The Philosophy of Physics, with Elise Crull

When scientists think about it, I think they're understanding not philosophy as a discipline, but they're thinking about a worldview. And we come to everything with a worldview, with a lens that's inescapable. I leave all philosophical preconceptions at the door. You can't do that to the extent that I'm able. I'm self-aware that I could be constrained by a philosophical thought. Your choice to set aside some world like so that you can be neutral. Yes. is itself a philosophical position. Okay, that's a very inelimable. She's about to say that's like being a little bit pregnant.

[Music] This is Star Talk. Neil deGrasse Tyson, your personal astrophysicist. I got Chuck Nice with me. Chuck it, baby. Hey, what's happening, Neil? All right. You love it when I look over and I see you there. Oh, you know the Felix Mutual. Oh, thank you. It's almost like I'm looking at myself. So, we're doing something we haven't yet done on this show. All right. We're going to do the philosophy of physics. What? I know. That's why we haven't done it. And we had somebody right up the street in the hood. Actually, literally in the hood, but up in Harlem. And this is Elise. How do I pronounce your last name? Crawl. Crawl. Elise Crawl. Elise Crawl. Welcome to Star Talk. Yay. Thanks for having me. Yeah. You're a professor of philosophy in the philosophy department. That's right. This is a cutuney. Yep. Yeah. And you authored a book just last year came out, but it was like a very serious academic tome. The Einstein paradox. You This is a very seductive title. Okay. Einstein paradox. Uh the the debate on non-locality and incompleteness. Oh, come on. Oh, in 19 in 1935. Yeah. So, the title actually comes from Schrodinger. He had a folder in his archive of cat of cat fans. And in fact, the cat was born in this correspondence with Einstein that he had labeled in German, the Einstein paradox. And so we translated those letters into English, many of them for the first time. And it's all the famous physicists talking to one another about what this physics is. So why can't uh regular people read this? They sure can. Uh it's just that uh the primary literature in particular just reading the way that Einstein and Schroinger and Heisenberg and Bour talked to one another. They had their own language. Wow. Yeah. Okay. They did uh and they had their own like twins. They just have like twins that get their own language except in this case their their own language was often German. Okay. Some Danish. But um but their Danish would be for right. But they all had really nuanced st like they had different ideas about what was problematic about quantum mechanics. Interesting because quantum mechanics is just being born right at that time. It's about 10 years in at this point. Yeah. And um what precipitated this was Einstein well Einstein had had conversations with two guys Pidolski and Rosen about what he felt was an issue that quantum mechanics was correct but it wasn't finished yet. It wasn't complete. And guess what? He was right. still isn't complete. So that book is by Cambridge University Press which which has quite the the catalog of astronomy and physics books for the public. Yeah. And I mean the book is intended for people who are interested in learning from the physicists at that time themselves their philosophical and physics sort of worldviews um and learning about this history. I don't understand the the use of philosophical when it comes to their physics. Well, let's start right there. Let's just You are a professor of philosophy specializing in the philosophy of physics. So, what is the philosophy of physics in modern times? Cuz I know what it was in the day cuz in the day, what's the day? Antiquity or the Renaissance? No, Newton. Post Galileo. Okay. Newtonian world. Yeah. Okay. Got it. Yeah. Back then, scientific revolution. Yes. Back then, uh, philosophers were physicists. I mean they were one and the same. That's right. And in fact the Newton's greatest work has the word philos the word physics is isn't even in the title. That's right. The Prancipia doesn't even have equations in the first part. Okay. It's it that the title is well in Latin but the mathematical principles of natural philosophy. Okay. That's right. Natural philosophy philosophy. Yeah. Natural philosophy was physics. It's the deep thinking about how nature works. Okay. So we got that. But into the 20th century, you get quantum physics where you can't deduce from an armchair and you have expanding universe who thought that up, right? And so all and the confirmation of all these things that were mathematically postulated and then proven to be the actual case. So what I noticed was that there was a sort of a separation of the turf. Yeah. And the philosopher couldn't really contribute to physics unless they were actually a physicist. They could still think philosophically, but you needed to be in the lab. You couldn't just sit back and observe and think deep thoughts. Well, Einstein was never in a lab. Right. But he was a physicist, not a philosopher. I don't think he would make that distinction. Let me say it differently. He was trained as a physicist, not trained as a philosopher. And and and that's the distinction I'm making. So here's the real test. That is that is the distinction I'm making. If Mel Brooks were doing a sketch with him, would he say to Einstein uh in the philosopher unemployment line, did you today? Did you try to today? Are you planning on bullshitting in the future? Is that from history of the world? History of the world. Actual quote. Yeah. So I'm I'm distinguishing between people who go to school to be a philosopher and then attempt to contribute to the physical sciences whereas that you could do that in the day and I don't see that happening today unless you're busting that wide open in your existence in