Daniel and Kelly’s Extraordinary Universe - Can science predict what you will do?

Episode Date: November 14, 2019

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Hey, Jorge, do you think science is good at predicting the future? It doesn't do very well with predicting the weather, does it? Well, here in California just says sunny every. day. Yeah, I guess that. Some states are easier to predict the weather. All right, but let me try my hand at it. I have a prediction of the future. Ooh, you're a psychic now and a physicist. Well, I predict that you cannot go a whole episode without talking about bananas. What? That's bananas. Boom. There you go. I'm totally psychic. You know the difference between a psychic and a physicist? Their salary? And where you put to age? That's the same. That's the same. That's the difference.

the only difference. Hey, I'm Jorge. I'm a cartoonist and the creator of PhD comics. Hi, I'm Daniel. I'm a particle physicist, not a particle psychic, and I'm a co-author of our book. we have no idea, a guide to the unknown universe. Welcome to our podcast, Daniel and Jorge Explain the Universe, a production of iHeard Radio. In which we talk about all the amazing, the fascinating, the hot, the nasty, the wet, the bright, the dirty, the soft, the quiet, the loud, the hot, the cold,

all the stuff in the universe that's fascinating and beautiful and amazing. And explain it to you in a way that we hope you actually understand and hopefully even enjoy. Yeah, and sometimes on the podcast we like to talk about predicting the future. What's going to happen? What's going to happen to the universe? What's going to happen to the Earth? What's going to happen to the solar system?

What's going to happen to this podcast? Where is this podcast going anyway? Yeah, we like to talk about what science does and doesn't know about the future. What we can predict about what's going to happen and where we are totally clueless. Yeah. Well, as we were saying earlier, there's a fine line between being a psychic and being a physicist. I would say it's a bright but fine line. It's a bright, okay.

It's an impenetrable barrier, quantum barrier. It's difficult to tunnel between being a physicist and being a psychic. But in some sense, we do have the same job. Physics also wants to predict the future. Yeah, that's kind of, I mean, that's kind of why, in a way, physics was invented, right? Like, we want to know where this catapult payload is going to land. We want to know how far my car is going to go. Were you there when physics was invented?

I didn't get invited to that meeting. Oh, yeah. I think Einstein was there and Newton was there. Dang, I knew I should have checked my email that day. He missed the calendar invite. That's right. And all those examples you mentioned are totally valuable and are examples of why science has an impact on everyday life.

You know, is my catapult going to get over those castle walls and this kind of stuff? But also, physics just wants to understand what's going to happen to us. What's our fate? How can we plan to live ahead? and can we understand the mysteries of everything around us so that we can know when lightning is going to strike or when disease is going to wipe out our cattle? Right.

In a way, that's kind of the standard for physics, right? It's like we say we understand something if in a way we can sort of predict what's going to happen. You want to verify that your theory of physics describes the real universe out there and not just some idea in your mind. You have to make a testable prediction. Einstein, for example, predicted how light was going to be bent

during an eclipse and people measured it and he was right and that's really when people started to believe his theory of relativity because if your theory can't predict the future then what use is it right that's what science does it predicts the outcome of future experiments yeah and you know I think people are comfortable with this idea that physics is able to some degree predict the future like if you told somebody hey physics predict that the earth is going to be around for a very long time or that the universe will never end that's those are comforting or if you eat that candy, you will get fat. Yeah, I think that's more of a physical education.

There's physics there. You're converting candy energy into squishy stomach energy. Yeah, so we're comfortable, I think, with some physics predicting some things about the future. But I think we're a little bit uncomfortable about physics describing other things about the future, right? Yeah, we like to use physics and science to explore the universe around us. and outside us, but then sometimes we turn that science on ourselves. Then we seek to gain insight into how we work, and then that makes you wonder. Yeah, it makes you wonder if you are predictable in a way, you know, like could physics

potentially one day, you know, simulate the human mind or simulate your mind and predict what you're going to think and do? It's a fascinating question because so many things that humans have puzzled over for so many years, how eclipses happen, where lightning strikes, all of this stuff, how reproduction works, all of these things have in the end been explained through science. It turns out they are mechanistic. We can understand microscopically how it works and predict what's going to happen in the future. And so then it's a natural question to wonder how far you can extend that strategy. Can you turn that around and extend it into your own inner life?

Right. Yeah, because, you know, like if physics can predict what, you know, a can of gas particles is going to do, why can it predict what a brain full of neurons is going to do? What's the difference in the end between a can of gas and a brain of neurons, really? Depends on the person, probably. Depends on what that person ate recently. Yeah. So it's a big question with, I think, some really deep philosophical implications, right, about who we are and whether or not we're predictable or whether or not we have this thing called

free will. Yeah, that's right. Like many of the topics we touch on in. this podcast, there are deep philosophical implications. And so I think today we should walk carefully and focus on the science and then think about what the philosophical implications are of what we do and do not know. Yeah. And so today on the podcast, we'll be tackling the question, can science predict what you're going to do? And I predict that there will be a lot of predictions in this episode, but maybe not a lot of answers.

Well, that's sort of our specialty, right? Opening questions and not really answering them. I think what you mean is getting people excited about the questions, right? That's right, yes. Sparking people's fundamental curiosity. Yeah. I think it's wonderful to talk about things that we don't understand very well because hopefully it's a preview for what's going to happen in the future.

