is the universe a computer? (split)

[Shrooms00087]

[...]

I inherited the thread, if someone remembers the original post I'll edit it.

 

[Psyduck]

Information ~= in-formation; matter is in-formed.... the most problematic term is here the word "in". What does that mean? How can we understand the term "in"?

but i'm interested to see if these ideas are gaining real momentum outside of the totally biased community i'm familiar with)

Contextualized... cf. the same problem at the beginning (= the end) of philosophy: Plato vs. Aristotle vs. Atomists.

Does form have existence independent of physical substrate. Yes, Plato would say. (cf. his dualism of two worlds, i.e. the world of ideas/forms and the sensible/material world).
Or do we only have bare matter then, like the Atomists in early Greek already said. Just bare matter without further qualities.

=> No, says Aristotle to both (1° dualism of matter/form; and 2° neglect of form). Question: how to understand then that matter is in-formed (=i.e. a hylomorphic substance constructed of hyle/morphe).

landauer was convinced that information IS physical, with no existence independent of its physical substrate- i'm not convinced of this.

I think Landauer makes a mistake too. The statement "Matter is form" (or in your contemporary terminology "Matter is information") seems false to me. However, one can say that "Matter is in-formed." This is essentially Aristotle's position. The big problem is of course that you must make intelligible how matter is in-formed, i.e. what does the word "in" mean here?

p.s. if you want a more recent philosophical basis for cellular automata and information theory etc. Cf. Leibniz's monad and moreover

http://en.wikipedia.org/wiki/Digital_philosophy

Leibniz's monad is essentially a neo-aristotelean conception of substance.

 

[twentysix]

Without reading (I will, though. No disrespect. It is interesting.), I want to chime in first and say that yes- the Universe is what it contains, as all things must be it. Computers are definitely reflective of the whole. Computers come at a point in our evolution, and seem to be part of the universe, "fulfilling" itself.

And http://youtu.be/D-j69l3uZzo.

 

[ebola?]

Vexingly, I find find this topic fascinating but also find my level of knowledge insufficient to comment substantively on the matter.

[content removed in accordance with author's wishes]

But can we increase entropy in the universe without destroying information? Relatedly, is the state of maximal entropy also that which contains the minimum possible information?

And for this layperson, what does it actually mean for a system to contain more or less information? Many would think of each bit of matter as being a sort of register, with a number of possible states (including conditions like spatial location, etc.). Thus, information should remain constant for any given collection of particles in any given space. I suspect this notion wrongheaded, though, as you mention. . .

do you think information, configurations of qubits, is the most fundamental physical quantity?

So how does it change things if we think in terms of configurations of qbits rather than classical bits (I'll have to admit my understanding of the former quite poor)?

do you think information is fundamentally physical? beyond making information theorists smug, do you think it matters?

I think that information theory is potentially ontologically useful, in that it presents a framework that could inhere logically prior to the emergence of both the physical and the mental, thus providing an account of both and their interrelation.

ebola

 

[hiphophippy]

No we cannot compute, understand or realize all physics. And no, the universe is not a computer. It just is.

no more of a computer than a rube goldberg machine.

 

[qwe]

Quite high.

do you think information, configurations of qubits, is the most fundamental physical quantity? do you think information is fundamentally physical? beyond making information theorists smug, do you think it matters?

information and data are artifacts of our consciousness' neuronal computational structure

consciousness-information (data) are the shadows of:
apparent discontinuities (separations) in our reality, which are the shadows of:
gradients of energy (spacetime, matter, energy; the mathematical dance of particles we know of), which are the shadows of:
i don't know? physical information..?.. it seems to be like my experience with salvia, everything slides into everything else at once, it's all a big glob of noodles slipping by each other (but they aren't actually separate)... ... hey, it's the philosophy forum

personally, i can't figure out why all of the universe isn't just evenly distributed in terms of information :S then again, i've been going through significant neuronal flux. it could all just be me. :D

i believe the answer has to be multidimensional... i wonder what role extra dimensions could play in our fundamental consciousness, and the energies used by consciousness.

