"It from bits"--the Universe is computable

[Anselm33]

I quote from the Wikipedia article on “digital physics”:
"

(the) universe is, at heart, describable by information, and is therefore computable."

en.wikipedia.org/wiki/Digital_physics
I haven’t read the article in detail, although as I understand it, one version (not the original) was given by the great American physicist John Wheeler. Looking at the summary of the article I also see that an extreme version of this is “The Matrix”, that we’re in the middle of super-gigantic simulation.

Without going into detail, I have a notion this is a wrong-headed notion because of Godel’s theorem , but I would like to hear from more knowledgeable people than I about the pros and especially cons of this idea.

 

[Touchstone]

I quote from the Wikipedia article on “digital physics”:
"
en.wikipedia.org/wiki/Digital_physics
I haven’t read the article in detail, although as I understand it, one version (not the original) was given by the great American physicist John Wheeler. Looking at the summary of the article I also see that an extreme version of this is “The Matrix”, that we’re in the middle of super-gigantic simulation.

As a software developer, the more physics advances, the more seductive this idea gets. Seth Lloyd’s Programming the Universe: A Quantum Computer Scientist Takes On the Cosmos, was, and is, frankly, a bit unnerving. If you take a simple question like “why does light refract through glass at the angle it does?” you end up at the Principle of Least Action and Fermat’s principle, which are very hard to understand outside of computation: *how does a photon know the ‘shortest-time’ path through the glass? *The photon itself doesn’t ‘know’ or ‘see’ anything, of course, but the system itself must resolve the optima, given all the other parameters. This is computation.

The famous Double Slit experiments point to the same thing. How does a particle “decide” which path to take, and how does it “know” to interact in such a way as to produce wave interference patterns? The particle doesn’t “know” anything, but the system knows how to compute *every possible path in the universe in real time, *as the phase space for selecting an actual path when one is needed. Again, computation. Which is not to say the universe is running on some Cosmic Kid’s iPad, but the heuristics involved are undeniably parallel to what we know as computing (just at unbelievably huge scales and processing speeds).

The strange interaction between observer and observed in quantum mechanics is another feature that will creep out a software developer/computing expert. One of the basic optimization principles of computing is don’t compute things before and unless you need to. For example, if you are programming a 3D game, you are very careful to to calculate just which objects and features of the scene need to be raytraced and rendered to present an authentic view to the observer. Occluded objects are just left out, and objects (perhaps) that are too small or too far away to even make a single-pixel impact are foregone. Objects “behind” the observer (assuming the game view doesn’t have a rear view mirror) may be left out if they don’t have specular or reflective features that affect the view in front of the observer.

The 3D game programmer ruthlessly reduces what he needs to compute to the minimum necessary to maintain desired fidelity. Other “model objects” are not realized for rendering until they are needed. This is strangely consonant with quantum physics, which to a programmer, seems immediately familiar with these principles of “late binding” and optimization (compute what is needed, only when it’s really needed). If the game subject “turns his head to the left”, a whole bunch of objects which didn’t need to be rendered, and were just ‘abstract’ a couple frames back are now reified by the rendering engine. The objects to the right that just went out of scope also now “disappear”, and no “wave collapsing rendering” so to speak is needed or done.

Nature appears to proceed this way, which conceited humans always seem to interpret as ‘hey, nature works like us’. If there’s a similarity there, of course, it’s man crudely mimicking nature, but it’s deeply interesting how “familiar” much of physics is to someone expert in computation.

Without going into detail, I have a notion this is a wrong-headed notion because of Godel’s theorem , but I would like to hear from more knowledgeable people than I about the pros and especially cons of this idea.

Gödel is no obstacle here. If we understand the world to be (the output of) a formal system, Gödel tells us that if that system is self-consistent, it will necessarily be incomplete, admitting of true propositions that are not derivable within the system. This is not problematic for the world-as-simulation idea, any more than it is for the large scale network simulations and models I write and run. Gödel’s insight is not a runtime problem, but an observation on our limits in building a comprehensive “catalog” of system outputs (Turing’s Halting Problem obtains for the same reasons).

-TS

 

[lemondiesel]

Is the universe computable, or do we only think its computable? I mean, hasn’t all our technology come from observation of the natural world? Its just predictable because we observe it that way.

 

[Touchstone]

Is the universe computable, or do we only think its computable? I mean, hasn’t all our technology come from observation of the natural world? Its just predictable because we observe it that way.

It’s undefined what “computable” means at the universe level. Ostensibly, the universe “computes itself”, yield the time-forward version of the universe. But that doesn’t seem very helpful, does it? What we can say is the there are strong parallels we identify between computing and the way the universe appears to function. Seth Lloyd’s book mentioned above is a pioneer in quantum computing, and the book pursues the idea of the universe as a giant, holistic quantum computer. But it’s hard to keep the metaphors distinct from the thing being subscribed, here. Nature is what it is, and while computing principles seem to be quite applicable to the way the universe works, you’re quite right to note a possible mistake; birds aren’t examples of intelligent design, but rather man-made flight is a kind of mimicry of successful designs found as impersonal natural searched the landscape, blindly for solutions. Similarly, the universe isn’t a “computer”, but rather, our computers are crude shadows and approximations of the way nature works, as nature.

