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Computation as a universal and fundamental concept

177 points by simonpure 3mo ago

sgt101 3mo ago
Computation has turned out to be a far more general concept than I think was imagined, up to the point that many computer scientists now seem to equate computation with the functioning of the universe. Recently it's been shown that there are real, physical processes which are undecidable (we cannot know if a latice of atoms has a spectral gap or not, we cannot determine if a specific particle in a fluid flow will reach a specific place or not, we cannot determine if a ray of light will reach a specific target in certain configurations of reflection). Our world appeared computable, but it isn't, even if P=NP.
- gradys 3mo ago
  It can be the case that both: - The physics of the universe can be completely modeled as computation, and - It's possible to pose undecidable problems about the way the universe unfolds This is intrinsic to the idea of undecidability even for Turing machines, e.g. "we equate computation with the functioning of Turing machines, but there are real processes executable in Turing machines that are undecidable".
  - sgt101 3mo ago
    Of course, if our universe is undecidable it must be the case that computable processes can be executed within it, and it might be the case that all of the processes that are ever executed within it are computable... but it might be that some of the processes that are executed are not computable... because the machine may.. or may not?
    - jerf 3mo ago
      I think there's an equivocation of "computable" going on here. Mathematicians talk about a lot of things like "uncomputable sequences" but that is usually making a statement about the sequence, not necessarily any individual member. The Busy Beaver sequence is uncomputable. You can, however, quite trivially compute BB(2), even in your head if you're a bit careful. You can set up individual elements of an uncomputable sequence in our universe, and you may be unable to state in advance what the system would do with anything less than simply letting it run and see what happens due to the complexity of the system, but being a member of an uncomputable sequence doesn't mean that you can't in fact set those things up and watch them run. The Universe doesn't throw an "UncomputableCircumstance" exception or anything. It just keeps advancing to the next state. Your inability to make certain statements about that next state or some future state is not its problem.
    - chriswarbo 3mo ago
      There's no way to empirically spot an uncomputable process, since it would require infinitely-many observations. For example, if aliens claim their machine solves the halting problem, we could test it on millions of inputs whose halting/not-halting behaviour we already know; but even if it works for all of them, there's no way to know that it works for all inputs. For all we know, it might be a huge lookup table which happens to cover all of those inputs we tried.
      - peter_m1 3mo ago
        No, you can prove things hold in the abstract mathematically, don't need to resort to physical systems.
        chriswarbo 3mo ago
        I was responding to this part: > if our universe is undecidable My point is, there would be no way to empirically test this; and therefore, it would make no observable difference, there would be no way to exploit/utilise such effects, etc. In essence: there's no way to tell the difference between a real halting oracle (which would imply an undecidable universe), versus a computable approximation which just-so-happens to be more powerful/sophisticated than the approximations we compare it against. Sure, we can prove that some abstract systems are undecidable and that others aren't. Yet that distinction is inherently unfalsifiable, and hence physically "useless".
    - peter_m1 3mo ago
      Quantum mechanics is intrinsically probabilistic.
      - GoblinSlayer 3mo ago
        Deterministic processes can be modeled probabilistically and are computable, so existence of a probabilistic model doesn't say much about computability.
  - woopsn 3mo ago
    A key thing about the undecidability problem wrt physics is preparation of the initial state. In math and computer science it is relatively straightforward to prepare such problems now (though this represented an enormous leap conceptually), but the "undecidability" of all physical problems relies on construction of materials that are clearly unconstructable - systems of infinite negentropy (eg Turing machines), infinite mass (the lattice), bespoke local interactions etc. Problems standing in the way of physics decidability are typically chaos, far from equilibrium mechanics, elementary SNR considerations and so forth, not problems of logic.
    - peter_m1 3mo ago
      In physics we don't talk about decidability, but solvability.
- Maxatar 3mo ago
  >Recently it's been shown that there are real, physical processes which are undecidable I want to push back a bit on this claim along two dimensions. Imagine a physical Turing machine built out of atoms, gears, levers, and an electron parked on the read/write head and ask whether that electron ever crosses some fixed plane in space, which it does only when the machine enters its halt configuration. That's now a purely physical question about a trajectory (does this electron ever reach a certain target), yet answering it for the whole family of such machines is literally the halting problem, so there's a physical process that's undecidable. Your examples about physical processes being undecidable are all basically just this... there examples of using reflections of light, or the flow of liquid, etc... and demonstrating that these physical processes in principle are sufficient to model a universal Turing machine. And while it's fascinating that certain things you may not have expected can be used to model computation, it's misleading, or rather it's too strong of a claim to believe that there exist actual/real physical processes whose outcomes are undecidable. That's a subtle but very common misinterpretation of what undecidability is. Undecidability, whether in physics or computer science, only applies to the infinitely broad class of a problem as a whole, it never applies to a specific instance of a problem. So it can never be the case that there's a certain configuration of reflections for which it's undecidable whether a ray of light reaches a target. Nor can it be the case that for a specific lattice of atoms, it's undecidable whether it has a spectral gap or not. It can only be the case that for the problem as a whole where the parameter space is entirely unbounded, there is no single algorithm that can decide if a ray of light reaches a specific target for all possible arbitrary (and infinitely many) configurations. Once you fix a specific system, then the undecidability goes away. Not claiming that you are necessarily making this misconception, but I often see people misinterpret undecidability to mean that there exists a specific problem, like with specific inputs, where it's somehow impossible to know what the answer will be. Undecidability always requires an infinite family of instances, and it's a statement about the nonexistence of a single algorithm that correctly answers every instance in that family. It says nothing about any particular instance being unknowable/undecidable.
  - eth0up 3mo ago
    If I am wrong, please pardon. I suspect I am. But was this comment edited by Claude? I ask specifically because it is well written, substantive, all which is expected here, but the "push back" part, to me, must be a) an artifact of Claude, either by osmotic assimilation (Which is happening to many innocent users) or b) Claude itself. Feel free to flag this comment if I get an answer. I do want to know.
- plastic-enjoyer 3mo ago
