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Comment by Diogenesian | Hacker News Reader

There are a lot of long comments basically saying what I am about to say so I will try to keep this brief:

Computation is a metaphysically universal and fundamental concept, since metaphysics is (tautologically) the domain of humans and we use symbolic communication. So of course very general theories of symbolic processes (e.g. Turing machines) are pertinent to the symbolic methodology we use to understand scientific processes.

But it is a fundamental mistake to jump from that to saying computation extends to a law of the universe. Computation reflects laws of the universe, but only in the exact same way that scientific and mathematical human speech do. The mystery (still totally unsolved) is how humans are able to intuitively understand space / time / causality / etc in order to define coherent symbolic rules that reflect real processes. That computers can seemingly always implement these rules having been given the symbols is of philosophical/scientific interest, but it's solipsistic to say it's a fundamental concept of the universe.

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This is a misconception. It’s more fundamental than that. There’s a fundamental connection between (Shannon) information theory and thermodynamics. The Landau Limit, whether blackholes can destroy information or not, quantum mechanics, etc.

Information is actually tangible. It’s not just an analogy or a coincidence that the word “entropy” is a word used in both physics and computer science (information theory). Thermodynamics, mind you, is perhaps THE most fundamental elements of physics and how the universe works.

Did you mean landauer?

Yes. Unable to edit it. https://en.wikipedia.org/wiki/Landauer's_principle

Information and computation are not the same thing. I was very specifically talking about Turing machines and other theoretical models of computation.

That said, you are still making the same mistake I pointed out, elevating human symbolic information to a higher plateau than it deserves. I think it's because you're being too vague about the connection, when it's fairly mundane. The "fundamental connection" is that physical quantities are information, and on the other hand information is always a large collection of semi-independent semi-stochastic physical objects and can be profitably modelled by some sort of statistical mechanics. Information theory is relevant all over physics because human agents collect all sorts of physical information. The universe "doesn't care" about information in and of itself. Shannon entropy and Boltzmann entropy have similar formulas because they measure precisely the same thing; put another way, a goofy but formally equivalent way to model a gas would be a noisy radio channel communicating each molecule's kinetic energy.

The problem with the black hole information paradox isn't that information is destroyed per se, but that it appears to be destroyed in a way that violates quantum mechanics (destroying quantum state without a measurement). The theoretically predicted destruction of information points to a more general problem.

The Laundauer limit is no more fundamental to the universe than "a mechanical crane cannot violate the laws of pulleys." It says that no matter how you design your binary (or whatever) computer, it must involve an ensemble of binary states, and statistical mechanics puts an absolute floor on how little heat is required to alter such states. Whether these states are gas molecules or the written symbols "0" and "1" is immaterial.

> Information and computation are not the same thing.

Shannon information, sure.

However, algorithmic information (Kolmogorov complexity, etc.) is based on computation.

But that just takes us even further from physical relevance / universal fundamentals. Kolmogorov complexity is fundamental in computation, but its relevance in physical science is pretty selective.

I’ve always hated the use of the word “information” in relation to things like spin.

Information and order are effects of human perception and preference. They exist as abstractions in the mind and not in reality.

Best way to show this is to implement information in multiple physical substrates. Make a book out of paper and make it out of clay. Same information. The physical substrate doesn’t matter.

A parallel concept to this is from functionalism/theory of mind in Philosophy is that of Multiple Realisability

It’s not as simple as for example degrees of freedom and the states for a system is “information” and those one can argue are physical.

This. I'll never understand people who reify "information" as though it is some object with independent existence from man.

No information without an interpretation. The "amount" of information is completely dependent on the observer.

You'd think people who work constantly with abstraction wouldn't fall prey to reifying abstractions but they actually seem more susceptible to it than anyone else.

I think you are prematurely dismissing something deeper here.

The more I learn about the fundamental nature of the electron, probability in quantum mechanics, and the wave function in general... the more information being fundamental substrate makes sense.

I'm not saying it is... just that it makes more sense the deeper you get.

Yeah, but my point is that "information" is not really a substantive concept. It is an abstraction. It is a useful technical tool. For the record, I am a nominalist when it comes to mathematics. Thinking that information is some "real thing" with meaning independent of theoretical context and interpreters is a definitely Platonisist perspective (the idea that our mathematical representations are not merely useful technical models but that they correspond to some real substantive elements of the real).

Claiming that "information" is the underlying basis of the real is the same as effectively saying that "stuff" is the underlying basis of existence. It's essentially Platonism. It is not informative. What is informative is the operational use of the mathematical concept of information as defined by Shannon to understand real things or to structure theories. But this is a very different thing than identifying a substance that exists, independently of us in the universe. This "making real" of what is ultimately a mathematical abstraction is precisely reification.

