Episode 134: The Deutsch Slot Machine

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Transcript

[00:00:00]  Blue: Hello out there! This week on the Theory of Anything podcast, Bruce makes his most epic statement about probability ever. He discusses Deutsch’s lecture, Physics Without Probability, and also pulls from our episode 100 where we interviewed Deutsch. Bruce then methodically goes through why Deutsch’s argument may be an example of word essentialism, i.e., an argument about words. He then makes an impassioned plea for someone out there to help him understand where precisely he is misunderstanding Deutsch’s argument. I felt like this was top shelf Bruce Nielsen. He goes on a long time, yes, but I personally think it’s worth it.

[00:00:52]  Red: Welcome to the Theory of Anything podcast, eh, Peter?

[00:00:55]  Blue: Hello, Bruce. How are you doing today?

[00:00:57]  Unknown: Good.

[00:00:59]  Red: Well, we’re going to finally cover Deutsch’s presentation, Physics Without Probability.

[00:01:08]  Blue: Okay.

[00:01:09]  Red: And let me just say that I did not answer my questions.

[00:01:15]  Blue: All right. Well, I rewatched it. I think I’ve seen it about four times. Given your background and what we’ve discussed on here, I think I’m almost getting my mind around this controversy.

[00:01:31]  Unknown: So

[00:01:32]  Red: what?

[00:01:33]  Unknown: A

[00:01:33]  Blue: little bit. I mean, I think the first time I ever watched it, honestly, it sounded like gobbledygook to me.

[00:01:38]  Unknown: I

[00:01:38]  Blue: just, I did not, I just didn’t, didn’t have the background knowledge for it. So I’m getting there.

[00:01:43]  Red: What is it you believe he’s saying? Like try to summarize what you think he’s saying.

[00:01:48]  Blue: Oh, well, I’m not sure I’m quite there yet, but it’s fine.

[00:01:52]  Red: Like it can be totally wrong. Like people watch this video, they’re clearly getting something out of it. They point it me to it all the time and they say, go watch this video, this explains, right?

[00:02:05]  Blue: Well, I mean, it sounds like it’s a defense of, I mean, he’s basically proposing the idea of constructor theory as an alternative to probability.

[00:02:18]  Red: Okay. So you perceive him as putting forward constructor theory as an alternative to let’s be clear probability theory?

[00:02:26]  Blue: Is that not right?

[00:02:28]  Red: No, no, no. I’m asking if that’s what you intended to say.

[00:02:31]  Blue: I think that’s what he pretty clearly says. I think that he says, you know, I was kind of before it’s kind of hung up on the multiverse angle. I don’t think that he’s saying that his argument is completely about the multiverse though. I think that he believes that probability is not, it just doesn’t have validity, even, even from a single universe perspective.

[00:03:06]  Red: So, okay, so let’s go with that. And then I

[00:03:09]  Blue: guess there’s just different levels of explanation and probability is just not, it’s just not has limits and very, very, it’s very limited in what it explains. I really like, I would just say one more thing. I really, what the point that resonated with me, I think it was from our last podcast that you said, I think you were describing what Deutsch believes, is that if there’s an explanation for why probability works, a coherent explanation, then it has validity. But without that explanation, then probability is, I guess, useless. So, it’s sort of, I think harkens back to the explanation view of reality. I don’t know. That’s what I got. I want you to explain it to me though.

[00:04:11]  Red: Okay, well, I’m not sure I understand it. Like, I think I understand it at times and I’m going to go through the math. I’m going to give examples. So, I’ve gone to great lengths to try to understand it and I either he is talking nonsense or I am just not getting it because I don’t think there’s any middle ground here, right? And I’m not sure what it is to be perfectly honest. I’m doing my best with it and this is something I want to kind of emphasize. I’m a layman. I’m stupid compared to David Deutsch. He probably knows both quantum theory and probability theory better than me. But I’m not an unknowledgeable layman, right? Like, I’ve got a master’s degree in machine learning. I had to have some familiarity with probability theory to get through that. I’m somebody who knows something about this subject. I know his theory is really well and it is not making sense to me what he’s saying. Like, it seems wrong to me. And I am struggling with trying to get at what he’s getting at. So, let me go ahead and take us through this. So, recall from past episodes, we’ve been doing this, building this slowly over time where I’m talking through, we had an episode about words and concepts, episode 112 and probability.

[00:05:42]  Unknown: And

[00:05:42]  Red: is the issue here that I was really kind of asking was, is David Deutsch really just arguing over definitions, maybe? And at times, it really feels like that. It really feels like he’s just making the essentialist mistake, that he is arguing over the definition of how to use the word randomness. And he’s picking a weird definition and I keep saying, that’s a weird definition. Why are you picking? Look, I’ll even accept your definition for the sake of argument. I’ll actually explain this from the past thing. And then I talked about in a different episode, I think it was 129, about this weird conversation I had with David Deutsch on Twitter where he insisted that he was wrong in fabric of a reality to talk about something being probably incorrect. And I can’t even make sense of why he would say that, right? It’s wrong to say that. And he keeps saying, well, it’s because there’s no such thing as the characteristic of being probably incorrect or either correct or you’re not. It’s like, that’s not what people mean by that term. That’s not what you meant by that term when you wrote it. And so it’s a struggle to figure out what he’s trying to get at. So let me go ahead and… Well,

[00:06:52]  Blue: here’s what my bestie, ChatGbt, says about his central thesis.

[00:06:59]  Red: Okay.

[00:07:00]  Blue: Deutsch argues that probability is not a fundamental feature of reality. It’s a useful approximation or tool, not something physically real in the deepest laws of physics. What really exists are deterministic physical processes. The seeming role of probability in physics, especially in quantum mechanics, arises because of how we describe outcomes and make decisions, not because nature is fundamentally random. I mean, that makes sense to me. I think we would probably both agree with that, right?

[00:07:37]  Red: Okay, so let’s take that. Let’s assume that that is his position. Okay.

[00:07:43]  Blue: Okay.

[00:07:43]  Red: Why would he say that saying that a simulation of a roulette wheel, because it always lands in the exact same thing, why would saying that probably shows that it’s incorrect, that it’s an incorrect simulation? Why would that, given what you just read, be a wrong thing to say? It doesn’t even make sense. Even if I accept exactly what ChatGbt says, I cannot make sense of things he’s saying. Well,

[00:08:20]  Blue: he does. He is clear that probability can be useful.

[00:08:24]  Red: Yeah. So why not say this is one of those cases where probability is useful? We can talk in terms of probability. It’s an approximation. The fact that he declared it an incorrect, and he said, oh, I was wrong to say that, right? I’m glad to say that Brett Hall has this right, and I was wrong to say it. How can that even be right, since he accepts it as an approximation?

[00:08:47]  Blue: Well, to be fair, he is a quantum physicist looking at the deepest theories of reality. Okay. So

[00:08:56]  Red: I’m confused. I’m genuinely confused as to what he’s trying to say. Even when you give me a summary of his view, I’m still confused because he does things that don’t match that summary. This is

[00:09:11]  Blue: what ChatGbt says is the takeaway. It says, Deutsche’s lecture invites a radical rethinking of probability. Rather than treating it as a core ingredient of reality, as many standard scientific interpretations, he proposes treating it as a secondary, explanatory layer useful, but not truly real.

[00:09:33]  Red: All right. Let’s go through the actual thing. So just last time on Through Anything podcast, we talked about actual randomness versus pseudo randomness. Okay. So what we have here is a picture that was from episode 112 of actual randomness. And you can see it’s actually random. This is a picture of pseudo randomness. Notice that there is a pattern. Okay. So pseudo randomness, it doesn’t necessarily have a pattern, but there’s no way to guarantee it doesn’t have a pattern. Whereas with actual randomness, you’re guaranteed to not have a pattern. Okay. So my point here is that there’s a physical real life difference between actual randomness and pseudo randomness. And any theory of probability or randomness or stochasticity that we’re going to come up with must take into account that these two are physically different and that you must be able to talk about both of them. Okay. And one of the things I mentioned in 112 is that fans of David Deutsch, who listened to this video of his, this presentation, come away with this idea that there’s only one kind of randomness, pseudo randomness. And that’s not true. Okay. By the way, these pictures come from BoAllen.com. Random numbers. You can go look at what he says about this if you want. Now, what’s the difference between these two? This one is unpredictable in principle. There is no way to predict it, period. Okay. This one is unpredictable only in practice. So as we’ve discussed when like in our Wolfram episode, deterministic processes are unpredictable usually unless they’re periodic. Unless you run them once, find out what they do and then go back and run them again. Then they’re completely predictable the second time. Okay.

[00:11:25]  Red: That’s the difference between pseudo randomness on the right side and actual randomness on the left side. Okay. So there is no general pattern for test for a lack of pattern. So you’re using pseudo randomness at your own risk that someone can exploit the pattern if it has one. Okay. Because of this, Las Vegas goes to great lengths to make sure they’re using true actual randomness and not pseudo randomness in their high quality slot machines and things like that. Okay. What do we mean by true randomness? We keep, I keep saying actual randomness true randomness. So there’s this, this site random.org. It’s an API that allows you to avoid using pseudo randomness in your software applications so that you can be guaranteed to have no pattern. So I, I, if I want to accept Dwight’s view, I could accept it. I could accept it as just essentialism that we’re just arguing over how to use the word randomness that there’s nothing fundamental at stake, that the two kinds of randomness that I understand to exist, the actual verse, the true versus the pseudo randomness that those still exist even under Dwight’s theory, but that he’s creating a third kind of randomness. He’s saying, okay, what I’m calling true randomness, that is the kind of stochastic event that would exist if we didn’t live in a multiverse and it doesn’t exist. Okay. Then the second type of randomness would be what I was previously calling true randomness. We’re going to call this apparent randomness. Okay. The kind of stochastic event from the point of view of an observer in a universe that actually does exist. It’s now known to split the multiverse. And then the third kind would be what I was calling pseudo randomness.

[00:13:15]  Red: I’m going to still call it pseudo randomness. It’s an unpredictable process that is determined at the level of a universe. Whereas type two is only determined at the level of the multiverse. Deterministic is what I mean at the level of a universe as opposed to being deterministic at the level of the multiverse like type two. And that it mimics stochasticity, but it’s actually a determined process and it potentially has patterns. You can roll it back and try it again and you can predict it perfectly. It’s got negative things compared to type two randomness. Okay. Now, if you, if this is what Deutsch is saying, and I’m fairly certain at this point, this is what Deutsch is saying, that this is literally just an argument over terms, then this must be true. We can ignore the type that doesn’t exist and we go right back to the original two types of randomness that I knew about prior to hearing Deutsch’s theory, which is why I don’t think that this is at all useful. When you argue over terms, it’s never enlightening. Okay. Okay, but it’s still kind of interesting, right?

[00:14:18]  Blue: I mean, if we live in a world where probably most people who’ve never really considered this issue from this perspective do believe that true randomness exists, I mean, it’s still an interesting argument. So, okay, so

[00:14:32]  Red: you just said they believe true randomness exists. Do they? I mean, like if, if I had never considered this what, what Deutsch is calling true randomness at all, like it wasn’t even on my mind, right? And so he suddenly introduces it, proves it doesn’t exist, and then I go back to the two things that I thought existed. Nothing has changed for me, right? And I, I mean, yes, anything can be interesting. This is interesting in the sense that, that you, let me even go as far as I can, trying to defend Deutsch’s view here, steelman it to the max I can. Maybe we could argue that because I was aware there was a multiverse, I was aware that this type, so let me go back one slide, that this type two randomness, I was aware it split the multiverse, but maybe nobody else was aware of that. So maybe we could argue that Deutsch is introducing the type one to make the point that what everybody else, maybe everybody else in the universe thought type two was really type one. And because I knew I was already familiar with Deutsch’s theories, I was already aware there’s a multiverse. I just happened to be thinking of type two as type two, right? And I never even occurred to me to think of type one because it doesn’t exist, right? So you might argue that what Deutsch is doing is he’s making you aware that the type of randomness that you believe in doesn’t exist, and that actually it’s caused by a deterministic process that splits the multiverse. Now maybe that’s a good argument, okay? And maybe he’s right, but I doubt it.

[00:16:08]  Red: I mean, I seriously doubt most people have thought that far about what randomness is, right? So this idea that they were all carrying around in their minds that it wasn’t a multiverse, like I’m not even sure why that matters, because effectively it doesn’t matter if the randomness is due to a stochastic event in physics, a true stochastic event in physics of the type Deutsch says doesn’t exist, or if it’s because the multiverse splits from your point of view inside of a universe, those will behave exactly the same way. You could just as well say, you know what, there’s only two kinds of randomness, that’s what everybody already believes, and what we’ve done is we’ve discovered that type one here, now type one is my kind of true randomness, the type one randomness, the actual true randomness, that kind we now know splits the multiverse and that every single type of possibility happens across the multiverse, and it’s deterministic at the level of the multiverse, but it’s still random at the level of a universe. We could have said that way, that would have been way less confusing than the way Deutsch is going about this, okay? And in this sense, randomness is very real. In fact, it is absolutely a part of physics, it’s a part, we now have quantum theory explains why true randomness exists, and that pseudo randomness is physically different from it, explains it now, it’s because the multiverse is splitting, okay? I don’t understand why we didn’t take that approach, because that’s a way easier to understand explanation. So that or else I’m just misunderstanding, David Deutsch here, okay?