It's like a fantasy for future science. Maybe in 500 years or in 1,000 years, science will have figured out the exact workings of the human brain. It can tell you exactly what you're going to do tomorrow. That would be amazing. It would totally change the way life operates, the way, what it's like to be a human being. Right.

Yeah, I mean, we wrote a whole book about all the things we don't know, Daniel. I'm sure we can pull off a podcast. Awesome. I predict we will. So, yeah, so this is an interesting question. And it kind of goes back to a long time ago when, you know, once science started seeing that the universe was what they called, deterministic, meaning like just a giant machine that follows the loss of physics like a clock,

then I think that's when people started to think like, hey, maybe our humanity is also predictable like a clock. Yeah, I think that's sort of shocking. I think when people first had that idea, it might have been a terrifying moment to imagine that this experience they were having might actually just be explainable, that things could be determined from the past. Yeah. Well, I think if you told my 11-year-old self that I was a robot, I'd be like, cool. Nowadays, though, you know, it's more of an uncomfortable statement.

You're a robot, and we gave the remote control to your sister. Sorry. No. I think also it's fun to think even more deeply into sort of the origins of human thought on this question is sort of the hubris that the universe is explainable at any level. I think 1,000 years ago or 5,000 years ago, people might have been comfortable with the idea that the universe doesn't follow laws. It just sort of is, and maybe there are these omniscient sentient beings out there

that are in control of stuff and they can do whatever they like. So the idea that the universe, that we could write down rules, we could discover rules that the universe follows and use those to predict what's going to happen. That's an incredible step forward in human intellectual history, but also it's not something we can necessarily explain.

Like, why would the universe be determined? deterministic. Why would the universe even follow laws? Is it true, even today, given our amazing success in science, is it true that everything we can discover, every natural phenomenon we discover will eventually be explained by science or can be explained by science? Those are open questions in philosophy. Yeah. And so I guess the question then is, you know, how far can we push science? Like if science can predict the future to some degree, like, you know, you can predict that the airplane is not going to fall from the sky or it's going to predict that, you If I shoot this laser, this is what's going to happen.

You know, how far can we push the science and maybe even predict what your brain is going to do? Fascinating questions. And I think you'll see from some of these reactions that there's a wide variety of opinions out there. So as usual, I walked around campus at UC Irvine and I asked folks this question. Can science predict what you're going to think or do? So think about it for a second. Do you think you're just a big, squishy biological robot machine? Or do you think you have some sort of free will

or some sort of free spirit that nobody can predict what you're going to think or do? Here's what people have to say. Not precisely. To an extent, there's just so many variables. No. No, why not? Because we're, humans are unpredictable.

I'm a psychology major, so, yeah, I don't believe that we can. We can try, but it's not likely. Yeah, I think so. You think so? Yeah. So then is there free will in that case? Like, are you making the decisions? Yeah, because it's still the person itself that's still middleism.

It's just the other person that's predicting correctly, so it's not their choice. Theoretically, I mean, if we did have this capabilities, then that might be possible. Okay. We just need to advance science as far enough to able to figure that out. No, I don't think so. So do you think the brain is, like, not described by physical laws, or there's something else happening there? No, I think strong determinism, I think, is a very optimistic. Yeah.

You do? Yeah. Why is that? I don't know. I just feel like it could. Okay. And if it does, does that mean that you have free will or don't have free will? If you can predict what people are going to think, then probably not.

Yes. Yes? Why is that? I don't know. I think I saw, like, a video where they're, like, trying to map out, like, a brain or something, and they were talking about, like, how to recreate it, and that everything we think is just, like, a series of decisions, and that you can put it in, like, binary or something, so, like, zero for yes or one for no, and it all leads to what choices you make.

I think that if there were a method for it, it wouldn't be super exact, just because there were so many factors that play into it. I don't think it's possible to be able to predict every single one of them. Yes. Yes? Why is that? Uh, I don't know. Uh, no.

No? So you don't think the brain follows physical laws? I think it does, but I think they're chaotic. Chaotic or random? Given enough information, are you just a complicated mechanical watch? Uh, no. I think I may or may not subscribe to the view that there's some quantum mechanics at play, so maybe. Maybe we're not... So you think quantum mechanics gives us an opening?

for free will? No, I don't know if that's true. I'm a pessimist. I feel like eventually, yes, but I feel like we're not there yet. So if so, does that mean that your brain is deterministic, but you're just a product of what's happened to in the past and the stimulus it's getting?

Obviously, there's, like, some varying factors, but I think there are some things that are, like, patternistic. Like, if you're going to wake up and, like, drink a coffee or if you're going to wake up and, like, go for a walk, like, those things are patterns that, like, are habitual, but then there's things that aren't. I feel like you could predict it to an extent, but not like every single, like, action by action.

Like, there might be, like, faults in the prediction, but, yeah, I don't know. Because it's hard to do or because it's impossible? Just I feel like that's probably impossible because things can change, you know? A very complicated robot, yep. Okay, very complicated robot. Does that mean that there is no free will then?

I am currently thinking that's, There's no free will. Yes. Awesome. Yeah, so maybe that's where it becomes a bit complicated to answer this question, because I do believe that the laws of physics govern everything in the universe. So that would include us. All right.

