Theories of Everything with Curt Jaimungal - Curt Jaimungal: Can Physics Explain Its Own Laws?

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Starting point is 00:00:22 19 plus Ontario only. Please play responsibly. Concerned by your gambling or that if someone close, you call 1866-3-3-1-2-60 or visit comixonterio.ca. Why do physical laws have the form that they do? Do we text the universe at 2 a.m. and say, hey, you up? Need to talk about fundamental constants. The question seems straightforward since physics ostensibly explains everything else. So what about its own foundations? Here's why I think this innocent query is beguiling and treacherous.

Starting point is 00:00:52 Physicists love to point to our explanatory successes. So we have Vigner or Wigner's classification, however it's pronounced, telling us that particle. are certain types of representations of certain types of groups. This quote-unquote explains why particles have the properties that they do. They're just mathematical consequences of space-time symmetries, yo. And then we have Nuthers theorem, which links against certain symmetries to conservation laws under some variational principles. For instance, you may have learned that spatial symmetry gives momentum conservation,

Starting point is 00:01:23 and time symmetry gives energy conservation. It's all beautiful, no? Now, Nuthers' theorem is said to, quote unquote, explain conserved quantities. Firstly, there are problems with defining energy in this manner, and you can click on this video here to watch what energy actually is in general relativity. But here's what many tend to not think about. We're actually facing another's inverse problem. So given a set of conservation laws, can we uniquely determine the symmetries?

Starting point is 00:01:52 The answer is no. Multiple Lagrangians can give the same physics, thus the map from, the symmetries to the conserved quantities is not invertible. Now, I should say there is actually an inverse nuthers theorem. See Harvey Brown's paper here, his recent work, the problem is that for these inverse nuthers theorems, you do require additional constraints, and it doesn't fully resolve the uniqueness issues. Also, there are conservation laws that can exist without variational principles, such as with dissipative systems and conserved quantities that lack a Lagrangian formulation. All of this, of course, presumes we even know what we mean when we say law. Now,

Starting point is 00:02:31 is the quote-unquote law of the excluded middle? Is that a law? What if I then called it the rule of excluded middle? Does it lose its lawhood status and gain rulehood? Okay, getting back to it, so when pressed about why do the laws exist, physicists tend to retreat to grander theories, because why not? So we have tag marks, mathematics, universe hypothesis. Reality is mathematics to him. Laws are invertible because they're just mathematical structures that exist in some platonic realm, and every self-consistent mathematical structure exists as a universe somewhere. I'm not sure he believes this. I did speak to him here. Then there's Lee Smollin's cosmological natural selection. This is where the universe reproduces

Starting point is 00:03:19 through black holes with slight mutations in their laws. We see our particular laws because they're going to be optimized for a black hole production by following natural selection. By the way, I've spoken to Lee here. And again, I'm not sure that even he believes that either. Then there's Wheeler's It from Bit that says that laws somehow emerge from information. Reality is fundamentally made of yes or no questions or answers to those yes or no questions, and physical laws are somehow patterns in this cosmic questionnaire.

Starting point is 00:03:51 And I've spoken not to Wheeler. I've spoken to Amanda Gefter on this topic here and John Norton himself has critiques here about physics as information. Now you may think that some of these solve the problem but in some manner it's probably not satisfying to you. It seems like each is just pushing the problem back. So Tegmark needs to explain

Starting point is 00:04:10 well why these mathematical structures and not some others and then Lee Smollin would need to have some meta laws governing the universe's reproduction and Wheeler as well. So why this information or what governs the laws of information, is it just math, then are we in a subset of the mathematical universe, and we inherit all the problems from that? And then, of course, there's the circularity of did the observers come first, what was there when there were no observers, and so on and so forth. I'm sure you get the idea. In fact, I've talked about much of these in this video about philosophers versus physicists, which has somehow gone semi-viral.

Starting point is 00:04:48 Now here's where philosophers earn their keep. Putnam's model theoretic arguments shows that even if physics could derive all of its laws from some fundamental principle, we couldn't know if we found the true explanation, the quote-unquote true explanation. The reasoning is that for any theory, let's call it T, that explains our observations, it has multiple models. You can think of these as different ways of mapping the theory's terms onto reality. This is actually one of the reasons why Putnam thought that the Loenheim Scholem theorems weren't a mere mathematical curiosity like most did and still do. To me, the real philosophical meat, or even just general meat, is in, what do we mean by law? But you are a clever chap. You saw that coming.