  > up to the point that many computer scientists now seem to equate computation with the functioning of the universe. Do you think that's a kind of tunnel vision? If the only thing you focus on is computation, you'll probably end up seeing computation everywhere - it became a way of seeing the world.
  - jerf 3mo ago
    It is a common accusation. There's a somewhat famous quote I've seen a few times: "It's interesting to look back through history on this one. Each age has its pinnacle of technology, and each age uses that technology as a metaphor for nature, for the universe. In ancient Greece, the technological marvels were musical instruments and the ruler and compass. The Greek philosophers tried to build an entire cosmology from number, harmony, proportion, form, and so on — from mathematics, basically. Remember the music of the spheres? The Pythagoreans believed that nature was a manifestation of rational mathematics. Later on the pinnacle of technology was the clockwork. Newton wanted a clockwork universe, the entire universe as a gigantic clockwork mechanism, with all the parts interlocking and ticking over with infinite precision. Then in the 19th century along came steam power, and the universe was then depicted as an enormous heat engine, or thermodynamic machine, running down toward its heat death. Today the computer is the pinnacle of technology, so it's now fashionable to talk about nature as a computational process." Which seems to source from https://www.edge.org/conversation/paul_davies-time-loops https://www.edge.org/conversation/paul_davies-time-loops . While "computer" may give us impressions of something with "a CPU" and "RAM" and "a disk drive", it does at least seem plausible that the universe as computation is a plausible base level, though. Unlike "the music of the spheres", which to the extent that it made predictions of the world, it got them wrong in the most basic way, viewing it through a lens of computation allows us to put some quite subtle and interesting limits on things. "Computation" is a pretty flexible substrate; it is difficult to imagine how the proposition "the universe is a computation and subject to the limitations thereto" could be falsified, and if it could, it is difficult to imagine how we would be able to know it was so falsified. Nevertheless the math of computation allows us to say non-trivial things about the universe as a result; it is not a vacuous generalization, though it is certainly a loose one... being able to say yet more concrete things about the nature of the computation, such as "this is exactly how gravity works", has quite a bit more utility.
- mondrian 3mo ago
  Undecidability is a problem of answer-extraction from a process, it doesn’t preclude the process from executing deterministically. The universe could well be the live execution of a deterministic, even basic algorithm, with all kinds of questions about its execution being undecidable.
- __rito__ 3mo ago
  One sentence I heard somewhere wraps up the totality of computing: "If Mathematics is the 'what', Computer Science is the 'how'". This applies to each and everything.
  - athrowaway3z 3mo ago
    If two people agreed on that statement, its entirely unclear if they agree with each other and if they found something profound in the first place. The imo much more foundational relationship not everybody is aware of is https://en.wikipedia.org/wiki/Curry%E2%80%93Howard_correspondence https://en.wikipedia.org/wiki/Curry%E2%80%93Howard_correspon...
- not-a-llm 3mo ago
  > Recently it's been shown that there are real, physical processes which are undecidable According to the currently known laws of physics. Which we know are incomplete/incorrect in several places.
- woopsn 3mo ago
  The infinite lattice doesn't represent a "real" physical processes, it's just mathematical technique for closing a (fundamentally) quantized combinatorial sum over millions of interacting elements. The gap problem exists in the limit. For real systems the spectrum can be measured (in principle) by probing the ground state. The computational paradigm is incredibly general but only within what's apparently a pretty atypical thermodynamic regime (the ordered universe).
  - peter_m1 3mo ago
    In this case quantum thermo.
- nl 3mo ago
  Undecidable isn't uncomputable. "Computable" can mean probabilistic, and classical computers can function over probability distributions just fine.
  - rudy6912 3mo ago
    This is incorrect. An undecidable problem is one for which no algorithm can compute the correct result for every given instance. Probabilistic classical computation is irrelevant here.
- spragl 3mo ago
  Both P and NP are computable. That is, a Turing machine can compute both of them. Those quantum processes are interesting. Take the random numbers generated from radioactive decay. They are (after some cleanup) truly random. That is what we think. But how could we tell the difference from pseudorandom numbers, generated by a sufficiently advanced algorithm? We couldnt. So particles could simply be Turing Machines running sufficiently advanced algorithms that we cant reverse engineer. If so, quantum mechanics is computable even if we cant compute it. (Particles being TMs doesnt mean they are FAs with an infinite tape, but that they are computationally equivalent to TMs.)
  - peter_m1 3mo ago
    There is such thing as a quantum Turing machine you know (Deutsch 1985).
    - spragl 3mo ago
      Yes I know. When I wrote Turing Machine, I was thinking about the classical determinstic Turing Machine. Im not super knowledgable about Quantum Turing Machines, but as far as I know, they dont do better than the classical deterministic Turing Machines when we are talking about computability.
summarybot 3mo ago
What even is computation? State-based inference. But intelligence itself does not rely on computation, only its biological counterweight seems to and only in certain situations. If Computation is a "Universal Concept" then there are at least 4 or 5 more "Universal Concepts" analogous to intuition and spontaneity.
jojogeo 3mo ago
Something has always nagged me about the halting problem, might be my mis-understanding of the problem space but; - You have a piece of software - That software does in memory compute only - The software does not touch any peripherals, networking, or any other external source which introduce unpredictability (x) I'm convinced that somehow this can be solved/proven whether the execution will halt or not. (x) The second you touch any external peripherals or networking, you're effectively asking the question of "If I phone my friend, will they pick up the phone?" -> to which the only answer is, "They'll pick it up, only if they pick it up/are there". You can't answer that question without trying it. Am I missing the point? I'm sure you can introduce other edges even in the limited model above, e.g. where a memory stick stops responding or something; but all in if you have reliable kit and don't touch anything external, why can't this be solved?
- makerofthings 3mo ago
  Imagine a program that generates the digits of pi, one after the other and stops when it is finished. A general purpose program analysing this program to decide if it stops or not would have to know about pi. And about every other possible algorithm.
  - jojogeo 3mo ago
    This is a brilliant explanation thank you.
- tromp 3mo ago
  It can be solved if the memory is bounded. But unbounded memory comes with undecidable problems.
  - jojogeo 3mo ago
    This truly leads into "computation"; when we're dealing with known quantities, yes, we can "solve" the halting problem. The second you move into "we don't know the answer yet", the can of worms opens. Thank you.
quux0r 3mo ago
