory is an example. There's certain theories where there's a certain kind of mathematical beauty to it. There's also, you know, 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 generally are. And sometimes they're built on a whole system
Starting point is 00:57:18 that you have to understand before. I mean, 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? To what degree do you think it's exceeded 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 a point because there's not some absolute thing.
Starting point is 00:57:48 And I think I do think that strength theorists were a bit overly ambitious, 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 theory don't exist. But they certainly weren't able to immediately solve all the problems I thought they could solve. But 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 do other examples. So the real physics insights often come from people who are thinking about physics as well as
Starting point is 00:58:34 the math. Because you mentioned AI is their 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 were able to discover novel insights about the world? That's a great question. And it depends on what kind of insights and what we're going to find that out. I mean, you know, it's because it's hard to think about something that doesn't quite exist yet. I mean, I could just think about something, take a step back. You know, it's a little bit like trying to understand three, four dimensions. You
Starting point is 00:59:13 go back to three dimensions, you know, so 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 can say, you know, has the internet helped do things. And that, 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. You know, I know that I, myself, wouldn't have been able to write books
Starting point is 00:59:35 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 an 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.
Starting point is 00:59:57 Or it could be like the parts of the internet that we can control, that it's ruining politics or whatever. And there's certainly a lot of indications that can do that. Then there are even bigger things that people speculate about, about AI, being able to do its own things. But in terms of actually figuring things out,
Starting point is 01:00:17 we're in the early stages. Yeah, there's several directions here. One is on the theorem-proversize, so we'll from alpha, where everything's 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. And that's a big problem for physics. So large language models are more or less like generalizations of stuff that we have. So the question is, so there's still breakthroughs in AI waiting to happen and maybe they are happening and maybe they'll be good, maybe not, but that's not quite the same.
Starting point is 01:00:55 I mean, maybe just some in some cases, it's just pattern recognition that leads to important things, but sometimes it could be something more insightful in 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 do that, then it's going to be a totally different ball game.
Starting point is 01:01:28 And so there are clearly kinds of connections that we don't know how we're making, but we are making them. And so that's going to be interesting. So 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
Starting point is 01:01:57 special about humans that we don't quite appreciate. You know, there could be things that are like 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, how will AI be used in the context of the world we living, which is based on, at least our country is based on capitalism and a certain political system, and how will global politics deal with it, how will our capitalist system deal with it, what will be the things
Starting point is 01:02:35 that we focus on doing with it, how much will researchers get control of it to be able to ask different sorts of questions. 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? 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. Which is really exciting if we can unlock the mystery of in the next few decades.
Starting point is 01:03:14 So is it what's the most beautiful and solved problem or what is the most beautiful and solved problem? I think we can make progress on. Oh boy. We make progress on in the next few centuries. There's, you know, this, most of the questions, the big questions have to do with what underlies things, how things started was at the base of it. There's also just basic questions like how, like that you asked earlier, how far will
Starting point is 01:03:39 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, are, if there are these other forces, if there is another way of seeing the world,
Starting point is 01:03:58 are there galaxies, you know, universes beyond their own, if 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 in trying to see what underlies both the small skills and at large skills. 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?
Starting point is 01:04:30 Because there's probably a lot beyond what we work on that's yet to be discovered. Yeah, understanding the actual 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 Prasad is, is finding out that 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 that
Starting point is 01:05:09 could be higher dimensions is different. It'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 your particle physics, from the point of your other kinds physics from point of view of other kinds of physics We're just beginning so who knows? You have the physics changes throughout is 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 except from career. What advice would you give to You've had an exceptional career.
Starting point is 01:05:46 What 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.
Starting point is 01:06:20 The other thing is sometimes, you know, if you get too far buried, you look out and you think, oh, there too far buried, you look out and you think, oh, there's so much out there. And sometimes it's just good to bring it back home and just think, okay, can I have as good ideas the person next to me rather than, you know, the greatest physicist 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.
Starting point is 01:06:44 But I think Wilson said it really well when he said, when they were building Fermilab, it was like, this won't defend the country, but it'll make it worth defending. It's just the idea that in all this chaos, it's still important that we still make progress in these things. And sometimes when major world events are happening, it's easy to forget that.
Starting point is 01:07:03 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 human special. So that's the big picture. Would you also lose yourself in the simple joy of puzzle solving? Yeah. Yeah. I mean, I, 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.
Starting point is 01:07:27 And it just will go in different directions to see how could these things fit together. So bugs you, but that motivates you. Yeah, totally. Until it doesn't. Because I think, because I have 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 it is the way it is.
Starting point is 01:07:52 I think, you know, we talk, I talk about effective theory in my second book, now I'm going to have a store 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. And we can, like I said, we can sometimes tell one that will 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?
Starting point is 01:08:15 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, you know, right, how many times I see a sunset, I will always find it beautiful. It's like, I don't think I ever see a sunset, I say, 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.
Starting point is 01:08:45 That's about us. But in terms of figuring out the universe, it's kind of amazing how far we've gone in. 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 a mind of big questions, but doing one small step at a time, exactly. Yeah, looking out to the stars, you said the sunset. For me, it's the sunset, the sunrise, and just looking at the stars.
Starting point is 01:09:17 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 for that are pushing it forward and 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.
Starting point is 01:09:43 To support this podcast, please check out our sponsors in the description. And now, let me leave you with some words from Albert Einstein. The 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.

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