When you’re a hammer, everything seems a nail. When you have a designing mind, everything is tempting to see as “designed by mind”.

-TS

 

[Anselm33]

The famous Double Slit experiments point to the same thing. How does a particle “decide” which path to take, and how does it “know” to interact in such a way as to produce wave interference patterns? The particle doesn’t “know” anything, but the system knows how to compute *every possible path in the universe in real time, *

 

[Touchstone]

Touchstone;7166283:

Feynmann’s path integral approach to quantum mechanics uses a least action principle (as in other areas of physics) but I’m not sure how to connect that with what you’ve said.

There’s a lot of “computing” implicit in physics, and despite the math intensity, it’s more descriptive in its math applications than algorithmic. If that doesn’t make sense, think of it this way: from a software programming standpoint, it’s not enough to understand Feyman’s reformulation of sum-over-histories conceptual, and mathematically, as a computing pro look at the problem, you wonder how that gets computed algorithmically such that it can behave in such a way.

Maybe it’s simpler to use the double-slit experiment. A physics prof will explain the concept of a probability wave, where a particle will “test” any and all possible paths in the universe in such a way as to resolve to the probability distribution for every single point in the universe (densely clustered around the general area between where the particle was fired from and aimed at, typically). Conceptually, that’s difficult enough to wrap one’s mind around (it really checks out paths that route it past Saturn to the other end of the galaxy and back here? really?), but if you look at that from the standpoint of someone who would try to write that as computing machinery, two realizations are immediately apprehended:

1. The scale of the computing problem is just about unimaginable. It’s scope is literally every location in the entire universe, in real time!
2. Even in light of 1), it’s algorithmic in nature – a parallelized search function that sums up all the results as they return to build a “landscape” of probabilities for the particle.

A lot of physics is like that – the scale and speed are unfathomable, but the “algorithmness” is often apparent or familiar to a software developer.

The interaction between observer and observed can, IMO, be most simply explained by the type of interpretation Raymond Chiao, Wigner and Von Neumann introduce: the use of consciousness, and I’m not sure how consciousness can come about through computation. (See below.)

Consciousness is computation, so far as I can see. It’s just computation that is so highly parallelized and diffuse (i.e. unlike our typical computing models for servers and the like), that it stuns us as magic (what’s that Arthur C. Clarke line?).

By observation, though, I didn’t mean “conscious observation”. I should have been more precise and referred to “events which trigger decoherence”, That is not a function of consciousness, but it is, again, immediately familiar as a computing problem, real-time resolution of otherwise-independent local systems that have interacted to an (irreversible) extent that they must now be harmonized.

After rereading the appropriate sections in Roger Penrose’s “The Emperor’s New Mind” and “Shadows of the Mind”, I think he would disagree with you. He shows, using Godel’s Theorem and the Church-Turing theorem that not all theorems in arithmetic can be solved algorithmically, although they can be solved otherwise. Accordingly, he says (and I paraphrase) that if a computer can not do what a human mind can do, then it can not be said to be intelligent. He rejects strong AI. John Searle does also, through his “Chinese Room” example.

OK, gotcha. I think Searle is lame, and the Chinese room is weak, conceptually – sophistry via lazy language if you want a more ornery take. I don’t take strong AI as a given or inevitable, but I’ve yet to see a computing-cogent case for dismissing it outright. It strikes me as the same kind of credulous thinking that supposes simple biological processes can’t produce fantastically complex and sophisticated structure and machines over deep time and cumulative progress.

But that’s another thread,

If a computer can not be intelligent and there is intelligence in the universe, could it be correct to say that the universe is a super computer?
I await enlightenment.
Anselm

I think the only sword left to swing against intelligent machines will be dogma – they can’t be intelligent because the cognitive dissonance is too severe, and it must therefore be false of necessity.

Thanks for the comments.

-TS

 

[MindOverMatter2]

If a computer can not be intelligent and there is intelligence in the universe, could it be correct to say that the universe is a super computer?
I await enlightenment.
Anselm

It depends on whether or not there is a computer designer. It seems to me that if you believe in the same God that Aquinas does, it seems reasonable to think of the universe as a simulations run by Gods mind. This seems even more true with Quantum physics and entanglement. In quantum physics, quantum particles don’t appear to behave as if they move and make collaborative structures according to the classic notion of physical cause and effect, but rather they behave in consistent unison as if they move in virtue of some kind of unknown program. They behave the way they do because they are programed to? It would seem to be the case if out of nothing comes nothing.

Anyway…touchstone might pounce on me, so i will leave it at that.