the world and in this office right now. Yeah. Yeah. Okay. Couple of comments. All right. Uh first of all in the German university system in which Einstein and Schroinger and Boore and all these guys were trained, they learned a hell of a lot of philosophy. Sure. and even Einstein into his I'm not saying people didn't have philosophy chops. I'm saying if you go to school to be a philosopher in the 20th century fair enough you became less and less useful to the moving frontier of the physical sciences. That's the only point I'm making. Now go unless you go and bust that open. Well the first thing is I don't accept your premise that in order to do what I do that's how you start an argument. I think we're start welling we're welling our way into a philosophical debate. Your premise is invalid. Okay, go. Well, a premise can't be invalid. Only a whole argument can be valid. But I'm being an on purpose because it's funny. Um the the idea that what I need to do is be useful to science to be important or worth doing as a human endeavor is a pretty narrow view except that's how it used to be. And that's that's so how what used to be philosophers were useful to the moving frontier of You have Kant thinking up stuff that the nebular hypothesis was kind of cool and you had uh so Einstein's own ability to get uh the theory of special relativity had to do with his taking a stud a different approach than Lorent and Panker and others who were looking for a similar theory. They said let's step back that is a philosoph like that is a choice to step back and say we have these data let's understand them a different way. That's now if you're saying it's about how we specialize into different disciplines. Yes. Yes. That is something that naturally occurred as our measuring apparatuses and our technology got better. Got it. We were able to be like and you go to a conference in astrophysics nowadays. How many talks do you even are interested in talking like hyper specialized? Fair enough. Yeah. I publish a paper 100 people in the world will understand it or or no 100 people in the world will care about it. For me it's like maybe six. Oh, this works. They're my buddies, you know. Okay. Yeah. It's like when people are like, "Oh, how do I find you on the internet?" Like, Google Elise and philosophy of physics cuz I think I'm the only one. So, let me let me just let me back up as a lay person and kind of broaden the view here. The intertwining that Neil was talking about that existed at one point that you now say has kind of dissolved because of highly specialized training. Yeah. Where does that intersection happen now? Good. Yeah, good question. That's great. And I think that's exactly the question we want to um So, you're asking am I blow am I going to blow it open now? I think the fringe like the edge the edge of science right now is in this place. So, you're talking about people who are looking for a theory of this place in this place. In this place, metaphorically and my office at the plant right now. It happens here and now localized entirely in this room. We're in the room. We're inhabiting. Okay. Okay. We're getting beyond our means to empirically test. And you know, as a cosmologist and astrophysicist, there's a limited amount of data that we on that frontier. Yes. On that frontier. And that's true also in looking for quantum gra theories of quantum gravity. Yeah. All of that. Uh I mean, we haven't yet found conclusive evidence for the lambda CDM model that is only for the lambda CDM model of cosmology. It's the best we have right now. It's the cold dark matter and and dark energy. It's just the concordance like the model we think is the best model of the universe right now. I just catch people up. So we we know the universe is accelerating in its expansion and what's causing that we call dark energy. We just call it that. We don't know but it's a black box quite literally. And then dark matter, right, is a mysterious source of gravity in the universe. In fact, it's 85% of the universe's gravity. And we don't know what that is either. But if we assume it's a thing because we measure it, right? And then we can calculate with it and with some assumptions about the behavior of matter, we get a sort of a kind of our own standard model of how the universe works. It's called Lamb of the CDM, Lamb of Cold, dark matter. And we we work with it. It gets us some understanding. does some good work. We did some Yeah. It's it's a we don't have direct but it's not a complete it's not a complete complete theory. Okay. Right. So this is true in a lot of arenas of physics. And so what philosophers of physics can do although I think there are many ways to be a philosopher of science is not just like you're trained in philosophy but you sort of ask philosophical questions of science itself. How many philosophers of physics are there? I don't know. More than five, but less than 200. Okay. Well, no, maybe there's more than 200. I It's hard to say. I You're the first one I've ever met. Oh, really? Yeah. I've met philosophers, but just think about everything, right? You know, well, it's a small field to be fair. And I will also say back to your early point, most of us have training in physics as well because that's important to us. Like what I Your undergraduate, my undergrad is in physics, but then I also continued I mean I wrote my doctoral thesis on quantum decoherence. So like I was learning about the models that people say physics. Yeah. So was that in the physics department or in the philosophy department? Um so I was in the philosophy department but I was part of a history and philosophy of science program but I also took a number of physics courses from the physics department. Okay. So you just you're just blending all that. Thanks. You just put it all together. However, that's what we need for someone to bust out. That's a great way to