[00:17:45]  Red: Like maybe I’m just not getting what his point is, but to me, this seems like an argument of no importance at all, because it’s just an argument over how do we use a term? And of course that’s not important, right? Do you understand what I’m saying here, what I’m saying? We could have instead of creating a third kind of randomness and then saying it doesn’t exist, we could have said the kind that does exist, we now know something more about it than we did before, it’s actually deterministic at the level of the multiverse. And then we just, we never have to introduce this third type just to say it doesn’t exist. Do you understand what I’m arguing here, okay? And why that would have been easier for people to understand?

[00:18:28]  Blue: Yeah, I understand, I guess I’m still… Skeptical? I’m just a little skeptical, I guess, about whether or not you’re really disagreeing with him in a substantial way. Okay, so if it’s just

[00:18:45]  Red: an argument over terms, we are not disagreeing in a significant way, right? We’re only arguing over which term, which way to define randomness is easier to make sense of.

[00:18:56]  Blue: Okay.

[00:18:57]  Red: And that’s it. And part of me really thinks that’s all we’re arguing over, okay?

[00:19:02]  Blue: You seem to be saying maybe Doich is just making it too complicated. Yeah. And should just state his ideas about probability in a more simple way that doesn’t confuse all his followers.

[00:19:15]  Red: Right. It’s not like I’ve documented in Episode 112, his followers are completely confused as to what he, if this is, if I’m understanding him correctly, which I may not be, if this is what he’s actually saying, what you’re seeing on the screen right now, then his followers are profoundly confused. Okay, he has profoundly confused them because they think there’s only one type of randomness, the type two pseudo randomness. They don’t understand anymore that there’s actually two kinds, true randomness and pseudo randomness. Okay. And of course they’re confused. He’s claiming true randomness doesn’t exist. And he’s not making it clear that he’s making a new definition than declaring that as not existing. And that the other two types still exist. Now, to make matters worse, we might, you might argue to me, no, Bruce, Doich is literally saying there’s only one kind. You have misunderstood him. That’s not true. Right here in Fabric of Reality, he outrightly states, quantum systems do not have, okay. Here’s the whole quote. It is perhaps worth stressing the distinction between unpredictability and intractability. Unpredictability has nothing to do with available computational resources. Classical systems are unpredictable or would be if they existed because of their sensitivity to initial conditions. Quantum systems do not have that sensitivity, but are predictable, unpredictable because they behave differently in different universes and so appear random in most universes. That is precisely what I’m arguing. Okay. Like exactly that if you’re talking about a classical system, he says they don’t exist. They do. A computer is a classical system. Now you might argue, well, it’s actually under the hood, a quantum system still and you’d be right. Okay.

[00:21:02]  Red: Let’s not get too into the weeds as to what a classical system is versus a quantum system. I would agree that strictly speaking, there’s no such thing as a classical system, but there are things that are very much like a classical system. There’s a reason why we still teach classical physics to people. Okay. Quantum systems become classical at some level of emergence. So a computer is classical at the level of emergence of computation. So if you’re doing a pseudo random number generator, it is unpredictable because it’s intractable. You have to run it to find out what the result’s going to be. There’s no way to predict it in advance. Okay. Quantum systems, this is Deutsch saying this. This isn’t me making stuff up. He’s saying quantum systems do not have that sensitivity, but are unpredictable because they behave differently in different universes and so appear random in most universes. He’s saying appear random. I would have changed that too and therefore are random from the point of view of a single universe. So there’s no doubt that the fans of David Deutsch have thoroughly misunderstood his point of view because he is right here in fabric of reality stating that there are two kinds of unpredictability or in other words, two kinds of randomness. There’s true randomness, the kind that’s quantum that’s unpredictable in principle. And there’s pseudo randomness, which is unpredictable because it’s intractable. Okay. He’s saying that. We’re agreeing on this. Okay.

[00:22:39]  Blue: Okay. So someone like, well, not so different than me, who is a fan of David Deutsch, loves his stuff, does not have a rigorous background in science and math, but finds these ideas interesting. What would I, can you steel man that position? Like what would I say about Deutsch’s ideas on probability?

[00:23:13]  Red: Well, if I understood them, so let’s go through this. Let me be honest. I do have a slide where I’m going to say this, but I’m going to say it in advance. It’s humbling to have to, on a podcast like this, I disagree with David Deutsch all the time, right? I love his point of view. That’s why this podcast exists. He’s my favorite author of all times. He’s amazing. He’s got to be one of the smartest guys on the earth.

[00:23:47]  Blue: Oh, sure.

[00:23:48]  Red: Right. Maybe even the smartest guy on the earth. I don’t know. Like that would be hard to judge because smart doesn’t really exist on an IQ scale of, you know, one to 200 or something. Right?

[00:23:59]  Blue: Sure.

[00:24:00]  Red: But like, he’s way smarter than me.

[00:24:03]  Blue: But that’s kind of the beauty of his worldview in a way is that, you know, he probably would say that even, you know, fairly average people can have

[00:24:14]  Red: brilliant

[00:24:16]  Blue: ideas and, you know, that’s real. That’s how I, I mean, and really smart people can be really stupid, too. I mean, that’s pretty, pretty, that tracks for me.

[00:24:29]  Red: Yes. So I am basically making one of two claims at this point. I am either really not getting his point of view and none of his fans are either or he is wrong. I don’t see a middle ground. Okay. If he’s wrong, which, which could be, right? Then if I were to try to explain to you his view, I would have to explain to you what he is mistaken about to be able to explain his view. Okay. And I could do that on the assumption that he’s wrong, but like, I don’t know that he’s wrong. Like, I may just, like maybe none of us are getting what he’s really getting at. Like there could be some deeper meaning here that I’m just missing. And I’m not that, you know what? I’m not that bright a guy, right? If you were, I’d never taken an IQ test, but if I were to take one, I’ll bet you I would be like 120 slightly above average, but like nowhere near genius level. Okay. Like not even close. And we can talk about whether IQ even means anything or not, because I know a lot of fans of David Deutsch think it’s completely meaningless. And I’m like almost agree with them. Like after going through Taleb’s disproof of IQ, I basically buy Taleb’s view. Okay. But even Taleb admitted that it did measure something. Okay. So I’m using that roughly as something and you can decide for yourself if it’s meaningful or not. I know I’m just not on David Deutsch’s level. So for me to say David Deutsch is talking nonsense is a ridiculous thing for me to say, because I just, there’s no way I can be sure of that. Like, they just can’t be. Okay.

[00:26:11]  Red: But well, you’re trying to

[00:26:12]  Blue: understand and that’s what we do on this podcast.

[00:26:14]  Red: Right. Okay. And he may be talking nonsense. Like that’s not an unthinkable possibility. Okay. It may be that the reason I’m so confused by what he’s saying is because he’s talking nonsense that that absolutely could be. Like you shouldn’t rule that possibility out on the grounds that he’s smart. Okay. But there’s no way that I could tell you in good conscience, you should accept what I’m saying. I understand this better than him. Like there’s just no way that’s true either. So we’re going to do our best. Right. I’m going to take you through exactly what he says and I’m going to explain it as best I can and then I’m going to explain what I think is wrong with it. Okay. Maybe. But like let’s just have epistemic humility here. Okay. Like it is so hard for me to in good conscience say, oh, I know what David Deutsch is saying and here’s how it’s wrong. Like I just can’t say that with a straight face. Right. So we’re just going to do our best. All right. So I’m very confused. So my argument is what you’re calling true randomness David Deutsch isn’t really random isn’t really randomness because so I’m arguing that David Deutsch is arguing what you’re calling true and isn’t really randomness because it comes from a determined process just like pseudo randomness. Now I asked David Deutsch that on episode 100 when we interviewed him that is precisely what he told me. He said it’s not randomness because it comes from a determined process but he means determined at the level of the multiverse not at the level of a universe. Okay.

[00:27:45]  Red: So my response is I didn’t say this on the podcast because I didn’t even think of it at the time. Yes. But there’s a huge physical difference between coming from a determined process in a single universe which would be pseudo randomness versus a determined process from the multiverse which would be true randomness because it’s truly unpredictable because one splits the multiverse and one doesn’t and that’s why they are physically different. So you still need this separation between true randomness and pseudo randomness. Like it doesn’t disappear just because you pointed out that true randomness is determined at the level of the multiverse. You still need those both those concepts. That’s why you can’t predict true randomness by the way even if you run the same process multiple times because it will just split the the universe in different way. The universe will split in exactly the same way. You will perceive it differently each time. Okay. That’s why random processes can guarantee a lack of pattern and pseudo random ones which are determined at the level of the universe can’t guarantee that. Okay. So I simply don’t understand why we’re insisting on making up a whole new category of randomness only then to declare it not real when there really is a real kind of random process that actually does exist due to the splitting of the multiverse. So it seems to me that nothing is at stake here beyond general crit -wrap confusion that is because we’re debating physics. We’re not debating physics. We’re debating how to use the word randomness. This appears to me to be nothing but an argument over definitions or essentialism. Okay. And that’s why you said I don’t feel like Bruce you’re substantially disagreeing with Deutsch. You’re right. I’m not.

[00:29:29]  Red: Okay. I if the fans of David Deutsch could accept that there’s three kinds of randomness. The first kind doesn’t exist but still accept the other two. David Deutsch’s point of view would work just fine because it would still capture the the actual physical difference between true randomness let’s call it apparent randomness and pseudo randomness. Okay. As long as you if you can for me I just look at two concepts true randomness and pseudo randomness and those are the two that exist. So I can I can talk about almost anything that way. Right. If you want to accept David Deutsch’s view you need three concepts of randomness. You need to declare the first one non -existent and then you still need the other two and then you’re the same as me and then there really is nothing at stake. Okay. It’s just an argument over terms and I’m happy to accept your version. My experience back in episode 112 was that the crit rats who said they agreed with David Deutsch had no idea they still needed two kinds of randomness. They entirely thought everything was pseudo random. They were factually confused. Okay. And that’s exactly the problem is that if we’ve got this if there’s nothing at stake if this is really just an argument over definitions what we could what I could criticize David Deutsch’s point of view on is that he’s chosen to say it in a way that is absolutely confusing everybody and so he should stop doing that and he should say it in a way that’s less confusing which would be mine which is there’s two forms of randomness. We’ve learned something about true randomness. True randomness is actually not stochastic at the level of the multiverse.

[00:31:07]  Red: Say it that way no one will get confused because now you’ve still got them with the two kinds of randomness and they understand the difference between the difference between the two. Okay. So at the time that that was all from episode 112. Those was a review of the slides for episode 112. I said I’m going to take a look at his actual talk the Deutsch’s quantum slot machine. Okay. So let’s examine. So one thing I’ve got to say is I’m mostly this the slides you’re looking at I’m like literally reading them so this audio versus video almost doesn’t matter. The reason why we’re doing it as a video is because there’s a bunch of equations and I can’t really read the equations very well. So I’m trying to make it so that if you’re listening it in audio just get the gist of what I’m saying and you’ll be fine. If you want to check my work you need to look at the video version and I hope people will check my work like maybe I’m wrong like maybe I’m as I put my equations out there maybe people will say oh you’ve misunderstood this I’ll go oh thank you for explaining this to me like I would really like to see what it is I’m getting wrong. So let’s examine Deutsch’s physics without probability to address my concerns. I’m trying to understand his argument but I’m I’m struggling like it’s a huge struggle I can’t make sense of his arguments either I’m misreading something or there’s a flaw in his reasoning. We should remain open to both possibilities. Okay. So Deutsch at the beginning of the talk says ordinary unitary non -collapse quantum theory i.e.

[00:32:33]  Red: many worlds provides a large part in large part of way out of the whole probability scandal. It’s called decision theoretic approach. So he’s going to go over the decision theoretic approach in this presentation which is what I’m going to cover.

[00:32:48]  Unknown: Okay.

[00:32:48]  Red: But just some for some background Deutsch claims there is no need for probability in constructor theory because things either are possible or not. So the first principle of constructor theory this is from the presentation his slides. All other laws of physics are expressible entirely in terms of statements about which physical transformation it is possible to bring about reliably in which are impossible and why. Okay. So the motivation for why he’s trying to do a way with probability theory is that it’s not consistent with constructor theory. Okay. But he says I’m not actually going to explain this in terms of constructor theory. I’m going to explain it without constructor theory. Okay. But he does have this he’s expressing this motivation that constructor theory is either possible or it’s not. There’s no probabilities in constructor theory. Therefore he’s trying to argue that we don’t need probability. Now I do have to say something about this. I agree constructor theory is about possible or impossible and I agree that constructor theory has no need for probability theory for that reason. I would say that probability is emergent and there’s nothing wrong with that. Like emergent explanations do not have second class status compared to what we would call quote fundamental explanations which is a term that is misleading because it makes them sound like their first class citizens and the emergent ones are second class citizens. Now this is an argument that Deutsche makes in fabric of reality. So I know Deutsche agrees with me on this. Okay. But if probability theory is emergent that doesn’t make it a second class citizen. It’s still physically real. Okay. It’s in this case due to the splitting of the multiverse. Okay.