 

[Touchstone]

It depends on whether or not there is a computer designer. It seems to me that if you believe in the same God that Aquinas does, it seems reasonable to think of the universe as a simulations run by Gods mind. This seems even more true with Quantum physics and entanglement. In quantum physics, quantum particles don’t appear to behave as if they move and make collaborative structures according to the classic notion of physical cause and effect, but rather they behave in consistent unison as if they move in virtue of some kind of unknown program. They behave the way they do because they are programed to? It would seem to be the case if out of nothing comes nothing.

Anyway…touchstone might pounce on me, so i will leave it at that.

RAR!



-TS

(“law” as in ‘physical law’ is really unavoidably close to kinds of effects one gets from structured software – developers who are particularly involved with simulations are regular stuck by these similarities with physics, physics just “feels” like a program. But that’s an intuition, you know what that will get ya… great for inspiration towards more research and exploration, pretty weak as the basis of belief.)

 

[MindOverMatter2]

I think the only sword left to swing against intelligent machines will be dogma – they can’t be intelligent because the cognitive dissonance is too severe, and it must therefore be false of necessity.

Thanks for the comments.

-TS

Firstly, while i am not saying that it is impossible, there is no a-prior reason to think that a particular structure moving in a particular way is the ultimate reason for intelligence, or will produce intelligence. We know that intelligence exists in structures of a particular kind, but we don’t know why any structure of any sort would be intelligent at all. It just so happens that a particular kind of structure possesses intelligence, and while it is true that we can learn how that structure moves or works, this doesn’t actually tell us why intelligence exists in virtue of that particular kind of structure moving in a particular manner; let alone why there is any such thing as physical laws and functional qualities in the first place. It can only tell us that an intelligence does in fact exist in correlation with certain conditions. Therefore this idea that complexity of information will necessarily lead to the existence of a self aware intelligence is a desired assumption. Without knowledge of the ultimate cause, we are in the dark about what can happen and what can’t happen.

Secondly; intelligence appears to arise in “biological structures”. Thus, while there is no proof that intelligence cannot arise in different structures, there is good reason to think that without any plausible examples to the contrary there is no good reason to think AI is possible. Perhaps fusion of the biological and the technological is a more plausible avenue of investigation. As this would almost probably involve human embryos i would have ethical reservations for such an investigation. I would much rather they continue to fantasize about a robotic AI.

 

[MindOverMatter2]

RAR!



-TS

(“law” as in ‘physical law’ is really unavoidably close to kinds of effects one gets from structured software – developers who are particularly involved with simulations are regular stuck by these similarities with physics, physics just “feels” like a program. But that’s an intuition, you know what that will get ya… great for inspiration towards more research and exploration, pretty weak as the basis of belief.)

LOL. If the world, especially at the quantum level, behaves like a program, why wouldn’t it be a good reason to believe that the world is a program? We make these kinds of inference all the time. Nobody knows that “quarks” exists, but the existence of quarks makes the best sense of what we do know. Thus people believe in them.

 

[Touchstone]

Firstly, while i am not saying that it is impossible, there is no a-prior reason to think that a particular structure moving in a particular way is the ultimate reason for intelligence, or will produce intelligence.

It depends on the particular structure, no? The structure of a rock, say, would not give the impression of “mental capability”. But a mesh of trillions of tighly interconnected electrical nodes, furiously consuming energy, with an array of active (name removed by moderator)uts it responds to dynamically, that sounds like a recipe for cognition. As we build software and computing machinery, we see the efficacy of that architecture as we progress.

That’s a post facto reason, one drawn from our experiences and knowledge of nature.

We know that intelligence exists in structures of a particular kind, but we don’t know why any structure of any sort would be intelligent at all.

If it’s a structure that can store (name removed by moderator)ut, process (name removed by moderator)ut, make inferences, and formulate output such that those inferences are subject to further feedback… it can learn. Having written evolutionary algorithms that work on data sets for large networks, it’s striking to see “just a bunch of code” learn and identify patterns in ways that were not even contemplated, let alone put into the software design as such. And that’s just some geeks working on network intrusion detection to make a buck or two. Those kinds of structures are not foreign or magical.

It just so happens that a particular kind of structure possesses intelligence, and while it is true that we can learn how that structure moves or works, this doesn’t actually tell us why intelligence exists in virtue of that particular kind of structure moving in a particular manner; let alone why there is any such thing as physical laws and functional qualities in the first place. It can only tell us that an intelligence does in fact exist in correlation with certain conditions.

That’s not much a criticism. That’s all we can know in any context. Any why can be restated as a pattern correlated with “certain conditions”.

Therefore this idea that complexity of information will necessarily lead to the existence of a self aware intelligence is a desired assumption.

It’s not an assumption – it’s something we’ve come to believe at length, after a whole lot of exploration and knowledge building. And I’m not aware of any necessity implicated in this. It’s not hard to imagine the “tape of earth’s history” being rerun, and life doesn’t arise before the sun explodes. Or maybe organic life evolves, but nothing we would call cognition arises before the sun burns out. It’s actual but I’m not aware of anyone who claims it’s necessary. Given the right chemicals combining in the right way at various crucial points in time, it would be necessary (physics just being physics), but that necessity only obtains when you’ve removed all the chance elements.