bust a great way to make sure that you get an A. Is that why? Because Yeah. Well, how does that correspond to getting a good grade? Here's how here's how it works for getting a good grade. Good. So, you have your philosophy people, they don't know crap about physics and your physics people, they don't know crap about philosophy. So, you're just like, "Yeah, you going to have to take my word for it." That's exactly right. We're all just pretending, right? No, go ahead. So this ties into your earlier question is like something about the um extreme specialization has meant that in particular the way we train physicists in the US even at in high school is so divorced from the deep questions about but why but how it's about following a scientific method. Did you study abroad? No, but I um when I um I've studied I've looked at education policies uh in other countries and sort of it's it's no surprise that that we're we're not you know we're still the best best place to go for STEM at the graduate level, right? Um but that's we're losing that. Yeah. And there's a history about that in particular. So there were decisions made in the cold war era to train people in science in a particular way that was going to get technologies built that was going to be good for industry for the department of defense. That's right. Weaponry and it became not just not in vogue but like in fact I have the original document in this office of the of the NSF creation of of of I have that document. Can I can I reach for it? Yeah. Show it show it to us. Let's have a visual here. This is what you were talking about. Yeah. Vanavar Bush, let's let our people at home making a case for why America needs to preserve and fund science. And I think that was an easy case to make because it was physics that won the war. Well, that that definitely helps an argument. I'm just saying. But there's a there's a reason this is good. This is good. This funny that's funny. Science the endless frontier. Yes. A report to the president. Yeah. This is 1945. Oh wow. This established So this went to the president. This right here. This he Vanver Bush was the basically the first science adviser to a president. Right. Okay. And he's advising I don't need one of those. Nobody knows more about science than I do. Really good. I know. I'm getting angry over here. That's how you know it. So, here's what I want you to do. Just read the chapter, the section headings there. Just read them. Read them. Introduction. Well played. Okay. Excellent. The war against disease. These headings you mean are like science and the public and public welfare, renewal of our scientific talent, a problem of scientific recon conversion. Wow. The means to an end. Responsibilities for the government. The Yeah. The means to an end. Okay. Okay. So this so everything I know and think of about how science happens in the United States when I pull up this original document it's all there and so I have maybe is it a bias I say that's how you do science but it's how you do are you suggesting there's another way to do science I'm suggesting that when you get to the level of how we educate when you divorce you you understand science as a thing that's about usefulness and application that is one very small color from a spectrum of colors. And I'm also suggesting that when we look at people who are trained in the history and philosophy of science along with the science itself in high school, they're testing off the charts in they're there's something about like being able to answer that or ask that why why are we using this equation to solve for the energy level of a hydrogen atom? Why that never showed up in any of my classes? That's right. That's absent. Were you taught you were taught it's amazing. was taught physics as a thing not as a way of thinking. I had to like realize that it was a way of thinking and and bring to it the bit of philosophical meanderings that I had engaged in my life. I had to bring that to the physics that was not there when it was taught and you're told not to have it there, right? Like well not explicitly it's not it's not encouraged and it's not rewarded. Okay, let me ask this. So what is it about asking these big questions? the why questions, the big why questions. What is it about that that contributes to the guiding principles of science itself? Because there's no one recipe for how to do good science. Okay. Okay. It is true. When I go to my different SC, everybody's got their own angle on the science. It's true. There was no centralized approach. Right. Well, but even if that So you're telling me that this centralized our approach, not to our greater good. I think it did in some ways to our greater good because I mean Vanavar Bush wanted the inner core of funding for NSF to be pure science. He thought there was always supposed to be a part of it left of it moment as of let us hang our heads is do I get a plane from the NSF? But did you know that if you drop a magnet into a glass of water, it loses its magnetism? Yeah, he said that. He said that. I love it. He said that. Yeah. And by the way, I'm still right. But it has to be Avon wise. Okay. Sorry. I'm sorry. Go ahead. Why you keep disrupting the ladies? I know. I'm so sorry. This is like real world out there, right? It's like we're trying to do scholarship and then things, right? But also, let me ask you this, Neil. Would you have been interested in doing science if it was just told it was taught to you as like following a recipe. I I had to like the scientific method. Like my philosophical interest in the universe was self-driven. It did not come from any book that I was taught. Right. Mhm. And and my writings today, I don't want to say they're dripping with philosophy, but they they take an angle on the content where it's not just here, learn this. It's think about it in this other way. That's very cool. So, I