 

[Shrooms00087]

One cannot help but drop this after hearing references of Thompson and noodles:

NSFW:

 

[Merkinsey]

There are some serious scientist experimenting to figure out whether all things within our Universe are some type of holographic projections. This is based on their mathematical discovery that everything that gets sucked into a black hole leaves the 2D information on the outer shell of the black hole that theoretically can be used to recreate the "lost" objects.

When scientists observed minute "distortions" in everything when looked in their atomic elemental level (or something to the effect - I'm paraphrasing to explain the gist of the idea), there came the idea that things might not be real but a type of projection from the 2D information on the outer shell of the Universe.

In Quantum theory, when an element is separated into two and the two separated elements are placed far apart from each other - even light years apart, if you change anything on one of the elements, the now separated the other element follows the exact change that is applied to the separated element, even though there is absolutely no link at all to the the now separated elements that are far apart from each other. As of now, scientists don't have an explanation for this behavior. However, if everything is holographic projection from far away on the outer edge of the Universe, it becomes plausible why two separated elements far apart with no link of any kind moves exactly same to the right when only the one of the two elements in moved to the right from far far away with no connection at all.

If the holographic theory is true, then it explains a lot of things like Quantum theory and all kinds of things and possibilities like god, afterlife, or some other possible form of living after death etc etc. Also, the question would arise that are the 2D information that we are projected from some sign of intelligence behind it or is it just something that happens to things that existed in universe at some point like things that gets sucked into black holes and disappear... interesting, eh? 8(

Google Holographic Universe if you want cite. http://en.wikipedia.org/wiki/Holographic_principle

 

[Portillo]

If the universe is a computer does that mean it is organized and designed?

 

[MikeOekiM]

No we cannot compute, understand or realize all physics. And no, the universe is not a computer. It just is.

no more of a computer than a rube goldberg machine.

nothing is known for sure so theres a chance the universe could be a computer.

 

[dkmonk]

A computer is Artificial Intelligence, and the Universe is governed by complex laws which are constant throughout, and the results of all this is life being created, so it seems very similar to one. I like to think of it more as a nerve network similar to mycelium, and the universe as an organism.

Sorry, that it isn't much of an informative post, but just an idea I have formed from my little understanding of how it works, and relating it to other life that I understand more, and can see similarities between. Taking mushrooms helped me feel this too.

 

[hiphophippy]

nothing is known for sure so theres a chance the universe could be a computer.

Please, ask them to break the matrix. Meanwhile I'll be down here thinking about things that are relevant.

 

[qwe]

If the universe is a computer does that mean it is organized and designed?

not necessarily (at all).

 

[polymath]

Here's an article from Scientific American Jan 2012: "Is space digital?" I happened to read the magazine in the local university library today.

Also see this article by Nick Bostrom: "Are you living in a computer simulation?"

I think its difficult to make this kind of conclusions about the universe as a whole... To do so we would have to observe the universe from the outside as an object. Being part of the universe ourselves, this is rather impossible. Also, what kind of an experimental result would prove that universe is a giant computing machine?

 

[MattPsy]

I guess you could call the universe a computer. They share the property that each can host a subset of itself and the other, interestingly (at least for me).
You could consider the universe to be a physical instantiation of the abstract concept of a non-deterministic n-dimensional (maybe 3 with time being iterative count, or more, it remains to see - I suspect there will be, to accommodate some of the more neat features of our universe like entanglement - also, if you aren't too familiar with the intricacies of computational complexity, it's worth looking it up! All of them, of course, should actually be equivalent, though I do wonder which dimensionality turns out to be most practical) Turing machine. (with the Planck Length being the 'cell' size on the 'tape' I suggest, as in previous discussions; this abstraction unfortunately doesn't translate too well past 1-dimension, let alone 3, but 4 is plenty plausible, just not very easy to comprehend natively, unsurprisingly)
This is pretty similar (identical?) to the cellular-automaton model. I'm not convinced there are any real differences between the two, so if you prefer one outlook over another, then I reckon go with that.

