[MauranKilom]

> The scientific method only works because the rules of the universe happen to be simple, while the set of observations it offers is vast. Kolmogorov complexity captures this defining characteristic of our reality.

I've never seen this spelled out so beautifully!

[ordu]

It is a funny statement, I like it. But due to a different reason: all we know about reality is our theories. How we could state, that rules of the universe are simple? As I see it, we could state, that our theories are full of simple rules. But the universe have no theories nor rules outside of human's mind. It is completely our inventions, our dreams, our hopes that the universe have some rules.

We could state that our simple rules works, but what does it mean "to work"? For example, a spider sees reality not like us, it feels vibrations of it's web, runs to a source of vibrations and start to bite, to wrap intruding object with web. It would do it to a tuning fork, if you pressed it to spider's web. His simple rules of reality works though. Despite the fact that sometimes spider bites steel of a tuning fork without any benefits for the spider.

How could we know that our theories not just extended version of spider's? With the same issues, like they make us to do something absolutely pointless. How could we evaluate this fact? To ask our theories? But our theories already predicted that this pointless thing we do would be a good thing. We might ask our theories again and we'd get the same answer.

This statement seems as a tautology for me. Our rules are simple, because they are simple. Our theories work because they tell us, that they work.

[MauranKilom]

I think there is a disconnect between the "rules of the universe" that the quote talks about and the "our simple rules" that your comment focuses on. Without getting too philosophical, I think we can agree that there are "rules" how the universe works (which is what the quote talks about), which are not necessarily the same as the rules that our theories postulate (what you talk about), although we of course try to get closer and closer.

That we can only observe, talk about and know reality in our subjective ways does not mean that there is no underlying mechanism by which reality "works". The quote points out that this "mechanism" is apparently sufficiently simple that we can effectively form and test hypotheses about it.

For example, we have no all-encompassing explanation of the universe that concludes R = U/I for electric circuits. Yet we can observe it to be accurate independently from the infinity of conceivable influences - there appears to be no influence on this observation from your lunch, the day of the week, whether your car is green or somebody was just born in Taiwan. We can't explain why these have no influence. We could imagine a reality where all of these (and infinitely many others) are confounders, in which case we could not effectively form theories about these rules. Yet the actual number of things influencing R = U/I observations in our reality are evidently very finite, allowing us to identify them and build our theories.

[ordu]

> Without getting too philosophical, I think we can agree that there are "rules" how the universe works...

Well, maybe I am too philosophical, because I feel myself reluctant to agree. I accept science method because I know nothing better. But I doubt the idea, that there are no possibility to invent something better.

> we have no all-encompassing explanation of the universe that concludes R = U/I for electric circuits

I'm not a physicist to argue with it. But somewhere deep inside me I see R = U/I as a tautology too. R, U and I was defined by a way, that made R=U/I true. There is some information about the universe encoded in this rule, but there also information about us there. How to separate information about the universe from information about us?

[DiogenesKynikos]

Science has an empirical aspect that you're ignoring here. Our theories are tied to nature through experiment. They are more than just inventions of the human mind. People come up with new ideas about nature all the time. Most of them are wrong, and we find that out by doing experiments.

[ordu]

Yes. If we take a look at social sciences struggling with experimental method, we'll see, that they get better with time. When experiments do not work, people somehow figure out how to do experiments better, and it changes things. It gives a hope that experimental method could falsify itself, so when it stops working we will be able to notice it. So if we do not see it to fail, we could assume that it works.

[6gvONxR4sf7o]

I disagree that the rules just happen to be simple. Thinking in dynamical systems or evolutionary terms, a language and mental model of the universe just won’t stick around unless it’s useful. Imagining that the universe happens to be horribly complex, but has some emergent phenomena that happen to be simple, we’re almost inevitably going to think in those simpler terms and go “wow the universe is simple!”

Then if the foundation underlying those simple emergent concepts turns out to be horrible complex, maybe we get stuck with the foundations at some point. Or maybe simplicity is relative and a visitor from a different hypothetical universe would be astounded at all the shit we have to simulate because the answer isn’t just obvious.

Like how macroscopic objects are an emergent phenomenon, but they’re simple. Maybe the universe at a fundamental level follows some ultra convoluted string theory. Doesn’t matter for us, the same way that flipping a coin is 50-50 regardless of questions about foundational physics.

It’s taken a long time to develop the hierarchy of physical and mathematical concepts in which we can usefully describe much of the universe as simple. And those concepts, the best we have so far, still don’t tell the whole story.

[lisper]

> if the foundation underlying those simple emergent concepts turns out to be horrible complex

That is extremely unlikely. The simplicity of the universe is not just an artifact of our best theories, it appears to be baked into the very structure of those theories. If our current theories are even in the ballpark, then there are very few places that hidden complexity could possibly hide.