[00:34:33]  Red: But it’s an emergent property that happens at the level of universes because of the splitting of the multiverse. That wouldn’t… Well in a way

[00:34:41]  Blue: it’s just like any other law of physics. Right. I mean pretty much all most laws of physics are radically different when we consider them from the perspective of the multiverse. Yes. Yes. Yes. Yeah.

[00:34:56]  Red: You could argue that all classical physics is emergent.

[00:34:59]  Unknown: Right.

[00:34:59]  Red: Yeah. Like all of Newton’s classical physics they’re all emergent. Okay. Probability is emergent in the same sense that Newton’s theories or Einstein’s theories are emergent. I don’t know about Einstein’s theories but Newton’s theories are emergent.

[00:35:12]  Unknown: Okay.

[00:35:13]  Red: So because of that you have to understand that it’s entirely one option that Deutsche never considers is that probability theory could be real but emergent. Okay. That it’s not a second class citizen that is it is a fundamental the wrong term in this case. It’s emergent part of physics but still very much a real part of physics and that constructor theory is simply looking at it from a different perspective and therefore doesn’t need it because it’s looking at the level of the multiverse what happens and doesn’t happen.

[00:35:46]  Unknown: Okay.

[00:35:46]  Red: But

[00:35:47]  Blue: you don’t think do you think he would substantially disagree with that or is he just kind of like… I have no idea. More like a question of emphasis.

[00:35:55]  Red: Well okay yes he would disagree with that. Okay. I’m about to actually do on the next slide I’m going to show where he disagrees with it. Okay. Okay. So he says however Deutsche concedes there might be a place for using probability theory as an approximation of reality. He likens this to treating the earth as flat. So for many purposes we can treat the earth as flat without any problems. This is where I start to disagree. Okay. So it could be that constructor theory has no need for probability but that other laws of physics do. Like if you’re trying to actually figure out what you’re going to see happen when you do the double split experiment since you exist inside the universe you may have a very real need for probability and probability may be the only really great way to only way to express it. Okay. And it may be exact. It may be that it’s not like a flat earth that it’s exactly describing proportions of the universe. Okay. Or it could be that it’s approximate like David Deutsche is saying and it’s like the flat earth it works in some cases but you don’t need it in all cases. What I’m trying to say is the motivation of constructor theory doesn’t differentiate between those two cases. It could be it’s exact but emergent or it could be that it’s approximate like the flat earth. Deutsche is arguing it’s approximate like the flat earth. He’s explicitly using the flat earth and I don’t think it’s an accident he uses the flat earth.

[00:37:22]  Red: He points out that like if you’re just like building something on the earth thinking of the earth as flat is perfectly acceptable because it is for the local problem you’re trying to solve. Okay. But he says it’s going to come back and bite you if you try to like think of the flat earth and you’re instead thinking about you know planets orbiting the sun or something like that. Flat earth is going to come back to bite you. Okay. If probability is emergent but real it will never come back and bite to bite you because it’s an exactly correct explanation of reality. Okay. It’s not like the flat earth. He’s claiming it’s like the flat earth so he’s making a stronger claim than it’s merely emergent. Do you see what I’m saying here? He’s saying that it will be wrong in some cases. By the way if we’re talking pseudo randomness I would agree. If we’re talking specifically pseudo randomness pseudo randomness is and everybody knows this kind of like the flat earth. Okay. Where it’s it never quite fits. It fits well enough but it will actually affect I just I just read E.T. Jane’s book the father of modern Bayesianism. He explicitly makes that argument. Okay. So he completely agrees that he doesn’t use the flat earth analogy but he completely agrees that the concept of random is emergent and approximate and in fact the reason why he’s arguing that is because he’s trying to argue that instead it’s degrees of belief for its credences. Okay. So it’s not something that’s physically real. So Bayesians have a strong reason to want to agree with Deutsch on this. Okay.

[00:39:02]  Red: I’m arguing that they’re both wrong that that quantum processes that when you observe them that they exactly fit probability theory and that there really is a random process that is exactly random just like the theoretical concept. And it’s it’s only quantum processes and it’s only from the level the point of view of the of a single universe. But that’s that’s all of us. We all live in the universes. So for us random processes exist and they’re not approximate. But pseudo random processes are approximate. We use random probability theory to deal with them. But we know but in E.T. Jane’s points out that famous statisticians not realizing that it’s only approximate will actually draw completely false conclusions and he gives examples of this. Okay. So I would agree that if we’re talking about a determined process then yes it is kind of like the Flat Earth. But if we’re talking about a quantum process I don’t see that it is. Okay. So no Deutsch claims probability theory was only invented by people that wanted to win at games of chance. So he cites Cardano 1501 to 1576. So thus Deutsch sees games of chance as sort of an idealized example of where probability where probability theory makes sense to use. With other examples let’s say the probability for probability for using probability for say life insurance being a sort of a less pure example compared to games. Deutsch also argues that those of this early era all believed in determinism. So they only intended their probability theory as a purely mathematical model not as something relevant to physics. Oh that’s true. By the way would agree with all that. So then he gives a list further applications of theory of probability.

[00:40:51]  Red: So he has I won’t read the whole list. It’s on the screen. The ones that are for our purpose is going to be important is first of all actuarial science. I’m going to come back to that one life insurance as an example of where you really need probability theory even though it is just an approximation. Okay but there’s not like there’s some alternative you could have used. Okay and then he really seems to be going after Bayesian philosophy. So he makes various claims about Bayesian Bayesian philosophy. He’s going about all this trying to prove randomness doesn’t exist because he believes that means he can disprove Bayesian philosophy. Now famously Bayesian epistemology and critical rationalism see them see each other as as in a war to the death over who’s got the true epistemology. So it makes sense that a critical rationalist would try to take down Bayesianism and a huge part of the motivation that Deutsch seems to have is that if he can show randomness doesn’t physically exist then he can show that Bayesianism is wrong. Okay Now here’s the thing I just mentioned this but let’s let’s go over it again. E.T. Janes who’s the father of modern Bayesianism from his book probability theory the logic of science I read just finished reading the basic section I’m not sure I’m going to read the advanced section it basic session was hard enough for me. Great book awesome book I understand Bayesian reasoning and Bayesian epistemology way better now that I did before I might understand it better than most Bayseans at this point because I’ve started to notice that a lot of Bayseans make a lot of mistakes that E.T. Janes calls out and explains why they’re wrong.

[00:42:37]  Red: Okay so I might understand Bayesianism better than most Bayseans at this point or maybe not I don’t know depends on the individual he was a physicist Janes was a physicist okay so he’s a physicist but he did statistical mechanics so he developed the Bayesian philosophy he didn’t himself develop it he did develop it himself he but he was building off of people who came before him that he thought were right like Cox we’re gonna talk about Cox’s theorem and he realized that this was saying something about probability theory that most statisticians were completely missing so he developed this Bayesian philosophy that he thought was the correct way to understand probability as a kind of form of logic that allowed for part that allowed for degrees of belief okay so he he Janes argued that randomness does not physically exist in nature and is therefore only in our knowledge and our ignorance so for Janes randomness reflects degrees of belief not a physical process so he attempts to prove there is no real randomness in nature because if he can show there’s no real randomness in nature that forces acceptance of in his opinion Bayesian philosophy now it’s interesting that Deutsch also argues that randomness isn’t physically real but he mistakenly believes that Bayseans root their philosophy in the existence of quote real randomness but that would actually be the frequentists that Deutsch would be disproving not the Bayseans okay so it’s interesting that Deutsch um it’s interesting that Deutsch claims Bayesianism is wrong because randomness does not exist while Janes claims Bayesian Bayesianism is right for exactly the same reason it I this one seems almost unavoidable to me Deutsch seems to misunderstand Bayesian philosophy because he’s making an argument that doesn’t make sense to a Bayesian I’ll have to ask Ivan the Bayesian to confirm that for me but it looks to me like Deutsch is making arguments that he really could probably benefit from reading ET Janes book and understanding the original Bayesian philosophy better now let me just say I’m not necessarily arguing that Bayesian philosophy is right that like there’s this is a deep deeply debated hotly debated topic even today and Deborah Mayo like after reading ET Janes book if I hadn’t read Deborah Mayo’s book first I probably would have said oh Janes’ arguments are so good they must be correct but I had already read Mayo’s book so I already knew there were some problems so it didn’t convert me to the Bayesian philosophy entirely but reading the book did make me realize just how smart the Bayesian philosophy actually is and they really are even if imperfectly they’re really starting to grasp something that I think critical rationalists would benefit a lot from even though we’re probably going to have to modify it and error correct it in some ways okay um so I highly recommend crit rats go read ET Janes book like like they need to read it they need to take all their misunderstandings of Bayesianism they need to get rid of those misunderstandings and they need to start to understand it correctly and they need to be able to criticize the actual theory not the

[00:46:05]  Red: strawman version that they’ve been criticizing okay so uh a Bayesian would actually welcome Deutsch’s argument here because it would put down the frequentist philosophy and leave theirs in their mind as the sole survivor okay now personally to me it seems like both sides are mistaken because quantum randomness appears to be physically real for the reasons I just demonstrated earlier so I actually think Janes is wrong about this Janes has a whole section on quantum probability where he tries to prove that quantum probability doesn’t prove him wrong and I’ll have to cover it on a separate podcast because he’s he’s clearly mistaken because he doesn’t know about the multiverse okay and so he he tries to prove that quantum randomness isn’t really randomness either but because he doesn’t know about the multiverse he he makes an argument that’s clearly mistaken okay and that quantum randomness actually is real randomness the kind that he thought didn’t exist okay um now Deutsch is going to use explain this decision theoretic approach using this idea of a slot machine so you’ve got the slot machine it has these eigen states um they’re at the top you have the result when you pull the thing and you get the payout okay so here’s my this part um this part of the the talk is obviously the part that you said was probably gobbledygook to you and it is kind of gobbledygooky unless you really understand quantum physics which I I have some familiarity quantum physics I I learned quantum computation instead of quantum physics and it’s kind of different quantum computation is isomorphic to quantum physics but their whole language and their whole approach is is drastically different because they’re trying to teach it to a computer scientist instead of to a physicist um so like when I did our podcast and we talked about with sam kipers uh c numbers like I had never even heard of them before even though they’re basic to quantum physics because the way you would do it as a computer scientist doing quantum computation you would just put it into a matrix it would give you the same result and you would just use regular numbers but like it’s a totally different way of viewing it right it’s been simplified down for a stupid quantum sorry computer scientists but it gives you the same results in the end okay so I I I had to like go look up everything doigt was saying to try to make sense of it and maybe I’m getting him wrong like like maybe I’m really misunderstanding him but I’m going to take his example I’m going to translate it into a simpler example that I think is equivalent and I’m going to try to explain it using that simpler example so that it isn’t gobbledygook to you okay but keep in mind I’m uh I’m a layman I might be misunderstanding him I don’t think I am but I might be misunderstanding him and I’m if so then this presentation will be available people can look it up they can check my numbers they can show me where I’ve misunderstood they can help me understand what doigt was actually saying okay

[00:49:06]  Red: so come on our podcast to argue with us it’s not it’s it’s not that hard low barrier for entry here yes okay

[00:49:16]  Red: so let me read what David Deutch actually says word for word and then I’m going to give a translation okay we imagine an array this is David Deutch we imagine an array of gaming machines you play by inserting one casino token the machine prepares a quantum system measures an observable x displays the results always an eigenvalue of x and then the machine delivers a payoff of the number of casino tokens different machines are identical except for the state psi written down written on the front as a superposition of eigenstates of x for machines whose psi is a single single eigenvalue playing is not a game of chance it’s just putting in one token and receiving back x tokens a classical machine a rational player will be willing to play when x is greater than one price one being the price of to play and unwilling when x is less than one okay that probably sounded like gobbledygook to you right like like when I first heard this I couldn’t even make sense of what he was saying okay so here’s an english translation using my example I’m going to use an example of a quantum die so you’re just rolling a die it gives you one to six instead of a slot machine because it’s easier to comprehend than a slot machine it’s more straightforward but I’m going to translate it so it’s exactly the same thing he’s saying or at least I think it’s exactly the same thing he’s saying but into this quantum die instead so that it’s easier to make sense of so plain english imagine a rigged quantum six -sided die that always lands on four you’re required to bet three tokens my version is going to be three tokens instead of one to play should you play yes you should always play because you will always come ahead out ahead by one you rolled the four it’s always rolls of four so you get four you pay three tokens you get four tokens back suppose instead the die was rigged to always be two now you would not want to play because you will always lose one token okay I’m