I feel like these answers were all very yes and no. You know, some people were like, no. Some people were like, yes. Nobody said like, maybe, I don't know. You know, like people had very strong opinions. They certainly did. And I should have taken some data to see if these were like all. science majors who had confidence that science would eventually figure it out or not.

But the last two were maybe the most fun because they turned out to be a husband and wife. And he said, yes, he's a complicated robot. And she says, no, we're not robots. And then after I left, I heard them arguing about it. Oh, that's funny. In a good-natured way. In a good-natured way. Oh, I see.

Oh, I see. One of them thought that the other one was predictable and the other one did not like to be predicted. Yeah, I thought that was fascinating. Maybe sparked some dinner table conversation. But you're right. And in contrast to some other questions, this is definitely a topic everybody felt comfortable giving an answer to. Sometimes I'll ask people a question and they'll be like, what? I never heard of that before or I don't know.

But here, everybody had something thoughtful to say. Yeah, because I think it touches something very deep within us, you know, just this idea that there's something more to me than just like a big biological clock or a big biological, you know, clump of. of cells doing what they would do without thinking about it. Yeah, I think most people feel like they are steering. Even if your body is a big biological robot, they feel like they're in charge, they're making choices. They decide to eat that cookie or they decide to step on that crack. They feel like they're making these decisions.

And so it doesn't sort of jive with that experience to imagine that those decisions are just the product of the situation you were in an instant before. It's hard to imagine how you could have such a very big. visceral experience of free will if you don't actually have it. All right. So let's dig into the question here is the question here, which is, could science predict what you're going to do? And so let's maybe paint a picture to our listeners about what that might look like.

You know, like how could science, physics or, you know, a combination of biology and computer science possibly predict what a human brain might think or do? Yeah. So the typical strategy for understanding something is to think about it in terms of its microscopic bits like what's going on inside of it can we understand those bits and from that build up some sort of understanding you know like if you wanted to say understand how a watch worked you would take it apart and you would say oh there's a gear here and there's a lever there and this lever touches that gear which turns this thing and that's how this thing works and if you can make a

model of all the things inside of it and each one of those things is following the laws of physics then together, the whole thing has to follow the laws of physics, right? If something is made up of pieces which are predictable, then putting them together, it should also be predictable. Right. You mean like a, so science would maybe break down your brain and maybe build like a computer model of each one of your neurons and that somehow, you know, acts exactly the same way that is put together

the exact same way that your brain is. And so maybe like if you capture your brain in a computer, could that maybe predict what you're thinking, what you'll think and do? Yeah, and it doesn't have to be a computer model. In the end, it just has to follow the mathematical laws of physics. And you can express those as a computer model. You could also build a mechanical model, right?

You can imagine building a basically a physical copy of your brain. So that's, I think that detail is not critical. The concept, the critical concept is understanding what's going on inside the little bits. and then putting those together to basically replicate your brain. But replicating is not enough. Like if I had a perfect copy of your brain, like if I created another Jorge, that wouldn't necessarily help me understand what you're going to do.

In order to predict what you're going to do, I need to be able to run experiments. And so, yeah, having a simulation of your brain, I could like say, well, what would Jorge do if I offered him a cookie? Would he say yes or no? So if I had a perfect simulation of your brain, I could run those experiments. Right. Yeah. And I think it goes to the idea that, you know, we're really complicated as human beings, as thinking beings. But, you know, if you break down our brain, it's made out of, you know, lobes and chunks of brain tissue. And those are made out of neurons connected to each other. And neurons are made out of molecules. And so all of these things down to the molecule level kind of follow the laws of physics. You know, it is sort of at the end, just a big and very, very complicated, but it's

still a big clock. Yes, and that's a really deeply powerful implication of this discovery that we made a long, long time ago, that everything is made out of the same bits, right? I'm made out of atoms, you're made out of atoms, this chair I'm sitting on is made out of atoms. Things are not made out of their own kind of stuff, which means that in the end, they all follow the same rules. The rules that hold a chair together are the same rules that hold your cat together and your hamster together and you together. So if we can figure out what the rules are that describe how molecules and atoms work, that in principle, and that's an important distinction, in principle, we should be able to extrapolate up and understand how you work.

Right. It's kind of like saying, like, you know, we are made out of inanimate bits. You know, we're made out of things that are just plain things, which you can maybe predict what they're going to do. And so does that mean that we are also inanimate in a way and predictable? Imagine you came across a robot, for example, and it was doing weird stuff and you want understand it. How would you understand it? You would take it apart and say, oh, it's made out of these pieces and can I understand each of

those pieces? And if so, you could put that together to an understanding of the whole robot. And so the idea is apply that to a person. Yeah, and you could do things like, you know, if I, you know, if I poke this little bit here and this engine, you know, I predict that the car is going to move forward or backwards. Exactly. And all of this happening, of course, assumes a few things. It assumes that you can get a picture of what's happened. inside your brain. The idea you presented requires that we know each neuron. We know the situation that neuron is in. Right. It's like for the watch, it's like that we know where the levers are

and where the gears are and that we can extrapolate up from those levers and gears to the operation of a whole brain. That's not trivial. And then, you know, there's questions about like, is it actually deterministic or is there like some funky quantum magic going on? Or is there something in there that like science can't describe? So it's not a trivial thing to say. it's just because your brain is made of atoms that we could therefore predict what you're going to do. Right. Yeah.

