On 28 Sep 2011, at 05:44, Pierz wrote:

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OK, well I think this and the other responses (notably Jason's) have brought me a lot closer to grasping the essence of this argument. I can see that the set of integers is also the set of all possible information states, and that the difference between that and the UD is the element of sequential computation. I can also see that my objection to infinite computational resources and state memory comes from the 1-p perspective. For me, in the "physical" universe, any computation is restricted by the laws of matter and must be embedded in that matter. Now one of the fascinating revelations of the computational approach to physics is the fact that a quantity such as position can only be defined to a certain level of precision by the universe itself because the universe has finite informational resources at its disposal. This was my objection to the UD. But I cansee that this restriction need not necessarily apply at the 'higher'3-p level of the UD's computations. What interests me is the question: does UDA predict that the 1-p observer will see a universe with such restrictions?

To be sure, this is an open problem. To be sure, this is an open problem for physicists too.

`Comp+"theatetus" will be refuted if the comp-physics will be quasi`

`*contradicted* by some precise physical fact, not by any physical`

`theory (unless they predicts that precise physical fact).`

If it explains why the 1-p observer seems to exist in a world where there is only a finite number of bits available, despite existing in a machine with an infinite level of bit resolution, then that would be a most interesting result. Otherwise, it seems to me to remain a problem for the theory, or at least a question in need of an answer, like dark matter in cosmology. I am going to have to meditate further on arithmetical realism. I don't believe in objective matter either (it seems refuted by Bell's Theorem anyway), but a chasm seems to lie between the statement "17 is prime" and "the UDA (Robinson arithmetic) executes all possible programs".

`Don't confuse the UD (Universal Dovetailer, a finite program) and UDA`

`(the UD Argument = the argument that, assuming digital mechanism,`

`physics is in principle a branch of number theory/computer science,`

`and in which the UD plays the role of the effective definable comp`

`ontological realm of *everything*).`

Just a vocabulary remark, to avoid possible future confusion.

The problem is one of instantiation. I can conceive of a universe - a singularity perhaps, with only one bit of information - in which the statement "17 is prime" can never be made.

`Don't confuse the sociological statement "some machine asserts "17 is`

`prime"", and the true fact that 17 is prime, which does not rely on`

`physical universes at all, a priori.`

To formulate, ie instantiate, 17, requires a certain amount of information.

`In some physical theory, but this is not an assumption in the theory.`

`You cannot refute an argument by adding new assumptions.`

To say that a program executes, as opposed to saying it merely is implied by a set of theoretical axioms, requires the instantiation of that algorithm.

In Aristotelian metaphysics.

`Also, even in platonia, a computation is described by a big number`

`(possibly infinite) of implications.`

I suppose this is a restatement of the problem above. Arithemetical realism then would be the postulate that everything implied in arithmetic is actually instantiated.

`Not at all. That would be a physicalist revisionist definition of`

`numbers. You need to "instantiate" 17, in some way, to talk about 17,`

`but 17 itself does not need instantiation. With or without any`

`physical universe, 17 remain a prime number.`

`Now, an instanciation, or emulation, can be defined from the numbers`

`alone. Some numbers are universal (a relative arithmetical property)`

`and we can say that a universal numbers instantiates 17 (say) if 17`

`appears in some of its purely arithmetical register.`

`To understand the detail of this, I can only refer you to some good`

`textbook in computer science. The main theorem for this is the proof`

`that all partial recursive functions can be represented in Robinson`

`arithmetic (Boolos and Jeffrey's book do this very well, Epstein and`

`carnielli also. ref in my theses).`

It seems to me I can grant 17 is prime, without granting this instantiation of everything.

Well, that solves you of a very long and not so easy work.

I'm also troubled by the statement that you have proved in the AUDA that any Lobian machine can apprehend the UDA. Is not a three-year-old child and a cat a Lobian machine? Or indeed my senile father. How can you assert they could comprehend such an abstraction? Either they aren't Lobian machines, or there's hole in the proof somewhere, surely!

`Recently I have updated my spectrum of Löbian machine to the octopus,`

`and the jumping spider. I can argue that they have the cognitive`

`ability to get UDA. But they don't have a sufficiently big brain to`

`exploit this, and they don't have the motivation to use diaries and`

`books, and language to generate their infinite "turing tape memory"`

`like we do.`

`Symptoms of Löbianity are believe in repetition and notice them (like`

`believing in a notion of anniversary), or having empathy for an other`

`creature, etc. This needs some form of the induction axiom. Robinson`

`arithmetic (and Universal machines in general) are not Löbian. Peano`

`Arithmetic is Löbian (it is reallu just Robinson arithmetic + the`

`induction axiom for the first order describable formula).`

But this is not important for the reasoning.

