What is superdeterminism?

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Speaker 1: Hey, Orney, what is your go to snack these days? Have you met me? Bananas? Of course, I knew you were going to say that. I knew I was predicted bulls like. I thought about saying something else, but you didn't. Yeah, then I figured you were expecting me to say something else, so saying banana was maybe the real surprise. Well that's very clever, but I actually predicted that to what impossible? Did you also predict what I'm gonna say next? Like weasel or yah my lama ding dong? Totally, that's exactly what I predicted. What how is impossible? Well? I wrote the script for this goal open, Yes, but I always go off script. Yes, but you do so very predictably. Hi. I'm or Hamming, cartoonists and the co author of Frequently Asked Questions about the Universe. Hi. I'm Daniel. I'm a particle physicist and a professor at U C Irvine, and I'm also quite predictable. Oh yeah, do you have a regular routine that you always stick to? I do two podcast episodes a week with my friend Jorge. Oh my goodness, that's a surprise that you're still friends with this horr guy and that people are still listening. But what do you mean you did not like surprises? I am a creature of habit. I like to lay out my schedule and follow it. My wife, on the other hand, likes spontaneous adventure, so you know, at least some interesting conversation. What about like lunch, Do you know what you're gonna eat for lunch every day? I do? Yeah, I eat exactly nothing for lunch every day, So it's quite predictable. That makes choosing easy. You don't have to think about it because there's nothing to think about exactly. And you know, in our family, we used to argue a lot about what to eat for dinner, and then we hammered it out into a weekly schedule. So we have you know, pasta on Mondays and tacos on two days, cetera, etcetera. Oh, my goodness, completely predictable then until the end of time. But what kind of tacos? See, that's a big question, you know, there's always room for improvisation. Yeah, we have to talk about it every time. Yeah, do you have corn or tias or flower tortillas? Is that in your schedule too? Oh we make our own tortillas. Yeah, corner flower combination corn and flour, corner and flower. Yeah, a little bit of each. It's like a quantum taco. It's a superposition. It's super taco and flower. Oh man, that's crazy. Is it also chicken and carnitas. It's delicious, is what it is. But anyways, welcome to our podcast Daniel and Jorge Explain the Universe, a production of My Heart Radio, in which we roll up all the deliciousness of the universe into a corn and flower and talk tortilla and serve it all up to you. We fill that taco up with the incredible mysteries that are the universe, the weird quantum effects that seem to govern the microscopic nature of reality, and the incredible emergent phenomena that we enjoy and gaze at every night when we look at the stars. We wonder about all of it. We talk about all of it, We explain all of it, and we take a big bite out of all of it with you. That's right, we talk about it with you because it is a pretty delicious and amazing universe ready to be rolled up and sandwich between amazing conversation and that jokes. Hold on, do we just move from tacos to sandwiches because like, not the same thing, man, well kind of. I think traditional tacos have two tortillas and then you roll them up what or fold them? What are you talking about? Seriously? You know how to taco from a taco truck. Yeah, but that's two tortillas underneath the filling, right, that's not the same as a sandwich and then you fold them over right. Gosh, so you're sandwiching kind of things between them, right, you're seeing a sandwich and a taco or topologically equivalent. We are waiting into a big question here. Pretty you're gonna be saying a hot dog is a taco? Mathematical food science? Yeah, well, I think that pizzas and tacos and sandwiches are topologically non identical. Well, here's a question. Is a cauzone a pizza taco really? Or a pizza sandwich? That's like second root of food food calculus. There, I think I have to go ask my friends in the math department about that one. Yes, I knew you were going to say that. But it is a wonderful universe full of amazing and incredible things that sometimes seem kind of unpredictable. And random and chaotic, But it's amazing that we've sort of looked out into the universe and figured out that there is a little bit of order to all of that. There are laws to the universe. Yeah. The great sweep of philosophy and science is you try to look out in universe and to wonder, are there laws that describe the incredible complexity that we see in the universe. Is that lightning striking that tree because it's determined by some physical law or is it just some god up there getting angry and deciding to smite that tree? And the universe actually be described in a compact set of mathematical rules which determine everything that happened, or is there still a little bit of fuzz left in those rules? Yeah? And if there are laws that govern how the universe works down to the atomic and particle level, does that mean that the universe is totally predictable because if it follows laws, then you know what it's going to do. Right, That's exactly right. And a few hundred years ago there was this growing realization that, wow, the universe does seem to be kind of explainable. And if the universe is explainable, even on a microscopic scale. Doesn't that mean it's explainable on a macroscopic scale. If everything is made out of tiny little billiard balls, and you can describe and predict what happens when two billiard balls bump into each other, then in principle, can't you describe and predict what happens when ten to the twenties six billiard balls bump into each other? Or even if you can't describe it computationally, doesn't that mean that it is determined? It's decided in advance. Yeah, it's kind of this idea that we sort of started to realize this we came to understand science and physics a little bit more. It's kind of this idea that maybe the universe was kind of like a giant clock, right, that everything was like clockwork, and that you could totally maybe predict or at least it seemed possible to predict what the universe was going to do in the long term, and sort of mind blowing, right to imagine that these tiny little brains on this little rock in the corner of the universe could like derive physical laws, could like get the universe to reveal its actual underlying mechanism and that might determine the whole future of the universe. I mean, like what humors, right, what incredible ego to imagine that we could understand the universe and predict its future, that we could like reveal its deepest mechanism, the rules that like force it to operate in a certain way. There must have been a mind blowing sort of moment for physicists. Yeah, it's