[00:51:12]  Blue: just hung up can you can you elaborate a little bit on what a rigged quantum die is okay

[00:51:17]  Red: so just think of it as a regular die

[00:51:19]  Blue: yeah

[00:51:20]  Red: it’s gonna as we’re gonna see it’s gonna need it’s going to in this example it doesn’t need super positions but

[00:51:27]  Blue: okay

[00:51:28]  Red: but in this example in future examples it will so just for now just think of it as a regular die and it’s rigged to always land on four and you pay three tokens to play

[00:51:39]  Blue: meaning it’s just like a regular rigged

[00:51:43]  Red: die that’s right okay so you bet three tokens it’s always going to land on four should you play okay okay so yes now let’s say yeah let’s say it’s rigged to always land on two should you play no you’ll lose a token every single time okay so far that’s all he’s saying very straightforward nothing to disagree with okay so now going back to dutch what about cases when psi is not an eigenstate call the dividing line v psi the maximum amount a player would be willing to play for a classical machine v psi is just the eigenvalue if the state is a superposition all of whose eigenvalues are greater than one it’s worth playing similarly with all eigenvalues less than one it’s not worth playing okay plain english

[00:52:33]  Red: again just treat it like it’s a regular die okay suppose you had a die that only had four fives and sixes on the face okay and again you’re going to bet three tokens would you be willing would it be worth playing so obviously yes it’s random it’s not it’s not determined anymore there is a random element but it’s always going to be four five or six so you’re always going to come out ahead so obviously you would want to play now let’s say that instead the die had only one twos and threes on it so it’s going to be random but it will always be one two or three would you would you want to play obviously not because you’re always going to lose money now note that even though there are superpositions the decision to play itself is non -random so there’s a random outcome but the random outcome doesn’t tell you anything about whether you should play or not collectively it does but it’s since it’s always either less than the amount you paid or more than the amount you’re paid in the two examples i’m using the decision is non -random all right now the hard case so those were easy cases all right so he’s setting up for the hard case but what if size a superposition of two states one below one below one and one above one collapse quantum theory tells us that probabilities are those coefficients squared and irrational players should value as if it were guaranteed to produce that expectation value in general axioms of stochastic theories are not explanatory now without collapse take in equal amplitude superposition eigenvalues x1 and x2 we aim to prove that v psi will be the average of x1 and x2 the devil is in the detail but elementary rationality gives two implications v psi does not depend on the exchange value of tokens and if two machines are used superpositions where each eigenvalue differs by a constant k the valuations also differ by k it follows that for the equal amplitude state v is the expectation value we can prove the same for a general state and that that’s qed so that was his whole argument and again that was probably gobbledygook to you right yes okay so let’s let’s let’s walk through what he just said using my quantum die example and it’s actually not too hard okay so plain english our quantum die now has all six values now you might wonder here since i keep treating it like it’s just a regular die why do i keep saying it’s a quantum die well

[00:54:58]  Red: here’s the thing i want it to be a quantum die because i i i don’t want to be talking about pseudo randomness i want to be talking about the true kind of randomness okay it’s the kind that splits the multiverse so we’re rolling this die and it splits the multiverse into six different branches of equal amplitude okay where you get a one you get a two a three a four a five a six etc okay but from the point of view and this is the point i keep trying to make from the point of view of an observer in a universe this is exactly equal to rolling a six -sided die you will get when you observe it you will get one of six outcomes and they will be equal chances of each one okay so we’re assuming equal amplitudes so this is a fair die should you on this die should you bet three tokens to play now let me actually this is just simple math don’t worry about the quantum aspects if you roll a six -sided die it’s a fair die and you bet three tokens and you win the number of tokens that is on the face of the die once you roll it should you play it’s one plus two plus three plus four plus five plus six divided by six which is three point five so the expectation value of a die is three point five

[00:56:11]  Blue: oh okay okay okay okay

[00:56:13]  Red: all right so calculate the expected value each side is one in six probabilities of showing so here’s the here’s the thing probability of one sixth probability one six this is what you just said probability one six for each of the faces so the probability of one one six the probability of two one six etc so the expectation value would be one six times one plus two plus three plus four plus five plus six which is 21 divided by six which is three point five that’s the that’s the right answer the expected value of a die is three point five now one thing to pay attention to here is that an expected value is not any of the possibilities so you can only get a one or two or three or four or five or six you can’t get a three point five despite that fact the expected value is three point five so if you’re gonna bet three tokens should you play is it rational to play there’s an obvious answer here and yet I would understand if you were hesitant to give it because there’s a good reason why people would be hesitant to give the right answer

[00:57:13]  Blue: just give me the right answer

[00:57:15]  Red: all right the expected value is three point five so on average you’re gonna win point five every single time you play

[00:57:23]  Blue: okay okay

[00:57:23]  Red: so it is rational to play this is how probability theory works this is what probability okay tells you now in real life we all know you might lose and that’s why people are sometimes hesitant to give the right answer because they think well I know on average I’m going to win but like I might still lose all my money right is it worth it to me to risk losing all my money when I only have a point five an expected value of point five and it’s well known that psychologically humans uh don’t treat winnings and losses the same we see a loss is more significant than a win you have to win quite a bit more to make up for a loss so yes I’ve noticed that in my life I mean

[00:58:06]  Blue: someone someone you win a thousand dollars it’s like well that’s great but you lose it it’s yeah it’s psychologically it’s much worse yes

[00:58:14]  Red: so many people would not play and they would not do the quote rational thing now you have to understand when we talk about rational decisions we’re talking about we’re not trying to talk about human psychology we’re trying to talk about um kind of the mathematics right that we’re just so we would say rationally you should play and we don’t really mean rationally you should play based on your psychology we really just mean the mathematics show that you will on average come out ahead okay yeah that makes sense

[00:58:48]  Blue: oh yeah

[00:58:48]  Red: okay so yes make the bet you’re expected to come out ahead okay but what we just did uses probability so what doige is saying is can we avoid using probability and come to the same answer okay so that we can do away with probability theory so doige argues we don’t need to need no stinking probability theory so he argues that the whole appeal to probability does not explain the expectation value rule he suggests that we instead we don’t even bother with the born rule okay we haven’t explained the born rule I’ll explain in just a second but the born rule is what converts the deterministic schrodinger equation into probabilities okay he just he just explained it but it was gobbledygook like he did actually explain it correctly but I will give you a simpler explanation so here is the setup of

[00:59:43]  Red: how doige this is the setup for what doige wants to do so the eigenvalues are the face payoffs so the eigenvalue what he’s calling eigenvalues they would be the faces of the quantum die one two three four five six they’re equal amplitude state so that would mean that the amplitudes for each of the eigenvalues is one over the square root of six okay which is a weird number but that’s the correct number because then they all have the this would be the normalized version they’ve now been normalized so they’ll all um when we when we do the born rule they all come out to a sum of one so recall the born rule is that you square everything so what you’re doing is is you’re saying it’s one over the square root of six you square it that’s going to turn into one sixth that will that will be one six per eigenvalue per face of the die okay so let v psi denote the value of the single play of the machine in state psi uh the maximum rational player um would pay to play we want to show that v psi is equal to one plus two plus three plus four plus five plus six divided by six which would be 3.5 how would we do this without an appeal to probability theory so the born rule this is from dutch’s slides he says if an observable x hat is measured the state vector psi of a quantum or actually i don’t know how to pronounce that one uh of a quantum system collapses to some x an eigenvalue x eigenstate with x hat with probability and then he’s got x by that quantum state squared for our purposes what we’re saying is is that you take the the amplitudes and you square them okay now that is what he’s saying on this complicated slide and i want to note that that that we’re assuming that the amplitudes are already normalized if they aren’t the born rule would would not be merely squaring them you would square them and then you would take the sum and you would normalize to a sum of one okay um

[01:01:49]  Red: so dutch’s slide here is assuming it’s normalized it doesn’t say that but apparently that is the norm is that you always normalize them so his his slide is accurate under the assumption that you’re following kind of normal quantum physics approaches where you would normalize the amplitudes okay now this idea that the born rule you square it and then you take the sum and then you you um normalize to some to one that may sound really familiar to someone if you’re familiar with probability theory and that’s not an accident okay it um if this looks like normalizing probabilities that’s not a coincidence that’s exactly what you’re doing with the born rule you are translating into probabilities okay by coming up with the amplitudes and summing to one

[01:02:36]  Red: so here is the standard born rule approach that uses probability calculus first okay so we’ve got the equal amplitude quantum die we’ve got um the uh quantum state here is one over the square root of six for each of the different eigenvalues so one two three four five six just the faces of the die basically we square each amplitude so now we got probability of one sixth per face of the die because it’s a fair die and then we take the expected values one six times one one six times two etc and it comes out to be three point five which is the correct expected value okay this uses probability theory though so deutch says in essence he’s arguing you could skip the born rule and just do this so here’s the deutch calculation without the born rule he takes the the vector states and he just says okay i’m going to just take each of the vector states there’s six of them i’m going to divide by six and that comes out to be three point five which is the expected value and i’m done okay and that’s true you have now skipped the conversion you didn’t use the born rule you did not um have to translate into the probability calculus and yet you still came up with the correct expected value so now he does add a few things that i feel like for completeness i need to mention although they don’t really impact anything that we’re discussing but let me go through them quickly he says the result is permutation invariant so for example one two three four five six we’ll get the same result as two three four five six one okay well that’s obvious it doesn’t matter like when you’re rolling a die which which numbers you have on which faces doesn’t matter as long as it’s the same numbers okay it’s also shift invariant let’s say that instead you had two three four five six seven on the die now obviously that does change the expected value okay but what it does i won’t i won’t read through all the numbers here because it’s unnecessary but it’s there for completeness if you want to see the video version of this podcast basically if your die says two three four five six seven that does change your expected value but it does so buy a value of k it’s a constant um so it would still be an expected value of three point five plus whatever that k is okay which in this case i think is one so it won’t actually change anything it does change the effective value but whether it’s rational the player or not will not change

[01:05:09]  Red: so um he makes a point of pointing this out so the main point seems to be that we never need the born rule to calculate the expected value therefore we need not appeal to probabilities therefore probability is unnecessary because we can make rational decisions without it qed that’s it he even said qed at the end okay i think this is his argument okay i think he’s he’s saying that all that gobbledygook quantum stuff basically says that you when you know the quantum states you never need to actually translate the probability theory and yet you can still calculate the expected value therefore you don’t need probability theory and probability theory is therefore unnecessary and therefore he has so he’s claiming proven that probability theory is unnecessary and doesn’t exist and it doesn’t really matter it’s just an approximation you don’t need it okay but does that argument make at least some sort of sense and have i properly still mend it for you it’s

[01:06:14]  Blue: interesting and it’s kind of inspiring me to want to learn more say that okay

[01:06:24]  Red: let me say that i actually don’t disagree with the specifics of what he said he was able to get to the expected value without using without using the born rule and therefore not having to calculate translate to the probability calculus if that’s what he’s saying and that is what he seems to be saying to me at least that’s all true now i did play with this a little like he’s he’s using equal amplitudes which makes it really easy to calculate the the expected value without translating to the board using the born rule to translate the probability calculus could you so i started playing with this could you do it if the amplitudes weren’t equal well you could it was it was kind of nasty like what you had to do to make it work but like there was always a way to make it work mathematically speaking even though it wasn’t it wasn’t the nice clear cut case that he’s showing in his presentation so i’m i’m even going to accept with a caveat that it’s kind of nasty that you you probably never need the born rule and you probably never need to translate to the probability calculus to be able to calculate the expected value therefore strictly speaking if when you say there’s no need to appeal to probabilities if you mean there’s no need to translate to the probability calculus then i his argument is correct okay that last that last caveat though is where i’m going to now make it take an issue so the slot machine example or my quantum die example uses a game of chance which doge says is a problem is probabilities original purpose since he can show with a game of chance that we don’t need probability doge is in essence i think arguing that for a crazier example like life insurance clearly his argument must work for that because it’s it’s an even crazier example less appropriate example of use of probability theory than a game of chance okay so yes we can make rational decisions for a game of chance without probability yet we can make a rational choice for a game of chance without probability theory so the argument goes probability must be unnecessary for anything on that list because everything else is even more approximate than a game of chance

[01:08:50]  Red: so do you buy this argument okay like i really want people to think about this for a second there’s a weirdness to this argument do you buy it does it make sense to you okay let me kind of go through my thoughts on this so side note as a quick side note i want to emphasize this again i already said this but i made this episode a