Jason mentions the anthropic principle (which of course I'm well acquainted with) and the idea of the computations which contain observers. I have read, without following, some of your propositions involving the Beweisbar predicate and self-referential relations and what have you. Is that the formalism that is supposed to define which computations are conscious?

`Not really. This is a subtle point. Notion like truth and`

`consciousness are not definable by any machine. But, like with God (or`

`Plotnus' one) we, the machines, can talk in indirect way, by taking`

`some precaution.`

Is there a summary somewhere?

`It is explained in the second part of the sane04 paper. AUDA is "the`

`interview of the Lôbian universal machine"`

I am wondering how consciousness can possibly be an attribute of some computations and not others,

`Let me be precise; consciousness is not an attribute of a computation,`

`but is an attribute of a person. Now a person can manifest itself`

`relatively to other person, once "enough" similar computations are`

`going through the states of the two person, in some sufficiently`

`cohesive way. The self-reference logics are used to single out the`

`conditions of cohesion (unlike in linear logic, or Girard geometry of`

`interaction, which extract such condition from symmetry intuition and`

`proof theory).`

and why, if it's a matter of some certain mathematical properties of the computations, we could not fairly easily write a conscious algorithm?

`It is easy. I tend to think, since recently, that all universal`

`algorithm are conscious. But their consciousness is disconnected, a`

`bit like if they were born ... in salvialand! And, yes, before doing`

`salvia I would have imposed Löbianity for consciousness, but I am much`

`less sure about that.`

`Now Löbianity is more than consciousness, it is self-consciousness.`

`Peano arithmetic is self-conscious, I think. That is why we can`

`discuss Plotinian theology with them, even without making their soul`

`falling on earth, that is without implementing them and sharing our`

`long story. Current computers have not yet long term memory, nor long`

`term goal. But I think that PA, the octopus, and the jumping spider`

`(but not worms, and most usual spider) are as conscious as you and me.`

`For the fun here is video illustrating that a jumping spider can do`

`some inductive inference requiring some implicit beliefs in`

`arithmetical induction (look hw she reacts when she looks behind the`

`mirror).`

http://www.youtube.com/watch?v=iND8ucDiDSQ

`As opposed, here is a typical non Löbian behavior, or a non jumping`

`spider (yet jumping, note):`

http://www.youtube.com/watch?v=lsqt2ywSqTQ&feature=channel_video_title

`If not finding food on a top of a plant, she is programmed to jump`

`randomly on other plant, and, in case she get the ground, to climb on`

`a nearest plant. Here there is only a pen, perpendicularly installed`

`on a flat ground table. She seems to repeat in cycle that behavior,`

`except for taking some rest.`

`But the bigger reason why I think jumping spiders are Löbian, is that`

`like cat and dog, they can bond with you, star at you, and perhaps`

`even recognize you. But this can be judged only by real interaction`

`with real spiders, not by looking at videoas, of course. Stiil, here`

`is a very cute one:`

http://www.youtube.com/watch?v=MQBAIud6Twg&feature=related

Surely complexity can't be the defining feature (at what arbitrary level of complexity does the light come on?), so it should be a simple matter.

`I agree. You don't need more than 10 lines instruction code for them,`

`well, in a high logical language like prolog, for example.`

(Though the proof of having created consciousness in the program would be a problem!)

`It is not a problem. It is an impossibility. You cannot prove that *I*`

`am conscious, can you?`

Don't we have to define consciousness (not necessarily self-awareness, or the awareness of being aware) as a property of numbers per se?

`A quasi-definition is the ability by some universal numbers to`

`discover some non communicable truth by introspection. Consciousness`

`is not much more than the state of believing in some reality.`

Sadly when you start to talk about the difficulty of proving that our histories in the UD are more random than the actual histories we observe, I can't follow you any more - too much theory I'm unfamiliar with. I can see however that many (nearly all) of the infinite computations passing through our aware states will destroy us,

Gosh! I don't see that. ... Ah, you mean in a third person way. OK.

as it were, so we can never exist in those computations (sort of anthropic principle). This also suggests a kind of immortality,

OK. This has been a recurrent theme on this list.

the same kind as I propose in a blog post I wrote called the 'cryogenic paradox' in which I argue that there can only be a single observer, a single locus of consciousness underlying all apparently separate consciousnesses, which would really be just different perspectives of this one observer.