pretty crazy. It's like a crazy plot twism. I wonder if the universe predicted that too. And it's sort of terrifying and also of relief. You know, Like it's terrifying to imagine that the universe is totally pre pdictable and that we are all sort of like locked into a future that's determined by the past. But it's also sort of terrifying to think that the universe like doesn't make sense or doesn't follow laws, that there are like capricious beings up there that could just like decide what gets that by lightning instead of you know, following some rules. I don't know which universe is more terrifying. I mean, I guess the one that's unpredictable. It's more terrifying to you Danny, all right, yeah, exactly. That was an hard question. But emotionally it's sort of fascinating, you know, to think about being locked into these physical laws. Of course, as a person, as an individual, I want to know what those laws are and how they work and spend my life unraveling that mystery. But to imagine that the universe is locked in, that everything that you do and that happens to you is determined by what happened in the past, that is sort of scary. Yeah. I feel like this is getting a little psychological here, Daniel. Is physics for you just one big quest to find order in the universe and predictability. I do this instead of going to therapy. It's a lot cheaper to probably I get paid to do this instead of paying someone to do that to you. No, I think it's psychological because it's philosophical. And the reason that we do physics is because there are big consequences to the answers that we reveal. When we learn the nature of the universe, it tells us something about what it's like to be human and what the rules are and what the boundaries are for our lives. And so I think, yeah, there are big psychological imvocations to understanding how the universe works, and so upen to maybe about a hundred years ago. We thought that maybe the universe was like a big clock and that you could predict what it was going to do like a giant instead of clockward gears following Uton's laws. But then somebody learned that things aren't quite that way at the molecular level, at the atomic level. That's right. You might be puzzling over why we're talking about the universe as deterministic, because quantum mechanics paints a different picture of the universe at its very smallest scale. Even though you're made out of ten to the twenty six little objects, those objects are quantum objects, and they don't follow the same rules as billiard balls or baseballs or any other kind of balls. They might not even be balls. They follow very strange rules, and their futures are not necessarily determined by their past. Are we talking about strange balls in this episode? That I feel like this might be going into not safe for work territory. But as you said, we learned that quantum mechanics cells is that there is sort of like an adherent randomness in the universe. At the very smallest levels, like there are things we can't possibly ever know, Like there's a certain uncertainty um at the very smallest levels of velocity and position. Yeah, it gives you a really different view of how the universe works, right, like the fundamental mechanism for how things operated the smallest level and really fascinating twist. Of course, it doesn't change how things work at the large level, right, Like you and me and baseballs and billiard balls can all still be deterministic, even if we're made out of tiny little things which are fundamentally fuzzy. I guess you can still predict what strange police are going to do. You can still predict that they will make Daniel giggle on the podcast. Yeah, so that was a big revolution in our thinking, going from like things are like clockwork in the universe too, maybe there's an inherent unpredictability or randomness to the universe that we can never ever predict, right. Yeah. It was a big shift and also maybe a bit of a relief, right, Like, oh, it turns out that maybe I'm not locked into a set of consequences that were determined by everything that happened in my childhood. You know, and there's philosophical consequences there. People wonder if it means there might be free will because our actions are not predetermined. So this question of quantum mechanical randomness and free will and like human autonomy and the soul and all this kind of stuff. There's been a lot of discussion about what it means for the universe to be fundamentally random, right, because I guess if tiny little particles are sort of random, right, or they act in random ways, then that means that you add them up, then maybe like people are random to or like unpredictable. At least there's a whole field of people trying to understand whether quantum particles and their randomness actually do add up to unpredictability for larger objects like me and you and hippos, or if it's more like baseballs, where the quantum randomness sort of like averages out and doesn't affect the path of a baseball. So that's been kind of our thinking for the last hundred years, that things are random at a fundamental level, But maybe things are starting to come back around from that today. That's right. There are a series of experiments in the last few decades which seem to conclusively prove that the universe is fundamentally quantum mechanical, that it is not deterministic at the smallest scale. But there's a lot of controversy about those experiments and exactly what they mean and what the loopholes are in those experiments, and there's some really fun ideas that might be able to recover deterministic thinking about our universe. So today on the podcast, we'll be asking the question what is super determinism. I thought you were going to say that in a sort of like a Superman voice. Super determinism is that like the alter ego of mild Manner determinism? Exactly? Determinism just works in the local newspaper and wears glasses. Did it escape from a dying planet in a pod? Yeah, it must have a fatal flaw. So what is the fatal flaw of super determinism. I think it's quantum mechanic paps, it's physics site kryptonite quantum mechanics. But this is an interesting idea. I feel like we've we're sort of swinging back and forth like a pendulum, like we thought we were like clockwork and deterministic, but then then quantum mechanics came around and we realized things, we're actually kind of random, but now it's kind of swinging all the other way around. That says that maybe quantum mechanics is not totally random. Yeah, and I think it's because it's hard to grapple with the consequences of these experiments. If you accept that the universe is fundamentally random, like that is weird man in even if it gives you an opportunity to not be predictable and you like that, it is strange to think about the universe picking numbers at random, deciding for every electron, so it's going to go left or oh, it's going to go right. That