This stance is very tempting because it appears so straightforward and no-nonsense. But there are issues which undermine it in my mind. Because, at a closer inspection, it itself doesn't seem informative, in the end coming down to a question of semantics, i.e. how we define the word "reality". Which then determines whether it encompasses the realm of mathematics or not. I wonder what definition you favor, but the language you use points towards something like "the totality of all things" or "everything that's made from a physical substance". Yet platonists and other realists wouldn't argue that numbers are made from a substance as you imply.

Physical reality is a slippery thing. Yes, at the level of our daily life it all seems very solid and obvious, but inspecting that foundation revealed a bewildering world of relativity and uncertainty. And one of the most intriguing ways out of this bewilderment seems to be the "it from bit" trend in physics, which makes information the fundamental reality.

I personally don't feel the need to tie the notion of reality to physical phenomena. I prefer something more along the lines of Philip K. Dick's "reality is that which doesn't go away when you stop believing in it", or, as you put it, "something which exists independently of us". The fact that there are an infinite number of primes, is such a fact. Surely any alien civilization would know this fact. Maths doesn't go away when we look away, and neither does the notion of computation. Sure, Turing machines are a human construct, and there can be others as well. But the Church-Turing thesis speaks about how these constructs all ultimately describe the same underlying reality.

"it from bit" is just "shut up and calculate", positivism. There are no bits in physics, and no boolean phenomena.

Let me try again. We use miles to measure distance. Hopefully you agree with me that, miles, being a system of measurement to express relationships of distance, have no ontological existence themselves. I would find it completely bizarre, for example, for someone to argue passionately that, "no miles are the real deal and something that exists in the universe and meters are a fabrication". Distance surely is a real phenomenon, but "miles" are a system of expression.

Bits and information are the same thing. They are a system of measurement to express relationships of difference. Difference and change as physical phenomena exist, but bits do not.

So, yes, pointing out that the limits of computation give us some useful facts about the way things change in reality is a useful perspective. Going further and saying something like "computation is the basis of reality" or similar extremes is too reductive and too abstract to really be a useful piece of knowledge in my view. Finally, to claim that information is somehow the important fundament of existence is patently absurd to me, since it would've similar to arguing that miles have some very special epistemic and ontological status.

That's just it though.

Yes, separating symbols/descriptions from the physics is a common conflation, rightfully avoided and called out here, but I think you might be overcorrecting unconflating the concepts too much.

Quantum information is strange precisely because the theory treats information-like relationships as physically consequential.

Entanglement, path dependent stuff, cloning theorum, black hole information paradox... There are so many areas you run into where its information-centric descriptions appear to fit unreasonably well.

Again, I'm not saying the symbolic representation is "real" per se (not saying it's not either, I simply don't know what it is).

I agree bits are just nomenclature, but I don't agree that "bits" and "information" are the same thing. Like distance, "information" has a deeper and general architecture to it.

And it's also weirdly physical in places that I wouldn't expect it to be, for reasons I simply don't understand at the moment.

I don't know enough about the quantum level to really understand whether or not that would change my view of things.

From Shannon's theory, it's abundantly clear that "information" is just a mathematical description of difference and expectation. I can frame anything as information. If I know who my parents are, a statement about who they are is not informative to me because it constitutes no difference. The entropy and expectation/surprise is low. If someone approaches me with a compelling argument that no, actually, my parents are not my parents I was adopted and my real parents are so and so, this is informative. The entropy is high.

Crucially, this all depends on me my personal history, and my status as an observer. It is in this sense that I find information to be a communications concept (which is how it started!) or semiotic concept more than a useful abstraction for organizing our knowledge about other parts of reality. Yes, the abstraction might still be useful if e.g. quanta end up behaving in some way according to shannon's laws, that is interesting, but to me uh at is not an argument that turns information into some kind of "universal substrate" of the real—it is just a surprising applicability of laws in one domain to another. Is it surprising that empirical data fit the model? Maybe. Idk, lots of empirical data can be made to fit all kinds of models (there are ways in which hI can reasonably take a Newtonian view of various aspects of my life and the data generally won't contravene the laws).

> From Shannon's theory, it's abundantly clear that "information" is just a mathematical description

That's a very narrow and technical definition of information. It's what people refer to by the word when they discuss things like: communication, medium, surprise, compression, etc. in a technical context. Otherwise one should refer to the dictionary definition, so we don't end up talking past each other.

If you'd like to get a better intuitive sense of what "it from bit" points at, check out David Deutsch's Constructor Theory and the Stephen Wolfram Physics Project. Also, Bernardo Kastrup, on the philosophy front.

> Finally, to claim that information is somehow the important fundament of existence is patently absurd to me, since it would've similar to arguing that miles have some very special epistemic and ontological status.