In both, an iteration should correspond to one unit of Planck time, since that is the length of time required for information/light/EM-radiation (these are equivalent) to travel one unit of Planck length. The speed of light is the fundamental limit of information propagation. Yes, there are phenomena such as quantum entanglement to be taken into account, but the requirement that two entities first be entangled before the subsequent instantaneous information propagation takes hold is pretty profound, and probably has a lot to teach us, along with some other striking practical consequences (probably). That's my impression anyway. FTL neutrinos redux: this doesn't pose too many problems from what I can see, since if they or similar entities do indeed exist, neutrinos carry less information than photons (less possible states), maybe this isn't violated?

Now, is such a model useful? Yes. The revelation that information content is isomorphic with entropy is probably the most interesting thing i've ever learned - you can use the same equations! With these ideas we might break down the information paradox - the paradox that information might be destroyed when it enters a black hole, as mentioned by a previous poster. Indeed, the information seems to be returned via Hawking radiation emitted from the event horizon. Black holes almost seem to function as a form of encryption/encoding. We might therefore be able to test our ideas about how the universe can be viewed as a computation by essentially doing "known-plaintext" or "chosen-plaintext" attacks - feeding "plaintext" (matter of known configuration) into black holes and observing the "ciphertext" emitted (Hawking radiation).

An computation-theoretic view of the universe is very compatible with the holographic principle, since this basically says you can encode an n-dimensioned (it's arbitrary) space onto a n-1 dimensioned space. You may notice this is the same as the conception of a Turing machine. Higher-dimensioned Turing machines can always be emulated by a single-dimension (or just n-1, whatever) Turing machine, just less efficiently.
It would also seem to be very compatible with loop-quantum gravity.

Something interesting about conceptualising the universe as a NTM (non-deterministic Turing machine) is that the state of the universe becomes an NP-complete computation. (I think?)
This makes our usual 'laws of physics' approximation algorithms. This would suggest why they break down under extreme environments, like how general relativity hasn't been reconciled with quantum mechanics.

Just a few ideas for now. I'll post more a bit later as I have more time and have some more ideas on what to post about! I'm extremely interested in this topic.
Sorry I haven't linked all these ideas together better, i'm mostly trying to just spit out some concepts for now, get people talking, etc.

polymath: Yes this is a problem if you were trying to simulate the entire universe whilst still in it. Systems can't transcend themselves, but they can reflect (with odd consequences see: mathematics) . This doesn't prevent you from building an abstraction.

chinup: on whether information exists independent of physical substrate: tough question but ultimately a non-sequitur, IMO. "not even wrong" as its called.
In my view: yes, it does in some sense (but is not worthy of calling "existence"), but is only realizable through a type of encoding in substrate. let's consider the idea of a triangle (since this is basically a Platonic discussion). You can't have a 'perfect' triangle in physical substrate, geometry-wise, not if it's made up of indivisible quanta [it's always 'lumpy'], but in that same substrate you can encode the 'idea' of a triangle (3 points, internal angles sum to 180 degrees in 2-dimensional space, etc) in various forms - indeed, I pretty much just did that - the idea of a triangle is now partially encoded in the substrate of my computer's memory, arrangements of atoms in particular patterns, and now rushing down to your computer (in a computer, in a computer ) in a burst of encoded photons and electrons. Interested on your take ?

Do you think a NTM or a DTM is a better model? Or, should I rephrase that as: do you think the 'fuzziness' that we see arises from insufficient data fed into a deterministic model, or is the state-shift process inherently non-deterministic? What consequences does this have? (keeping in mind that 'sufficient data' for a DTM of our universe, hence universe-size, with us IN it, might be impossible)

Oh, and as to whether it's [the universe = computer] a trivial assertion: yeah, in some sense (damn, that answer seems to come up lots). Is it the most useful model? For what uses? It strikes me as the most likely contender for the concrete 'fundamental' nature of the universe: information transforms. Whether it proves to be the most useful one remains to be seen. I suspect it will prove really useful in some applications, and be overkill in others. You could draw a comparison between low-level and high-level programming languages - use the higher level interpretation normally, but where extra speed or precision is required, use the lower-level interpretation. And, whenever using the higher-level interpretation, always remember the lower-level one exists.