mean, here's a metaphor if you like. Um, I mean, a lot of people can follow recipes and make really good dishes, really tasty dishes. So, there's something wonderful about that. But the truly inventive chefs are the ones who say, "Well, or or even the better cooks. I'm a terrible cook, but like are the ones who say, "But why do I melt the butter to this temperature? Why do I add the salt at this stage? Or why is this these flavors work together?" Expertise is something that our country is not has a very interesting relationship. Yeah, that's right. So, let me ask you this. Often philosophy is thought of as a belief system. Okay. But in science, less so in the sciences, right? That's what I'm saying. But in science, you definitely don't want to be biased by your beliefs. So the one thing you want to do is divorce yourself so that whatever results you get, you're able to accept irrespective of how you feel about them or what you believe. How is that reconciled? Good. And let me add something to that. Yeah. Okay. A lot of good questions. Let's go back to Kepler who was, dare I say, philosophically driven to think that the orbits of the planets could be nested in such a way that they resembled the platonic solids, nested spheres, which always makes me think of Tupperware for some reason. But yeah, so what he knew was that geometrically in mathematics there are only five what are called platonic solids. These are solid shapes where every surface is the same two-dimensional shape. So a cube is such a thing. Every side is identical and has six sides. A pyramid is the same. Okay, four sides. So you have four triangles and they can all be equilateral triangles. So there five of these shapes. He saw that there were six planets and he thought to himself maybe there's a divine connection between the two. Uhhuh. Because the planets it's it's it's the universe. It's where God lives, right? And then we're just mere mortals here. God surely knows what he's doing. And math is perfect, right? Ma math is badass. So he he nested these in different ways to try to find out whether the separations of the planetary orbits could match what these solids would be if they were nested Tupperware style. Okay. He was also thinking in terms of harmonic resonances but yeah right and so my question to you is he I don't want to say he wasted 10 years. He devoted 10 years to this point of view and it took him that long to abandon it in favor of something that was not so philosophically beautiful. So in that case, getting back to Chuck's point, the philosophy prevented him from seeing the answer because he was driven by this concept of divine perfection. So there's a couple of different ways we're talking about philosophy, right? There's the philosophy of just I mean if you go to a philosophy section at Barnes & Noles or whatever what they have there in the metaphysics section is some weird newagy stuff. Yeah. It has nothing to do with what academic philosophers are doing. Okay. And academic philosophers are asking questions about what is the nature of of personhood? What what is knowledge? Do different people reason in different ways? What are ethical questions? Like what is the philosophy of law, philosophy of science? These sorts of things. They're they're they're um we have a specific we have specific tools that we bring to bear on that. When scientists think about it, I think they're understanding not philosophy as a discipline, but they're thinking about a like a worldview. And we come to everything with a worldview with a lens that's inescapable. Now, you're right that part of what scientists want to do is sort of shield, maybe not shield for that or at least normal neutralize it in some way. We want to think about whether our comments are valuel laden. And I don't just mean value in an ethics way, but maybe also do I privilege certain epistemic values like beauty or uh solarity and many do many do. But I can tell you this to the extent that I can understand myself. I leave all philosophical preconceptions at the door. You can't do that though. I said to the extent that I'm able, I'm self-aware that I could be constrained by a philosophical thought. So I remain open to anything I see. and anything I measure and what that could possibly mean and without discounting it. And the reason why I'm going there is I had an issue in Hamlet. Okay. One of the lines is there's more between betw twix heaven and earth than I dreamt of in your philosophy. Right. And I never understood that comment ever because as a scientist, if a ghost shows up, I'm fine. Let me make some measurements. I have no issue with that. So why does that sentence make any sense at all? Until I realized that people who are deeply into a philosophy of belief do close off their access to things that fall outside of their understanding or their awareness. And and so so a good scientist has no philosophy, otherwise they're going to miss stuff. Bad scientists will have a philosophy and they'll miss everything. Your choice to set aside some world like so that you can be neutral is itself a philosophical position. Okay, that's a very inelimable in a way. Ineliminable that you are going to walk in with some interpretive frame. Inelimable inelimable cannot be eliminated. Cannot be eliminated. Inelimable inelimable. I've got some big words. I would say that the philosophy that I have no philosophy is a very mild version of a philosophy. The point is that you cannot Yeah, I was going to say she's she's about to tell you. No, she's about to say that's like being a little bit pregnant. Let me hear what she said. Okay. You can't be a little bit pregnant. Can we hear the lady? Okay, go. Yeah. Well, so when you're when you walk into the lab or whatever, it's not like you take off your religious hat or you take off your culture, like you're an integrated whole person and how you were trained and