is really funky and it really counter to our intuitive understanding of how the universe works. And so that's been very difficult for people, including physicists right like Einstein, to swallow. And so it makes people think creatively and try to like find ways around it, like are you really sure that it has to be that way? Couldn't it possibly actually still be deterministic? Yeah, But it's always good to ask these questions because you never know maybe what do you think is true is actually not true. You just have to ask the question and come up with the experiment. I remember, it's the experiments that really tell us what we know. It's thought about these theoretical constructs. It's about what the experiments have said, and so it's really crucial to understand what are the loopholes in those experiments, what did they really measure, and what did that actually tell us about the universe, because sometimes all the interesting stuff is in the loopholes. So as usually are wondering how many people out there had heard of this theory of super determinism, So Daniel went out there into the wild of the internet. I think right, yep. These come from our cadre of Internet volunteers who are willing to answer weird philosophical questions about tricky physics topics without any chance to look things up. So thank you very much to everybody who participated. If you enjoy hearing these and you'd like to hear your voice on the podcast, please don't be shy. Right to us. Two questions at Daniel and Jorge dot com. To think about it for a second, what do you think super determinism is? Here's what people have to say. It sounds like a made up word. Um, so I'm going to say it's the kind of intense determination than has exhibited when obtaining the infinity stones. I have absolutely no idea. I'm going to say it has something to do with um, the fact that I've heard it said we actually have no free will and cause an effect stems from entropy or something like that. I don't know. I guess that super determinism means that the universe at the macroscopic level is predictable. It does indeed act like clockwork because of the quantum effects being statistically averaged away on a large scale. So perhaps at the macroscopic level, God doesn't play dice. Well. I don't know exactly, but it must be something, something interesting because starts with super I think it has to do with determinism, with the fact that knowing a particles position and velocity at any given time, you could determine the position and velocity of that particle at any other point in time, so you could say that the future is fixed. I say it has something to do with that super determinism is something that only philosophers worry about at night or particle physicists, and it must have to do with fate destiny. If determinism is just things being very determined. Super determinism would be things being very much very determined. So I guess like that everything is very much predetermined, so like extreme cause and effect of things and particles. I don't know. I'm just gonna guess on this one. Also, I think, you know, determinism is the fact that there's no such thing as free will, So maybe super determinism is the opposite that there is a way to find free will in the world. All right, very determined answers, very very determined, a little predictable. Though I knew that were going to say this exactly. Some people here confused it with the idea of being determined, like having a lot of purpose and will power. Yeah, I think my teenagers are super deterministic. Sometimes they're determined to be undetermined. They determined not to listen to me. So let's dive into this, Daniel, super determinism. I guess determinism wasn't doing it, so they have to call in superdeterminism, you know, as reinforcements. But then, who knows, maybe the next episode will cover ultra quantum mechanics. Quantum you knock it down, We just come back with something stronger. So maybe it's start with the basics. Here is there sort of like a physical or mathematical definition of determinism. So a deterministic view of the universe is one in which the future is completely determined by the past. So you have a set of initial conditions, meaning like you know the location and the velocity of every object in the universe, and you have rules for what's going to happen to those next, including like collisions or near misses. Then you can predict exactly what's going to happen. So the future is determined by the past. The initial conditions and the rules of the universe determine exactly what will happen. It's a deterministic set of laws, right, Like if you have a little ball, strange or not, and you have a little ball and you know where it is and what velocity it's going at, you can sort of know the future, right Like you know the trajectory that bought gonna take through the air, and you know where it's going to land and soil you can go there and catch it. That's really like predicting the future, right, It really is predicting the future. And when I was a high school or first taking physics. That's the thing that attracted me to it the most. I was like, oh my gosh, you can actually predict the future with physics. It's sort of incredible. It's an amazing power, and it's something that you also sort of know intuitively. Right, if you're throwing the ball to somebody who's running with your fast you know sort of how to throw so that it gets to them at the right moment. You know, you factor in their velocity, in their direction, and all this kind of stuff. You don't expect that when you throw the ball it's going to take like a random left turn or a random right turn. You think that mostly it follows the same rules. And that's why we practice sports, right, pictures practice pitching because they can throw the ball the same way over and over again and get it into the captures Mith right, right. Unless you're using strange balls, then who knows what they thought? We were staying away from that joke, man. Predictably, I cannot strange balls and strange strikes in this case. So that's the deterministic university idea that, like, you know, if you can predict where a ball is gonna allod mebe you can predict everything down to like planets and galaxies, and also down to the small levels, like you know, it's tiny little particles if they move like little balls, and you can sort of predict what they're gonna do, and you can maybe predict the entire universe exactly. So that's fascinating. But then, of course quantum mechanics sort of up ends that, right. Quantum mechanics says that things are not determined. Things are sort of random at a very basic level, like you can't know something's position of velocity perfectly. And it's important to understand what quantum mechanics sort of does and doesn't say about the universe. It doesn't say that like things are totally random, that electrons just like do whatever they want. You know, there's