For those that are unfamiliar, Tim Roughgarden is a phenomenal instructor, and has made significant contributions to the field of algorithmic game theory, which has strong connections to a lot of the work he appears to be doing here. I highly recommend his excellent introductory lectures on the subject, especially if you're interested in pursuing his ideas here more rigorously: https://www.youtube.com/watch?v=TM_QFmQU_VA&list=PLEGCF-WLh2RJBqmxvZ0_ie-mleCFhi2N4 https://www.youtube.com/watch?v=TM_QFmQU_VA&list=PLEGCF-WLh2... His website also hosts a bunch more work as well as various lecture notes and exercises: https://timroughgarden.org/ https://timroughgarden.org/ Tim's lectures helped me a lot during my PhD when I was getting up to speed on this subject, and some of the more nuanced ways that computer scientists have worked with these broad algorithmic problems.
- willtemperley 3mo ago
  I loved his Algorithms course on Coursera which I did during the brief moment Stanford MOOCs were all free. So useful for a non-CS grad doing any kind of algorithmic programming. Those were good days.
ChrisArchitect 3mo ago
Related: Ergo: Long Form Philosophy Lectures https://news.ycombinator.com/item?id=48840497 https://news.ycombinator.com/item?id=48840497
sim04ful 3mo ago
I really do think matter wants to be sentient, being sentient is natural. Why i think that exactly, i'm not sure why, it just seems intuitive.
- peter_m1 3mo ago
  Your intuition could also be dead wrong.
jdw64 3mo ago
Is 'computation' really universal and fundamental? Turing machines, lambda calculus, algorithmic notations, they're all human-made formalisms. Are the halting problem and the limits of computability actually constraints that exist only within these human-made formal systems? When we constrain a formalism to reduce complexity, it feels like necessity emerges from within those constraints. For example, when we say 'CRUD app,' we immediately think of a specific pattern. In the same way, once you adopt a 'form,' the constraints that come with that form progressively expand the state space. In that sense, it feels like both discovery and invention. Famous mathematicians and scientists often distinguish between model and reality, yet we tend to mistake the model's shape for reality itself. People like John Wheeler and Stephen Wolfram argue that computation is a fundamental property of the universe. But can we really say that when we downcast reality to fit human cognition, losing information in the process, and then upcast it back, the information is fully restored? I always find this point difficult. Landauer's principle says that abstract logical operations, information erasure, necessarily increase physical entropy. That shows there's a thermodynamic cost to physically implemented information processing. But I don't think that proves computation is fundamental. Whether it's computation or geometry, they're all abstract formalisms created by humans. But when we actually measure things, they're subject to physical laws. Still, whether that makes them fundamental is a difficult question. I think these are just results of the process where humans name phenomena and constrain them. I don't think they're the cause. You can define computation broadly enough, as 'a process where a state changes to another state according to rules,' to make almost everything look like computation. But being able to explain something with computation and claiming that computation is fundamental are different things, aren't they? Meaning exists within the structures and constraints of human-made formalisms. We artificially lower cognitive complexity and translate things into human language. Whether that's fundamental, I'm not sure. Maybe I'm a reductionist. Plenty of intellectually brilliant scholars make those claims, but people like me, with slower minds, end up thinking these kinds of stupid thoughts. I wish I could organize my own thoughts bette
- jojogeo 3mo ago
  Ahhh this is fantastic thank you; it _is_ hard to reconcile whether problems come with the original topic or whether they are introduced by the abstraction that we _need_ to make in order to quantify a thing/explain it to ourselves and others. Regarding the downcast/upcast; I think it _can_ be possible to do this successfully; > I have a glass, I throw it at a hard surface. What will happen? Well (duh) the glass will (most likely) break. This hypothesis completely ignores nearly 100% of all relevant physics and the laws surrounding the problem; the arrangement of air molecules, the arrangement of the molecules in the glass, the physical forces governing me, it reduces the entire equation down to some really basic napkin physics. But; does the outcome work? Has my interpretation of the universe and its physics actually predicted what will happen? Probably a stupid example, but I think that a lossy picture of the universe can still yield a correct answer. I can't physically run a simulation of the entire universe in my brain, as my brain is part of that same universe. Lossy representations/models are a necessity in the thinking-ham bound world in which we exist.
jeffrallen 3mo ago
Discrete math and Algorithms were two of my favorite college classes. They were really the only part of computer science that was mind blowing. The rest was software engineering, which was transparently "possible". Like, yes, big programs and OSs and numerical models exist, and yes I will graduate and work with them and add to them, someday, yeah sure. But decidabilty, Godel's theorm, busy beaver numbers, etc... those were unexpected and worth the price of admission. Thanks Prof Hadas, you made it fun to have my mind blown.
- peter_m1 3mo ago
  Theoretical computer science is where it's at.
__rito__ 3mo ago
From the site's "About" section: > "Ergo is a nonprofit that publishes long-form philosophical lecture courses with leading scholars. Everything we publish is freely available, without ads or paywalls." I know what to do this weekend if it rains!
sdevonoes 3mo ago
From my naive pov: Related to computation is the concept of state (I know, functional languages can get away without it, sort of). I always wondered how the universe “knows” the mass of the sun. If there are some underlying functions/computations “running” in the background to keep planets moving and so on, and if the mass of planets is a key element in such computations… then either: the mass is calculated “on the fly” every time (seems expensive) or it’s a variable (how is it updated? Where is it “stored”?)
- AlotOfReading 3mo ago
  The somewhat abbreviated answer is that the "state" is formalized into the concept of fields. All the physical properties we can observe are from coupling with the relevant fields. The speed at which changes can propagate in fields is C, hence the speed of light being the same value.
- dleeftink 3mo ago
  As far as I understand it, the storage is the space, or rather, spacetime emerges from a system's informational capacity and the degrees of freedom along which information can spread. On the balance all information is retained but undergoes various phase transitions (the 'computations').
- khalic 3mo ago
  Functional programming very much has states. But you’re describing the transitions instead of the states directly. What it does is removing the hidden states and effects and makes them typed, explicit and contained
- amwet 3mo ago
  I think it’s easier to conceive of it like this: Each point in spacetime IS storage. Storage can be queried by interacting with it (in a variety of ways), though the process of querying affects the value not only of the querier, but also the queried, which may have side-effects as well. The interaction itself is the computation. A simple example for the computation: It’s like placing boxes next to each other. Yes I could say 1 box + 3 boxes = 4 boxes, via explicit calculation. I could also simply place 1 box next to three boxes, and without having to explicitly calculate, by nature of the interaction, the result (4 boxes) has been produced There is no background computation or storage. The universe IS computation and storage. Each spacetime quanta IS storage, and each interaction IS computation.
Diogenesian 3mo ago
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.
- Robotbeat 3mo ago
  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.