[01:09:09]  Red: video so i could show my work i’m an amateur in quantum physics i have a master’s in machine learning with some exposure to probability theory but i i’m an amateur with probability theory it’s possible i misunderstood doge or unintentionally misrepresented his argument if so i genuinely want to know where i misunderstood him that’s only possible if i show my reasoning step by hence the video format so that there’s just no doubt as to what i thought he said okay even if people disagree with me i hope they can see that i am making a really serious effort to understand him okay um far more effort than i think any of the crit rats i’ve talked to who have tried to explain it to me have put in okay if i’m i’m a fairly informed lay lay person yet i am really struggling to grasp doge’s point in fact my background keeps suggesting to me that something is off with his argument but doge is an actual true qm expert and his grasp of probability is like even though he’s not an expert in that it’s likely better than mine so it wouldn’t surprise me if i’m misunderstanding him nor would it surprise me if he made a mistake somewhere right we’ve talked about all sorts of mistakes david doge has made on this podcast so he makes mistakes he’s human he makes mistakes that’s just the way it is it could be either okay

[01:10:30]  Red: furthermore at some level i feel like i there’s a certain level of emergence at which i agree with what david doge is saying here so let me try to state what that is okay so here’s my pro david doge argument first let’s read doge as charitably as we can hear his specialized definition of randomness is effectively this the kind of stochastic event he’s defining randomness as the kind of stochastic event that would exist if we lived in a single universe rather than a multiverse so it’s quantum physics is exactly the way it is today but quantum events all collapse and all the other realities disappear only one universe remains that would be what he’s calling randomness nothing else changes quantum theory is still the same this would be the collapsed version of quantum theory this would be the kopenhagen version we’re saying if kopenhagen were true and there were no multiverse that is how he’s defining randomness okay

[01:11:29]  Blue: so it seems like his stuff works if he if if you interpret him as making an argument about physics rather than an argument about probability yes and

[01:11:44]  Red: that’s what i mean would you say

[01:11:45]  Blue: that’s true and that’s kind i mean it is to be fair it is called physics without probability that’s right it’s doesn’t say probability without physics or something i don’t know it’s yes

[01:11:56]  Red: okay so under that narrow definition i agree with most of what he says okay if i can wrap my mind around the fact that he’s being an essentialist that he’s actually arguing over a definition it seems to me that what he’s saying is mostly correct there’s a few things i still think are wrong but like it’s mostly correct so physics does not need this kind of randomness why because we actually live in a multiverse not a kopenhagen universe okay and his critique of quantum his critique of quantum physicists who reject many worlds when seen in this light is fair because we do live in a multiverse not a kopenhagen universe if this is what he’s saying like there’s nothing to disagree with yes this is exactly correct in that specialized definition of randomness that only applies only allows you to call it randomness if you live in a kopenhagen universe rather than a multiverse he’s right that that kind of randomness we’ve got no no use for so if all dutch means is that we shouldn’t expect built in stochastic events in a single universe physics without a multiverse then i agree he’s right okay the talk is literally you just pointed this out the talk is literally called physics without probability he’s shown we do not need probability as he has chosen to define it thus qed he’s right okay nothing to for me to disagree with him over if i accept his definition of randomness okay now what’s the problems that i’ve got with this presentation so

[01:13:33]  Red: as early episode one as episode 112 i documented the confusion among dutch fans about what he’s actually saying they apparently don’t see his point as merely a call to discard a narrow definition of randomness in physics which is as we just steal manned if i read him that way i agree with him but then you have to understand him as not making a substantial argument about probability but simply saying we shouldn’t call it randomness it’s just a debate over terminology that is clearly not what people are coming away from this presentation thinking he said okay instead they take it as a sweeping claim that all randomness in nature is fundamentally pseudo randomness this is a false claim as discussed in episode 112 and discussed in this episode we just repeated most of those arguments it is it’s just a factually false claim it is wrong it is wrong it is wrong okay easily refuted um i just showed you that physically real randomness from quantum events and pseudo randomness look different feel different act different they are physically different okay so the the meaning people are taking from this presentation is for sure false whether it was deutch’s intended meaning or not is a different question by episode 112 which is is probability real fans were making even broader claims based on this presentation they were denying probability for asteroid impacts that that there was such a thing as the probability that an asteroid would destroy the earth or there was no such things the probability that agi would wipe out humans both of which have perfectly good probabilistic interpretations okay is

[01:15:21]  Red: this just another case of fans jumping to wildly inappropriate conclusions that that weren’t intended by deutch now we know the fans of david deutch do this they they take what he says and they just leap to wild conclusions sometimes and then they claim that it came from him and this is a problem is that it’s often very difficult to differentiate between what david deutch actually said and meant and what his fans thought he said and meant in fact there are all sorts of problems like that however unfortunately deutch himself makes similar overreaching claims so in episode 129 deutch i covered how deutch denied that probabilistic falsification that was the term or um and renown it was actually probably incorrect was the term he used and he renounced a paragraph in his book fabric of reality for saying probably in inaccurate it was probably inaccurate with what he said he said that was wrong for me to say that

[01:16:19]  Red: deutch does allow that probability theory exists as an approximation so why does he object to use of the phrase probably inaccurate deutch thinks seems to think that probably inaccurate as a phrase implies a physical probability property like a roulette wheel having a physical attribute of being being probably inaccurate rather than referencing what we know about a theory about a wheel okay surely that’s not what anyone normally means when they say probably inaccurate the idea that when somebody says oh that’s probably inaccurate they’re claiming that that that phenomena is probably that theory is probably incorrect versus being either correct or not correct like there’s just no way people mean that like there’s no way people mean that and there’s no way deutch even meant that when he wrote that in his book back then okay so it seems to me that deutch also not just his fans is making far -reaching claims based on what he’s discussing here that just just don’t seem to work in real life and and just don’t even ring true to me okay so why am i emphasizing this try to avoid the mon the montan bailey fallacy here some are going to say deutch just means we don’t need randomness in the schrodinger equation you don’t disagree with that do you no i don’t the schrodinger equation famously is entirely deterministic there is no randomness in it okay but his claims and those of his followers go far beyond that and they always point to this talk as proof they’ll make these claims there’s no such thing as the probability of an asteroid hitting the earth there’s no such thing as the probability of you know they make these far -reaching claims there’s no such thing as a theory being probably inaccurate okay and you go i don’t get that that doesn’t make sense like let’s talk about this and they’ll say oh just go look at this this this video from david doye she explains it and those far -reaching claims are not justified by anything he says in this video so it this does feel to me like he’s making a point that is valid but then we’re just jumping off the deep end into other things that just do not follow from what’s said in this video

[01:18:40]  Red: okay so let’s uh let me give a deeper example here okay so let’s go back to the calculation there’s a deeper problem i want to call out so we have deutch’s calculation where we had the one over square root of six per eigenvalue per face of the die and then he calculates by taking each of the eigenvalues dividing by the number of them and he gets the expected value at the end now suppose a sincere so he skips the probability theory and he just he just does this calculation he says oh i look at this quantum state and i can see that all i need to do is take each of them divide by six and i can go to 3.5 oh you should play this game and you and suppose a sincere questioner were to to look at that and go look i don’t understand what you just did like what is it that you just did why does this work why should i use this decision theoretic approach instead of probability theory and so they might ask a rather reasonable question something like this okay so here’s our sincere questioner on the other side on the left side on the right side we’ve got our our person trying to explain deutch’s theory okay so some sincere questioner okay but why should i care about this decision theoretic calculation and the the deutch defender says because there aren’t enough universes in which you win to make it worth the cost and this questioner says well why does that matter because there won’t be enough versions of you that come out ahead i still don’t see why that matters

[01:20:20]  Red: well the odds of coming out ahead are too low wait strike that i’m not supposed to say odds

[01:20:27]  Blue: so you mean the probability

[01:20:28]  Red: of winning is too small yes i mean no i can’t use the word probability what i what i mean is the port the proportion of universes where you win is too small and that proportion is calculated how from the amplitudes you square and normalize them to work out so you mean the born rule converts the amplitudes into proportions equivalent to probabilities don’t we’re not allowed to say that either but that is what you’re saying right that i should bet based on my personal odds is determined by the born rule

[01:21:06]  Unknown: sigh

[01:21:07]  Red: so my point here is is that even though he skipped over the probability calculus step it doesn’t if you try to explain what’s going on to a sincere questioner you need to explain it to them still in terms of the probability of them winning there’s still an implicit probability going on as part of the explanation the mere fact that he he he skipped the math didn’t remove that implicit explanation of probability at all as far as i can tell if you want to explain here’s why the decision theoretic approach matters to you you have to be able to say because you are an observer in a single universe and from your point of view your odds are not good enough and you have to say that or you will never be able to explain to the sincere questioner why this matters so i don’t see i don’t see him as having actually removed probability from the explanation i think he simply didn’t mention it but it’s still implicitly there so yes deutch calculates a rational decision without using the born rule or the probability calculus but a simple analogy shows why this is not remarkable at all okay so you don’t need quantum physics to make this argument classical physics you could make exactly the same argument suppose someone told you that you have no need for probability theory to work out the expected value of a fair die even if you’re assuming only classical physics so here’s the argument now you say see bruce we don’t need probability theory at all we can just use frequencies so let’s calculate the expected values using only frequencies so a frequency of one out of six for the first value and then for two one out of six so we take one out of six divided by one plus two plus three plus four plus five plus six that equals 21 divided by six oh we got the expected value of 3.5 i never needed to to translate to probability calculus bruce i just used frequencies so we don’t need probability theory at all it’s the exact same argument okay so voila i just proved that we can make rational decisions without reference to probability theory hooray so probably probability theory is unnecessary right of course this is a silly argument we all know that frequencies are a type of probability they’re the same thing right so converting to a probability calculus is unnecessary to quote be using probability theory probability theory is more encompassing than merely the probability calculus you can represent it as the probability calculus for convenience but you don’t have to okay so now granted funny looking imagining numbers may look look different from straight frequencies but you’re doing exactly the same thing here okay so here was the dutch calculation where we we used the one over the square root of six notice that that that little one over the square root of six that’s a frequency in disguise

[01:24:11]  Red: like it’s the same thing the reason why it looks different is because it’s in a mad it’s a complex number that has an imaginary component in this case the imaginary component is zero but because it exists as a complex number to be able to work out the actual comparative amplitudes you have to square them all and normalize to one okay but that really is represent that it’s an amplitude it’s the same as a frequency it’s just in a different format okay the born rule converts amplitudes into a normalized measure obeying the probability calculus the probability probability calculus is just measure theory scaled for convenience okay the probability calculus is not mandatory now cox’s theorem which we will do an episode on cox’s theorem because i think it’s a really important thing for critical rationalists to understand cox’s theorem is famous for basions not for critical rationalists and it was the basis for basian epistemology okay that et jane started with cox’s theorem showed what a deep theory it was theorem it was and how deep its implications were and then from there he derives what today we would call basian reasoning basing philosophy i mean okay so cox’s theorem is super important to basians so cox’s theorem i i went through line by line every single part of cox’s theorem when i read et jane’s book to make sure i understood every single step and i do not see any problems with it at all okay cox’s theorem shows that there are infinitely many equivalent

[01:25:48]  Red: isomorphic representations of probability okay it makes no claim you have to calculate have to convert to probability calculus what it actually says is there’s an infinity of different ways you can represent this but for convenience the probability calculus is the easiest one for humans to understand okay so cox’s theorem absolutely has no problem with the fact that you can represent probabilities physically using complex numbers and it has no problem at all with the fact that you don’t have to convert to the probability calculus okay so just as you can make rational decisions using frequencies instead of the probability calculus you can of course make rational decisions using qm amplitudes which are equivalent to frequencies from the point of view of a member of someone in a single universe that is so the born rule is the function that maps between representations just like cox’s theorem promises will be possible this does not remove the probabilistic structure it merely changes how it’s represented claiming that this quote eliminates probability risks misunderstanding the role of the probability calculus surprisingly deutch at one point admits that there is a physical way to understand probability in terms of proportions of the multiverse which is what i’ve been arguing okay though he doesn’t dig into it further but let’s look at the actual quote because i think it’s important because it’s a place where i he says what i’m saying okay so this is at in the presentation 16 11 16 minutes 11 seconds deutch claims that the probability probabilistic statement that a probabilistic statement is not a statement about reality so he this is from his slide factual statement a straight flush beats a full house that’s obviously a factual statement a probabilistic statement drawing to an inside straight is very risky that’s a probabilistic statement it’s not a factual statement this is what argue what deutch is arguing okay so deutch goes over the counterclaim so when you point out that it’s not a factual claim he claims that people who are defending it will say this here’s the quote now the statement it was too risky is about the physical world it refers to all the players who drew to an inside straight and lost and it refers to the fact that there are more of them they outnumber the winners so this isn’t deutch’s argument this is deutch explaining a steelman version of the other point of view deutch refers to this argument as a sort of quote a sort of desperate denial deutch explains there have only been finitely many poker games in the world and they do not match probability theory now that makes sense so probability theory is the way it’s typically explained like in class they would say if there were an infinite number of poker games then what you would find is that drawing an inside straight is very risky but deutch is saying there ours isn’t an infinite number of poker games there will never be an infinite number of poker games so you can’t appeal to this infinite number of poker games and therefore turn that probabilistic statement into a factual statement so far so good i agree with him on that okay but there’s a problem he’s he’s missing something important here which he then brings out and this is where i found so interesting he then says ignore for the moment the fact that there are parallel universes and in those the particular players both win and loses in different universes quantum theory does in fact solve some of these problems