no like brain in their deciding. There's just going to cruise over here and cruise over there. Right, Quantum mechanics is still deterministic in one way, it's just not deterministic about specific outcomes. Instead, it's deterministic about probabilities. Like quantum mechanics, there are laws and it says the electron has a certain probability to be here in a certain probability to be there that's fixed based on the previous data, Like what happened to the electron in the past determines the probabilities for its future. It just doesn't determine the actual outcome. When it comes to like measuring where the electron is, the universe then decides, well, is it actually over here or is it actually over there? Is it's beIN up or is it spin down? So the actual specific outcome for a quantum object isn't determined until you measure it, but the probabilities are determined in advance. Right, Although in quantum mechanics, isn't it sort of impossible to know the initial conditions of something of like an electron or a particle that you can't ever know where it is and where it's going, right, You're exactly right. You can't know all of the information about its specific location and its velocity. Here, what we mean is you know it's quantum state, which includes all of that fuzz So if you know the quantum state of the electron, it's probability for where it is right now, then you can predict its quantum state in the future. It's probabilities for where it's going to be in the future. So you have an electron over here and it's doing something. You don't know exactly where it is, but it has some probabilities to be here there, and you do something out of like you fire a photon at it, then you can predict what its new probabilities are, So you don't have to know exactly where it was, but you can predict how it's probabilities will evolve with time. Right, it's almost like if you throw a ball, you don't know if it's going to be a right or left, but you know that half of the time maybe it's gonna veer right and half of the time it's gonna bear to the left, but you know you don't know in any particular throw which way it's going to hear exactly. Or if you roll to dice, then you know what the distribution of outcomes are, even though you don't know what any individual outcome are. Now that's a little bit of a tricky analogy because dice actually are deterministic, and the reason you don't know the outcome is not because they're truly quantum mechanical and random. They're actually just chaotic, so it's approximately random. The universe we think is actually random, but it's sort of in the same way that it describes the probabilities of various outcomes very specifically, but doesn't actually pick which outcome until you collapse the wave function. For those of you who wonder, like, well, how does that happen? Does it mean to collapse the wave function? What's going on there? Check out our episode about wave functions and collapse with Adam Becker. Cool. So that's kind of the prevailing view of the universe, that it's quantum mechanical and that it's random at a very fundamental level, that it's not deterministic. But maybe there's something wrong with the experiments that natives think that way. So let's get into what those experiments are and what is superdeterminism. But first let's take a quick break. Alright, we're talking about superdeterminism, which is I guess it's superpower determinism, Like it can run faster than a speeding prediction. Yeah, exactly, it's a souped up version. It's got like, you know, extra exhaust, and it's a low rider. It's a shiny paint. Should have gone with turbot determinism. That would have been a more fun name. So there's this idea that quantum mechanics tells us that the universe is random and a pretty ball, and you can actually sort of test this, right, Like you can do an experiment that tells you if something truly is random or not, or maybe like it's actually not random, but you just think it's random. Yeah, because when this whole idea came out, people were skeptical because you don't see this process, right. You can never like see the universe going from fuzzy to specific, going from like the electron has a probability to do this to the electron is actually here. You can't observe that process because of course any observation collapses the way function. So people were wondering, like, how do we know this is real? How do we know that the path the electron isn't actually just determined? But there's some like information we're missing, you know, like the electron was going to go that way the whole time, we just didn't know it. You're not comfortable thinking about electrons, you know, think about scenario where you have, for example, two balls, a red one and a blue one, and you put one red ball in a bag and the blue ball in another bag. So you can't see them, and then you and your friend just like randomly picked bags. You look in your bag, You're gonna have either a red ball or a blue ball, right, And you might say, oh, well, it was determined the whole time, Like the ball is either red or blue the whole time. Right. It's not like magic that I have a red ball or a blue ball. And so people are wondering, like if the same thing holds for quantum particles, like are they actually determined in advance? How can we tell the difference between they're being really random until the moment you check for them having been determined the whole time. Right. That's kind of the basis of this famous experiment that sort of proves the randomness of quantum mechanics called Bell's experiment, Right. It it's sort of like if you take, as you say, at a red ball and a blue ball, and you put them each into bags so you can't see their color, and then I guess, what do you do? You like hide them behind your back and makes them up, and then you give one to one person and they know they want to the other person. It's not like the ball suddenly lose their color or they're both colors at the same time. It's like, you know, one of them clearly has the red ball and the other one clearly has the blue wall. We just don't know what it is. And so that's kind of the alternative to the idea of randomness and quantum mechanics. It's like, well, that's not like the balls like do something magical. We just don't know which balls in which back exact. And the philosophically that goes by the name of hidden variables. People think, well, maybe there's just some information we don't have access to, so it seems random to us, but it's not actually random, right, there's some hidden variables, some details, some information that's being carried along with the ball or the electron whatever that's determining the actual outcome, and you can't actually change it. The quantum mechanics is a very different view, right, And the analogy of the balls, it would be like, you know, the ball has not always been read or always been blued the whole time. It has a