Without knowledge of the ultimate cause, we are in the dark about what can happen and what can’t happen.

I can’t agree, but on that view, nihilism. On my view “ultimate cause” is a non-starter, a completely opaque, inscrutable target. We build knowledge from the inside out; from the local, tentative, immediate, outward. We never reach "ultimate’, but we can and do make good progress, as reading this sentence on your computer shows.

Secondly; intelligence appears to arise in “biological structures”. Thus, while there is no proof that intelligence cannot arise in different structures, there is good reason to think that without any plausible examples to the contrary there is no good reason to think AI is possible.

By that measure, we couldn’t believe airplanes couldn’t fly. For all we could see is that flight can arise in biological structures, and without any non-biological examples to the contrary, there is no good reason to think airplanes could fly.

And that’s a good example to view this through. Biological flight isn’t the apotheosis, but just a “pointer” to the underlying physics - thrust to weight ratios, lift, airfoils, drag, etc. We learn about flight from the bird’s wing, but the bird is not flight, but a partaker in flight.

So too, intelligence. Humans are the apotheosis (and in some ways, we are utterly pathetic), but just a pointer to the underlying physics – concept formation, network topologies, inference engines, feedback loops, stimulus/response patterns, cumulative processes, etc. We learn about intelligence from the mind, but the mind is not intelligence, but a partaker in intelligence. Like the airplane, computing machinery is a platform nor partaking in a non-biological way, grounded in the same physical principles as its biological counterparts.

Perhaps fusion of the biological and the technological is a more plausible avenue of investigation. As this would almost probably involve human embryos i would have ethical reservations for such an investigation. I would much rather they continue to fantasize about a robotic AI.

Yeah, that would be an ethical challenge for sure. Strong AI is a sobering view on the remarkable complexity and refinement of the human brain. But the more we go along, the problems appear more and more to be problems of scale, and performance than architecture or capability. Problems that technical progress has a history of crushing under its heathen wheels…

-TS

 

[Anselm33]

Anselm33;7167677:

There’s a lot of “computing” implicit in physics, and despite the math intensity, it’s more descriptive in its math applications than algorithmic. If that doesn’t make sense, think of it this way: from a software programming standpoint, it’s not enough to understand Feyman’s reformulation of sum-over-histories conceptual, and mathematically, as a computing pro look at the problem, you wonder how that gets computed algorithmically such that it can behave in such a way.

Maybe it’s simpler to use the double-slit experiment. A physics prof will explain the concept of a probability wave, where a particle will “test” any and all possible paths in the universe in such a way as to resolve to the probability distribution for every single point in the universe (densely clustered around the general area between where the particle was fired from and aimed at, typically). Conceptually, that’s difficult enough to wrap one’s mind around (it really checks out paths that route it past Saturn to the other end of the galaxy and back here? really?), but if you look at that from the standpoint of someone who would try to write that as computing machinery, two realizations are immediately apprehended:

1. The scale of the computing problem is just about unimaginable. It’s scope is literally every location in the entire universe, in real time!
2. Even in light of 1), it’s algorithmic in nature – a parallelized search function that sums up all the results as they return to build a “landscape” of probabilities for the particle.

A lot of physics is like that – the scale and speed are unfathomable, but the “algorithmness” is often apparent or familiar to a software developer.

Consciousness is computation, so far as I can see. It’s just computation that is so highly parallelized and diffuse (i.e. unlike our typical computing models for servers and the like), that it stuns us as magic (what’s that Arthur C. Clarke line?).

By observation, though, I didn’t mean “conscious observation”. I should have been more precise and referred to “events which trigger decoherence”, That is not a function of consciousness, but it is, again, immediately familiar as a computing problem, real-time resolution of otherwise-independent local systems that have interacted to an (irreversible) extent that they must now be harmonized.

OK, gotcha. I think Searle is lame, and the Chinese room is weak, conceptually – sophistry via lazy language if you want a more ornery take. I don’t take strong AI as a given or inevitable, but I’ve yet to see a computing-cogent case for dismissing it outright. It strikes me as the same kind of credulous thinking that supposes simple biological processes can’t produce fantastically complex and sophisticated structure and machines over deep time and cumulative progress.

But that’s another thread,

I think the only sword left to swing against intelligent machines will be dogma – they can’t be intelligent because the cognitive dissonance is too severe, and it must therefore be false of necessity.

Thanks for the comments.

-TS

I’m going to back off for a few days on this thread, because I’m doing a rapid review of Penrose’s arguments against both strong and weak AI (i.e. computational consciousness),
and for his “new physics” to explain consciousness. I should add that I am uncomfortable with strong AI as a complete explanation of mentality (whence values, ethics, beauty) but not yet ready to offer rational arguments against it. One appealing aspect of the “it from bits” picture is that for me, it’s possibly easier to think of God as that big programmer in the sky than as another disembodied agent to affect reality .