what you were thinking about that morning and what you're predisposed to look for in the equations themselves. Those things play a role. Now there's a huge conversation in the philosophy of science about whether certain things are more or less appropriate when you bring in but that you bring something with you that is how we do science is a is a is a personal and social endeavor. So so let me all I did say I think was I reduce it as much as I knowingly can. That's what you said. So what she's saying is there's no extent to which you can actually know because the holistic person that you are you are inexurably tied to your philosophy except even when you try to divorce yourself except in the movie. So you guys are talking about a philosophy like like like and I think this is fair because I think a lot of people do this like like it is a political position but I'm talking about something not just a I'm talking about the way you view the world. Now watch more comprehens. Do you remember the show? I like that. The XFiles. I like that. Of course. Best show ever. Okay. Xiles. The X Files. Yeah. I'm watching the show. Okay. Okay. And there's like the skeptic science Scully Skully. And then Mold Mer Moulder. Moulder. Mold. Mold. Excuse me. Moulder. Moulder. And I've watched them interact and I'm thinking, "No, no." Okay. there was some glowing mass in a in a vestibule. Okay. And Moulder says, "Oh, this must be an interdimensional for He just goes right to to the most wild explanation for it." And Scully is saying, "Uh, this can't possibly be real. It must be a project." And she's all discounting of it because it doesn't fit her philosophy that that can't exist. And I'm telling you're making my point for me right here. Right. Good. Good. And it's the chemistry of those two perspectives that leads them to certain certain discoveries and so on. You call that a chem? They look pretty immissible to me. How's that for a chemistry word? Did you remember immissible? I missable. Oil and water. Don't mix. You know how to missile them? I do not. You You take a little bit of Cuz when you're making um Are we talking about skull scully and molder? Yes. How do we do it? How do we get the vinegar? You learn this in I learned this in chemistry class and then I applied it at home. So you have oil and vinegar and you shake it and it'll still separate. But it's it's together for like for a few seconds. All right. But you can get an emulsifier to put in there and it'll connect chemically to both sides and bring them together. But so I think I want to know the answer. A little bit of egg yolk will do that. Egg yolk is an emulsifier. That's right. I know that from baking, believe it or not. And yeah, I was going to say that's egg yolk is used as an emulsifier in a lot of lot of cooking. So it brings it together. So they needed egg yolk. Fair enough. But I mean, but I like what you're saying. You're saying this is not philosophy in terms of I believe blump bl is philosophy in terms of how do you know what questions are good questions to pursue? How do you know when your apparatus is measuring what you want it to measure? Well, let's let's let's anchor this back in time. Please compare for us the philosophies of the two greatest physicists there ever were. Okay. So I'm you said this. So I was going to say so he's talking. So one of them has got to be Isaac Newton. That's got to be one Einstein. So tell me cuz you've clearly you studied this cuz you writing about the man and everything. So and I love the fact that we share sort of access to history and what that means in the present. So I just want to know how would you characterize Newton's philosophy relative to Einstein's philosophy? And I have here hang on before I earned enough money to buy an actual book from Isaac Newton's days. I got this paperback called Newton's Philosophy of Nature. Okay. Little paperback selections from his writings. So, and it's it's it's not only from his great books, but also his writings. Yeah. Yeah. Yeah. So, may I No. Oh, that's just a paperback. I thought I was thinking that's your original. I thought it's my original like it's a teddy bear or something. This me Yeah. But see, I've been all up in it, right? You got every all the pages of I've had this since uh middle of high school and so me and Newton go back and don't you badmouth the Newton in I'm not going to badmouth Newton. I love Newton. Good. I've he is a primary source in my philosophy of space and time class because students that's a class you take. I want to take that class. I would love to have you teaching it in the fall. Also, Einstein as philosopher is a course I'm teaching in the fall. Got it. Anyway, Newton was motivated at least in developing by many things, but in developing in particular his theory of gravitation in an essay called de gravitation. I don't know how to pronounce the Latin, but there it is. He's responding to Deart who had three laws of motion. But Deart thought that all motion was relative. And so it is in developing his response to Newton uh to Deart's theory of motion entirely on philosophical grounds. He is reasoning from his armchair how he can understand motion. He must have had a badass armchair. I want to see he did. He also invented the calculus from that same armchair. Einstein is responding to Newton. He was bothered by the fact that in a fully physical worldview that Newton said he was presenting, you nevertheless had a background spaceime that was not that was influencing matter but not itself able to be influenced by matter. this asymmetry of dynamics bothered him. So what let me restate what I think you said that Newton is describing a universe embedded within space and time sort of a theater yeah background in which a theater set yes okay and so whereas Einstein wanted the theater set and the players in the theater to interact with one another that's