probability to be either, and it's in some weird quantum mechanical mixture state that you can never see. But once you look at it and boom, it collapses into red or blue. And the craziest thing about the quantum mechanical interpretation is that this can happen even if you're really far apart, Like you know, if I take one bag and you take the other bag, and we got on spaceships and go ten light years in opposite directions and then look at our bags simultaneously, quantum mechanics says that those balls are not determined until one of us looks. If I look at my bag and I see red, then your bag instantaneously is from undetermined to blue, even if you're ten light years away from me. So that's the part that really got people confused, especially Einstein and his collaborators, and made him think like this can't be true because it would mean that the universe is like non local, that this is like instantaneous effect that happens across space time, which really bothered folks like Einstein, right, because as soon as you open one bag, you're sort of like you're determining what the other bag is gonna be, even though it's really far away, exactly right, And I guess the interesting thing is that the universe or quantum mechanics seems to have these bags in them, right, Like there's some something about the universe sort of obscures things or hides them from us until we actually look at them. Right. That's a weird thing about the universe. Right, It's a very weird thing about the universe. And it relies on this interpretation or quantum mechanics called the Copenhagen interpretation. Says that quantum objects or quantum objects and they like, have weird fuzziness to them, and that's cool, except when a classical object like a person, looks at them, that all of a sudden they collapse and they can only have one possible result instead of having probabilities of multiple results. And as we've talked about the podcast a lot, that's really problematic because we don't know what we mean by classical object. We talked about this in the quantum eraser experiment. It's really weird and fuzzy. And so there are other views of quantum mechanics that try to avoid this, like bowl mean mechanics that says that there are these weird initial conditions. But all this weird quantum behavior was described by Einstein as spooky action at a distance, like he couldn't imagine a way for the universe to do that if I look at my ball and it goes from like undetermined to red, that somehow that's going to make your ball go from undetermined to blue. He couldn't imagine that happening. He proposes as a thought experiment. He was like, isn't this ridiculous. Here's an example of what your quantum mechanics would have to do for it to work. So then John Bell came up with a series of experiments, try to see if we could tell the difference. Can you tell the difference between those balls being actually determined the whole time or them being undetermined until the moment you look at them and those wave functions sort of sign multaneously collapsing across space time, right, And I think the idea is that, you know, if you do this experiment or this like hiding balls and put them in bags and take them far apart with like actual physical billiard balls, like a red Billard ball and a blue Buildard ball, then there's no question, like there's no randomness in there, right, Like there is an actual blue ball in my bag and an actual red ball in your bag. There's no randoms there. But the I think the idea is that if you do it with electrons or something really really small, where you maybe have with some experiment that takes an electron and splits it into two, like a red electron and a blue electron, and it's a quantum mechanical process, then that's when things start to get weird, right, that's when things sort of become spooky. Yeah, exactly. Nobody thinks that that ball is actually red and blue simultaneously, because it's not a quantum object. We're just using that as a way for you to sort of grapple with these things because it's hard to think about electrons. But now let's think about electrons. Let's think about a quantum object. As you say, electrons have these weird properties, and so the key is that those two things are somehow constrained. Right. We used red ball and blue ball because implicitly we were saying they could only be one red ball and only one blue ball. So if mine is red, yours has to be blue. The constraints for the quantum objects is things like spin. You create two electrons together or electron depositron or whatever so that their total spin is zero, and if I measure mind to be spin up, then yours has to be spinned down, even if you're ten light years away from each other. Now, the cool thing about this, the reason that it's different for electrons and for balls, is not just because they're tiny quantum objects, but because they can have multiple versions of these properties. Like, when I measure the spin of the electron, I can choose what direction to measure the spin around right like the top when you spin it, it spins around in access. So when I measured the spin of the electron, I can choose like some direction and measure the electron spin, and the other electron ten light years away has to have the opposite spin along the same axis. The crazy thing about electron spin is that you can't measure its spin simultaneously multiple directions. You measure it one direction that fuzzes the spin in the other direction, sort of like momentum and position. John Bell was able to take advantage of this and came up with this crazy set of experiments. We take our electrons far apart, we agree randomly on three directions that we can measure the electron on three axes, and then we do a bunch of measurements. And he showed that in the quantum mechanical case, where these things are not determined and they sort of like measurement along one axis fuzzes the measurement along the other axis, then in that case you'll get a different set of statistical correlations between your measurement, and in the classical case where it's hidden variables, where things are like determined in advance. So sort of mind blowing that he came up with this crazies beautiful, elegant set of experiments to force the universe to reveal the fact that it was making these decisions on the fly, that these things were really collapsing at the last moment, not in advance, that there's no information going with these electrons. It's helping you determine where their spin is, right, because I guess the you know, the counter the theory or the counter proposition is that you know, you took this electron, you split it into a spin up and a spin down, you put him into different bags. He took him far apart, and so you could say that, well, you know, we don't know whether the electrons are spin up and down, but the electron sort of know, like just like the red ball and the blue ball, like obviously one of them has