 

[Psyduck]

i hadn't thought of this in monadic terms, as qubits, as quantum systems certainly don't have intrinsic identity in the metaphysical interpretations of quantum theory that i have seen. modern physics supports ontic structural realism (osr), which cannot accommodate Aristotelian conceptions of objects. i think the conception of the universe in information theoretic terms is consistent with osr and hence with the metaphysics suggeted by modern physics. there are various flavours of osr but the basic idea divides reality into objects and relations, the relations form a structure, and the objects within these structures, if they exist at all or can legitimately be called objects, cannot exist independently of them.

For Aristotle substantial forms (such as: animal, dog, cat, chair, table) preside over pieces of matter. In the sense: that heap of matter is gathered and unified into something concrete (a hylomorphic substance). The heap of matter is organized such and such, for example: that wood is organized as a table, and not organized as a chair. Because over the matter presides some substantial form (tableness/chairness) we get concrete things: tables/chairs.

Now... Leibniz's monads are more sophisticated. They are also composed of matter/form (but in a different way)... monads don't even belong to space/time; nonetheless, they "correspond" (big problem in his philosophy!) somehow to the spatial/temporal embodiement of concrete things; they represent the phenomenal world (everything we perceive, feel, hear, think, etc.). In a certain sense one can say that monads are the cause of it, or perhaps stated more carefully "they are the condition of possibility for it."

This is probably from a positivistic POV not interesting, absurd and metaphysical BS.... on the other hand, logical positivists lack the sexyness of Leibniz's philosophical thought! Leibniz does not "take for granted" that "there are" (!!!) appearences; empiricists will just presuppose this and only scrutenize/describe those appearences (e.g. describing the mechanical laws which one can perceive with empirical eyes).

But it's far from obvious why there should be appearences at all. Leibniz thus questions into the ground of the appearences (i.e. a metaphysical question). Appearences must be taken in wide sense; everything "that appears" (thoughts, sensible images, feelings, pain, galaxies, the sun, planets, stones, atoms, electrons, protons, animals, etc.) can be called an appearence. So it's not only about appearences "to" the human consciousness. But the whole universe itself is "appearing" or "presenting itself" and "sustaining this presence." However, one must be cautious here... monads don't fill an abstract empty Newtonian space (a container), but they "make up" the phenomenal world (on which our thought can impose some three-dimensional structure though)... I repeat: everything in front of you is "made present" by monads. Your table and computer are not just "placed in" a Newtonian space (= big Euclidean-or-whatever-geometrical-space which can be filled); it's a different kind of space that gets filled, which is something really hard to grasp... but if someone would be interested, I suspect this to be similar to Plato's notion of the chora/receptacle in the Timaeus.

Monads most primordially (for Leibniz) produce phenomena, more specifically they also harmonize all their representational acts. For example= "I feel pain" = appearance-1; "the doctor presses a needle in my arm" = appearence-2. That's with regard to the body/mind problem... but take another example, namely gravity: the movement of sun and that of earth "harmonize" phenomenally which each other. The sun [or gravitational field] doesn't "act on" the earth. For Leibniz there is no causality (cf. also Descartes, or Malebranche occassionalism). However, the many monads "corresponding" to the sun, and the many monads "corresponding" to the earth "harmonize" with each other, and bring about natural phenomena in a harmonized fashion (i.e. the movements of the earth/sun, about which the human mind can claim some causality; but "in reality" for Leibniz there is no causality.)

http://www.iep.utm.edu/leib-met/#SH8b

Each monad contains everything there will happen in the world. So, here you can make the link with information theory. Each monad "contains" all the (relational) information of the universe already; monads don't interact; monads (or qubits in your term?) don't interact with each other, they only harmonize. Moreover, another characteristic of the monad is that it has its own principle of transition in itself (appetito); moving from perceptio1 to perceptio2 (or in your term: computer state-1 to state-2).

Another addition (I'm in in a hurry): why is the whole universe in a single monad? For example:

P=possibility
p1=I stay inside, because it rains outside
p2=there exists a house in the universe
p3=there are some clouds in the air
p4=there is a certain temperature that makes the clouds condense (or whatever what produces raindrops)
p5=this temperature is related to heat sun, orbit of earth,...
p6=the heat of the sun is related to its age
p7=its age is related to nature of some other stars in the cosmos, etc.