As the sibling comment says, no, it is like arguing that distance/space/extension has a special ontological status — which it does. "It from bit" is just using the word "bit" for the rhyme, the theory is quite profound and compelling, at least to me.

Then there's also Max Tegmark's "Mathematical Universe" idea, which makes the symbolic world the fundamental one. It goes a bit far for my taste, but it has its own internal coherence.

This is the way. But what is interesting to contemplate is _why_ smart people try to reinvent religion. I think it reflects their deep need for meaning and immortality. Religion in the naive sense, a bunch of stories, myths and bearded gods, if obviously silly and childish. The modern rationalist who has not managed to shed his reflex/need for religion, then reifies (or perhaps better said... "deifies") information, and thus introduces all kinds of potential immortality and an ideal realm. Just like the myths of religion did, in a more naive sense, since time immemorial.

Landauer’s Principle (a direct consequence of the Second Law of thermodynamics) shows there’s a very clear physical manifestation of information and information theory, it is not just human perception and preference. https://en.wikipedia.org/wiki/Landauer's_principle

A more concise explanation is that, computation is the transformation of information. Any transformation of information is computation, and is thus subject to some theory of computation. A physical process involves the transformation of information, so can be studied with a theory of computation.

> A physical process involves the transformation of information, so can be studied with a theory of computation.

A rock rolling downhill has state-dependent future behavior you could describe informationally, but nothing is gained by modeling it with automata theory instead of Newtonian mechanics, and it isn't computing in any substantive sense.

Quantum mechanics is pretty fundamental but you wouldn't use it to describe a rock rolling down hill either.

> It’s not just an analogy or a coincidence that the word “entropy” is a word used in both physics and computer science (information theory).

Shannon asked von Neumann what to call it, and von Neumann said "You should call it entropy, for two reasons: In the first place your uncertainty function has been used in statistical mechanics under that name, so it already has a name. In the second place, and more important, nobody knows what entropy really is, so in a debate you will always have the advantage."

I’m aware of the von Neumann joke.

There is, however, a direct equivalence between them derived from the 2nd Law of Thermodynamics. https://en.wikipedia.org/wiki/Landauer's_principle

Um, only the second part was a joke. The first part was confirmation of your statement that it's not just an analogy or coincidence ... and Shannon followed von Neumann's advice (not joke).

You can say things like, “In the domain of physics, X,” “Assuming the scientific method, X,” or “Assuming the premises of logic, X.”

But “computation is a fundamental aspect of the universe”, in the way it's being understood in this thread (as opposed to the article) does not remain within any of those frameworks. It makes a claim about reality as a whole.

Once you make that kind of universal claim, all the assumptions built into “computation” - about identity, distinct states, lawful transitions, causation, logic, etc. - become part of the claim. You cannot use those assumptions silently and then present the conclusion as framework-independent.

And those frameworks come with consequences. Using the language of computation, they come with "lossiness" wrt modelling "reality".

(see Aristotle Metaphysics -> Kant CoPR -> later Wittgenstein)

The Heisenberg Uncertainty Principle and the Laws of Thermodynamics are pretty d*mn fundamental.

The Church-Turing thesis (the fact that all models of computation we've been able to come up with are equivalent) gives the necessary weight to that claim.

The Church-Turing thesis is a statement about symoblic processes, and symbolism is simply not fundamental to the universe. It is fundamental to how humans understand the universe. That's the distinction.

Thank you. I’ve been thinking about this for a while now and couldn’t express what I was thinking about… but when you linked information theory to thermodynamics, it clicked.

Given the quantum fields were collapsed in the early universe, I’m now wondering how information theory looked like during the different phases on the universe

A related question might be, what's the difference between mathematical (Godel), computational (Turing,) and physical (Yang-Mills) undecideabilty/computability?

Agreed. I’ll also make an observation based on this thread: the idea of computation as a fundamental law is most believable (and desirable) to people who like computers and want to reduce reality to a computer.

The belief is like a cheat code: somehow our tinkering and 9-5 job somehow grants us, the computer nerds, a deep understanding of life, the universe and everything. Deeper than scientists, philosophers, etc. It’s epistemic catnip and pretty tasty at that!

Prove any of this. Or at least provide a cogent argument for it. To me it looks riddled with mistakes, like

> metaphysics is (tautologically) the domain of humans

which is frankly incoherent.

Metaphysics operates one level up from physics or the sciences, asking what reality has to be like for anything, including the sciences, to be possible or meaningful at all.

I know what metaphysics is (and your description isn't accurate--science is a knowledge-producing method that doesn't depend on metaphysics in order to be meaningful), but that has nothing to do with my statement. And it's called "metaphysics" because Andronicus placed that volume after the "physics" volume when he organized Aristotle's writings.