I think that's at the core question here. And so let's get into it. And just to save you some time, Daniel, I will always take the cookie. You don't need a fancy computer simulation to predict that. I will take the cookie. All right.

I'm going to cross that off my deep questions of the universe list. Yeah. So let's get into it a little bit more deeply and figure out how you might even do this or whether we can. Or if there is some kind of quantum magic that might give us a little bit of a loophole to get free will.

But first, let's take a quick break. Imagine that you're on an airplane, and all of a sudden you hear this. Attention passengers. The pilot is having an emergency, and we need someone, anyone, to land this plane. Think you could do it? It turns out that nearly 50% of men think that they could land the plane with the help of air traffic control. And they're saying like, okay, pull this, until this. Do this, pull that, turn this. It's just, I can do it my eyes close.

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I ended up having amputation below the knee of my right leg and the traumatic brain injury because I landed on my head. Welcome to Season 2 of the Good Stuff. Listen to the Good Stuff podcast on the IHeart Radio app, Apple Podcasts, or wherever you get your podcast. All right, we're talking about whether science can predict what you're going to think and do. And we talked about, yeah, that maybe your brain is made out of

little bits and pieces, which are sort of little biological machines. And so does that mean that your whole brain is just a machine or like a robot, which anyone could predict what they're going to do? So let's get into it. What are some of the things, Daniel, that physicists know or think that might make that picture really difficult or maybe impossible to predict what you're going to do? The first thing that comes to my mind is just knowing the current status of your brain. Like if I wanted to model the flight of a of a baseball. If I wanted to know exactly where a baseball went, I would need to know its current position and its current direction. If you wanted to know, if you wanted to predict where it's going to land, you would sort of need to know,

you know, where it is and where it's going at any given time. Yeah, and at any moment, just one moment in time would determine where it's going to be. So if I knew where that baseball was now and where it was going in which direction it was going in, I could just apply the law of physics and propagate that information forward, I would say, oh, it's going to move in a certain path under gravity, and I can tell you exactly where it's going to land. That's physics predicting the future. And that works for one little tiny particle or a baseball or whatever. But in order to do that for your brain, I would need to know the current situation of your brain. Like, what is the situation of every neuron? Is it about to fire a little pulse? Is it not about to fire a pulse? How

strong is this connection between it and the next neuron. And you know, there's billions and billions of neurons in your brain. So we're talking about an enormous amount of information you'd need to know. I think what you mean is that even if I had a giant computer simulation of your brain, I would need to give each of the neurons kind of a starting value, right? Or like, I would need to know where each neuron was in order to predict what the whole brain was going to do. Precisely. If I had a computer program that could simulate an arbitrary brain, I would somehow need to configure it to your brain. And that would mean knowing where all the neurons were and how they were connected to each

other and all that kind of stuff. Just like if you want to calculate where the baseball is going to go, you need to know the initial conditions. You need to know where it is now and which direction is going in. So like even if I had that computer program, even if it was possible to use that computer program to predict the future, how do I get that information from your brain? Do I have to like scan your brain somehow? Do you have to take your head off and slice it into how?

hyperfine little bits. Like, how do you even physically do that? Right. Because each neuron might be in a different state. You know, like one might be more excited than others or you might be, you know, you might be in a bad mood. And so there's a general, I don't know, dopamine levels that are, you know, suppressing some of your neurons right now. You need to know that in order to predict what you're going to think and do.

Yeah, and you need to know it all at the same moment, right? I don't want to know what the left half your brain is doing right now and the right half your brain is doing two seconds ago, I need a complete picture of your brain at one moment so that I know what direction everything is moving in. I'm just thinking of your brain as like a lot of tiny little baseballs. And so I need to know where all those baseballs are at the same time. So even slicing your brain, you know, like a ham sandwich or whatever wouldn't work. I need to somehow instantly scan everything in your brain. And that just seems almost impossible, right?

It seems almost impossible. I mean, I read a lot of science fiction, and there's some good stuff where the people are uploading brains into the cloud, and sometimes they talk about how scanning the brain is a destructive process, but they never talk about how fast it has to be. Like, if you want to scan the brain, it's got to be a snapshot. You've got to know where everything is in an instant, or it's all averaged, like over the last five minutes or 10 minutes or 20 minutes or however long it takes to scan the brain, and that's going to be a disaster.

So this is a technological issue, not philosophical, but I don't know if that's even possible. Oh, I see. Okay, so that's kind of the first barrier that might prevent you from predicting somebody's brain is getting a snapshot of it. And it sounds impossible, but I think technically you can't rule it out, right? Like, it's not technically or theoretically impossible that maybe one day people will come up with a brain scan that can somehow capture all of your brain in one instance. That's right. Unless you need to know it's sort of at the level of quantum mechanical objects, like if you need to know the exact location of every electron, then it's theoretically impossible because you can't measure the perfect quantum state of the entire brain all at the same time. I think that's theoretically impossible. But as long as it's, you know, not necessarily sensitive to quantum effects,

in theory it's possible, but technologically way out of our grasp today. Today. But yeah, let's assume that that's possible and then think about what the other problems would be. Yeah, yeah. Because that's not the only problem is scanning your brain there are...