[01:29:31]  Red: oh hell yeah it does that’s me let me put this in plain english there are in fact an infinite number of poker games but they’re across the multiverse not inside a single universe and because that’s true the probabilistic statement drawing to an inside straight is very risky is a factual statement i’m gonna say that again drawing to an inside straight is very risky across the multiverse is a factual statement because it’s about the proportions of the multiverse okay so i don’t see this as a desperate denial it’s true that when those that have defended this didn’t believe in the multiverse they weren’t sure how to explain this so they would say something similar to deutch’s steelman version of them they would say the statement it was too risky is about the physical world it refers to all the players who drew to the inside straight and lost okay i agree that that’s an imperfect answer that the right answer is the statement it was too risky is about the physical world it refers to all to the player who drew to inside straight and lost the number of proportions of the universe where that happened once you realize that all you have to do is reference the multiverse here this does become a physically real statement and it’s factual statement so what do i just said that is what i’ve been arguing all along okay one fair way to interpret randomness is as proportions of branches across the multiverse these proportions yeah but

[01:31:06]  Blue: if i say that my my high school uh algebra class i think they’re gonna when we’re talking about probability they’re they’re they’re probably gonna think i’m crazy i mean

[01:31:19]  Red: yeah a lot of

[01:31:20]  Blue: mold already do i keep thinking of that if i brought up some of this stuff

[01:31:25]  Red: the world isn’t ready for the truth that’s what you’re okay

[01:31:28]  Blue: so these

[01:31:31]  Red: proportions the which of the born rule magnitudes exactly fit the probability calculus and of course they exactly fit the probability calculus the born rule when normalized by design it maps to a value between zero and one for convenience just like what we do with probability theory if it’s a one it happens in all universes if it’s a zero it happens in no universes if it’s between zero and one it happens in that proportion of universes this doesn’t it’s not an accident this looks exactly like probability theory okay drum roll this is exactly equivalent to probability theory and of course it is cox’s theorem predicts that in a case like this it should be mappable to probability calculus and it is cox’s theorem we need to cover it as a separate podcast and it’s it’s a tough subject because it took me like two months or something to go through the cox’s theorem because he kept losing me but it’s very complicated proof it’s probably not a very complicated proof it’s very complicated proof for a layman like me is what i should probably say um cox’s theorem it starts with it starts with certain axioms they don’t call them that but it starts with certain axioms and it tries to show that you can come up with different ways of representing

[01:32:57]  Red: these axioms but they will always be equivalent to probability theory so if mathematically for something to be self -consistent where multiple things happen across multi multiple universes it had to be in some way mappable to the probability calculus like cox’s theorem says it must if it’s not true if the quantum multiverse is not mappable to the probability calculus cox’s theorem would be wrong and you would actually have disproof of cox’s theorem but there is no disproof of cox’s theorem it’s presumably it’s because it’s correct right so we’re talking an exact fit this is not a flat earth approximation we’re talking about okay the born rule maps precisely to probability calculus because cox’s theorem says it will okay now as

[01:33:53]  Red: noted in episode 129 there is a physical property corresponding to the probability agi will wipe out humanity that is done in terms of physically this means the proportion of universes where agi wipes out humanity it has to be from a given moment in time i should know it’s not across the entire multiverse it would be you would pick a certain certain world a certain moment in time and then you would say what is the probability from this moment of agi wiping out humanity there is some proportion of the of the multiverse from this moment in time forward for us where agi wipes out humanity in the future that is our probability that agi will wipe out humanity now that probability changes over time because at each moment in time you’re now in a different part of the multiverse and the branches that remain are different now okay so the proportions change and obviously if you were to do something like let’s say you enslaved all the agis in that report the proportions of the multiverse where agi rebels and wipes out humanity is going to go way up okay so the probability in that case based on your decisions changes okay and yet this is what probability of agi wiping out humanity means it has a physical meaning across the multiverse it’s physically real so the claim there’s no such thing as the probability that agi will wipe out humanity is a factually false statement okay now sure we don’t know the value okay basians who make who guess at the value they are making crap up okay and you can ignore them because of that i don’t think basians the ones who are into this sort of thing have any clue what would lead to agi wiping out humanity versus not agi wiping out humanity i think their whole philosophy is flawed on this point so i think when they make up values of here’s the probability agi will wipe out humanity i think it is a meaningless number even though there is a probability of agi wiping out humanity they don’t know what it is and you can ignore them their theories about it are disconnected from whatever’s going to happen in the multiverse so there’s no reason to reference them okay

[01:36:09]  Blue: it really is even i can see that much that really has a ridiculous line of reasoning okay

[01:36:14]  Red: but the claim there is no such thing as the probability that agi will wipe out humanity which in episode 129 was made by one of the crit rats okay based on what he claims came from david deutch which i think he probably was right about that’s a false claim okay so key takeaway probability randomness randomness have a very real physical instantiation under many worlds physics needs probability but it needs it at an emergent level the born rule is the emergent level because it translates between the deterministic multiverse into the probabilities that an individual observer is going to see okay and that is part of physics so physics needs probability in this sense physics without probability is only possible under an incredibly narrow and i would say misleading definition of probability as a side note i talked here about agi okay what about asteroids the is there a probability that asteroid will hit the earth

[01:37:17]  Red: now that is different it’s there is no proportions of the multiverse where an asteroid is either an asteroid’s either going to hit the earth or it’s not that is not some from this moment in time forward what are the odds that an asteroid hit the earth this year let’s let’s start with this what’s the probability that an asteroid will from this moment forward hit the earth this year that is not something that branches across the multiverse that asteroid exists at such a large macro level that there aren’t really quantum events that are impacting its movements okay so maybe really tiny quantum events very slightly but for the most part there is no physical meaning to the probability that an asteroid will hit the earth okay does that mean there’s no such thing as the probability that the asteroid will hit the earth no you have to understand that the asteroid example is different it’s a pseudo random uh probability so it is only a flat earth approximation but it doesn’t just because it’s a flat earth approximation doesn’t make it wrong or not real okay it’s still really meaningful the way you calculate the probability of an asteroid hitting the earth if you know nothing else is that you start with the assumption

[01:38:33]  Red: that the number of asteroids that exist in the path of earth is constant and therefore the ones in the past are going to be the same as the number the number of hits will be spread out in frequency exactly the same as the numbers in the future now that may be a false assumption okay like like it’s just a theory right um it could be that we just barely moved into a part of the galaxy where there’s you know 10 times as many asteroids as there was prior to this point in which case that probability that you’re going to calculate using frequencies from the past is going to be false okay but you have no reason to believe that if you have a reason to believe that then yes you would use what you see the frequency is going forward but if you got nothing else to work off of your best theory from a critical rational standpoint is that you’re in about an equal distribution of asteroids in the past as you are in the future therefore the frequency of hits on the earth prior to this point is your best theory as to how many your hits you’re going to have going forward now this is how you use probability theory yes as a flatter approximation I will admit but what it still has a meaningful

[01:39:50]  Red: it still has meaning right like it’s not a meaningless thing for you to say even though it doesn’t have proportions it doesn’t have a physical meaning anymore in this is a case where it is much closer to the Bayesian example where it’s really about your knowledge your state of knowledge and your degrees of belief your credences okay and it does have it if you don’t like the term degrees of belief or credences because you have an allergy to them because you’re a critical rationalist there is a critical rationalist version of this I just tried to explain it and it’s really about the assumption that there’s an equal number of asteroid your best theory is that there’s an equal number of asteroids in the past is there is in the future because the proportion of them in the universe hasn’t changed you’ve got no reason at this point to believe that’s changed okay if you did you’d have a different theory

[01:40:39]  Red: and there is a critical rationalist way of looking at this that’s completely valid that’s maps mathematically to what Bayesian’s called degrees of belief and yes that is different than the probability of agi wiping out humanity where it has a physical meaning there’s no physical meaning here instead it’s an approximation anyhow I’m just trying to make a point here that there is a difference between these two cases but that they both map to the probability calculus but in different ways with slightly different interpretations this is something we need to come probably come back to when I understand it better I’ll try to explain this better okay let’s now look at several arguments Deutsch makes in the presentation that to me some of them seem kind of questionable okay so at 3615 there are no stochastic processes and no credences in the sense of beliefs with numerical measures that obey the probability calculus no credences affect the decisions of any rational person making decisions about quantum systems now I do not see how this is correct do it seems to me to be misunderstanding what a Bayesian credence is now we are already mentioned that do it seems to misunderstand the Bayesian philosophy okay that I gave an example of how he thinks if he can show there’s no random no true randomness that that undermines the Bayesian philosophy when actually it would support it okay now you can’t know a quantum die result but amplitudes the proportions of universes or frequencies in a single universe proportions of universes or think of that as the frequencies in a single universe they do guide your betting decision okay you don’t know if you will personally win but you know the proportion of universes i.e.

[01:42:24]  Red: the odds of winning this is with the quantum die example so using the born rule shows that proportion is mathematically a credence not using the born rule doesn’t remove the credences it just represents them differently so let me let me say this okay multiple times Deutch has said that there are no credences in the sense this is a quote create no set no credences in the sense of beliefs with numerical measures that obey the probability calculus the

[01:42:55]  Red: way he’s saying that it’s weird he’s almost saying what popper said um but he’s saying it slightly differently and the way popper said it makes sense to me but the way Deutch is saying it doesn’t and I think about the episode I don’t remember the episode number but we did the episode on induction where Kiran the inductivist was making arguments and I tried to show that he was actually just using an immunizing strategy in that episode go back and look at it in that episode I explain the paparian sense in which theories do not believe in theories do not obey the probability calculus okay and I I what I tried to explain and I was intentionally doing that first so that I could explain this later when I was talking about Deutch’s version I was trying to explain that there that you cannot use the probability calculus in an absolute sense to measure the probability of the theory is true that’s just not how the probability calculus works that’s not how Bayesian reasoning philosophy works now I understand that there’s a lot of Bayesians it’s particularly the effective altruists who use it in that way but they are at odds with their own epistemology or their own philosophy I should say because arguably all of Bayesian epistemology is wrong it’s the Bayesian reasoning portion that’s correct okay Bayesian philosophy kind of sits in between those it’s got some errors and it’s got some things correct and someone who says I’m a Bayesian epistemologist they’re probably as likely to actually understand Bayesian philosophy as most crit rats are likely to understand poppers critical rationalism which is to say most of them misunderstand it right these are tough subjects there’s misunderstandings are common okay um so you can’t really look at Bayesian philosophy and determine it based on what people on the internet are saying you have to almost go to an expert like et janes which is what i’m trying to do and you need to actually look at what a knowledgeable person said about it and then try to get it get rid of a lot of the bad examples of it okay now it’s true that popper said belief in theories does not follow the probability calculus okay and that’s true and the reason why is because there’s different reasons why you would accept or not accept a theory and they can’t be put into a numerical measure like that that’s why they disobey the probability calculus but if you have a specific model that you’re looking at and under that model you’re choosing between theories it absolutely obeys the probability calculus i’m gonna say that again if you’re looking at a specific model so you’ve got certain background knowledge that you’re working with and you’re accepting is true for now you don’t know if it’s true for sure but you accept industry with your best theories in that case when you’re choosing between theories it absolutely obeys the probability calculus and it has to because coxis theorem says it will it

[01:46:19]  Red: depends on what your context is do you mean it in an absolute sense where you’re trying to measure not only the probability between two theories given some background knowledge but you’re also trying to measure the probability that your background knowledge is correct if that’s what you’re trying to do and i’ll admit effective alters try to do that okay then they have misunderstood Bayesian philosophy because that is impossible and poppers right that does not obey the but the probability calculus but if you are looking at it from the standpoint of someone who is assuming for the moment tentatively that their background knowledge is correct and that their best theories are correct in that scenario it will always obey the probability calculus when do it says this that there are no credences in the sense of belief with numerical measures that obey the probability calculus he’s making too broad a claim and the claim is therefore false even though it’s true in some cases okay it’s also false in some cases and he’s not differentiating between the two i always felt like popper did a better job differentiating between the two kind of because he’s a little more clear but i always sort of got the sense that popper didn’t quite understand the difference between these two either and this is one of these cases where i think critical rationalists would really benefit from understanding Bayesian philosophy even though Bayesian philosophy will ultimately prove false it’s got a lot of truth to it okay it’s got verisimilitude if you will and it’s got some things that critical rationalists do not properly understand and need to adjust their thinking on that need to error correct on okay okay and