right and in particular Newtonian mass is inertial mass it's it's an intrinsic in the old school philosophy tradition. It is a property that belongs to the thing in virtue of the thing itself. This also mass. Yeah. Just remind people, you know, Weight Watchers is really mass watchers, right? If you want to weigh less, just go to the moon. Yeah, go to the moon. There you go. Thanks, Oprah. There's a lot of ways to weigh less. And so, how do you get the money to go to the moon in the first place? But I just want to just clear. So when you're rem when you reduce your number of fat cells in your body giving it up to energy uh then you're reducing it's a mass you're you're cutting from yourself. It's supposed to be some deep essential like meaning essence of the thing. This also bothered Einstein. He didn't think that things should have innate properties in this way. Wow. And so one of the things that motivated him going from special to general relativity was a paper he wrote in 1913 where he predicts gravitational waves. by the way. So he didn't want mass to be something that just belonged because God decreed it thus. Uh and so he developed a he developed a way of accounting for mass that was also dynamical. We give something inertial mass because it's following a geodeic. It's following a particular path through spaceime. And that is why we call something having inertial mass. It is not an intrinsic feature of a geodessic on earth is a path that you would take where if you're sliced through that path your slice goes through the center of the earth. Mhm. So it turns out if you do the math it's the shortest distance between so that's why you see on a map you see these loop plane map they have arcs if you made that a sphere that would be the shortest we call that a geodessic meaning earth but now you're taking it and using it for the whole universe because another thing he was doing in this 1911 in these papers when he's developing what's called the antiver like the in between theory between general and special relativity he's working toward general relativity publishing along the way um and he's realizing that the effects due to acceleration are the same as the effects due to gravity. So acceleration and gravity are like two sides of the same coin. So even every time I hear it I'm like this is so brilliant simple. But he was motivated by Newton's account not answering his why questions. This asymmetry between like space and time being this god-ordained theater in which things happened, but the things themselves couldn't affect spacetime was a principal motivation for his wanting to dig deeper and come up with a theory of space and time and gravitation that didn't sort of wasn't ordained on high. But even if he apologized to Newton, I have no idea. Somebody did Einstein apologize to Newton? I perhaps ingest I I have a memory because his his whole understand general theory of relativity supplants Newton's gravity and I think he apologized at some point like well it's got to be one of those sorry not sorry I was going to say is it like the way you apologize to Pluto was like you could also apologize to somebody while saying but I did a better job right like he's still Clearly, sorry for blowing you out of the water. You have but also you know we're building on the people who came before us in developing our viewpoints of the world. So he owed a great deal to Newton. So this started with Decart is what you're Decart himself took three laws of um motion from Kep like Kepler's this thing had this game had been going on for a while. Yeah. Wow. Yeah. From a philosophical standpoint, all of these are philosophies. If you mean it in the sense that they're trying to ask the deeper questions, why do the things that I observe behave the way they do? Yeah. Yeah. Yeah. Why does Newton have only three laws of motion and not four or two or 10? He thought that three laws of he describes this in the general scolium at the beginning which is all philosophical arguments for why he thinks absolute motion can be differentiated from relativistic motion and he needs relative motion I'm talking about Newton yeah Newton skull the general skull said relativistic and that's I meant relative motion relative sorry from cartisian or deart's relative motion he thought that that's what he needed to ex to give all of the the account of all the motion We come out of Newton. We go through Einstein and the these are still they still make sense even if they're weird. You can still see why they make sense mathematically. But you go into the 1920s and then quantum physics descends and nothing makes sense. But it works. It works. You can make predictions. the understanding of the periodic table of elements, of molecules, of atoms, all clicks into place and everybody's scratching their head. So, what does a philosopher do then? All the things. It's so much fun. Yeah. So, you just like it when we don't know what what we're doing. No. Uh no. Uh I think we we would say that all of physics involves interpretive moments, but they're particularly painful in the case of quantum mechanics. And it's fascinating. Let's go play. like let's go talk about it. That's there's a word for that. It's called sedto masochism. It's like it's particularly painful. Yeah. Let's get it. Yeah. But I mean we but it's also like these are the questions that keep you awake at night. There's pain but joy. Yes. So So it didn't come out of nowhere, right? I mean there was an old quantum theory that Borren Zmerfeld who was a physicist in Munich had been working on in the 1910s to account for atomic spectra. Zmerfeld or Summerrfeld. Zrfeld. Summerrfeld. Yes. Zmerfeld. I pronounced it in the German way. Oh, excuse me. Okay. I saw an S there, so I just said Somerfell. I had one of his books. Yeah. Okay. Yeah. Yeah. He was um really important. He he was also the the doctoral adviser