First, we have to achieve this almost impossible sounding technological feat then we got the real problems. Yeah, well, you know, that's what they said about the iPhone and look where we are now.

Is that what they said about the iPhone? Was that at the physics meeting you had with Einstein and Newton, all those guys? Well, it was science fiction like 50 years ago, right? Like this device

that fit in your pocket and you can talk video with people and play addictive video games on for hours. I mean, that was like Star Trek, you know? That's true. And it'd be folly to say, this kind of technology will never be developed

or would take years or centuries or whatever because those kind of predictions are always, people always look silly five years later after making those predictions. Right. So we should avoid that. And maybe technology will progress rapidly and they'll invent a brain scan next week

and they'll have a brain scan app that you can put on your phone. Maybe. But then there are other things that would make this really difficult or that kind of make your brain almost pretty much unpredictable, right? Yeah, there are a lot of practical issues

in actually accomplishing predicting what your brain is going to do. Say we had a snapshot of your brain. We knew the current status of every neuron. We could load that into the computer. And we wanted to run that forward. We wanted to say, all right, well, what's this person going to do in five minutes?

That's not always easy. Some systems, even if they're made of atoms, which follow physical laws, And even if you knew where all those atoms were, are hard to describe. Yeah, because they're, you were telling me earlier, they're not easy systems to kind of simulate or they're not easy systems to kind of predict what they're going to do. Yeah, and this is, again, a technological problem, but it's a real problem. Like, why can't we predict the weather?

In theory, weather follows rules that we understand, water droplets and air resistance and wind, and all that stuff. That's not complicated physics. They're just atoms. Yeah, they're just atoms. Bouncing around. And we don't even need to worry about the atoms. We can think about the water droplets and the temperature and stuff.

So why is it so hard to predict when it's going to rain or when a hurricane is going to come if it's following the laws of physics? And we have amazing satellites that are like gathering all this data about what the temperature is everywhere. It's a very similar problem. The reason that weather is hard to predict is not because it doesn't follow the laws of physics. It's because it's very, very sensitive to. the exact tiny details of the situation.

A small change in temperature over here leads to a big change over there. That's something we call chaos. Right. It's this idea that kind of goes back to that whole butterfly idea, right? Like they say that if a butterfly flaps its wing in one part of the world, it can actually affect the weather in another part of the world just because it's so sensitive to even small things like a butterfly flapping its wing. That's right.

And not every system is chaotic. Some things are not, right? Some things, for example, when you throw a ball, you throw a ball, if you change the angle you're throwing it at by a tiny bit, then the outcome is changed by a tiny bit. You throw it a tiny bit harder, it lands, it goes a tiny bit further. But other things, if you change how you do them by a tiny bit, you get a very different outcome, like rolling a die. If you roll a die slightly differently, you spin your hand a tiny bit differently. You get a four instead of a two or a five instead of a one. So the outcome depends very, very sensitively on exactly how you did it.

It's not random. It's following the laws of physics. In theory, it's predictable. But in practice, it's very difficult because the outcome depends very sensitively on how you flap those butterfly wings. Yeah. Or how you throw the dye. Like to predict a die roll, you would need to really kind of like pay attention to the exact angle that each dye is at when it leaves your hand. And you have to predict also or simulate how like when the corners hit the ground, how that's going to affect the spin of the dye.

And so it's really, it's just a much more complicated system to simulate and predict than like just throwing a baseball. So then the question is, is your brain like a big bag of dice where each one very difficult to predict and bouncing off the other one? It's a very complex thing. Or is it made out of things which are easy to predict? and if you knew pretty much the current situation that you could predict how it's going to come about, you know, is your brain a hurricane or is it just a baseball? Right. Or, you know, if I have butterflies in my stomach

and those, they flap, how is it going to affect my decision to eat a cookie or not? Exactly. So the point is that even if you knew exactly the current situation of the brain, could you have a powerful enough computer to predict what's going to happen going forward? And in the end, that's really the limitation. For example, for hurricanes,

If we knew the location of every drop of water on Earth and its current position and velocity and we had a super-duper powerful computer, then yeah, we could probably predict the weather very accurately. But we don't have those computers. Right. Well, I feel like we're getting better, though, you know, like sometimes I'm really impressed by how far ahead we can predict the weather and how somewhat accurately we can. This is just a hurdle of technology.

Something like 80% of the fastest computers in the world, like the supercomputers, are all devoted to this problem, predicting the future of the weather, understanding the atmosphere and knowledge of it's chaos. And so it's really just like throwing more computational power at the problem. Well, and that's because weather is a chaotic system, right? Definitely, weather is very chaotic. It's very difficult to predict the outcome, even if you know the current conditions. But do we know if the brain is chaotic or humans are chaotic?

Humans seem chaotic to me. I mean, some of them I've known for decades, and I still don't understand why they make the decisions they do. And not just your children. Not just my children. No, we don't know for sure, but it seems to me very likely. I mean, it's a hyper-connected, very sensitive set of neurons. It seems to me very unlikely that it wouldn't be chaotic. But we don't know.

It might be that there are sort of emergent phenomenon, that you're not really sensitive to all the little details and that you could build a model that predicts roughly where things are going if you don't care about the details. You can tell whether somebody's going to have a cookie and who they're going to vote for the next election. It's possible that you could build those models. But that requires sort of another layer of insight. Imagine you only knew the baseball in terms of little particles inside of it.