Hence every possibility (or all the happens in the universe is related to each other). Even though the monads to my body represent p1, p1 itself is not an isolated possibility, but p1 implies p2; p2 implies p3; p3 implies p4, etc... as a consequence p1 implies the whole universe; that's how you must understand that Leibniz says that every monad "contains" the whole universe.

When Leibniz says that the whole universe is in every monad he doesn't mean that all galaxies/stars/earth/... are "inside" the monad; just that all "information" of the phenomenal universe is "in" the monad; which they consequently will unfold in producing the phenomenal world.

In Leibniz's case God created the harmony of the universe before creation, such that

M1: p1(t1) -> p1(t2)
M2: p2(t1) -> p2(t2)
M3: p3(t1) -> p3(t2)
etc...

and all transitional states of the monads harmonize.

In the current context of physics, one may indeed "replace Leibniz and God's creative/combinatorial activity at the beginning of creation;" and the physicists can reclaim the predictions of the transitional states of monads/qubits.

But... a last difference must be pointed out... this is important! for Leibniz the monads are non-extended (= not spatial/temporal; they don't have the kind of matter you can hold with your hands or put under microscopes); your suggestion of contemp. physics seems to differ on this point; they claim that the fundamental computer-states can be measured; this computer states (=qubits) are physical things for them (not?)... whereas for Leibniz the monads are not physical, they are metaphysical... they are what creates/produces phenomena, more specifically: the phenomena "in which" we discern, observe and measure 'physical' things...

In this sense Leibniz is an idealist (all there is are minds/spirits and their representational/perceptual acts); "this table" is first of all synthesized appearance produced by the perceptual acts of infinitely many monads; and only secondly (=phenomenally) this might be called something material which our hands can hold; which thirdly (= human mind) can be said to be "in" a Newtonian container. The human mind adds this spatial structure to the phenomena.

*Addition. The "material" stuff in the phenomena (you might say) is not spiritual. Indeed you can lift up this chair with your hands; there is nothing "spiritual" about this chair, my hand touches some "material stuff." So one might say: this chair is definitely material you crazy person!.... But wait a second, for Leibniz (in reality) there is just a flux of flashing images/phenomena (of different phases of your lifting the thing up). Cf. a movie that is being projected in the theater on some screen; you see "people" moving 'on' the screen, whereas actually there is just a flashing of new images/phenomena; and "in reality" there is just some projecter playing the movie. The phenomena (playing movie on the screen) has only a derivative reality, whereas the "projecting movie tape" (monad) is more REAL [see N1* below].

The monad/projector is the "condition of possibility" for appearences to appear [see N2* below]. Or stated differently: "the condition of possibility for the Universe to present itself;" that is, "the condition of possibility for all happenings/events/occurences to happen." This is how it works for Leibniz. The sensible/empirical reality is just a well-founded phenomena, and there are infinitely many monads harmonizing; representing themselves just like in theater there would be infinitely many projectors playing the same "abstract movies" together. However, each projector has a different point of view. Projector-1 is representing "the top of the screen," whereas projector-2 is representing "the bottom of the screen." Just like in reality there are "different regions" happening, nonetheless (ultimately) all projections are overlapping on exactly one "sensible screen."

In reality the universe doesn't change (cf. problem Being/Becoming); the "movie tapes" in the projector do not change; they are "unities," however they just turn arround (Leibniz calls this appetitio) and they show different parts (Leibniz calls this perceptio; you might call it "computer states") of the movie.... and this projector can be contrasted with the "appearences," i.e. the screen on which you see a multiplicity of images appearing; which is always changing without unity. (cf. flux of Becoming of Heraclitus). Maybe people can afterwards (when they go home) recall all different parts of the movie and reconstruct it as a unity, but this is for Leibniz a "phenomenal unity" provided and constructed by the human mind. The real unities for him are "movie tapes" (monads) which have gathered apriori all images (call it nowadays: state of affairs, logical possibilities, information, etc.) that can possibily appear and express themselves in the phenomena.

*N1: A really hard question is whether or not we must distinguish between the "movie tape," the "projector qua enactment of movie," the "screen qua receptive medium" and the "screen qua presenting medium."
*N2: If one is interested, check out wikipedia for the historical background on Kant and German idealism with regards to transcendentalism.