Take quantum randomness, for example. It used to be thought that the apparent randomness could just be papering over our ignorance of some hidden underlying mechanism, but it turns out that we can prove that this is not the case. We can eliminate entire classes of theories based on finite observations, and one of the classes that we can eliminate (with very high probability) is theories with high Kolmogorov complexity.

[6gvONxR4sf7o]

I assume you’re taking about the Bell experiments. Imagine that it’s the nonlocality side of things that ends up being correct. In that case, a full foundation of QM could be a nightmare.

Regardless, we don’t have a full unified theory of everything, so it seems premature to say we know how complex it’ll end up needing to be.

Also, the universe isn’t just an time evolution differential equation. It’s that, plus all the initial/boundary conditions. Saying the Kolmogorov complexity of the universe is small while only looking at the side that’s simplifiable seems circular.

[willis936]

Not everything that is true is simple or catchy. Biasing towards it is a trap.

PBS SpaceTime has a good discussion on this topic.

https://youtu.be/xFKgIOX8IRE

[jhardy54]

Neat video, but it specifically disagrees with your point. He advocates for applying scientific rigor between leaps oc intuition. There's nothing wrong with GP appreciating beauty.

[willis936]

My point isn’t contradicted by the video. My point is not "beauty should not be appreciated". My point is that we should not dismiss models of nature based on aesthetics. Nature has no preference on what we see as beautiful. The video makes the point that beauty should be treated as a guiding principle, not as a hard and fast rule to sniff out truth.

[dkersten]

> The scientific method only works because the rules of the universe happen to be simple

Are they simple though? That's not the impression I get from physicists, eg, the famous Richard Feynman quote: If you think you understand quantum mechanics, you don't understand quantum mechanics.

We haven't even managed to find a unifying theory yet, but the current contenders, like Loop Quantum Gravity are anything but simple.

[Igelau]

> The scientific method only works because the rules of the universe happen to be simple

It's simple in the sense that the universe seems to be the kind of place where inductive reasoning mostly works. For the most part we seem to be able to expect things like predictability and causality at the scale of the objects and processes in our everyday life. If it wasn't like that, things would be a lot more complicated.

[BalinKing]

As I understand it: The rules are simple, but not necessarily intuitive.

[lisper]

Exactly right. The rules of quantum mechanics are in their essence not much more complicated than high school algebra. It is the logical consequences of those rules that are hard to wrap your brain around.

[dkersten]

I have a couple of books on quantum field theory and it looks a lot harder than high school algebra.

[lisper]

Go read a book on number theory some time. It looks hard too. But it is about nothing more than the properties of the natural numbers, which any grade schooler can understand.

Likewise, QM looks hard, but at its core it is little more than linear algebra, which any high-school math student can (or at least should be able to) understand.

[dkersten]

Everything can be broken down to simple easy to understand little bits. The complexity comes from there being many, many of these little bits.

[jhayward]

I've always taken the Feynman quote to mean: just because you understand the rules doesn't mean you understand the implications, which are varied, vast, and counter-intuitive.

[edna314]

Because others already questioned the first part, I’ll question this:

> the set of observations it offers is vast

Actually, in an experiment there is always only one observation at a time. That we group multiple observations together is kind of arbitrary and relies on the hope that the experimental conditions are the same and therefore one experiment is analogous to the next.

[MauranKilom]

Yes, that's exactly the heart of the quote to me: There is sufficiently little complexity in the causality of observable behavior that with sufficiently controlled and repeated experiments/sampling, we can uncover regularities and patterns in it to fuel our predictions (and hypothesize about these causalities).

Does the reading of your multimeter depend on the digits of Arnold Schwarzenegger's phone number? Do you have to repeat the experiment if his phone number changes? Indeed, we assume that this is not an "experimental condition" to take into account. There is no way to determine this a-priori, and one could conceive of a universe with an arbitrary amount of such strange influences. But we do not appear to live in such a universe, which is why we get to apply Occam's Razor.

[edna314]

> Does the reading of your multimeter depend on the digits of Arnold Schwarzenegger's phone number? Do you have to repeat the experiment if his phone number changes? Indeed, we assume that this is not an "experimental condition" to take into account. There is no way to determine this a-priori, and one could conceive of a universe with an arbitrary amount of such strange influences. But we do not appear to live in such a universe, which is why we get to apply Occam's Razor.

I think this is not true for every experiment. For example if you measure the polarization of a photon it will have the same polarization in any subsequent experiment, no matter how hard you try to reduce complexity.

Also, my comment was rather directed at the fact that any experiment has a unique outcome. In that sense we we can’t have perfect control over an experiment, since at least time must have passed between subsequent measurements, such that the experimental conditions are different.

[karmakaze]

The patterns in our observations appear simple, the rules are deeper: e.g. newtonian motion vs relativistic.