  - chermi 3mo ago
    Did you mean landauer?
    - Robotbeat 3mo ago
      Yes. Unable to edit it. https://en.wikipedia.org/wiki/Landauer's_principle https://en.wikipedia.org/wiki/Landauer's_principle
  - Diogenesian 3mo ago
vatsachak 3mo ago
Computation is in the eye of the beholder
lo_zamoyski 3mo ago
I'd have to look deeper into his views, but I've already come across what seem like similar claims that try to attribute computation to the laws of physics or to matter in general or whatever. However, these rest on category errors. Consider two characterizations of computation: 1. A mental process constituted by logical and intentional acts. 2. A mathematical model or formalism (or a set of formally equivalent formalisms). In the case of (1), intentionality rules out computation as an extra-mental phenomenon. Things in the world aren't about something else; they just are what they are. But computation as a mental act is about something else. To claim otherwise would be like claiming deduction is a broad feature of reality, which is effectively some kind of panpsychism. In the case of (2), if it's a mathematical model, then either by definition it doesn't exist outside the mind as such, or it must be instantiated in some objective manner. The trouble with finding instantiations is that it's not clear what constitutes an instantiation. Can you find correspondences? Sure. In fact, our physical computing machines correspond to these models in some way. But instantiation is more than mere correspondence, and this becomes even more the case when you consider that the lambda calculus corresponds to the Turing machine. Another problem is that even mathematical models of computation cannot be said to encode mathematical operations as such. Is a Turing machine moving symbols around on an abstract tape actually adding two numbers? I would say that it is merely simulating the addition by producing results that afford that kind of interpretation.
kaashif 3mo ago
I like how every time a new technology is invented and becomes big, people start to think it explains everything. Like how in the 16th/17th centuries some people thought the universe was a big clock. Or how in the 19th centuries people thought the universe was like a big steam engine. Or now we think the universe is a big computer. Not saying this is wrong or that I've watched all of the lectures above or anything, but it's just funny to imagine that aliens might look at us the same way we could look at a monkey society saying that the universe is like a big one of those rocks they use to smash nuts open. Computation and information really does seem universal though, so this is just a funny thought and not serious commentary.
- GoblinSlayer 3mo ago
  It's just Pythagoreanism.
- unknown_user_84 3mo ago
  It strikes me that this is a kind of an escalating pattern though I don't suppose it has to be. Clock -> Steam Engine -> Computer -> AGI -> Skynet -> Throw rocks at robots -> Judgement Day. Also very not serious commentary. On I suppose a slightly more serious note it also strikes me that there will eventually, probably, maybe be _something_ that fits best; though we are not promised to find it. And it seems wild to say that about a model because all models are fundamentally wrong, but they are usually group-able by less-wrongness, so probably fundamentally feasible.
- pilgrim0 3mo ago
  Couldn’t all of them be right, though? In the sense that every technology associated with the functioning of the universe had a systemic, spatiotemporal and evolutive dynamic, which appears to be the sensible facets of the universe’s behavior? In that sense computation is no different, just has more primacy. It gives me some Hofstadter vibes, meaning whatever complex thing we produce within the universe is hopelessly bound to be analogous with it.
- peter_m1 3mo ago
  Yes, these are all our attempts at explaining the nature of reality. A kind of reaching into the unknown. A desire to understand the universe and our place in it.
quantum_state 3mo ago
Would like to think we human are better than what is implied by the course in that we would not mistaken our model of reality as reality itself.
dboreham 3mo ago
I saw the title and assumed an article by Wolfram. But it's by Tim Roughgarden who I know from algorithmic game theory. Anyway, I'll register my membership in the "it's more fundamental than that" camp.
nullbio 3mo ago
The universe is a giant transformer.
- peter_m1 3mo ago
  Attention is all we need.
voidhorse 3mo ago
Computation as realized by computers is a formalism invented by Turing, Church, Kleene and others to make precise the intuitive notion of "algorithm". An algorithm, at its root, is a procedure rooted in human understanding that human beings can follow. When Turing and others first introduced this formal notion, not all mathematicians were even fully convinced it was an adequate representation of the informal intuitive notion. For example, some argued it was too broad because traditionally knowing that an algorithm eventually terminates was one of the requirements (to some) for something to be a legitimate algorithm. Why? Because the idea is rooted in human practical concerns and human understanding. Depending on what one cares about, one could actually reject the Turing formalization of algorithm on grounds of the class containing non-convergent (partial) functions. All this is to say that "computation" is very much a human invention and little more than a formal model of human behaviors (we want to manipulate things algebraically). Elevating it to some objective substance of the universe is just doing 17th/18th century philosophical Idealism wrapped in new clothes.
- peter_m1 3mo ago
  The computational view of the universe and the nature of reality has provided us with some new insights.
  - voidhorse 3mo ago
    Sure, others would also claim the "financial view" of the universe has also provided insight. That doesn't mean I go around claiming the money is some fundamental universal substance of the real.
deleted 3mo ago
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peter_m1 3mo ago
Here is a brief history of computability I wrote as a blog a few months ago, https://deeplp.com/blogs/f/the-birth-of-computability-theory https://deeplp.com/blogs/f/the-birth-of-computability-theory. Hope it's helpful to the conversation.
ramdy00 3mo ago
[flagged]
warumdarum 3mo ago
Shouldnt physicsifthe universe was a sim, should have an affinity the power of two
MAESTRO1955 3mo ago
Computation cannot simulate consciousness! https://deepmind.google/research/publications/231971/ https://deepmind.google/research/publications/231971/
- Diogenesian 3mo ago
  Read the title a little more closely :) As far as we know computation actually can simulate consciousness: - given any system of quantum particles, a sufficiently large Turing machine can solve the matching system of Schrodinger equations - the human body, including the brain, is certainly a system of quantum particles - even if you think quantum behavior is directly relevant to consciousness (I don't) certainly there is nothing "beyond" quantum mechanics that would be necessary to explain it, so our system of Schrodinger equations should be able to model human consciousness - so a Turing machine can simulate a human, including consciousness The paper argues that this simulation of consciousness is not the same thing as actual consciousness.
  - MAESTRO1955 3mo ago
    You are right, of course I was in a rush to type, so I misspoke. What I meant to say is that computational simulations of consciousness may make it impossible for anyone to definitively diagnose whether it is a simulation or real consciousness. So, computational simulation of consciousness may render any consciousness detection tools useless. Again, my apologies for my earlier mistake.
- GoblinSlayer 3mo ago
  > we do not need a complete, finalized theory of consciousness to assess AI sentience Erm... this can't possibly work, can it?