>>>> anyways, returning to the original body of the text now (before my addition)

.... Materialism "takes for granted" the thereness of "material stuff" whereas Leibniz tries to think how the thereness "gets there" (by monads representing the universe; making things present by perceptual/spritual acts of representation.

You can maybe compare it with the human mind: whereas "we make the 'outside' present" for Leibniz the whole universe (stones, grass, atoms, and all other 'material' things) are produced by infinitely many spiritual substances (=monads); the phenomenal/material universe is produced by an infinity of spiritual substances and their perceptual acts (harmonizing phenomenally coherently (like it were some unified dream of an infinity of spiritual substances). This can be compared with the representational power of the human mind/consciousness; Just like the "color red" is in the human mind and not something "really real".... in Leibniz's philosophy we can say analogously that "all there is" in the phenomenal universe (stones, matter, atoms, water, oxygen,...) is not "really real" too, but merely in the perceptual mind (representational act) of an infinity of monads representing (= making phenomenally present) the universe; cf. also panpsychism.

Some last thing, saying that there are only monads/spirits/souls doesn't contradict atomism/materialism or mechanical philosophy. In the phenomena we can still find material atoms (just like we "see" material bodies on the movie screen); similarly, we can also see in the phenomena objects moving according to mechanical laws through space (Newton, Galileo, etc.); these are indeed the 'basic things' and 'laws' of phenomena; but Leibniz wonders what produces the phenomena; there is no contradiction between spiritualism and materialism. Something spiritual produces the phenomenal universe, in which we can find 'material' stuff that behaves according to the mechanical laws of physics. It's important not to confuse the whole picture: monads are not "in front of us" (they are not 'part' or 'elements' of the phenomenal/material universe); they are what produces the phenomena; in a certain sense they are thus pre-phenomenal and transcendental (= condition of possibility for something to appear).

*Last addition: Another metaphor you might find useful (or like). The noumenal (= Kantian term) world of monads can be compared with the hardware of a computer; the phenomenal world can be compared with the audio-visual appearence on your computer screen. The hardware (infinity of monads) produces (i.e. "makes present") something coherent on your computer screen (phenomena). You don't see monads "in" the phenomena just like you don't see an electric circuit on your computer screen; you see on your screen what the hardware produces. N.b. this only remains a metaphor, since for us both hardware and the appearances on the computer screen belong to our phenomenal world (whereas the metaphor wants to suggest the distinction between both).

* Now, the really last addition (just to make my post more sexy and get people to read it)

The Matrix.

Ok, I got people's attention (yay!). Hopefully they keep on reading while I continue with some serious philosophical questions... for instance, in the above metaphor of the "movie tape" how can the "abstract movie" be translated into the "phenomenal movie." The "movie tape" (for example DVD) must "translate" the binary into the visual/sensible reality. Yes, human technology managed to accomplish this (we have dvds and tvs), but remember we are still on a metaphorical level.

Repetition:

abstract movie (DVD, 01010101111) represents the concrete sensible movies

~= metaphorically ~=

the abstract universe as gigantic computer (containing all information) represents the empirical universe

~=

the world of infinite monads (and their perceptions) represents the phenomenal universe


But there is a problem. The Universal Cosmos or "Reality in itself" as a gigantic computer "needs a trick" to translate the digital into the phenomenal. Let's consider again the above "metaphorical analogy" of binary code on the DVD (10110011) which needs to be translated into a "visual movie." This leads us to our non-metaphorical metaphysical situation... namely we must now try to philosophically understand how the monad/qubit (having 'abstract' cosmic information) can produce the phenomenal reality (having 'concrete/empirical' things like: colors, smell, animals, living things, human feelings, organic bodies, blood and flesh, geometry, etc.). Actually... maybe Kant's schematism can provide some help. The big question is of course how spatiality/geometry etc. can arise from something that lacks these properties all together (e.g. 'abstract' information, 10101100111).


*** Actually, Plato (and his theory of forms/ideas) already had to confront this problem in the beginning (=the end) of philosophy. My whole post tried to point out the historical/philosophical origin of the contemporary use of the word "in-form-ation" in physics. Plato too needed a trick to "translate" the world of "forms" into the sensible world (geometry/color/spatiality/etc.). As a reward for keeping up with all the hyper-abstract (borderline schizophrenic) philosophy, here is some free movie-trivia. Did you know that The Matrix was a rip-off from Plato's Cave Allegory already written two thousand years ago?