[01:48:01]  Red: there is cases where specifically when you’re being a critical rationalist when you’re accepting your current best theories as true for now that is the condition under which choosing between theories using experiments let’s say will always follow the probability calculus and that distinction is necessary here okay you can’t just say credences in the measures do not obey the probability calculus that is too broad a term you that’s false the way you just said it you have to make the distinction it depends on whether you’re talking about inside the model or outside the model inside your background knowledge inside your theories or outside your theories and with that distinction i think it then becomes a true statement but i don’t think it is without okay sorry i probably lost everybody there and i will try to do an episode where i explain this better in the future this is maybe a setup for when we talk about Bayesian reasoning and my current understanding of it as i struggled to learn it myself but i want to be clear that deutch is showing a misunderstanding of Bayesian credences here because he doesn’t make the necessary distinction between inside of our theories or outside of our theories

[01:49:14]  Red: okay at 36 36 deutch says but it’s even better than that those decisions now on the right hand side are not only derived but unlike in the collapse case they’re explained because we don’t have to introduce all those unexplained probability prostitutes now let me just say i’m not arguing that the constructor theory of probability isn’t adding to our body of knowledge i think the constructor theory of probability is correct in so far as it goes this is similar in my mind to the whole universal explainer ship thing where that is a correct theory but that deutchian crit rats and deutch himself pull implications from it that are false that aren’t actually part of the theory i think the same thing’s happening here the constructor theory of probability does not seem to me to be wrong he is correctly explaining certain things using the multiverse that explains what probability is in a way that we couldn’t have understood well without it so there is a genuine additional explanation here that bayseans would benefit from learning and coming to understand and understanding how their theory fits their philosophy is right and wrong okay so this one i kind of agree with deutch on that a reasonable reading is that deutch is arguing that many worlds explains what probabilities actually are physically that’s the way i would say it it’s not the way deutch says it but that’s what i would say would say it okay and it allows you to make a difference to understand the difference between the probability of agi wiping out humanity which has a physical interpretation of probability and something like an asteroid hitting the earth which is really just a matter of credences or degrees of belief based on a current best theory okay it’s a theory that has problems and would have to be

[01:50:57]  Red: improved once your additional knowledge comes in okay and i think it allows us to understand something like why bayesian philosophy works so well in so many cases and also where it goes wrong so from this standpoint i kind of agree with this statement now however i’ve got some concerns over his wording the posture it’s a probability theory don’t need a physical explanation and he’s kind of acting like they do he’s kind of acting like well they have to have a physical explanation they’re supposed to be consequences of mathematics he’s right that originally it was physics and cox’s theorem shows that any decision making process that matches certain reasonable does it does it how do you pronounce that does it drata so desired odda is what it’s spelled like but does it drata so for our purposes we’re going to call them axioms any any rational decision making process that matches those axioms will always mathematically be equivalent to probability theory that’s what cox’s theorem really shows okay but it’s a mathematics like it’s it’s literally how our physics matches that why our physics matches that that is what constructive theory of probability is explaining and it’s that’s a that’s a correct explanation that we should be interested in but it would hold for any laws of physics okay dwight sees probability theory as non -existent unless you can connect it to physics

[01:52:39]  Red: but it doesn’t have to be that way it could have been that the universe was entirely deterministic and probability theory would still have worked as an approximation admittedly and in fact bayesian philosophy would have been entirely correct had that been the case because then probability theory would only be about degrees of belief or credences okay and the fact that that’s not true the fact that there actually is a physical interpretation of probability in some cases actually undermines bayesian philosophy okay so what cox’s theorem does is it’s pure mathematics it just simply says no matter which universe you live in whether whether it’s a quantum multiverse where probabilities are real and there’s real frequencies or if it’s collapse or not collapse if it’s purely deterministic and it’s just initial conditions in every single one of those cox’s theorem says your rationality will be mappable to probability calculus and that’s true there’s just no way around that right it doesn’t matter you could make up entirely new physics and probability calculus would still apply because it’s just a consequence of mathematics

[01:53:48]  Red: at forty oh seven he says i don’t mean that the mathematical formalism of quantum theory isn’t sometimes useful i’m saying that the quantities called probabilities in that formalism do not refer to any stochastic random process in nature nor to anything in rational minds such as degrees of belief or credences nothing in physics or in minds thinking about physics so this honestly the statement makes no sense to me the born rule is useful precisely because it translates amplitudes into the probability calculus understanding a quantum state in terms of proportions of universes as zero to one measure has only one consistent way to do it the born rule because of cox’s theorem that had to be true it does refer to a real stochastic process from the point of view of an observer in a universe okay the claim about nor anything in a rational mind such as degrees of belief or credences is unclear qm amplitudes themselves aren’t Bayesian credences that that’s true but to explain a quantum outcome to a sincere questioner you necessarily refer to odds and probabilities which are Bayesian degrees of belief even if you just say trust me it will work and try to avoid that part of the explanation you’re still implicitly using credences in a different representation to calculate the expected value so I this statement I just can’t make sense of what he’s trying to say here

[01:55:18]  Red: at 4948 he says now I hope I have shown you can that ability can doesn’t make sense as a description or explanation of what really happens it can be a metaphor a technique for calculation or something approximate or an approximation in a certain sense but an approximation to make sense has to be an approximation of something so probabilities are to inform decisions in some approximate way there has to be an explanation rooted in a description of an actual physical world in which events and processes happen not probably happen and not just some just fire some axiom some ad hoc axioms so I hope I’ve also persuaded you that it it’s right and proper to try to expunge every trace of probability of randomness from the laws of physics now I’ve read this repeatedly and I don’t know what it means like I can’t make sense of what he’s saying cox’s theorem is a mathematical claim not a physical one probability calculus is a convenient representation not a physical fact in the qm many worlds proportions of in the qm many worlds version of quantum mechanics proportions of universes physically exist which cox’s theorem guarantees can be represented as the probability calculus which it can be this representation is exact not merely an approximation or a metaphor claiming we should remove every trace of probability of randomness is misleading from this point of view since proportions of universes are literally equivalent to probabilities

[01:56:52]  Red: so at 50 33 repeating this part for emphasis so I hope I’ve also persuaded you that it’s right and proper to try to expunge every trace of probability of randomness from our from the laws of physics from our conception of the world and from the methodology of science so that we may fully restore realism as well as rationality. Deutsches lost me entirely at this point probability theory is mathematics mapping it to reality is interesting but it would hold under any laws of physics according to cox’s theorem what could he mean in the case of say life insurance okay let’s use life insurance now as our example is he saying that we should not use probabilities at all for life insurance and must always go back to quantum states to compute expected values no presumably not like that would be silly so there’s no way he would say that okay so if he then admits okay in this case use probabilities because they’re a good approximation since you can’t know the quantum states uh in such case then why what’s the point of expunging them for rational decisions such as life insurance where apparently you need them right like I I he’s saying we need to get rid of it to be rational and I don’t see that like it seems to be like the exact opposite is true you need to understand the physics so that you understand how to properly apply probability theories to be rational you’re not expunging you’re not removing it to be rational you’re trying to understand it better but it’s real it’s something you still need to understand it’s a

[01:58:25]  Red: still a huge part of rational decision making and it’s not going away it’s never going away there’s never going to be a time where they’re going to do away with probability theory to do life insurance and instead they’re going to use quantum states that’s never happening you will always use probability theory for that even though it’s an approximate match only okay so and you would need to to be rational so like to me I read this and it just seems wrong to me okay so some probabilities are not approximations so for example the double split experiment what it triggers a detector is exactly determined by proportions of universe fully matching the probability calculus okay george might counter this meant that measurements are never exact so probabilities are approximate and he did counter that in episode 100 to me but this is misleading there two things can be approximate here are we saying that probability theory itself is approximate or are we saying that our measurement values are approximate but the theory is actually correct

[01:59:33]  Red: limited measure limited measurement in precision does not justify the claim that probability theory itself is merely an approximation of reality and it’s not understand this is true of all theories like would you say oh you know quantum physics is is only approximately correct because we can never exactly measure the size of the slits in the double slit experiment like when george claims probability theory is only approximate because we can’t measure the size of the slits he might as well have said quantum theory is only approximate because we can’t measure the size of the slits it’s he’s he’s he’s right that we can’t measure the size of the slits he’s right that the values we use are approximate and therefore the results will be approximate but the theory itself is not approximate. Okay. Once we are, one might argue, Bruce, you’re a layman, I’m mature and Deutsche is a world face, world famous professional physicist. Why should I take your word for word instead of his? I have to admit the justice of this argument like I do. And quoting Popper that there are no authorities and we should judge arguments on their own merits is never going to change people’s minds. However, let me let’s look at this from the point of view of Ivan, the Bayesian who listened to this podcast fairly religiously. He’s going to respond and tell me what he thinks. Okay. A Bayesian would be right to expect answers to the questions I’m raising. The burden of explanation is on Deutsche and his decision to the erratic approach. Okay.

[02:01:06]  Red: I’m raising these issues because I understand critical rationalism and Bayesianism enough that I can immediately see there’s a problem and I’m going, look, I, I don’t think a Bayesian would find these arguments compelling even slightly. Right. Like to me, if I’m a Bayesian, I’m listening to this. I’m going to go, Dwight doesn’t know what he’s talking about. He’s totally misunderstood Bayesianism. He’s totally misunderstood probability and what it means to me as a Bayesian. And it’s going to lead to questions. Right. And these questions are valid and they need to be answered. Questions must be answered substantively. They can’t be glossed over. They can’t be hand -waved. Cox’s theorem is real. It’s mathematically clear. Any serious approach must demonstrate familiarity and show how its framework is framework addresses Bayesian concerns that they’re going to raise with this presentation from Deutsche. Okay. Saying probability is only approximate under my narrow definition of randomness. It’s merely an argument over definitions and a Bayesian is going to go. I just don’t define, define randomness that way. To me, it was always about degrees of belief and credences. Right. I never thought it was part of physics. The current presentation therefore gives a, the impression of a lack of familiarity, lack of familiarity with Bayesian theory, particularly with Cox’s theorem. Now, I’m a layman, yes, but one familiar with critical rationalism and machine learning. I also recently went over Cox’s theorem line by line to make sure I understood it. Even from a layman critical rational standpoint, I can see that there are fair non -trivial questions that are raised that deserve robust answers. I could not begin to guess how to robustly respond to the questions that I’m imagining Bayesians asking here. In

[02:02:55]  Red: fact, the reason why I believe I can’t respond to them is, is, is because I don’t think Deutsche has this right. Okay. Now, I might be wrong. He might have this right and I might just be misunderstanding, but if so, he needs to explain it. Like, like it, the burdens on him to explain what’s really going on, what he really means. Like when he says there’s no such thing as a credence or degrees of belief, there are so many cases where there are, like, there’s all sorts of cases where it works perfectly. He has to explain why that is, right? From his viewpoint. So I’m not proposing an alternative theory here. I’m asking for clear reasoned responses that show the approach truly addresses the concerns being raised. And that I guarantee, like, I’m seeing them, I’m sure Ivan’s going to go watch this, watch Georgia’s real original presentation and go, Yeah, I just, I just don’t think he answers any of the questions I would have raised at all, right? So I, Bayesians going to ask these and the burden is on us as critical rationalists to say, you know what? We got to take these questions seriously. Like, we cannot just wave them away. We’ve got to really say, what is it that’s going on? What is a degree of belief? What is an approximation of? And I just don’t see how do I just presentation even begins to address these issues. Okay, so perhaps I have misunderstood, this, this is absolutely possible. Okay, I’ve spoken to several critical rationalists defending his view. And I’ve noticed that they interpret his theory such that they are making factual mistakes. Okay, where they think all randomness is pseudo randomness, for example.

[02:04:33]  Red: So either they understand, understand him correctly, in which case he is wrong. Or they two are misunderstanding him, which this suggests that his arguments might not be as clear as he intends. For example, I struggle with his claim that randomness is like the flatter theory. I agree that for pseudo randomness, that’s true. What he seems to have in mind is that it’s roughly correct in some cases, but it’s misleading in others. Using the born rule to calculate probabilities from the point of view of observer universe seems to me to be precisely correct, not a flat earth approximation. Now, Cox’s theorem predicts that proportions of the universe will align with probability calculus when making rational decisions. And that’s true. This in turn points to two kinds of randomness true in pseudo do it seems to introduce a third non existent kind, and then shows it doesn’t exist, which just returns us to the original two. I also worry that defenders of his theory seem to go too far, making wide claims, strong claims, that probability of AGI risks or asteroid impacts are meaningless, not approximations meaningless, they’re claiming it’s meaningless, not approximations. I mean, you have to see this, right? Like if if the person, the crit rat who had said, there’s no such thing as the probability that an asteroid will hit the earth, if he had said, well, there is a probability the asteroid will hit the earth, but it’s an approximation of something else, right? And it’s not, it’s not an actual stochastic event. That would have been okay. Like that would have been a correct answer. But he was declaring it as just meaningless. There’s no reason to bring it up. There’s no reason to talk about it. It’s just not true.