Starting point is 00:05:38 You make me work hard. So when physicists say law, they usually mean something like F equals M.A. and of course there are more complicated versions of this. But philosophers have been sharpening their knives on this for decades. So there's the Humean view, not the human view, although it's related to that, where laws are just patterns in the mosaic of events. In other words, they describe regularities, but they don't govern anything. So David Lewis, for instance, champion this, that laws are whatever give us the best combination of simplicity and strength in systematizing facts.

Starting point is 00:06:13 There's also the non-human view, where laws actually have some genuine oomph, like they're not just these descriptions, they're prescriptive constraints on what happens. The recent Eddie Chen paper on the laws of physics frames this whole debate as fundamental laws are constraining physical possibilities. I've spoken to him along with Barry Lauer on this exact topic of what constitutes the laws of physics over here. But you probably think this is recursive, and I'm with you there. Are we defining laws by what's physically possible? Okay, that's defined by what? The laws or some meta-law? Constructor theory, by the way, also does what's possible versus impossible, but to me, that's akin to assuming a law of possibilities,

Starting point is 00:06:58 a law of laws. Also, I'm just in general not a fan of, quote-unquote, in-principle arguments. Like, what does in-principle even mean? It turns out when you examine this, it's not so clear. There's several types of in principle. There's physical in principle, logical in principle, and so forth. I've written about that on my substack here. With Amex Platinum, $400 in annual credits for travel and dining means you not only satisfy your travel bug, but your taste buds too. That's the powerful backing of Amex. Conditions apply.

Starting point is 00:07:35 As an aside, it's not even clear is F equals. M.A., which I said was a law before, is that a law, first of all, or is that a definition? So maybe the problem isn't that physics can't explain whatever that means its own laws. It's just that the concept of explanation seems to presuppose some regularity. But then regularity seems to just be another synonym for something that's either the law or law-like. It's like asking, well, is influencer a job? Or is it just unemployment with better photos? Okay, so let's think about this.

Starting point is 00:08:10 What does it mean to explain something? Generally speaking, it means to connect something that you're trying to explain to something else via some reliable pattern. Okay, so a law. I'll give you an example. So let's say that an apple falls. Why? Then you invoke gravity. However, then to explain gravity, you may invoke, well, there's curved space.

Starting point is 00:08:37 FaceTime, whatever that means, and some Einstein equation. So then to explain those, it's like you need ever more laws like a Russian nesting doll made of disappointment. Even distinguishing laws from something that are accidents, quote unquote, presupposes laws. So why is that? Look, if you have something and you're like, this is a law here, and then this guy here is a mere accident, you can't say that without having a criteria for what's the law, which itself, is grounded in laws. I understand that Barry Lauer tried to escape this with his package deal account

Starting point is 00:09:15 that says that we get laws and natural properties together and somehow this bootstraps our way out of circularity. But is this just pushing the problem back? Do we now have to explain why is it this package and not another? I don't know in this case because I don't grasp a Barry's concept,

Starting point is 00:09:33 but I'm just letting you know about it and placing links in the description in case you're interested in. learning more, and feel free to comment and fill in my benightedness. Also about explanations, I spoke to David Deutsch. He has fairly developed views on what distinguishes good from bad explanations. So part of the issue is that it seems like whatever justification you give will always have one of three problems.

Starting point is 00:09:58 This is called Agrippa's Trilemma. It's also known as Munchausen's Trilemma for some reason. So one is this infinite regress. each law is then going to be explained by some deeper law. If it turns out there is a simple ultimate law that explains everything, so be it. That would be very nice to discover it. If it turns out it's like an onion with millions of layers and we're just sick and tired of looking at the layers, then that's the way it is. The second is circular reasoning, that you presuppose what you're trying to explain.

Starting point is 00:10:25 So if the laws explain themselves, then we would consider that to be a circular account. Third, and you've probably guessed this, it's called foundationalism, is that you have or you assert that something is just a brute force fact at the foundation. It's like a dogmatic assertion that you cannot justify, and if you could justify it by pointing to something else, then that something else would be itself the foundation. Or again, the infinite regress or circularity. Now, none of these are satisfactory to most people,

Starting point is 00:10:54 at least not most people that I talk to. Most physicists are either consciously or unconsciously choosing option three, like some brute fact. The universe just has these symmetries or what have you, But is that an explanation to you? Or is this some admission of explanatory defeat dressed up as profundity? It's like asking, why is logic logical? The question seems to use the very thing it's questioning.