177 points by simonpure 3mo ago

Computation has turned out to be a far more general concept than I think was imagined, up to the point that many computer scientists now seem to equate computation with the functioning of the universe. Recently it's been shown that there are real, physical processes which are undecidable (we cannot know if a latice of atoms has a spectral gap or not, we cannot determine if a specific particle in a fluid flow will reach a specific place or not, we cannot determine if a ray of light will reach a specific target in certain configurations of reflection). Our world appeared computable, but it isn't, even if P=NP.

gradys 3mo ago
It can be the case that both: - The physics of the universe can be completely modeled as computation, and - It's possible to pose undecidable problems about the way the universe unfolds This is intrinsic to the idea of undecidability even for Turing machines, e.g. "we equate computation with the functioning of Turing machines, but there are real processes executable in Turing machines that are undecidable".
- sgt101 3mo ago
  Of course, if our universe is undecidable it must be the case that computable processes can be executed within it, and it might be the case that all of the processes that are ever executed within it are computable... but it might be that some of the processes that are executed are not computable... because the machine may.. or may not?
  - jerf 3mo ago
    I think there's an equivocation of "computable" going on here. Mathematicians talk about a lot of things like "uncomputable sequences" but that is usually making a statement about the sequence, not necessarily any individual member. The Busy Beaver sequence is uncomputable. You can, however, quite trivially compute BB(2), even in your head if you're a bit careful. You can set up individual elements of an uncomputable sequence in our universe, and you may be unable to state in advance what the system would do with anything less than simply letting it run and see what happens due to the complexity of the system, but being a member of an uncomputable sequence doesn't mean that you can't in fact set those things up and watch them run. The Universe doesn't throw an "UncomputableCircumstance" exception or anything. It just keeps advancing to the next state. Your inability to make certain statements about that next state or some future state is not its problem.
  - chriswarbo 3mo ago
    There's no way to empirically spot an uncomputable process, since it would require infinitely-many observations. For example, if aliens claim their machine solves the halting problem, we could test it on millions of inputs whose halting/not-halting behaviour we already know; but even if it works for all of them, there's no way to know that it works for all inputs. For all we know, it might be a huge lookup table which happens to cover all of those inputs we tried.
    - peter_m1 3mo ago
      No, you can prove things hold in the abstract mathematically, don't need to resort to physical systems.
      - chriswarbo 3mo ago
        I was responding to this part: > if our universe is undecidable My point is, there would be no way to empirically test this; and therefore, it would make no observable difference, there would be no way to exploit/utilise such effects, etc. In essence: there's no way to tell the difference between a real halting oracle (which would imply an undecidable universe), versus a computable approximation which just-so-happens to be more powerful/sophisticated than the approximations we compare it against. Sure, we can prove that some abstract systems are undecidable and that others aren't. Yet that distinction is inherently unfalsifiable, and hence physically "useless".
  - peter_m1 3mo ago
    Quantum mechanics is intrinsically probabilistic.
    - GoblinSlayer 3mo ago
      Deterministic processes can be modeled probabilistically and are computable, so existence of a probabilistic model doesn't say much about computability.
- woopsn 3mo ago
  A key thing about the undecidability problem wrt physics is preparation of the initial state. In math and computer science it is relatively straightforward to prepare such problems now (though this represented an enormous leap conceptually), but the "undecidability" of all physical problems relies on construction of materials that are clearly unconstructable - systems of infinite negentropy (eg Turing machines), infinite mass (the lattice), bespoke local interactions etc. Problems standing in the way of physics decidability are typically chaos, far from equilibrium mechanics, elementary SNR considerations and so forth, not problems of logic.
  - peter_m1 3mo ago
    In physics we don't talk about decidability, but solvability.
Maxatar 3mo ago
>Recently it's been shown that there are real, physical processes which are undecidable I want to push back a bit on this claim along two dimensions. Imagine a physical Turing machine built out of atoms, gears, levers, and an electron parked on the read/write head and ask whether that electron ever crosses some fixed plane in space, which it does only when the machine enters its halt configuration. That's now a purely physical question about a trajectory (does this electron ever reach a certain target), yet answering it for the whole family of such machines is literally the halting problem, so there's a physical process that's undecidable. Your examples about physical processes being undecidable are all basically just this... there examples of using reflections of light, or the flow of liquid, etc... and demonstrating that these physical processes in principle are sufficient to model a universal Turing machine. And while it's fascinating that certain things you may not have expected can be used to model computation, it's misleading, or rather it's too strong of a claim to believe that there exist actual/real physical processes whose outcomes are undecidable. That's a subtle but very common misinterpretation of what undecidability is. Undecidability, whether in physics or computer science, only applies to the infinitely broad class of a problem as a whole, it never applies to a specific instance of a problem. So it can never be the case that there's a certain configuration of reflections for which it's undecidable whether a ray of light reaches a target. Nor can it be the case that for a specific lattice of atoms, it's undecidable whether it has a spectral gap or not. It can only be the case that for the problem as a whole where the parameter space is entirely unbounded, there is no single algorithm that can decide if a ray of light reaches a specific target for all possible arbitrary (and infinitely many) configurations. Once you fix a specific system, then the undecidability goes away. Not claiming that you are necessarily making this misconception, but I often see people misinterpret undecidability to mean that there exists a specific problem, like with specific inputs, where it's somehow impossible to know what the answer will be. Undecidability always requires an infinite family of instances, and it's a statement about the nonexistence of a single algorithm that correctly answers every instance in that family. It says nothing about any particular instance being unknowable/undecidable.
- eth0up 3mo ago
  If I am wrong, please pardon. I suspect I am. But was this comment edited by Claude? I ask specifically because it is well written, substantive, all which is expected here, but the "push back" part, to me, must be a) an artifact of Claude, either by osmotic assimilation (Which is happening to many innocent users) or b) Claude itself. Feel free to flag this comment if I get an answer. I do want to know.
plastic-enjoyer 3mo ago
> up to the point that many computer scientists now seem to equate computation with the functioning of the universe. Do you think that's a kind of tunnel vision? If the only thing you focus on is computation, you'll probably end up seeing computation everywhere - it became a way of seeing the world.
- jerf 3mo ago
  It is a common accusation. There's a somewhat famous quote I've seen a few times: "It's interesting to look back through history on this one. Each age has its pinnacle of technology, and each age uses that technology as a metaphor for nature, for the universe. In ancient Greece, the technological marvels were musical instruments and the ruler and compass. The Greek philosophers tried to build an entire cosmology from number, harmony, proportion, form, and so on — from mathematics, basically. Remember the music of the spheres? The Pythagoreans believed that nature was a manifestation of rational mathematics. Later on the pinnacle of technology was the clockwork. Newton wanted a clockwork universe, the entire universe as a gigantic clockwork mechanism, with all the parts interlocking and ticking over with infinite precision. Then in the 19th century along came steam power, and the universe was then depicted as an enormous heat engine, or thermodynamic machine, running down toward its heat death. Today the computer is the pinnacle of technology, so it's now fashionable to talk about nature as a computational process." Which seems to source from https://www.edge.org/conversation/paul_davies-time-loops https://www.edge.org/conversation/paul_davies-time-loops . While "computer" may give us impressions of something with "a CPU" and "RAM" and "a disk drive", it does at least seem plausible that the universe as computation is a plausible base level, though. Unlike "the music of the spheres", which to the extent that it made predictions of the world, it got them wrong in the most basic way, viewing it through a lens of computation allows us to put some quite subtle and interesting limits on things. "Computation" is a pretty flexible substrate; it is difficult to imagine how the proposition "the universe is a computation and subject to the limitations thereto" could be falsified, and if it could, it is difficult to imagine how we would be able to know it was so falsified. Nevertheless the math of computation allows us to say non-trivial things about the universe as a result; it is not a vacuous generalization, though it is certainly a loose one... being able to say yet more concrete things about the nature of the computation, such as "this is exactly how gravity works", has quite a bit more utility.
mondrian 3mo ago
Undecidability is a problem of answer-extraction from a process, it doesn’t preclude the process from executing deterministically. The universe could well be the live execution of a deterministic, even basic algorithm, with all kinds of questions about its execution being undecidable.
__rito__ 3mo ago
One sentence I heard somewhere wraps up the totality of computing: "If Mathematics is the 'what', Computer Science is the 'how'". This applies to each and everything.
- athrowaway3z 3mo ago
  If two people agreed on that statement, its entirely unclear if they agree with each other and if they found something profound in the first place. The imo much more foundational relationship not everybody is aware of is https://en.wikipedia.org/wiki/Curry%E2%80%93Howard_correspondence https://en.wikipedia.org/wiki/Curry%E2%80%93Howard_correspon...
not-a-llm 3mo ago
> Recently it's been shown that there are real, physical processes which are undecidable According to the currently known laws of physics. Which we know are incomplete/incorrect in several places.
woopsn 3mo ago
The infinite lattice doesn't represent a "real" physical processes, it's just mathematical technique for closing a (fundamentally) quantized combinatorial sum over millions of interacting elements. The gap problem exists in the limit. For real systems the spectrum can be measured (in principle) by probing the ground state. The computational paradigm is incredibly general but only within what's apparently a pretty atypical thermodynamic regime (the ordered universe).
- peter_m1 3mo ago
  In this case quantum thermo.
nl 3mo ago
Undecidable isn't uncomputable. "Computable" can mean probabilistic, and classical computers can function over probability distributions just fine.
- rudy6912 3mo ago
  This is incorrect. An undecidable problem is one for which no algorithm can compute the correct result for every given instance. Probabilistic classical computation is irrelevant here.
spragl 3mo ago
Both P and NP are computable. That is, a Turing machine can compute both of them. Those quantum processes are interesting. Take the random numbers generated from radioactive decay. They are (after some cleanup) truly random. That is what we think. But how could we tell the difference from pseudorandom numbers, generated by a sufficiently advanced algorithm? We couldnt. So particles could simply be Turing Machines running sufficiently advanced algorithms that we cant reverse engineer. If so, quantum mechanics is computable even if we cant compute it. (Particles being TMs doesnt mean they are FAs with an infinite tape, but that they are computationally equivalent to TMs.)
- peter_m1 3mo ago
  There is such thing as a quantum Turing machine you know (Deutsch 1985).
  - spragl 3mo ago
    Yes I know. When I wrote Turing Machine, I was thinking about the classical determinstic Turing Machine. Im not super knowledgable about Quantum Turing Machines, but as far as I know, they dont do better than the classical deterministic Turing Machines when we are talking about computability.