 

[Psyduck]

Ok, no problem.

I've kept on editing my post another hour after your reply. If you are interested some time later, you can always read the latest version (or ask questions).

 

[MattPsy]

chinup: Yeah, I too prefer the cellular automaton model. I find it far easier to conceptualise - you just think of the cell size as a register, as ebola said, and then extend this through n-dimensions with iterative steps being time. However, i'm more familiar with the computational complexity classes and their implications as elucidated by turing machines, so I used that terminology.

I disagree that they disallow nonlocal phenomena. This depends entirely on the cell rules (they could potentially be quite complicated, referencing cells that are not immediately adjacent, or even dynamic, with rules changing under some conditions. This doesn't necessarily make them nondeterministic, however, as the dynamicism itself could be rule-bound), and the dimensionality. As far as I can see anyway.

It strikes me that the Turing analogue of this is a n-dimensional (3?) tape/lattice, with a single read head for simplicity, that traverses the entire tape. I'm not sure what time corresponds to, perhaps you could say one unit of Planck time has passed in a single locality for each state change. Or is it per the entire lattice having been traversed once? I think the former one. This is just an abstraction though. The cellular-automaton interpretation is a lot easier to understand. In some sense, though, I think the cellular-automaton is a direct analogue, since you must traverse every cell (programatically) to iterate its state. Hard to think about. Brain meltdown . (I wonder how the halting problem applies to this? Can we link this to entropy somehow?)

[content removed in accordance with author's wishes]

Well, unless you have a complete state table of all cells in the universe (impossible whilst being in it), there are going to be computational omission errors, so you can't run a perfect simulation. This is the extreme case, I admit. A more benign (but still suffering from the same problem) version is where you choose to only (understatement of the year) simulate a small subsection of the universe -say, our Solar System. Because you are omitting all data outside this space, again you get errors. Perhaps a large comet was outside these bounds, rushing toward the Earth to obliterate it; the model will not contain this data so all subsequent states will have large errors, such as the Earth being obliterated. However, let's consider a more realistic scenario, where you have a vacuum filled, mirror-surfaced, cosmic-ray-stopping sphere floating out in interstellar space (so less gravity to screw with things), with some complicated nanotechnological structure (or my black-hole universe-debugging/codebreaking thought-experiment) inside it that you wish to simulate in full (reductionism++!) with such an cellular-automaton model of physics to evaluate.

OK, so we've done more or less our best to reduce errors of omission and interference. Depending on how the cell rules work, this automaton is going to fall in some complexity class, and its almost assured to be pretty damn hard. Achievable though, perhaps - if the space size is not too large so we can probably finish the simulation in a workable amount of time (it sure would be nice to know if P = NP, say - but it almost certainly doesn't, IMO), and to an incredibly degree of accuracy (you still might get the occasional many-TeV-energy particle spat out from a quasar or suchlike ruining equivalence with our perfect simulation in the 'real world' by whacking an atom or two, but not much you can do about that). The other approach is to do the same thing, but with a non-information-theoretic model (traditional physics) - this approach may give us more or less the same answer, with a lot less computational time and memory - except under certain conditions where the approximations fail. Compare this to, say, the knapsack problem or other NP-complete (or worse, like EXPSPACE, etc) problems - there still do exist algorithms which usually can produce a correct or close to correct answer in a tractable amount of time with most inputs - it's just that the worst-case is really bad to solve exactly and with all inputs. I consider these cases to cross over pretty well - you sacrifice some accuracy for general tractability. Maybe this is why we sometimes get answers of infinity in physics - speculation .

re:

[content removed in accordance with author's wishes]

What I meant by 'fuzziness' is quantum indeterminacy, how spacetime seems to be foamy and chaotic at base level - phenomena like vacuum energy and the [Heisenberg] measurement problem.

Psyduck: I don't see the distinction between Leibniz-monads and materialism, not really, though admittedly I know nothing about monads. Isn't this just the "can information exist outside a physical substrate" question restated? You could say that material is an emergent property of information, or the other way around - does it matter?
Would appreciate clarification.