spin up and the other one's spin down. We just don't know what it is. And then when you open it you might be surprised. But you know, somebody who is tracking these electrons all along and totally knew which one was up and which one's down. But I think the kind of the power of the Bell's experiment is that it somehow, through you know, complicated probabilities and scenarios, it sort of proves that no, like not nobody knew knows what these electrons were the whole time, like nobody, not even like whoever is making the universe or running the universe exactly, It's not determined. And the important thing to understand here is that it's not a single measurement. It's not like I measure spin up and you measure spin down and then we say, aha, it wasn't determined. You can't decide that from one measurement, right because that could have been determined. And if we're measuring along the same axis, like I'm always going to get the opposite answer as you. The genius of Bell's experiment is that it's statistical, is that I'm measuring a bunch of different directions. You're measuring a bunch of different directions, and the quantum mechanics comes in with a correlation of our multiple measurements. It's very subtle effect. You can't see it from just one measurement. You can do multiple measurements and study their correlations. So it's not like super smoking gun, but it's very clear evidence because the correlations you get from quantum mechanics are very different from the correlations you expect in the case you describe where it's like all secretly determined in advance, and when we do these measurements and people have actually done these experiments, they get the numbers that agree with a quantum mechanical prediction, not the hidden variable prediction. Right. It's kind of like you can't tell if a coin is like a fake coin or a bias coin, but with one flip of the coin, you need to like flip it a lot of times, you know, like, oh wait, actually it's heads, you know, fifty one of the time this is a theater's coin. Right. That's kind of like the YEA behind builds experiment is that you run this experiment where you split the electrons a whole bunch of times and somehow you know the probabilities, the way you set up the experiment, it tells you that the universe is actually random. Yeah, And it's more than just that it's random, right, It's more than just that it's not determined until the moment you look at the electron. It's also that it's weirdly nonlocal. And these effects are somehow happening across great distances in space time. And they've done these experiments, you know, where things are close to each other because they're complicated, and then they've managed to do them further apart and further apart and further apart. And now we've done them so far apart that there's no possible way information can travel from one of the electrons to the other. Not like you're looking at one electron and then zoom at the speed of light. It tells thegether electron what to be, you know, I'm red, quick be blue. There's no time for that to happen. These experiments have been done so far apart with synchronized clocks and everything, so there's no time for that to happen. And yet they still see these results, which means that the universe must be non local. Right, that like the is happening in one place can instantaneously affect things happening somewhere else. That's like really hard to swallow, right, And here I thought we were supposed to shop local environment. Well, I think the point is that, you know, we thought that maybe quantum mechanics meant that the universe was random, and we've actually proved it with Bell's experiments, and we're actually going to dive into or at least trying to dive into Bell's experiment in a later episode. But I think the main point is that, you know, at least until a few years ago, Bell's experiments sort put the nail on the coffin that said that quantum mechanics is right, things are sort of unknowable and truly random at their court. And so Bell's experiment shows that there can't be any local hidden variables, right, that there's no information being carried along with the electron that secretly determines in advance the outcome of all of those experiments. And so now there's a theory that says that maybe the Bell's experiments are not all they're supposed to be, or maybe they're not set up right, or maybe there are things actually in the universe that we're not seeing that maybe do make the universe totally deterministic or at least super deterministic. So let's get into that. But first let's take another quick break. Alright, we're talking about super determinism, which is um pretty super I guess at least super recent. Right, it's sort of a new idea that maybe Bell's experiments are not quite properly set up, right. I think super determinism maybe oversells it, you know, I would call it like bonkers determinism. It's like deterministic determinism. It's like people who are really determined to find deterministic loopholes, you know. I think most people are convinced by Bell's experiments and the way they've been done. It's really impressive to or to force experimentally. I think people are pushing hard to find loopholes, to say, like, are we absolutely sure is there a way you can interpret these experiments and still have the universe b deterministic. Not like we want to reject Bell or anything. It's just like, let's just make absolutely sure is no other interpretation. So this is sort of like an exercise in philosophical thorough nous, So it's more philosophical, it's not physics, you know what I mean, Like, are you looking for loopholes in like the arguments of Bell's experiment, or looking for loopholes in like the mechanics, or like the details of how it's carried out? Well, I think it's all connected, right. The details of how it's carried out tell us exactly what we can and can't conclude. The first iterations of Bell's experiments they did them sort of close by, because it's hard to have quantum particles that are entangled survive travels long distances without getting perturbed by other stuff. To preserve that entanglement over distances is challenging. So the first iterations of Bell's experiments were sort of nearby, and there weren't that precise. People thought, well, you know, these electrons could still be communicating. There's still time for them to send messages back and forth somehow. So then they did them further and further apart, which is harder and harder, and now we're sure that they can't be communicating. So that's the kind of thing we're doing, is like looking for those loopholes and then trying to close them wondering, is there a way we could do this experiment in a way that proves that that crazy alternative interpretation of Bell's experiment can't be the case? So super determinism is in that category. It's like, well, are you sure it's not this crazy other bonker's idea? How