summarybot 3mo ago

What even is computation? State-based inference. But intelligence itself does not rely on computation, only its biological counterweight seems to and only in certain situations. If Computation is a "Universal Concept" then there are at least 4 or 5 more "Universal Concepts" analogous to intuition and spontaneity.

jojogeo 3mo ago

Something has always nagged me about the halting problem, might be my mis-understanding of the problem space but; - You have a piece of software - That software does in memory compute only - The software does not touch any peripherals, networking, or any other external source which introduce unpredictability (x) I'm convinced that somehow this can be solved/proven whether the execution will halt or not. (x) The second you touch any external peripherals or networking, you're effectively asking the question of "If I phone my friend, will they pick up the phone?" -> to which the only answer is, "They'll pick it up, only if they pick it up/are there". You can't answer that question without trying it. Am I missing the point? I'm sure you can introduce other edges even in the limited model above, e.g. where a memory stick stops responding or something; but all in if you have reliable kit and don't touch anything external, why can't this be solved?

makerofthings 3mo ago
Imagine a program that generates the digits of pi, one after the other and stops when it is finished. A general purpose program analysing this program to decide if it stops or not would have to know about pi. And about every other possible algorithm.
- jojogeo 3mo ago
  This is a brilliant explanation thank you.
tromp 3mo ago
It can be solved if the memory is bounded. But unbounded memory comes with undecidable problems.
- jojogeo 3mo ago
  This truly leads into "computation"; when we're dealing with known quantities, yes, we can "solve" the halting problem. The second you move into "we don't know the answer yet", the can of worms opens. Thank you.

quux0r 3mo ago

For those that are unfamiliar, Tim Roughgarden is a phenomenal instructor, and has made significant contributions to the field of algorithmic game theory, which has strong connections to a lot of the work he appears to be doing here. I highly recommend his excellent introductory lectures on the subject, especially if you're interested in pursuing his ideas here more rigorously: https://www.youtube.com/watch?v=TM_QFmQU_VA&list=PLEGCF-WLh2RJBqmxvZ0_ie-mleCFhi2N4 https://www.youtube.com/watch?v=TM_QFmQU_VA&list=PLEGCF-WLh2... His website also hosts a bunch more work as well as various lecture notes and exercises: https://timroughgarden.org/ https://timroughgarden.org/ Tim's lectures helped me a lot during my PhD when I was getting up to speed on this subject, and some of the more nuanced ways that computer scientists have worked with these broad algorithmic problems.

willtemperley 3mo ago
I loved his Algorithms course on Coursera which I did during the brief moment Stanford MOOCs were all free. So useful for a non-CS grad doing any kind of algorithmic programming. Those were good days.