of like Heisenberg and Powley and a lot of these guys who went on to be important progenitors of the of the new quantum theory. Um but they they were trying to understand these empirical data, right? The the spectrum. By the way, every one of these people got a Nobel Prize. Oh, yeah. Every one of them down the list. Einstein's Nobel Prize was not for relativity. It was for the photoelectric effect which was dealing with quantum and brownie in motion. And brownie in motion. Yes, that's right. Brownie in motion which is to do with uh getting microscopic about quantum effects. Wow. Um but yeah uh so brownie emotion you you suspend a particle like a pollen grain like pollen. Yeah. You put it in in a fluid and it just bounces around. Yeah. And that wasn't fully understood like what's going on. Looks like it's random motion. Right. Right. And then you have to calculate there's particles hitting it, right? That are that are smaller than it that are hitting it. And you realize there are more molecules of water in a glass of water than there are glasses of water in all the world's oceans. And we didn't have insight into that until Einstein explained Brownie emotion to understand what the hell is going on in there. Yeah. we don't know inside like the insides of atoms very much yet like there's so little known about the structure of atoms and so that's partly what they're debating and part of what allowed um Heisenberg and Pi and some of the people working at the forefront in the 1920s they were looking at these description you remember Boris's planetary model of the of the atom right it's part of why we call them orbitals because he made it look like but there are huge mysteries with this model it doesn't account for all the all the spectra spectrum the data the spectra they're seeing Mhm. I'm using all the right Latin plurals here, I hope. But also, how is it that it jumps from one energy level to the next? And it does it discreetly. That's right. It does it quant like there's no actual physical motion from one place to the other. What does the philosopher say about this? Yeah. Well, they were boring. You've been here sitting here for half hour. I'm about to deliver the the kudigraph if you would shut up. Okay. Go. All right. at least finish him. They were trying to describe the electrons using classical terms for particles, position, momentum. Heisenberg said, "What if we use totally different things to describe the electron? What if we try to write down instead of equations of motion in this classical way, we we think about the electron in terms of wave, like by writing down the intensity, by writing down the amplitude, like a like a wave." Yeah. Sort of. But he didn't use quite that language. But he said let's look he used what's called fier like f o u r i e r another French term fier analysis to look at it and he got these equations out that worked and it was only by sort of stepping back and saying the language we're using is presenting to us a world that is a classical a philosophical pivot it was a new it was a new approach it was a new lens for looking at the problem it was a new lens for attacking right because if you if you believe or you think that these other metrics are what actually matter Right. And if they don't actually matter, you're going to get the wrong answer. And Schroinger continued to argue like he developed wave mechanics in 26. Heisenberg did this in 1925. 1926. Yeah. Yeah. So right on the heels of this, Schroinger gives a description in terms of wave and everybody knew wave. We love waves. We see waves everywhere. Sound waves, water waves, we understand how waves behave at the macroscopic level. And so when Schroinger gave a version of quantum mechanics that was all written down in terms of waves, people said, "I can visualize that. I can understand how to model that. But it didn't quite do all the things Heisenberg's matrix mechanics did. But they were arguing about these viewpoints in a philosophical way. Like what what do we need when we have a full scientific theory? Do we need to be able to visualize in space and time what's going on or do we need the right equations? All right. So they did their duty and we are now 100 years later. They are 100 years on. There's certain quantum questions that the lay person sees unanswered over that entire century. How can two particles be entangled? What does that even mean? And how is it you observe it over here and then instantly not even the speed of light. It's instant. And people want to wrap their head around this and you have not given us an answer to it. Yeah. At least we haven't figured it out yet. It's an ongoing puzzle. It's an inversation. Well, maybe it's not something to be figured out. It just is. Here's where this matters. Don't think about it. No, I'm just I'm I'm saying maybe you're trying to bring a classical sensibility to something that has a different reality. I agree with you and I get a lot of for that in the philosophy community. I think a lot of the interpretations of quantum mechanics that are proposed are trying to tell a story about how we get from a probabilistic set of solutions to an actual solution. And I think the world just makes a choice. There are some dynamic considerations in there. It's a much more nuanced story than what I'm giving you right now. But I think you're right that we're still like very much mored to these classical we because we because classical pictures make sense in an armchair. But you start saying all particles pop in and out of existence the tunnel they do this and that and and I as a as a scientist as an astrophysicist I accept what quantum physics does for me to understand what the universe is doing. And and I've learned to not lose sleep over trying to understand why. If you were working in quantum cosmology, you would want to know because we don't have a theory yet that brings