do you actually know? All right, Well, then what are the sort of the arguments of super determinism. What are they saying about Bell's experiments? So super determinism and this is going to sound sort of nutty, says that, like the whole universe has basically been contrived to trick us into thinking that the universe is random and quantum mechanical, but actually the whole thing is just like a setup. You're right, it does sound bonker. Wait, you're saying the idea is that the universe is not random, it's just sort of built in a way to make it look random. Maybe everything really is determined, and it's like determined all the way back to the Big Bang, you know, like things back in the very early times in the universe determine things that happen now, including things that seem to be usually separated in a way that you couldn't coordinate them. Maybe if you just go like far enough back in time and hatch your plot, you can arrange things so that they look random, but they're actually determined. I guess, how do you make something look random? And what's the difference between something looking random and actually being random. Well, let's take your example of a coin. Right. Let's say I give you a coin and I wanted you to test to see if it's fair. What are you gonna do. You're gonna flip it a thousand times or a million times. You'll measure the fraction of times that you get heads or tails. Right now, what if I give you a biased coin, one that gives you heads seventy of the time, but I somehow arranged to influence you and the way that you do your experiment. I distract you with bananas or you know, I do a silly dance because I know how you flip the coin, and I know how to affect you and bias your experiment so that it looks like it's fifty percent of the time. Then you're going to measure the coin to be fifty percent of time heads. You're going to declare that it's a fair coin. Even though it's not. So if I can somehow interfere with the way you do your experiment because I know you and I know how to manipulate you, then maybe I can affect your conclusions of that experiment. Whoa, whoa, Wait a minute. Okay, So here's the set up, the setup. As you gave me biased coin, like a cheater's coin that's actually gonna give me heads seventy of the time. But you're saying that somehow, when I go to flip my coin a thousand times, you're somehow going to you know, blow some air or something so that it lands heads fifty percent of the time during my experiments. But then when I go place a big bed, then you don't do that. Is that what you're saying? Yeah, something like that. And it's not even as involved as I'm gonna blow some air. I'm gonna specifically interfere with the experiment. I'm gonna let you do your experiment, but i'm gonna manipulate you somehow into thinking you've done it randomly, because when you flip a coin, you know it's not actually truly random, right, Like you flip a coin the same way twice, you're gonna get the same answer. It's just sort of very difficult to do that. So imagine I'm some super powerful demon and I know exactly how to make you flip a coin just the right way to get heads or tails, And I'm some super powerful mind controller guy, and I can make you do that somehow. This is a very ridiculous, obviously, but it is a possible interpretation of the experiment, right, I mean, it's absurd and outlandish, but it's sort of possible. But I guess my question is, how exactly are you manipulating me? Like somehow you know how I'm holding the coin or somehow you know, like if I start with my coin one way in my palm before I toss it, then you're gonna do something so that it actually I read it as heads or tails later on? Does that what you mean? I'm not going to change how you read the coin. I'm not going to change how the coin flies through the air. I'm just gonna change how you throw the coin, because how you throw the coin determines actually what happens. So if I can get you to throw it in a certain way, then I can change the outcome of the experiment. Oh, I see, like somehow this cheater's coin. If you throw it a certain way, you'll get heads tails, but if you throw it maybe a regular way, then you get heads tails. You're sort of controlling how I throw it either way way or the seventy percent way. And when I do the experiments, you're controlling me to do it, to toss it the way. But when you when I go to place the bed like for real, then you you have me through it the other way way. And so that sounds ridiculous and contrived and implausible to you. Then getting ready for Bell's experiment and the effects of superdeterminism, that says that maybe the whole universe is set up in a way so that the people who have been doing these experiments, which requires some randomness, right, because they're choosing these axes on which to make these electron spin measurements. What if those aren't actually random? What if that's been sort of like contrived throughout the history of the universe, including like how these people grew up, how they designed their experiments, how they chose to try to find random information to conduct their experiments. All of that has been controlled since the beginning of time, such that these experiments would look like the random even though they're not. That's super determinism. You're saying that, like in in Bell's experiments, you know, um, it's an experiment and it's random, And so even if you like do the experiment perfectly, there is a possibility, because it is sort of an experiment, that it might tell you that the coin is fair even though it's not right, because it's still a coin. Like even if I take a fake bias coin, you know, and I tossed it a thousand times, it's still technically possible for me to get fifty heads tail. And so I think you're saying that somehow my coincidence, Um, the universe since the beginning of time has been set up in a way so that every time somebody runs Bill's experiments, somehow they always pick the direction that tells me that the coin is fifty, when actually it's exactly because there's this step in these experiments when you have to pick what access I'm not going to measure my electron on. You have one electron over here and one electron over there, and each electron you need to pick one of three ACTSI and then Bell's experiment tells you how often you'll get the same result and how often you'll get opposite spins. But you need to pick the axti randomly so that you add up to the right correlations. And so if you're not picking those randomly, if you're like contriving those to always be the same direction, for example, then you're not going to get one third. You're gonna get this kind of stuff. And so it's possible to manipulate these experiments in theory to make that happen. Now in practice, the folks that do these experiments, they're very careful about this. They don't just like use some random number generator off the internet, like. They have developed