You're like, oh, there's no way I could predict the way this baseball is going to move. There's 10 to the 23 particles. It's impossible. But if you took a step back and saw the flight of it, you could say, oh, actually, I can describe this and ignore all the particles. I can ignore all those details. They're not relevant. and I can just describe this in terms of simple motion. So it's possible that there's an emergent theory of psychology,

mathematical psychology, that could describe the motion of the brain. We just don't know. Or I wonder if it might vary with people. Some people might be more predictable than others. Yeah, I certainly know some people who seem pretty chaotic. All right. Well, those are two pretty big hurdles. But then there's another hurdle coming up and or possibly a loophole that might

still let us have some free will in this deterministic machine-like universe. So let's get into that, but first, let's take a quick break. Imagine that you're on an airplane, and all of a sudden you hear this. Attention passengers, the pilot is having an emergency, and we need someone, anyone, to land this plane. Think you could do it? It turns out that nearly 50% of men think that. they could land the plane with the help of air traffic control. And they're saying like, okay, pull this, until this.

Do this. Pull that. Turn this. It's just... I can do my eyes close. I'm Manny. I'm Noah. This is Devin. And on our new show, no such thing. We get to the bottom of questions like these. Join us as we talk to the leading expert on overconfidence. Those who lack expertise lack the expertise they need to recognize that they lack expertise. And then, as we try the whole thing out for real. Wait, what? Oh, that's the run right.

I'm looking at this thing. Listen to no such thing on the Iheart radio app, Apple Podcasts, or wherever you get your podcasts. Your entire identity has been fabricated. Your beloved brother goes missing without a trace. You discover the depths of your mother's illness, the way it has echoed and reverberated throughout your life, impacting your very legacy. Hi, I'm Danny Shapiro. And these are just a few of the profound and powerful stories I'll be mining on our 12th season of Family Secrets.

With over 37 million downloads, we continue to be moved and inspired by our guests and their courageously told stories. I can't wait to share 10 powerful new episodes with you, stories of tangled up identities, concealed truths, and the way in which family secrets almost always need to be told. I hope you'll join me and my extraordinary guests for this new season of Family Secrets. Listen to Family Secrets Season 12 on the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts.

Hey, sis, what if I could promise you you never had to listen to a condescending finance bro? Tell you how to manage your money again. Welcome to Brown Ambition. This is the hard part when you pay down those credit cards. If you haven't gotten to the bottom of why you were racking up credit or turning to credit cards, you may just, recreate the same problem a year from now. When you do feel like you are bleeding from these high interest rates, I would start shopping for a debt consolidation loan, starting with your local credit union, shopping around online, looking for some online lenders because they tend to have

fewer fees and be more affordable. Listen, I am not here to judge. It is so expensive in these streets. I 100% can see how in just a few months you can have this much credit card debt and it weighs on you. It's really easy to just like stick your head in the sand. It's nice and dark. in the sand. Even if it's scary, it's not going to go away just because you're avoiding it. And in fact, it may get even worse. For more judgment-free money advice, listen to Brown Ambition on the IHeart Radio app, Apple Podcasts, or wherever you get your podcast. maybe affect what we see as free will or whether it can affect whether or not we can predict what people will think or do.

The whole premise here, the assumption we're making is that the brain should be predictable if its various bits are predictable. If it's made out of predictable bits, then you should be able to put those predictable bits together into a predictable brain. But listeners in the podcast are probably wondering, are those bits predictable? The brain is made of atoms and atoms are made of protons, electrons, and all this stuff. And we know that those things are quantum mechanical. And we talked on the podcast recently

about the crazy probabilistic nature of quantum mechanics that things are not determined until they're measured, that there is really true randomness at the quantum scale. So you might be wondering, how can you build determinism on top of this fuzzy quantum randomness? Yeah, because we talked about some of the challenges, right? We talked about scanning your brain and about chaos. But those are technical problems.

You're saying that maybe just in the bits themselves, of the brain, there is some inherent randomness that might make it impossible to predict. Absolutely. We know that there's inherent randomness. Everything, as we say, is made of atoms and those things are governed by fundamentally quantum mechanical properties. What we don't know is if that matters, right? It certainly doesn't matter for predicting the motion of a mechanical watch. People can build mechanical watches that are super accurate for years at a time. We can predict the flight of a baseball without even knowing that quantum mechanics was a thing. Remember, quantum mechanics affects things only on super duper tiny scales.

The uncertainty principle, delta X, delta P, the relationship between the uncertainty in motion and position, the uncertainty there is related to this Plank's constant, H-bar, which is like the fundamental unit of the universe. But this is a super tiny number. It's 10 to the minus 34 joules. And so it might be that on top of the... the quantum randomness, we do have a layer of physics which is deterministic.

Or it could be that the quantum randomness sort of seeps up from below and affects the working of the brain. Okay, so you're saying that there is a fundamental randomness in the universe and in my brain cells. Like, to the

smallest level, I can't possibly predict my brain. But maybe if I go up a few levels, then the brain starts to be more predictable. We see this in physics. We see at the very smallest levels, you cannot predict what's going to happen. You shoot the same photon into the same experiment twice.