Science absolutely does depend on metaphysics. Most famously: the validity of the scientific method is ultimately a metaphysical extension of our intuitions about inductive reasoning and causality. There is no scientific proof that the scientific method is valid. ("Our intuitions" is why I said metaphysics is tautologically the domain of humans. This is essentially Kant's philosophical legacy: science will describe what it does, but humans intuitively understand reality in ways that defy noncircular scientific description, and metaphysics must be invoked to have a rational and grounded discussion about these intuitions.)

Isn't it obvious that scientific method is fallible? It's just statistically better than pure reason, which should be possible to demonstrate statistically. It's a product of trial and error, and there were many errors, I don't think there's much metaphysics there.

The problem is not that it's fallible, but that there's no noncircular explanation for why it seems to work. Inductive reasoning doesn't have a rational explanation, only an intuitive one.

I don't think your claim is possible to prove statistically - what does "pure reason" mean? And of course it's "pure reason + empirical observations": even if they're not running reproducible experiments they still see natural phenomena.

It works because humans looked for a method that works, they tried different methods and chose one that works best, actually it gradually evolved over time.

Pure reason is conjecture with little empirical input (and big intuitive or memey input) and little verification of output, i.e. a large deviation from empiricism.

I asked for proof of claims and I just get "it absolutely does" and a bunch more assertions, and word salad like "the validity of the scientific method is ultimately a metaphysical extension of our intuitions about inductive reasoning and causality" -- there's nothing "metaphysical" about it ... the scientific method is a disciplined application of an effective process of discovery. And '"Our intuitions" is why I said metaphysics is tautologically the domain of humans' is more word salad -- "tautologically" has no business in that sentence, and none of the rest of it makes any sense either. Humans have multiple domains, not just "the" domain. Metaphysics is a field of study that non humans capable of studying can also study. Metaphysical facts govern everything, not just humans. etc. I consider this sort of junk to border on bad faith ... it certainly isn't of any use to me, and I have no interest in engaging with it.

> There is no scientific proof that the scientific method is valid.

The scientific method is provably effective in a lawful world. That the scientific method isn't provably effective is because the world is not provably lawful ... it's logically possible for the "laws" of physics--which are simply regularities that we have discovered--to suddenly change, oscillate, be random, etc. But as long as they don't the scientific method works ... and we can't do better. (Not in this world, anyway ... in some other world there might be oracles (aka gods or bibles) that always have the right answer and we could simply query them. Of course, such oracles are also not provably correct.)

There is no single "scientific method" to speak of. Your epistemic position is ultimately just as faith based as you claim faith in God etc. is, the sciences (plural) just have a set of operations which, as you point out, seem to have practical utility and seem to be better than certain alternatives for building up shared epistemic structure.

The attitude of "we can't do better" is precisely the kind of attitude that would have hampered the creation of various sciences and their methods in the first place, and the production of scientific thought is often not as pure or logically consistent as all the methodological purists or Popperians seem to believe it is. Feyerabend, Quine, Von Foerster, Dataon and Gallison and several others have made this pretty clear and make the argument pretty forcefully in my opinion.

All sciences carry an ontology and value system along with them. Religion is also a rich and highly effective epistemic structure when your underlying ontological assumptions, values, and goals differ from those established and implicit in the scientific (predominantly utilitarian) Western enlightenment value system. Science is not able to found itself on some irrefutable bedrock "truth" correspondence any more than religion is. There is no basis by which we can actually solidify empiricism as somehow more privileged and more capital T true if we admit the possibility of human error.

Agnosticism is an example that nobody wants a theory that works but not empirically. If a theory works, then it must work empirically, in this sense empiricism is tautological.

> Your epistemic position is ultimately just as faith based as you claim faith in God etc.

This lie is so tiresome.

It's notable that science has a history of effectively producing confirmable fact whereas religion produces only falsehoods.

You are missing the point. Let me use "fabulashinaism" which is a theory I just made up that posits that the universe is made up of little gnomes called atoms.

There is a sense in which all of my observations hence will be "theory laden". When I seek "proof" i'm likely to do so within the constraints of fabulashinaism.

Science proceeds in the same way. Only crises, which are unpredictable and may have much more than simple "new data collected" behind them actually drive theory change. Beyond the theoretical assumptions, many of which are not proven but are constraining hypotheses, there are the social value assumptions I mentioned as well. As someone else said in the thread, science cannot prove science. You can be of the opinion that it's been more effective than alternatives, and I would agree, but there is no way to prove this because it is ultimately a question of theoretical assumptions and of values.

Observable effectiveness can be demonstrated statistically. The only option I see is if it's unobservably ineffective, which can't be ruled out experimentally.

I'm not missing any point and I have no interest in engaging with anyone who opens with that sort of strawman ad hominem.

Also Ramanujan summation.

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