 

[Touchstone]

Touchstone;7167806:

I’m going to back off for a few days on this thread, because I’m doing a rapid review of Penrose’s arguments against both strong and weak AI (i.e. computational consciousness),
and for his “new physics” to explain consciousness. I should add that I am uncomfortable with strong AI as a complete explanation of mentality (whence values, ethics, beauty) but not yet ready to offer rational arguments against it. One appealing aspect of the “it from bits” picture is that for me, it’s possibly easier to think of God as that big programmer in the sky than as another disembodied agent to affect reality .

Yeah, as a longtime professional software developer, I feel the same way. The more I learn, though, the more my discomfort with strong AI appears to be simple conceit. Doesn’t mean I’m any more comfortable with the idea, but if such obtains, it is easier to see that as a reality being “computistic” (with or without the Great Programmer in the Sky™) as opposed to “personalistic”.

Which is not to say that you are going to find a complete explanation for “beauty” as a feature of strong AI. Even if such a thing is possible and obtains, we don’t have a robust model for such as of now.

Or do we? One of the more fruitful avenues of exploration in strong AI in past years has been the realization that it is fundamentally stupid to think of human minds as simply the brain organ. The human mind is an integration of the whole body. There’s no reason to expect we should be able to construct a “brain simulation” that just implements a virtual brain and proceeds to process and develop ideas about “beauty” as we do. To do that, we would have to model the whole human, and incorporate all the features we know are involved. Emotions, the “visual history” of the organism, the binding of visual images and happy moments in very young, formative periods of the mind.

There’s a realization that 3D programmers eventually get as they work on modeling and rendering real world scenes: the real world is fantastically complex to model and render. Well, duh, but that’s not the key point. A ramification of that realization is that the only way to achieve “strong 3D” in the sense of “strong AI” is to model the entire physical environment.

This is why the disembodied brain can never achieve strong AI; strong AI is a function of the body and the whole person connected to the brain. Nerves, synapses, organs, enzymes, blood sugar levels, all that that would have to be rendered and modeled to duplicate “human AI”. Just like “modeling the whole universe” in 3D is totally impractical, “modeling the whole human” to prove out “strong AI” (our conceited view of what ‘intelligence’ must mean) is totally impractical.

So don’t hold your breath on the the sense-of-beauty-as-proof-of-AI thing. I don’t see any barriers in principle, but the practical demands are just staggering. You’d have to build a complete virtual human to show that humans can be completely virtualized. The exquisite resources and effort that would require are much more profitably invested elsewhere.

-TS

 

[yppop]

If reality is computable, one has to ask: what is being computed? If the answer is that reality is a cosmic simulation, then what is the “hardware” that produces such a simulation? In other words: is there a model describing how reality could be the result of an algorithm that computes the sequence of material configurations that comprise the evolving structure of the universe?

I believe there is; but in order to be applicable to the “it from bits” concept, reality at the ground state would have to consist of a granulated substrate, and the only granulated substrate imaginable would be discrete space, i.e., space defined by the rational numbers.

Consider the following:

Gregor Chaitin, Meta Math, The Quest for Omega, page xiii: “The computer has provoked a paradigm shift: it suggests a digital philosophy, it suggests a new way of looking at the world, in which everything is discrete and nothing is continuous, in which everything is digital information, 0’s and 1’s. So I was attracted to this revolutionary new idea.

Paul Davies: The Mind of God, page 124 “It has to be pointed out that our present theories of physics are not generally formulated in quite the same way as computer algorithms because they make use of quantities that vary continuously. In particular, space and time are considered to be continuous. ‘The possibility that there is to be an exact simulation, that the computer will do exactly the same as nature,’ explains Richard Feynman ‘demands that everything that happens in a finite volume of space and time would have to be exactly analyzable in a finite number of logical operations. The present theory of physics is not that way, apparently. It allows space to go down to infinitesimal distances.’ On the other hand, the continuity of space and time are only assumptions about the world. They cannot be proved, because we can never be sure that at some small scale of size, well below what can be observed, space and time might not be discrete.”

Chaitin, Feynman, Davies are not the only thinkers that entertain the notion of a computable universe based on a discreteness, there are a good number of other thinkers now engaged in the study called Digital Physics. I contend that such effort is based on the belief that physical science may accurately “describe” objective reality, but it doesn’t “explain” reality’s fundamental nature. I believe, as I argued in my thread, “God Exists, but How”, that reality based on the discreteness of space allows of a dual nature—material and psychical—of reality. The truth lies at the ground of reality, where science, if it accepts the discrete view, will eventually find God, for the idea that discrete space is the substrate of reality, for which algorithms replace equations as the means of description, and information replaces energy as the impetus of objective reality, leads to a more complete and comprehensive model of reality.