[02:06:16]  Red: Okay. So I started with this all this with a set of fair questions. And I feel I’m ending with the same set of fair questions. But at least I’ve tried to lay out my reasoning as clearly as I can. If I do have this wrong, which I may, I really hope someone will kindly try to build a bridge for me to make sense of Deutsche’s arguments, because they’re not clicking with me at all, like not even a little bit are they clicking with me? They seem wrong to me. Okay. Now, building this bridge shouldn’t be that hard. If Deutsche’s right, he’s making factual claims. He’s saying he argues probabilities like a flat earth theory, it’s an approximation that sometimes predicts correctly and sometimes fails. Think about flat earth. It’s sometimes corrects. It’s as a theory, it sometimes predicts correctly. And it sometimes predicts completely wrongly. Okay. That’s what he’s saying is true of probability theory. So I don’t see how that applies to QM such as a double split experiment. Once you apply the Born rule, you get an exact proportions of universes, at least as exact as you can, according to your ability to measure the size of the slits. Okay. Not an approximation. So now I did ask some of these questions in episode 100, although I didn’t understand it as well back then. And I’ll have to cover in another episode what Deutsche’s answers were. I don’t want to go into it too much. Let me just say that the answers he gives me don’t really answer the question as far as I can tell. Okay. So that’s why I still feel very confused. I will cover what his answers are.

[02:07:55]  Red: And then I will explain why they don’t seem like good answers to me. But like I won’t go into it for this episode because that probably deserves its own episode. Let me also say that when it comes down to it, the question I asked, Deutsche, in episode 100 was really the question I’m looking for. Okay. I said, is there a theory, like is there a theory we’re waiting for that’s going to be better than probability theory? And then we can do away with probability theory. And then that theory will make better predictions than probability theory. Because that’s what, I mean, he’s saying it’s like the flatter. That’s exactly what I should be looking for, right? Because you give me this other theory that does everything probability theory can do. Plus it can make better predictions in some cases. Okay. Think about Newton versus general relativity Einstein. Okay. That’s what I’m looking for. If you’re telling me it’s a flatter approximation, I want that to know what that other theory is that makes better predictions. And then we just take the case where the new theory makes a prediction correctly and the old theory makes a prediction wrongly. And when we do that, we now refute the old theory and probability theory goes away. And we have this this replacement theory. Okay. This isn’t an unreasonable thing for me to be asking for. When I asked dutch that in episode 100, he said, Well, there is such a theory, it’s the decision to the erratic approach that I’ve published. But it makes exactly the same predictions. Okay. This isn’t what I’m looking for. If it makes exactly the same predictions, then it’s not like the flat earth. It’s it’s not an approximation.

[02:09:35]  Red: This is what I keep trying to get at, right? If you got two theories and they make exactly the same predictions, to popper, we covered this in the concepts episode to popper, those are the same theory, because they make exactly the same assertions about the world. Okay. So that’s not good enough. You can’t tell me that the decision to the erratic approach is better than the the probability theory, but makes the same predictions as it. That simply confirms probability theory as correct. Even if you want to reword it into different concepts and words that feel very different. Okay. According to popper, we covered this in the past episodes, that’s still the same theory. No matter how much it feels different, how much it sounds different, no matter how many different words we use, different concepts we use, those are all instrumental. And ultimately, if they make the same assertions about reality, which is saying that they do, then they are the same theory. And you can’t say it’s a flat earth approximation anymore. Okay. So it seems like if this is a flat earth approximation, it’s so easy just produce the other theory, show it makes better predictions. If there is no such theory, then it’s not a flat earth approximation. And that’s a misleading thing to claim. Now, when we’re talking about pseudo randomness, probability theory, I will admit is like a flat earth approximation. And I keep wondering if maybe that’s what he means, right? Like he’s being unclear. And he’s maybe even in his mind got a little bit muddled between the quantum version of randomness, which is not an approximation. And the pseudo randomness, which is an approximation, mathematically speaking. Okay. The reason why pseudo randomness is always an approximation.

[02:11:19]  Red: And this is something that ET James brings out. Okay. We talk about like so ET James is thinking that when you roll a die, it’s all classical because he’s not a quantum physicist. He was a statistical mechanics. And so when you roll that die, there’s an initial condition, it’s all entirely determined, there are no quantum events, there’s no splitting of the multiverse. And you get this result, it’s entirely determined, but you just can’t measure the starting values well enough to be able to predict the outcome. If that’s true, if that were actually the real world, and there was no quantum randomness, like ET James thought there was no quantum randomness, then ET James points out, so this is the Bayesian we’re talking about the father of Bayesianism we’re talking about, he points out that there’s really no such thing as randomness in this case that it that it’s just an emergent idea that we use. And that really, if you if you just calculated a little bit more, you could figure out what that die was going to land on. And it would be predictable. And there would be no actual randomness in that case. So what you really mean is, is that there’s a certain amount of ignorance that I have of the starting conditions because I roll that die all around and I throw it high enough, he points out that if you roll it really close to the desk or something like that, it’s not random, right? It’s not disobeys the probability calculus. That’s the thing that George always points out, but ET James points it out too.

[02:12:46]  Red: And so you’re making certain assumptions, you’re saying, well, if I if I roll it enough, my ignorance grows to the point where any guess is equally good. And in this case, it’s going to, at least in the short term, obey the probability calculus, but in the long term, it’s not going to, you know, the die is going to get chips, it’s going to change its shape as you roll it. And the long term, it’s not really going to obey the probability calculus anymore. And so James argues that there’s really no such thing as randomness and that we’re, that we’re not even trying to work out randomness in terms of frequencies that really it’s about our degrees of belief or it’s our credences, it’s our ignorance of that initial starting condition. And that’s what probability calculus is really a plausibility calculus. It’s got nothing to do inherently with frequencies or randomness or stochastic events. This is his whole argument. In that case, I can see that probability theory really works more like a flat earth approximation. And in that particular case, I can see that’s correct. Now, if you knew the exact dos conditions, you can make perfect predictions, but that’s not true for QM. So I’m seeking a real life QM slash born rule example where probability theory makes a false prediction compared to a better theory. If probability theory is a flat earth approximation, such an example will exist. If it’s not, then such an example will not exist. And when I did ask this, he said they made the same predictions. So apparently it doesn’t exist, which is why I question why we’re calling it a flat earth approximation. Right? Now, again, maybe I’m just misunderstanding.

[02:14:30]  Red: Like I keep, I feel this humility over this, that there’s just no way like he’s saying so many amazing things in this presentation. And I keep wondering, have I just lost he just lost me? I just totally misunderstanding his point. And I’m doing my best to explain myself. I’m doing my best to show my work and I’m doing my best to say, look, I’m digging into this, it’s still not making sense. And that’s really where I think we’re leaving this, right? I’m not going to go on record as saying he’s wrong. I just don’t know that that’s the case. I do think it’s possible he’s wrong. I do think it’s possible that he is confused and that he’s absolutely gone the wrong direction on this. And I even think that’s my best current tentative theory. Like my best current tentative theory absent someone actually explaining to me what I’m misunderstanding is that this, that he’s got a misunderstanding, a probability theory that he’s misunderstood. I think there’s good signs that he’s misunderstood Bayesian philosophy for sure. That doesn’t surprise me much. He’s not into Bayesian philosophy. He sees it as dismissible because he’s a critical rationalist. He’s never really looked into how much of it might be true. And this is something that I do feel critical rationalists make a mistake on. Critical rationalism contains errors. So does Bayesian philosophy. Both of them have some bare, bare similitude. What you really want is you want to understand both. And I think when you do understand both, you do find that critical rationalism is the true preeminent epistemology, not Bayesian philosophy, Bayesian epistemology. But I do think it clarifies where critical rationalists have made mistakes and where they have misunderstood things.

[02:16:06]  Red: So I think they should learn both. Like I just don’t think you should ignore it. And I do think he for sure makes some mistakes in this area. But it’s so hard to tell with the rest, the whole decision. I know there’s a paper out there and I probably need to go to that paper next where he actually explains in detail the decision theoretic approach. And I will do that. I will go I haven’t read it yet. But I will read that paper next. And then once I’ve kind of comprehended it, I will do another podcast on it. But at least as far as the presentation people have pointed me to, I do not feel it answers my questions. In fact, I think if anything, it undermines Deutsche’s points. And at this point, I think that is the state for me at least that is the state of the critical discussion is that Deutsche seems to me to be on a wrong path here. And that there really is such a thing as random this quantum randomness, and that there are two kinds of randomness pseudo and true randomness. And that we do need probability as part of physics up. Immediately, it’s an emergent idea. But the born rule is an important part of physics is not you know, you can’t you can’t do away with the born rule. You can make rational decisions without it. But that’s only because that’s only because Cox’s theorem says you can represent decision like that in multiple different formats. You’re still kind of the fact that you skipped the probability calculus means nothing. Okay. And I think this is my state of the for me. This is the state of the critical discussion.

[02:17:38]  Red: I think he’s on the wrong path. I think he’s misunderstood numerous things. But I may just be wrong. And I don’t know where to get it’s difficult. You go and you ask people questions. I’ve tried asking him questions. I’ve tried sending him questions. He’ll give me really, really short responses. It’s just not enough to get into the very difficult questions I’m trying to ask here. That I think are valid. That I think have to be answered if we’re going to be serious about this. And so and this is where this is really the end. I’m sorry. This one went kind of long. But I’m putting this out there. I’m very much putting myself out there opening it up to criticism and discussion. I’ve shown my work. It should be easy to criticize me at this point. I do want you to be kind. Right. Like don’t be a jerk about this. There’s no reason to be a jerk about this. Like I’m very sincerely, very sincerely digging deep, trying to make sense of Deutsche’s view here. And it just isn’t it just isn’t coming for me. Right. It keeps looking like he’s making he’s misunderstanding things. And if that’s wrong, I would like to be corrected. And I would like to understand what really he’s getting at. But to such a large degree, it feels like ultimately it’s a collection of misunderstandings and an argument over terms. In which case, I don’t think it’s that interesting. And honestly, I feel like it shows some of the misunderstandings of Bayesian philosophy that the critical nationalist hold that we need to do away with. We

[02:19:14]  Red: need to we need to if we’re going to going to argue against Bayesianism, which I think we should do because I do think Bayesian epistemology is false in important ways. But if we’re going to make those arguments, we need to find the arguments that are correct and not use kind of hand wavy made up straw man versions. Right. And so based on that, I don’t feel like this helps at all. Like nothing in this seems to me to be even slightly useful in dispatching with or even explaining what Bayseans are getting wrong. And if anything, I think a Bayesian would look at this and go, Oh, he doesn’t know what he’s talking about and they’d be done. So OK, sorry, I feel like I’m repeating myself now. I’m just doing my best to explain. I’m not trying to be hostile. I’m not trying to be hostile here. Like I totally accept I may just be missing this, but I am missing it. If that’s the case.

[02:20:09]  Blue: OK, well, I think you’re coming at this with the right critical rationalist attitude. I guess we’re done with shorter episodes now. So that was that was great while it lasted. But this feels like your most epic statement ever on probability. And you’ve obviously put your heart and soul into this podcast. I hope I’m worthy to listen to you. But I don’t know who else is going to edit it. So I guess just you’re you’re stuck with me here, Bruce. And it’s been a wild ride as usual. And I appreciate you and love what you say. And I hope I hope one of your critics lessons too.

[02:20:57]  Red: All right. And if so, if you think you can explain this better, like first contact me, let’s talk. I’d love to have you on the show and we can maybe and I’m not I’m not in debating. I’m a terrible debater, right? I just want to understand like my goals always just to understand. And I would love to have someone just kind of walk me through this and help me understand. OK, and I talked to like some pretty knowledgeable people and they often point out stuff like, well, but this is in advance because blah, blah, blah. And I’m not denying that. Like like I want to make sure it was clear, even though it wasn’t a huge part of this podcast. I don’t doubt that the decision theoretic approach and that this whole constructor theory of probability approach has value. Like like I think it does. I think it’s kind of a slightly deeper version where we’re connecting the mathematics of probability theory in a good way to physics. And I’m not doubting that it does so in a way that is particularly for quantum physicists helps helps push you back towards the correct many worlds interpretation and away from the wrong. Copenhagen interpretation. And in that in so far as that’s what we’re talking about, I definitely think that there’s value in the way Deutsche is presenting this. But a lot of it just breaks down for me. So come on. Talk to me. Let’s let’s do a zoom. Let’s do face to face. Walk me through this in detail. Help me understand where I’m just not understanding this.

[02:22:42]  Blue: OK, well, I’ll look forward to that conversation. OK, thank you, Bruce. And have a wonderful day.

[02:22:47]  Red: All right, you too.

[02:22:56]  Blue: Hello again. If you’ve made it this far, please consider giving us a nice rating or whatever platform you use or even making a financial contribution through the link provided in the show notes. As you probably know, we are a podcast loosely tied together by the Popper Deutsch theory of knowledge. We believe David Deutsch’s four strands tie everything together. So we discuss science, knowledge, computation, politics, art, and especially the search for artificial general intelligence. Also, please consider connecting with Bruce on X at B Nielsen 01. Also, please consider joining the Facebook group, the many worlds of David Deutsch, where Bruce and I first started connecting. Thank you.

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