Starting point is 00:11:18 You can't, or at least it's difficult, to stand outside logic and examine it objectively, because your examination itself would need to be logical, or you could be illogical, in which case, good luck with that, or you can be extrological, give it some special dressed up name, it's metological. At that point, you're touching on something that may be theological, where reason gives way to faith, as Kierkegaard would say. Note that I've spoken to Jonathan Pajou about this here, and Jonathan actually consistently asks the question of, from where do you stand when making some critique or claim, whether it's for God, against God, or four signs,

Starting point is 00:11:54 whatever. Many of us think that we're standing from some objective place of nowhere, some point of view of the universe, but Jonathan, and he's in the good company of other philosophers, believe that that's an assumption with embedded values and that this will always be the case for any perspective. Now, there are ways of getting over this Trilemma, and I'll explore more of these later on this channel. I've talked to Jennifer Nagel about this, but feel free to subscribe if that's interesting to you.

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Starting point is 00:12:40 Or even tea time, tea time, tea time you. So update on Dave. It's up to you. We'll take the laundry. Rinse. It's time to be great. Recent papers keep trying to square this circle. Like there's a law without law. That's a literal title of a paper. And it appeals to emergent regularities from quantum mechanics.

Starting point is 00:13:00 but, of course, quantum mechanics itself has the Schrodinger equation and the Bourne rule, so then law without law becomes like alcohol-free beer. Why are you even here? Cupid approaches say that laws are features of our beliefs, not reality, and then they claim that this dissolves the problem by denying that there's anything to explain. You probably don't buy it, and neither do I, though I am glad that it allows me to say, it's not you, it's quantum mechanics, as a valid breakup line.

Starting point is 00:13:29 Perhaps asking physics to explain its own laws is like asking a system to step outside itself and justify its own foundations. It's like asking English to explain why does it have grammar, though Elon Bernholz has thoughts on this, by the way. This is extremely deep to me because the concept of explanation itself seems to me to presuppose lawhood. Now, if explanation means subsumption under laws, then asking for an explanation of laws is like asking for the laws to subsume themselves. By the way, I have tried to subsume myself, and it's not pretty. Still hurts. I'm deeply interested in this line of thinking because I'm terribly interested in what it means to understand and what it means to explain, and I think this will lead to revelations about that. I think what does explanation mean itself is actually at the heart of

Starting point is 00:14:21 what one wants when one searches for a theory of everything or a theory of nature or even purpose. So I don't think this seeming impossibility of physics explaining its own laws is actually a failure. It's only a failure if you think physics is supposed to explain itself. But to me, this whole line of questioning is the success of clear thinking about what explanation can and can't be. Basically, every theory of everything has this problem. So even if we found some unique mathematical structure that gives rise to our universe, we'd still need to explain, well, even why mathematics at all, why these mathematical structures have physical instantiation compared to others,

Starting point is 00:15:02 why the correspondence between math and physics. By the way, in case you're wondering, I don't think there's an unreasonable effectiveness of math, but that's a present deliberation of mine that I oscillate on back and forth. I keep a list of these problems that I frequently 180 my mind about, and I write about that on my substack here. The usual move is to just take one of these or something else and just say that's fundamental.

Starting point is 00:15:24 Look, here it is. stop asking questions, shut up and calculate, and that's fine for physics, for the practical aspect of physics, but it's intellectual surrendering for understanding reality. Maybe the actual answer here is that explanation itself has limits. Look, math has limits. In some cases, though that's been overblown, here's my video dispelling the myths of girdles and completeness theorem, but anyhow, science itself has some limits in a Putnamian sense. So perhaps the same goes for explanation in general, not because we're creteness or haven't found the correct theory, but because explanation by its nature is a concept that only makes sense

Starting point is 00:16:05 within a broader scaffolding of regularities. So remember the opening question. Why do physical laws have the form that they do? The answer isn't that we don't know yet or we just need a better theory, it seems like any possible answer itself would be a law or require its own explanation. At least this is my present deliberation. Subject to change pending new explanations. Unwrap holiday magic at Holt Renfrew with gifts that say I know you. From festive and cozy fashion to luxe beauty and fragrance sets. Our special selection has something for every style and price point. Visit our Holtz holiday shop and store or online at Holtrenfrew.com.

Theories of Everything with Curt Jaimungal - Curt Jaimungal: Can Physics Explain Its Own Laws?

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