Yppop

 

[Touchstone]

If reality is computable, one has to ask: what is being computed?

It’s computing itself. If its a computing platform, it is resolving itself, constantly (and this actually has a nice dovetail with the “arrow of time” problem, as it ties change to ‘forward resolution’).

If the answer is that reality is a cosmic simulation, then what is the “hardware” that produces such a simulation?

Imaginations vary, but the cluster of ideas I’m familiar with coalesces around the idea that it’s not a simulation at all. That is, it’s not simulating or emulating some other environment. It’s the real thing, and the “hardware” is STEM – space/time/energy/matter, with physical laws being the “software”. We use “simulation” because it’s common that our most impressive or “world-like” virtual environments are simulations of some aspect of the real world, or an imagined fantasy world. But the idea of the universe being computing machinery has itself as the object, from all the notions I’ve heard. On a Many World’s Interpretation, view, though, this world would be a simulation of a future path of a forked parent, one concrete instance of n possible forked child universes for every decoherence…

In other words: is there a model describing how reality could be the result of an algorithm that computes the sequence of material configurations that comprise the evolving structure of the universe?

Yes, physics! In programming terms, the universe appears to have runtime aspects that suggest with a declarative language paradigm in the vein of Prolog or Fortran. But that is likely just because of the way we do science – by reverse-engineering nature’s behavior. That biases one’s results toward a set of descriptive principles, which natural match declarative computing models. If we could look at the “machine language” of the universe, we’d likely conceive of it (and our physics) in terms of procedural language paradigms.

And of course it’s blatant anthropization of the subject to talk about this in terms of languages, symbolic systems that reduce to executable runtimes. We’ve no reason to think that’s anything more than “humanifying” the computing-like aspects of the universe.

But Seth Lloyd and several of his peer “quantum mechanics” had a historic “lightbulb moment” when he/they came to the realization that the universe was perhaps actually computable. The problem with that was you’d need a universe of qubits to calculate the universe. If that seems like a joke from Lloyd it’s not; his idea is profound, that a qubit is the basic information and computing element of the universe, and that qubits can actually be used for real computers, quantum computers. Assemble enough qubits working together, and you have a real, functioning universe.

I believe there is; but in order to be applicable to the “it from bits” concept, reality at the ground state would have to consist of a granulated substrate, and the only granulated substrate imaginable would be discrete space, i.e., space defined by the rational numbers.

I think that would be an exercise in quantizing all of reality; that could be how things are, but such an adjustment creates all sorts of problems that are hard to solve. General Relativity assumes a continues spacetime topology, for example (although loop quantum gravity may be a way to adjust GR for a quantized spacetime).

That seems like forcing reality to be apprehendable on our familiar, human terms, though. The more we learn, the more this strange thing called the qubit looks to be the basic computing resource/unit of the universe. Qubits rather than bits. It’s a quantum universe, computing in quantum units and by quantum rules. Macroscale is just statistical summaries.

-TS

 

[Touchstone]

Consider the following:

Gregor Chaitin, Meta Math, The Quest for Omega, page xiii: “The computer has provoked a paradigm shift: it suggests a digital philosophy, it suggests a new way of looking at the world, in which everything is discrete and nothing is continuous, in which everything is digital information, 0’s and 1’s. So I was attracted to this revolutionary new idea.

Could be. Would be a wonderful breakthrough if some discovery was made that supported that. But again, I think {0|1} is likely to give way to {http://upload.wikimedia.org/math/4/...th/e/e/7/ee73186e90463a7382893d182c1314c3.png}, if the universe should turn out to be computable.

Paul Davies: The Mind of God, page 124 “It has to be pointed out that our present theories of physics are not generally formulated in quite the same way as computer algorithms because they make use of quantities that vary continuously. In particular, space and time are considered to be continuous. ‘The possibility that there is to be an exact simulation, that the computer will do exactly the same as nature,’ explains Richard Feynman ‘demands that everything that happens in a finite volume of space and time would have to be exactly analyzable in a finite number of logical operations. The present theory of physics is not that way, apparently. It allows space to go down to infinitesimal distances.’ On the other hand, the continuity of space and time are only assumptions about the world. They cannot be proved, because we can never be sure that at some small scale of size, well below what can be observed, space and time might not be discrete.”

Yes, that’s good. Any paragraph that relies on Feynman has something good going for it. But even if spacetime is quantized, that’s different from being digital, or discrete on some binary level. Again, that could be the case, but a quantized universe doesn’t have to break down to bits, but maybe qubits. Briefly, qubits are similar to bits, in that they can take polar values (0|1), but can also store a superposition of both values.

Chaitin, Feynman, Davies are not the only thinkers that entertain the notion of a computable universe based on a discreteness, there are a good number of other thinkers now engaged in the study called Digital Physics. I contend that such effort is based on the belief that physical science may accurately “describe” objective reality, but it doesn’t “explain” reality’s fundamental nature.