The Universal Cosmos or "Reality in itself" as a gigantic computer "needs a trick" to translate the digital into the phenomenal. Let's consider again the above "metaphorical analogy" of binary code on the DVD (10110011) which needs to be translated into a "visual movie." This leads us to our non-metaphorical metaphysical situation... namely we must now try to philosophically understand how the monad/qubit (having 'abstract' cosmic information) can produce the phenomenal reality (having 'concrete/empirical' things like: colors, smell, animals, living things, human feelings, etc.)

Isn't this pretty much a version of the so-called Hard Problem or, alternatively, qualia? (dammit)
I don't see any problem here, no trick. If you simulate a universe, and then organise matter in it in such a way that the computation 1+1 is carried out, the answer "2" is just as real, isn't it, as in this universe?
It should follow that within internal context (that "simulated" universe - again, I don't believe in the distinction), all objects and truths (geometry, logic, etc) have just as much validity.

Abstract information such as binary streams (... 01000101001011 ...) turn into 'real' things all the time, now. The firing of neurons is pretty abstract, and yet we see with optic nerves. Likewise with light transduction, the conversion of photons (which again is an abstract stream of information) into electrical energy to fire a neuron. And then there are our own computers, where images, video and other data are encoded in abstract streams.
(hums "lookin' for a skyhook")

 

[Psyduck]

Psyduck: I don't see the distinction between Leibniz-monads and materialism, not really, though admittedly I know nothing about monads.

I will be very quick. I spent too much time on my above post and am really tired.

Do the following: "think of a circle" (privately in your own mind). Something is made "present" in your mind (namely the idea of circle). The essence of this "psychic act" is the making present "out of" non-presence. Leibniz applies this scheme to the whole universe. The whole universe is the result of perceptual acts of monads.

Just like you "made present the idea of a circle in your mind," an infinity of other monads makes the current universe (the sun, stars, animals, water,...) present in a certain way too. This scheme is founded on an "ontology of appearences" stressing the basic presencing nature of all that exists. Cosmologists might say that this rock has travelled for billions of years through absolute Newtonian space. In this scheme one presupposes that space is something Absolute (viz. a big container) in which one can observe the movements of all elements. Observing these movements one can next construct an infinite causal sequence of spatial locations of some object. But in Leibniz the causality is different, namely the monad causes something to come into presentness/beingness "out of" non-beingness/presentness. This can be understood analogous to "the making present of the idea circle in your mind." Materialism ignores this appearing event and focusses on a different kind of causality, which has of course some problems (cf. the infinite regress of (absolute) spatial motion, which goes back to Zeno's paradox).

Moreover, Leibniz would probably say that you don't even have a material body, but that there is only a continuous flashing of new phenomenal images ('about' your body). So, if you have lifted up your arm a distance D, Leibniz would not say that there was a displacement of a 'material object' in Newtonian absolute space from (x,y,z) to (x,y,z+D), but only a continuous stream of new phenomena/images, which are misleading us into thinking that there would actually be some spatial movement.

Let's return to our experiment above:
- your mind first "thinks of a triangle"
- next "it thinks of a square" (and coincedentally makes the 'triangle thinking-act' non-present)
- next "it thinks of a circle" (and coincedentally makes the 'square thinking-act' non-present)
etc...

So, analogously to this, we can also say that in the example of the lifting hand above, there is merely a continuous stream of representational/perceptual acts of spritual monads. These monads (Leibniz also calls them souls/minds) are constantly representing themselves differently, and are responsible for the different appearances (and also for putting back others into non-presence). One might say that monads are just constantly "flashing light-streams" which are "bursting out new phenomena into light" and "putting back other phenomena into darkness."

 

[qwe]

i may have some thoughts on this later after some digestion. but,

Black holes almost seem to function as a form of encryption/encoding. We might therefore be able to test our ideas about how the universe can be viewed as a computation by essentially doing "known-plaintext" or "chosen-plaintext" attacks - feeding "plaintext" (matter of known configuration) into black holes and observing the "ciphertext" emitted (Hawking radiation).

dude. awesome.