these hilarious efforts to make their experiments like really random and impossible to manipulate. In the case of these experiments I was reading about in two thousand and fifteen, the measurement decisions were determined by applying some operation to three bits of information from three independent sources, one of which was random digits of pie, another was binary strings derived from Monty Python and the Holy Grail transformed into a bit sequence, another from episodes of Saved by the Bell, which I love because you know, this is Bell's experiment, and so they're using episodes of Saved by the Bell, converting that script into a series of numbers, and using that to generate part of their input. I'm not sure they're making the experiment more legit, you know what I'm saying, Like, I'm listening to this and I'm thinking it's less legit. So these crazy antics, Now you know how television production works. In order to manipulate Bell's experiment, Not only do you have to manipulate all these experiments across space and time, you also have to somehow manipulate these meetings where they talk about the script for these television episodes in a way that determines the outcome of these experiments. Like it's ridiculous. You know how impossible it is to get that through network executives. Well, I think it is that, you know, when you run Bell's experiment, and again we'll get into more details of it in a later episode, but I think the it is that there's some choice in the experiments, Like you say, okay, we'll measure along this access, and it is technically possible to pick an access that tells you that the coin is fair, right, Like, technically it's possible, And so the it is that you know, maybe every time they've run this experiment and they've picked a random direction, they've somehow picked the direction that tells you that the coin is fair, meaning like it's some strange, super weird coincidence that someone we think the universe is random, but really we just lived in this crazy universe where every time we run Bell's experiments, we've always somehow chosen the direction that makes it look Yeah, maybe these electrons really are determined by local information that's not available to us, and we do these experiments to try to suss that out. But the experiments have a bit of a random element to them, and if it's not actually random, and we think it's random but were being tricked and manipulated, and then we could conclude that the universe has this random element, that there is this non local random thing happening, when in reality it's not, And so that sounds ridiculous and unlikely, and it is. You know, it's the state we're at where we're like trying to swallow the weirdness of quantum mechanics and just trying to make sure before we accept the universe is this weird way that there is no other possible explanation, and so again this is like an exercise and philosophical thoroughness, just to make sure we thought about all the other possibilities. Well, I guess you know, it could be like, um, maybe we live in some kind of multiverse and we just happen to live in the multiverse where every time we run Bell's experiments we think it's a fair coin, But really we're just somehow fooling ourselves into thinking the coin is fair. Yeah, it's possible, right, It seems really unlikely because there's been so many iterations in these experiments in different conditions, and so it just gets more and more implausible the more times we tested, and the more times it comes out like bang on exactly what quantum mechanics predicts. So it's not something anybody should take seriously as anything other than like an interesting thought experiment, like how far do you have to go to rescue determinism? How ridiculous do you have to imagine the universe is in order for it to not be quantum mechanical in this way that we are slowly coming to grips with. I see, so when you say super determinism, it's really more like super stubborn determinism, Like it's not actually like likely that it's true, but it's you're still clinging to the idea that maybe the universe is determined. It's like super desperate is um. People are desperate not to give up on determinism. Super desperate determinism. It's like the bizarro superman. All right, well, what what does it all mean? Doesn't mean that there that we're increasingly thinking that there is free will or unpredictability in the universe, right that we've now maybe are getting closer to leaving behind this idea that the universe is determined. Well, we are definitely coming to grips with and accepting this consequence that the universe is nonlocal that they have to somehow make this collapse decision off space in no time, which is sort of amazing. And you know, another interesting loophole or wrinkle to this interpretation of Bell's experiment is that we have to remember that Bell's experiment just tells us that there are no local hidden variables. It's possible for them to be global hidden variables. Maybe there's like some bank somewhere that keeps all this information and is arranging all of this stuff. And can transmit it across space and time instantaneously. That's basically bow Mean mechanics. We had an episode about that last year, so check that out if you're curious about that interpretation of Belle's experiment, which is actually one of Bell himself's favorite interpretations. But I think that most people understand it to mean that the universe is fundamentally random, that there are these decisions being made sort of at the last minute by the universe when the wave function collapses. What that means for free will is a question for philosophers. All right, well, I guess um, maybe we should change their name to sad determinism. But do you know, I thought maybe in our last episode we talked about how there is no simultaneity in the universe, right, this idea that there's no real sort of like fixed time in the universe. Could there be some sort of loophole there? That's a good point, right, how can you even talk about simultonay across space and time? There isn't a loophole there because they've separated them so far apart that we know that these things cannot be costly linked to each other. So while we can't say exactly which one happens first, this electron measurement or that electron measurement. We do know that they can't be costly linked because they're so far apart in space. All right, well, then I guess maybe the universe is really is random and unpredictable. Um, let's test this right now. Daniel, what am I going to say next? It's gonna be some joke about strange balls. Wrong. I was gonna say, thanks for joining us. We hope you enjoyed that. See you next time. Thanks for listening, and remember that. Daniel and Jorge Explain the Universe is a production of I Heart Radio. For more podcast from my Heart Radio, visit the I heart Radio app, Apple Podcasts, or wherever you listen to your favorite shows.