Understand. I don’t recognize “fundamental nature” to be a coherent concept, however. How we would distinguish a robust description from a fundamental explanation, I have no idea.

I believe, as I argued in my thread, “God Exists, but How”, that reality based on the discreteness of space allows of a dual nature—material and psychical—of reality. The truth lies at the ground of reality, where science, if it accepts the discrete view, will eventually find God, for the idea that discrete space is the substrate of reality, for which algorithms replace equations as the means of description, and information replaces energy as the impetus of objective reality, leads to a more complete and comprehensive model of reality.

Yppop

Hmmm, didn’t really follow that, but also didn’t get the sense (as I often do with others) that you aren’t following what you wrote, either. How would a discrete spacetime (spacetime is broken up into indivisible, discrete “chunks”, very, very small chunks) assist with the psychic or God?

-TS

 

[sinnerdexter]

The Universe has to be computable otherwise it wouldn’t be able to sustain itself within reality.

Whether the Universe is actually the product of an external force that is doing the computations, is a more philosophical matter. Probably something concerning the ontological properties of cutlery.

 

[Anselm33]

Could be. Would be a wonderful breakthrough if some discovery was made that supported that. But again, I think {0|1} is likely to give way to {http://upload.wikimedia.org/math/4/...th/e/e/7/ee73186e90463a7382893d182c1314c3.png}, if the universe should turn out to be computable.

Yes, that’s good. Any paragraph that relies on Feynman has something good going for it. But even if spacetime is quantized, that’s different from being digital, or discrete on some binary level. Again, that could be the case, but a quantized universe doesn’t have to break down to bits, but maybe qubits. Briefly, qubits are similar to bits, in that they can take polar values (0|1), but can also store a superposition of both values.

Understand. I don’t recognize “fundamental nature” to be a coherent concept, however. How we would distinguish a robust description from a fundamental explanation, I have no idea.

Hmmm, didn’t really follow that, but also didn’t get the sense (as I often do with others) that you aren’t following what you wrote, either. How would a discrete spacetime (spacetime is broken up into indivisible, discrete “chunks”, very, very small chunks) assist with the psychic or God?

-TS

I’ve spent some time (four days) going over Chapters 1 and 2 (and skimming Chapter 3) in Penrose’s “Shadows of the Mind” in which he lays down the reasons for his belief that mind (awareness) is non-computable. I tend to agree with him, even though my math is really challenged at several points in his argument. One particular thing he brings up that I would appreciate comments on is an example of a deterministic but non-computable “toy” universe, tiling the plane with polyominoes (links to sites are too long; use a Google search with search terms “non-computable” “polyominoes”). There are other examples of non-computable functions and procedures (Penrose gives the Halting problem–again do a Google search using the search term “non-computable”)

OK, so I ask, if these functions are non-computable in principle, how can the Universe be computable?

I await enlightenment.

anselm

 

[Touchstone]

I’ve spent some time (four days) going over Chapters 1 and 2 (and skimming Chapter 3) in Penrose’s “Shadows of the Mind” in which he lays down the reasons for his belief that mind (awareness) is non-computable. I tend to agree with him, even though my math is really challenged at several points in his argument. One particular thing he brings up that I would appreciate comments on is an example of a deterministic but non-computable “toy” universe, tiling the plane with polyominoes (links to sites are too long; use a Google search with search terms “non-computable” “polyominoes”). There are other examples of non-computable functions and procedures (Penrose gives the Halting problem–again do a Google search using the search term “non-computable”)

OK, so I ask, if these functions are non-computable in principle, how can the Universe be computable?

I await enlightenment.

anselm

Well, I’ve not read Shadows of the Mind, but I have read parts of Penrose’s The Emperor’s New Mind, and lots of related discussion online, over the years. I think this bit from Penrose on the subject here is relevant:

There’s a connection between this area of physics and consciousness, in my opinion, but it’s a bit roundabout; the arguments are negative. I argue that we shall need to find some noncomputational physical process if we’re ever to explain the effects of consciousness. But I don’t see it in any existing theory. It seems to me that the only place where noncomputability can possibly enter is in what is called “quantum measurement.” But we need a new theory of quantum measurement. It must be a noncomputable new theory. There is scope for this, if the new theory involves changes in the very structure of quantum theory, of the kind that could arise when it’s appropriately united with general relativity. But this is something for the distant future.

    Why do I believe that consciousness involves noncomputable ingredients?          The reason is Gödel's theorem. I sat in on a course when I was a          research student at Cambridge, given by a logician who made the point          about Gödel's theorem that the very way in which you show the formal          unprovability of a certain proposition also exhibits the fact that it's          true. I'd vaguely heard about Gödel's theorem — that you can produce          statements that you can't prove using any system of rules you've laid          down ahead of time. But what was now being made clear to me was that as          long as you believe in the rules you're using in the first place, then          you must also believe in the truth of this proposition whose truth lies          beyond those rules. This makes it clear that mathematical understanding          is something you can't formulate in terms of rules. That's the view which,          much later, I strongly put forward in my book *The Emperor's New Mind*.