You get two different outcomes. There's really true randomness there. And that breaks determinism. So photons not deterministic. Electrons not deterministic. Protons not deterministic. But somehow, when you put these things together, you put enough of them together, all those random fluctuations average out.

They basically cancel each other. This is a deep theorem in physics. It's called the Aaron Fest theorem, that you have enough of these things, and it doesn't matter anymore. As long as you're measuring things on the sort of classical scale and sizes that we care about, centimeters, millimeters, even, then the quantum mechanic effects average out, which is why we didn't notice quantum mechanics for thousands of years. It's hidden inside the summation of all of these quantum little events.

Yeah, which is why it was so hard to accept, right? We had just accepted the mind-boggling consequences of a deterministic universe. Like, wow, the universe seems to follow rules, and we can. predict it. And then we discovered, oh, actually, no, at its deepest level, it seems weirdly random. And that was totally in contradiction with everything we thought we understood, which is why quantum mechanics were so counterintuitive and so fuzzy. But still, it didn't mean that all those things we'd learned were wrong. It just meant that they applied at sort of the larger scales, that those same rules can't be applied to electrons and protons, but they can still be applied

to baseballs and watches. So then the question is, is your brain a baseball and watch or is it an electron? Yeah, it's kind of like if I said, Hey, Daniel, I'm going to flip this coin. And if it's head, I'm going to take your cookie. And if it's tails, I'm not going to take your cookie. Then it's kind of like, then you might say it's unpredictable what I'm going to do, right?

Because you don't know. Except that a coin is deterministic. A coin is a classical object. If I knew exactly how you were going to flip it, I could predict exactly how that coin was going to land. And I would know that you were going to take the cookie, no matter how the coin flipped, actually, because I know you as a person.

But yeah, exactly. The coin flip is not random. But if you, for example, had a radioactive particle and you said, I'm going to wait one minute. If the particle decays within this minute, I'm eating the cookie. And if it doesn't decay within this minute, I'm not eating the cookie. Then I can't predict whether or not you're going to eat the cookie. That's because you've linked a macroscopic action eating the cookie to a quantum mechanical thing.

That's rare, right? That's a whole Schrodinger's box argument. It's very difficult to find quantum mechanical effects that you can see on the macroscopic scale. Oh, I see. Like, if I made my cookie eating dependent on whether this particle decays or not, then it's unpredictable. But if I make my eating the cookie dependent on whether the particle will decay over a minute, then we know a lot more, right? It's less unpredictable. Because you know that on average, most of these particles, let's say like 90% of these particles, decay within a minute. Yeah, that's true.

And if you want to make statements about averages, then you're a rock solid footing, even quantum mechanically. Because quantum mechanics doesn't mean things don't follow laws. It just means those laws are probabilistic. And so you can say, on average, this is going to happen. On average, that's going to happen. For one particular particle, you can't make any predictions on a quantum mechanical scale. But you know, what quantum mechanical effects do you observe as a person?

Like for something to affect your life that's really random, it has to have an impact like that. somebody's measuring this quantum mechanical thing and making a decision based on it. It's really pretty rare for quantum mechanical randomness to affect the macroscopic world. People do really complicated experiments to try to set this kind of thing up, like Bose Einstein condensate is like a macroscopic quantum state that you can see that actually behaves quantum mechanically. It's really weird and amazing.

People won the Nobel Prize for that. So for the brain to be dependent on quantum mechanical randomness, you'd have to show somehow that like the motion of these electrons or this weird quantum mechanical effect was triggering neurons that neurons were somehow sensitive to these things yeah so it's it's fundamentally random but the question it seems like the core and the key question here is whether that randomness at the quantum level really affects whether I'm going to eat my cookie or not or whether that all gets drowned out by the bazillion electrons that I have in my brain and there are some folks who've made that argument and I think that that argument

is largely in response to fear of determinism. They don't want to think that the brain is just a mechanical watch that can be predicted. So they're sort of striving for some way to leave a window open for free will. And they say, oh, well, if we can connect it to quantum randomness, then, you know, you can't be predicted and therefore there might be room for free will. And famous people like Roger Penrose make this argument. But it's just a, it's more like an outline of an argument. There's no evidence that the brain is dependent on quantum mechanic.

It's just like, can we find some path to maybe go down that leads us to a non-deterministic brain? There's no real evidence or argument there. It's just like a suggestion. Well, I think the thing is that it's a yes or no decision, right? Whether I eat the cookie, it's either yes or no. So I'm kind of like sitting on the edge of a really thin knife, right? And, you know, who knows? Can you really rule out that, you know, how one particular electron behaved?

it was resulted in pushing me one way or the other? Or are you saying that pretty much that's unlikely? No, I'm not saying that we can rule it out at all. You're totally right. And it could be that there are quantum mechanic effects that determine whether or not you make that decision. It's possible. But I'm saying we have no evidence for that.

Nobody has shown that. We don't even understand the mechanism of it. That doesn't mean it's not happening. It just means that it's more of a suggestion, an open door than an actual idea. All right. Well, I feel pretty good. I feel like we're right where we predict that we would be.