ChrisArchitect 3mo ago

Related: Ergo: Long Form Philosophy Lectures https://news.ycombinator.com/item?id=48840497 https://news.ycombinator.com/item?id=48840497

sim04ful 3mo ago

I really do think matter wants to be sentient, being sentient is natural. Why i think that exactly, i'm not sure why, it just seems intuitive.

peter_m1 3mo ago
Your intuition could also be dead wrong.

jdw64 3mo ago

Is 'computation' really universal and fundamental? Turing machines, lambda calculus, algorithmic notations, they're all human-made formalisms. Are the halting problem and the limits of computability actually constraints that exist only within these human-made formal systems? When we constrain a formalism to reduce complexity, it feels like necessity emerges from within those constraints. For example, when we say 'CRUD app,' we immediately think of a specific pattern. In the same way, once you adopt a 'form,' the constraints that come with that form progressively expand the state space. In that sense, it feels like both discovery and invention. Famous mathematicians and scientists often distinguish between model and reality, yet we tend to mistake the model's shape for reality itself. People like John Wheeler and Stephen Wolfram argue that computation is a fundamental property of the universe. But can we really say that when we downcast reality to fit human cognition, losing information in the process, and then upcast it back, the information is fully restored? I always find this point difficult. Landauer's principle says that abstract logical operations, information erasure, necessarily increase physical entropy. That shows there's a thermodynamic cost to physically implemented information processing. But I don't think that proves computation is fundamental. Whether it's computation or geometry, they're all abstract formalisms created by humans. But when we actually measure things, they're subject to physical laws. Still, whether that makes them fundamental is a difficult question. I think these are just results of the process where humans name phenomena and constrain them. I don't think they're the cause. You can define computation broadly enough, as 'a process where a state changes to another state according to rules,' to make almost everything look like computation. But being able to explain something with computation and claiming that computation is fundamental are different things, aren't they? Meaning exists within the structures and constraints of human-made formalisms. We artificially lower cognitive complexity and translate things into human language. Whether that's fundamental, I'm not sure. Maybe I'm a reductionist. Plenty of intellectually brilliant scholars make those claims, but people like me, with slower minds, end up thinking these kinds of stupid thoughts. I wish I could organize my own thoughts bette

jojogeo 3mo ago
Ahhh this is fantastic thank you; it _is_ hard to reconcile whether problems come with the original topic or whether they are introduced by the abstraction that we _need_ to make in order to quantify a thing/explain it to ourselves and others. Regarding the downcast/upcast; I think it _can_ be possible to do this successfully; > I have a glass, I throw it at a hard surface. What will happen? Well (duh) the glass will (most likely) break. This hypothesis completely ignores nearly 100% of all relevant physics and the laws surrounding the problem; the arrangement of air molecules, the arrangement of the molecules in the glass, the physical forces governing me, it reduces the entire equation down to some really basic napkin physics. But; does the outcome work? Has my interpretation of the universe and its physics actually predicted what will happen? Probably a stupid example, but I think that a lossy picture of the universe can still yield a correct answer. I can't physically run a simulation of the entire universe in my brain, as my brain is part of that same universe. Lossy representations/models are a necessity in the thinking-ham bound world in which we exist.

jeffrallen 3mo ago

Discrete math and Algorithms were two of my favorite college classes. They were really the only part of computer science that was mind blowing. The rest was software engineering, which was transparently "possible". Like, yes, big programs and OSs and numerical models exist, and yes I will graduate and work with them and add to them, someday, yeah sure. But decidabilty, Godel's theorm, busy beaver numbers, etc... those were unexpected and worth the price of admission. Thanks Prof Hadas, you made it fun to have my mind blown.

peter_m1 3mo ago
Theoretical computer science is where it's at.

__rito__ 3mo ago

From the site's "About" section: > "Ergo is a nonprofit that publishes long-form philosophical lecture courses with leading scholars. Everything we publish is freely available, without ads or paywalls." I know what to do this weekend if it rains!

sdevonoes 3mo ago

From my naive pov: Related to computation is the concept of state (I know, functional languages can get away without it, sort of). I always wondered how the universe “knows” the mass of the sun. If there are some underlying functions/computations “running” in the background to keep planets moving and so on, and if the mass of planets is a key element in such computations… then either: the mass is calculated “on the fly” every time (seems expensive) or it’s a variable (how is it updated? Where is it “stored”?)

AlotOfReading 3mo ago
The somewhat abbreviated answer is that the "state" is formalized into the concept of fields. All the physical properties we can observe are from coupling with the relevant fields. The speed at which changes can propagate in fields is C, hence the speed of light being the same value.
dleeftink 3mo ago
As far as I understand it, the storage is the space, or rather, spacetime emerges from a system's informational capacity and the degrees of freedom along which information can spread. On the balance all information is retained but undergoes various phase transitions (the 'computations').
khalic 3mo ago
Functional programming very much has states. But you’re describing the transitions instead of the states directly. What it does is removing the hidden states and effects and makes them typed, explicit and contained
amwet 3mo ago
I think it’s easier to conceive of it like this: Each point in spacetime IS storage. Storage can be queried by interacting with it (in a variety of ways), though the process of querying affects the value not only of the querier, but also the queried, which may have side-effects as well. The interaction itself is the computation. A simple example for the computation: It’s like placing boxes next to each other. Yes I could say 1 box + 3 boxes = 4 boxes, via explicit calculation. I could also simply place 1 box next to three boxes, and without having to explicitly calculate, by nature of the interaction, the result (4 boxes) has been produced There is no background computation or storage. The universe IS computation and storage. Each spacetime quanta IS storage, and each interaction IS computation.

Diogenesian 3mo ago

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.