This I think clearly locates Penrose’s objection in his understanding of Gödel Incompleteness. He talks later in the article about various criticisms of his take on this, and allows that Daniel Dennett’s “bottom up” argument is one that bears more analysis (which I think an understatement, but a fair one), but the problem is more fundamental, I say: Gödel’s theorem needn’t apply for strong AI, or “computational consciousness”. All computational systems we have now that are formal such that Gödel’s theorem applies still compute, still resolve. Gödel’s insight doesn’t invalidate or change that. Rather, it just notes that the system has transcendental limitations. It’s self-consistency necessarily means it cannot possibly be complete in its expositions, it’s proofs.

That in no way denies strong AI in principle, and if you’ve read Penrose on this, you know that he doesn’t claim is does. He just thinks there’s something “simply non-computable” in consciousness. You don’t need to rely on Gödel for that, and Gödel can’t even help you get there, or show that to be true.

Penrose says this later in the article:

      I apply the Gödel argument to bottom-up systems too, in my most recent          book, *Shadows of the Mind*. I make a strong case that bottom-up          systems also won't get around the Gödel argument. Thus, I'm claiming,          there's something in our conscious understanding that simply isn't computational;          it's something different.

There’s nothing to “get around” to establish the viability of strong AI, per Gödel, that I can see. Any “computable consciousness” would have true propositions that were non-computable, but so does any formal system, and we have plenty of examples where that is no crisis of computation. I’ve read a lot of Penrose, but not all, but from what I gather, he never shows us where the limitation actually obtains. That makes sense, and is fairly obvious, because we don’t have a working, robust model of consciousness yet as a reference point. We don’t even know what we are applying Gödel to, if it is even applicable.

Have I missed the main substantive point from Penrose here?

-TS

 

[Touchstone]

I’ve spent some time (four days) going over Chapters 1 and 2 (and skimming Chapter 3) in Penrose’s “Shadows of the Mind” in which he lays down the reasons for his belief that mind (awareness) is non-computable. I tend to agree with him, even though my math is really challenged at several points in his argument. One particular thing he brings up that I would appreciate comments on is an example of a deterministic but non-computable “toy” universe, tiling the plane with polyominoes (links to sites are too long; use a Google search with search terms “non-computable” “polyominoes”). There are other examples of non-computable functions and procedures (Penrose gives the Halting problem–again do a Google search using the search term “non-computable”)

OK, so I ask, if these functions are non-computable in principle, how can the Universe be computable?

I await enlightenment.

anselm

Hey, so I found Shadows of the Mind online, sort of, on Google books, here:

books.google.com/books?id=gDbOAK89tmcC&pg=PA33&lpg=PA33#v=onepage&q&f=false

I think that page is the one where he’s introducing the toy model universe you are referring to, here. If so, a couple of comments, just based on the bit of reading I’ve done there:

1. Computability is not determinability. The set of computable problems or states is a subset of the set of deterministic states. Or, not all deterministic chains are computable chains.
2. 1. does not mean that consciousness is therefore non-computable. It’s quite possible to construct virtual systems that are both formally deterministic and non-computable in practice. But that says nothing about whether consciousness gets placed in one category or another. It may be that consciousness in the set of of practically computable tasks, even if Penrose’s toy universe is not (and it’s not).
3. Conscious is not necessarily deterministic or “discretely computable”. As above, we don’t have a robust model of human cognition yet, but what we do understand incorporates halamo-cortical neurons working in synchronously oscillating feedback loops. What that means is that there may not be any “fixed answer” for what we “compute” with our consciousness, and a “neural correlate” machine for our brains would be incorporating noisy feedback and stochastic (name removed by moderator)uts that keep the algorithm static (sort of, the neural nets are constantly rewiring here and there), but have random influences that make a true “computational consciousness” fuzzy, because our consciousness is fuzzy in the same way.
4. Ultimately, Penrose’s position comes down (like Searle’s) to incredulity toward the idea that a “simulation”, even a perfect one is qualitatively the same thing as consciousness. If we put the ultimate Turing Test beater in front of him, Penrose, as I read him, would maintain that there was “still something missing”, even if there was NOTHING, nothing at all missing in every test he could apply.

If that’s the case, I think it becomes quite uninteresting, quickly. For this just stops all further discussion. It’s dogma at that point, and admits of no change or consideration, no matter what further evidence comes up. If I cannot provide any practical test or means of differentiating machine consciousness and human/biological consciousness, I have to wonder on what grounds I would maintain a distinction.

Of course I know those grounds, having held that position at one time. Intuitional grounds. It just… seems like it must be different.

My question for you is: what is your criterion? Would a perfect pass on the ultimate Turing Test convince you of strong AI? If not that, what would, if anything? Or is it just not possible, no matter what, somehow?

I’ll keep reading this Google book version of the Penrose book. It’s interesting.

-TS