together that brings together general relativity when the large or small the and quantum mechanics, right? And in fact, most of these interpretational debates are happening with respect to non relativistic quantum mechanics. But we know that the final theory we think will be relativistic. It'll be a relativistic quantum. So you foresee philosophers helping the physicists towards this goal? I don't I mean having a conversation with I would say and and I would say the physicists are also having this conversation. Yeah. So for instance there's there's a real question as to whether certain inflationary paradigms um that are thinking about how we get to effectively classical like field modes for the different parts of you know gravitational field modes or you know matter field modes whatever you want but we think the initial state was a quantum one. So, we need to know a story about how we get from a quantum state to what looks like what we are now. That's right. Because you're saying that if there is a model that makes sense. It started with the field. It started with kind of like what we would call nothing, but really it's everything all at once being nothing and then out of that pop and then boom and then all of this. No, it's everything everywhere all at once. Oh, I'm sorry. You found one. I gave a talk on entanglement that was about that like had that title but I watched the movie on the flight and had to cross that title out. I was like ah it's not quite what they're doing there. So if I understand you correctly we went from a quantum state to a macroscopic classical state and there had to be a transition somewhere in there that allows us to bring these sensibilities together in a coherent understanding. Well, even when we're trying to understand what the universe looked like in those early stages before we got to the big asymmetric distribution of matter we have now, those are stories that rely on um our understanding how we get classical field modes, classical values for field modes out of a quantum soup. And so these questions show up there. Here's another Are they being answered by your brethren or by they're not being answered by anybody. We're talking about them together. Um and there are you know some cosmologists who want to understand like these early they're asking whether or not we can have whether we could find residue of entanglement from this early state. And that's where I say even as a philosopher no because entanglement relations are going to be so damped down by interactions with the gravitational field mode and all these others that we could never measure them. But that doesn't mean they're not a part of the story. So, we're having conversations with one another about these things because the answer is unclear. All right. Yeah. Well, there's still those mysteries. You better get No, I give me my gummies. Give me get my edibles, please. Get my edibles right now cuz damn. You know, I'm a philosophy professor. I should be on board. Like, I have the worst I've had the worst experiences. I just can't do it. I people around. There are no edibles in this office. There we go. Okay. People were like, "Is your color red the same as mine?" I was like, "Yeah, Hobbs thought about that 2000." Like, who cares? You know, let's go on from that. Leviathan Hobbs. That Hob That same Hobs. Yeah, we all thought about that. Not Calvin and Hobs. That's the Hobs. That's Hobbs is Kelvin is named after John Kelvin, which is, you know, John Kelvin. And Hobbes is named after the philosopher, the philosopher, and political theorist Hobbes. And how about the the the tiger? And the tiger is hobbs. The tiger is hobbs. Oh, that's Oh, I forgot that. Okay. And and this is super important. Now, who is Marmaduke named after? Thank you. That's the one. This is beyond my realm of expertise, y'all. This is beyond my realm of expertise. All right. You got to land this plain, but this has been highly confusing, simultaneously enlightening and confusing. Is that possible? I I have to say, do you have a word for that? To be a philosopher. There you go. Oh, full circle, people. That was the way. That was That's how you do it. Full circle. Let's keep talking about it at some point. Not now. You have other things going on. So, that brings us to a close. Sorry we didn't fully answer everybody's questions. Well, there are no the answers the answers are out there, Scully. No, the the answers aren't known yet. No, you know, it is. That's the beauty of it. Seek and you probably won't find. Seek and you will find what's maybe not the case. Oh, that's a good one. I like that. No. Seek and you may find the answer to the question you have not yet posed. There you go. Oh, wow. That's true. Let me tell you something. Jesus is happy he didn't say any of those things. People would have checked right out. Like fancy. All right. What fascinates me most about the frontier of science is to do it right. Yes, you got to keep at least one foot in the perimeter where we at least think we know what's going on. And then you put the other foot outside and test the waters for new ideas, new perspectives, new ways to think about how the universe works. But for me, it may be a specious goal to believe that the more you do research, the more you understand about the universe. Because what remains true is that as the area of our knowledge grows, so too does the perimeter of our ignorance. And if that's true, that might mean that science is indeed the endless frontier envisioned by Vanver Bush in 1945. That is a cosmic perspective. Thank you, Elise Crawl. Thank you. Yes. Thanks for for coming down to share some of your vision and expertise with us here. Yeah, it was great. All right, Chuck, always good to have you, man. Always a pleasure. This has been Star Talk, the quantum philosophy edition. Neil Degrass Tyson as always bidding you to keep looking up. [Music]