Robotbeat 3mo ago
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.
- chermi 3mo ago
  Did you mean landauer?
  - Robotbeat 3mo ago
    Yes. Unable to edit it. https://en.wikipedia.org/wiki/Landauer's_principle https://en.wikipedia.org/wiki/Landauer's_principle
- Diogenesian 3mo ago

vatsachak 3mo ago

Computation is in the eye of the beholder

lo_zamoyski 3mo ago

I'd have to look deeper into his views, but I've already come across what seem like similar claims that try to attribute computation to the laws of physics or to matter in general or whatever. However, these rest on category errors. Consider two characterizations of computation: 1. A mental process constituted by logical and intentional acts. 2. A mathematical model or formalism (or a set of formally equivalent formalisms). In the case of (1), intentionality rules out computation as an extra-mental phenomenon. Things in the world aren't about something else; they just are what they are. But computation as a mental act is about something else. To claim otherwise would be like claiming deduction is a broad feature of reality, which is effectively some kind of panpsychism. In the case of (2), if it's a mathematical model, then either by definition it doesn't exist outside the mind as such, or it must be instantiated in some objective manner. The trouble with finding instantiations is that it's not clear what constitutes an instantiation. Can you find correspondences? Sure. In fact, our physical computing machines correspond to these models in some way. But instantiation is more than mere correspondence, and this becomes even more the case when you consider that the lambda calculus corresponds to the Turing machine. Another problem is that even mathematical models of computation cannot be said to encode mathematical operations as such. Is a Turing machine moving symbols around on an abstract tape actually adding two numbers? I would say that it is merely simulating the addition by producing results that afford that kind of interpretation.

kaashif 3mo ago

I like how every time a new technology is invented and becomes big, people start to think it explains everything. Like how in the 16th/17th centuries some people thought the universe was a big clock. Or how in the 19th centuries people thought the universe was like a big steam engine. Or now we think the universe is a big computer. Not saying this is wrong or that I've watched all of the lectures above or anything, but it's just funny to imagine that aliens might look at us the same way we could look at a monkey society saying that the universe is like a big one of those rocks they use to smash nuts open. Computation and information really does seem universal though, so this is just a funny thought and not serious commentary.

GoblinSlayer 3mo ago
It's just Pythagoreanism.
unknown_user_84 3mo ago
It strikes me that this is a kind of an escalating pattern though I don't suppose it has to be. Clock -> Steam Engine -> Computer -> AGI -> Skynet -> Throw rocks at robots -> Judgement Day. Also very not serious commentary. On I suppose a slightly more serious note it also strikes me that there will eventually, probably, maybe be _something_ that fits best; though we are not promised to find it. And it seems wild to say that about a model because all models are fundamentally wrong, but they are usually group-able by less-wrongness, so probably fundamentally feasible.
pilgrim0 3mo ago
Couldn’t all of them be right, though? In the sense that every technology associated with the functioning of the universe had a systemic, spatiotemporal and evolutive dynamic, which appears to be the sensible facets of the universe’s behavior? In that sense computation is no different, just has more primacy. It gives me some Hofstadter vibes, meaning whatever complex thing we produce within the universe is hopelessly bound to be analogous with it.
peter_m1 3mo ago
Yes, these are all our attempts at explaining the nature of reality. A kind of reaching into the unknown. A desire to understand the universe and our place in it.

quantum_state 3mo ago

Would like to think we human are better than what is implied by the course in that we would not mistaken our model of reality as reality itself.

dboreham 3mo ago

I saw the title and assumed an article by Wolfram. But it's by Tim Roughgarden who I know from algorithmic game theory. Anyway, I'll register my membership in the "it's more fundamental than that" camp.

nullbio 3mo ago

The universe is a giant transformer.

peter_m1 3mo ago
Attention is all we need.

voidhorse 3mo ago

Computation as realized by computers is a formalism invented by Turing, Church, Kleene and others to make precise the intuitive notion of "algorithm". An algorithm, at its root, is a procedure rooted in human understanding that human beings can follow. When Turing and others first introduced this formal notion, not all mathematicians were even fully convinced it was an adequate representation of the informal intuitive notion. For example, some argued it was too broad because traditionally knowing that an algorithm eventually terminates was one of the requirements (to some) for something to be a legitimate algorithm. Why? Because the idea is rooted in human practical concerns and human understanding. Depending on what one cares about, one could actually reject the Turing formalization of algorithm on grounds of the class containing non-convergent (partial) functions. All this is to say that "computation" is very much a human invention and little more than a formal model of human behaviors (we want to manipulate things algebraically). Elevating it to some objective substance of the universe is just doing 17th/18th century philosophical Idealism wrapped in new clothes.

peter_m1 3mo ago
The computational view of the universe and the nature of reality has provided us with some new insights.
- voidhorse 3mo ago
  Sure, others would also claim the "financial view" of the universe has also provided insight. That doesn't mean I go around claiming the money is some fundamental universal substance of the real.

deleted 3mo ago

[deleted]

peter_m1 3mo ago

Here is a brief history of computability I wrote as a blog a few months ago, https://deeplp.com/blogs/f/the-birth-of-computability-theory https://deeplp.com/blogs/f/the-birth-of-computability-theory. Hope it's helpful to the conversation.

ramdy00 3mo ago

[flagged]

warumdarum 3mo ago

Shouldnt physicsifthe universe was a sim, should have an affinity the power of two

MAESTRO1955 3mo ago

Computation cannot simulate consciousness! https://deepmind.google/research/publications/231971/ https://deepmind.google/research/publications/231971/

Diogenesian 3mo ago
Read the title a little more closely :) As far as we know computation actually can simulate consciousness: - given any system of quantum particles, a sufficiently large Turing machine can solve the matching system of Schrodinger equations - the human body, including the brain, is certainly a system of quantum particles - even if you think quantum behavior is directly relevant to consciousness (I don't) certainly there is nothing "beyond" quantum mechanics that would be necessary to explain it, so our system of Schrodinger equations should be able to model human consciousness - so a Turing machine can simulate a human, including consciousness The paper argues that this simulation of consciousness is not the same thing as actual consciousness.
- MAESTRO1955 3mo ago
  You are right, of course I was in a rush to type, so I misspoke. What I meant to say is that computational simulations of consciousness may make it impossible for anyone to definitively diagnose whether it is a simulation or real consciousness. So, computational simulation of consciousness may render any consciousness detection tools useless. Again, my apologies for my earlier mistake.
GoblinSlayer 3mo ago
> we do not need a complete, finalized theory of consciousness to assess AI sentience Erm... this can't possibly work, can it?