I think you deserved a cookie. Or a banana at the very list. Oh, no, wait. You said I wouldn't say that. There you go. But I think that there's some fascinating questions there. Even if you knew the answer to this question, even if you showed that the brain was deterministic or wasn't,

that the brain was quantum mechanically random, what would that mean for this experience of free will? Let me see if I can recap what I, we learned. We learned that it's predicting what people are going to do is super technically hard with the scanning all of the neurons in your brain and chaos may be playing a large part of making it unpredictable. But let's say like we invented technology to take care of that. There's still sort of the question of whether randomness trickles up to influence decisions. You know, randomness at the quantum level, whether that trickles up to influence decisions.

And it sounds like we don't know. It sounds like we can't say either way. That's right. Quantum mechanics might make it theoretically impossible to predict the brain. We don't know. And if it doesn't, if it doesn't make it impossible, we know it's still super duper hard because you need to know the exact state of the brain

and you need to overcome the potential overwhelming chaos of your billions and billions of neurons. So even if it's not impossible, it's definitely very, very tricky. Right. And then we could probably have a whole podcast, just on the implications on how we feel about free will and whether it would still exist, even if it was governed by quantum randomness. That's right.

And this is an area of philosophy, and neither you nor I have formal training in philosophy. What do you mean? I have a doctorate in philosophy in engineering. So then let me ask you, Jorge, if I could prove that you were deterministic, does that mean you don't have free will? Does being a big mechanical robot mean you're not making choices? Or is that just describe the choices you are making? I think that would be bananas. No, I think for me, it sort of doesn't matter.

I feel like it doesn't matter. I'm not someone who sweats free will too much, to be honest. Like, I feel like I might be a robot. That's fine. And, you know, currently, it's almost like who would want to predict what I'm going to do? Do you know what I mean? Like, it's such. You're like, why is this problem even interesting?

Yeah, who would take the time to care about what I'm going to think and do? So as long as nobody else can think or would want to know what I think and do, then to me like, okay, I could be a robot or I could not be a robot. Well, I think there's an implication of moral responsibility. We've been talking about you eating a cookie. What if that was somebody else's cookie, right? And you ate that person's cookie. Then could you say, hey, I didn't make that choice.

I have no free will. And therefore, I can't be morally culpable. If everybody's deterministic and people aren't making choices that our sort of whole theory of morality kind of falls apart. and we can't really punish anybody for anything. All right. We'll say that for our other podcast, Daniel and Jorge explain the moral universe. Daniel and Jorge blather on about philosophy that don't really know what they're talking about. I would listen to that, and I predict a lot of people will probably not.

But I think these are, like many of the things we talk about on this show, there are deep implications for just what it means to be a human being. Often we talk about how the universe was created and how it came to be in its future. and that has deep importance for what people think about their place in the cosmos and how they should live their lives. And this is similar. It's a question, you know, is this a threshold that science will ever cross? And if so, what does it mean?

And so I love the fact that science is so relevant sometimes that it really touches the deep core of how you're going to live your life and what it means to be human. Yeah, it's amazing to think that physics can have such an impact in who we are in our souls, in our conception of who we are. Well, physics is deep in my soul, and now maybe you're discovering it's actually deep in your soul as well. We got you. We infected your soul, dear audience, with physics. All right, well, thanks for joining us.

We hope you enjoyed that, and we hope that met all of your expectations about what this podcast was going to be. That's right. Thanks for tuning in. And for those of you who wonder whether science can actually explain the universe, remember that we don't know. Science has worked pretty well so far and been able to explain a lot of what we've seen. But if there might be some day in the future where we find some phenomenon that can't be explained by science or by our current envisioning of science or our mathematical rules, so we are continuing on this journey of trying to explore and explain the universe we find around us. Thanks for joining us. See you next time. If you still have a question after listening to all these explanations, please drop us a line. We'd love to hear from you.

You can find us at Facebook, Twitter, and Instagram at Daniel and Jorge, that's one word, or email us at Feedback at Danielandhorpe.com. Thanks for listening, and remember that Daniel and Jorge Explain the Universe is a production of IHeartRadio. For more podcasts from IHeartRadio, visit the IHeartRadio app, Apple Podcasts, or wherever you listen to your favorite shows. I'm Dr. Scott Barry Kaufman, host of the psychology podcast. Here's a clip from an upcoming conversation about how to be a better you. When you think about emotion regulation, you're not going to choose an adaptive strategy

which is more effortful to use unless you think there's a good outcome. Avoidance is easier. Ignoring is easier. Denials easier. Complex problem solving takes effort. Listen to the psychology podcast on the iHeartRadio app, Apple Podcast. or wherever you get your podcasts. Every case that is a cold case that has DNA.

Right now in a backlog will be identified in our lifetime. On the new podcast, America's Crime Lab, every case has a story to tell. And the DNA holds the truth. He never thought he was going to get caught. And I just looked at my computer screen. I was just like, ah, got you. This technology's already solving so many cases.

Listen to America's Crime Lab on the IHeart Radio app, Apple Podcasts. or wherever you get your podcasts. Get fired up, y'all. Season two of Good Game with Sarah Spain is underway. We just welcomed one of my favorite people, an incomparable soccer icon, Megan Rapino, to the show,

and we had a blast. Take a listen. Sue and I were, like, riding the lime bikes the other day, and we're like, we! People ride bikes because it's fun. We got more incredible guests like Megan in store, plus news of the day and more. So make sure you listen to Good Game with Sarah Spain,

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