`Nice. I agree with this, although it is not part of the reasoning. But`

`it makes the reasoning and comp fitting quite well with some aspect of`

`the salvia experience. Many mystics, including the greeks, thought in`

`that way. Ramana Maharsi too.`

It seems irresistible as a conclusion (from philosophical arguments quite different to the UDA), and yet also kind of horrific. Only a sort of state-bound recall barrier prevents us from being aware that we suffer every fate possible.

`Yes. It is a bit frightening. It heals the fear of death, but can`

`expand the possible fear of life.`

I agree re academia. From all I can observe, it is a viper's pit. The ground of accepted truth is fought over as hard as any piece of the Holy Land, and in this as in all struggles, power matters. It is hardly the free and unbiased exchange between equal and curious minds! We are not so different today from the cardinals who refused to look down Galileo's telescope.

`To be sure Galileo makes the big mistake too, in pretending that the`

`church was wrong and that he was right. He should have simply`

`pretended that his theory was more plausible, and more economical,`

`like the Church asked. But I see and follow your point.`

Finally, I despise all theory that makes obscurity a virtue. Compare Lacan's tedious impenetrability

`Lacan was a great "humorist", except that its disciple did not`

`understand the joke, and Lacan falls in the idolatry trap.`

`In some seminar, he succeeded in being rather clear, and he said quite`

`genuine things on Gödel's theorem, which is rare.`

`Usually non-logicians say lot of crap on Gödel's results. Lacan and`

`Hofstadter are rather exceptions here.`

`But I think you are right, some text of Lacan were voluntarily`

`obscure, and I think that the purpose was a real mockery of its`

`audience.`

with Einstein's almost childish simplicity and profundity.

Sure.

Obscurity is the darkness which merely clever minds use to cover their nakedness (to invoke the emperor again). No insult to you, Bruno, intended, this time.

`We have to be a little cautious here. Even Einstein said that God was`

`simple but not that simple (I forget the exact quote). And the unknown`

`is obscure, quasi by definition, and with mechanism, we can explain`

`why some part have to remain obscure. But then this motivates the`

`honest researcher to be even more simple and clear. Obscurity should`

`not be a tool to hide ignorance (or more sinister intentions). Yet,`

`obscurity, in some field, cannot either been brushed away by pure`

`willing. That would be sort of wishful thinking.`

Bruno

On Sep 27, 2:08 am, Bruno Marchal <marc...@ulb.ac.be> wrote:On 26 Sep 2011, at 04:42, Pierz wrote:OK, well first of all let me retract any ad hominem remarks that may have offended you. Call it a rhetorical flourish! I apologise. Thereare clearly some theories which require a profound amount ofdedicatedlearning to understand - such as QFT. I majored in History andPhilosophy of Science and work as a programmer and a writer. I amnota mathematician - the furthest I took it was first year uni, and Icouldn't integrate to save myself any more. Therefore if the truthofan argument lies deep within a difficult mathematical proof, chances are I won't be able to reach it.That is the reason why I separate UDA from AUDA. Normally UDA can be understood without much math, which does not mean that it is simple,especially the step 8. (but the first seven step shows already thebigpicture). AUDA, unfortunately, needs a familiarity with logic, which unfortunately is rather rare (only professional logicians seems to have it).Then my ignorance would hardlyconstitute a criticism, and so it may be with UDA and my complaintofobscurity.When I teach orally UDA. The first seven step are easily understood.This contains most of the key result (indeterminacy, non-locality,noncloning theorem, and the reversal physics/theology (say) in case the universe is robust. The step 8 is intrinsicaly difficult, and can be done before. A long time ago, I always presented first the "step 8" (the movie graph argument) and then the UDA1-7. I am still not entirely satisfied myself by the step 8 pedagogy.On the other hand, it seems to me that ideas about the core nature of reality can and should be presented in the clearest, most intelligible language possible.I have 700 pages version, 300 pages version, 120 pages version, up to sane04 which about a 20 pages version. The long version have been ordered to me by french people, and are written in french. The interdisciplinary nature of the subject makes it difficult to satisfied everybody. What is simple for a logician is terribly difficult for a physicist. What is obvious for philosphers of mind,can make no sense for a logician or a physicist, what is takengrantedby physicists are total enigma for logicians, etc.I can't solve QFT equations, but I can grasp the fundamental ideas of the uncertainty principle, non- locality, wave-particle duality, decoherence and so on. I'm not arguing for dumbed-down philosophy, but maximal clarity.OK. Note that my work has been peer reviewed, and is considered bymany as being too much clear, which is a problem in a field(theology)which is still taboo (for some christian, and especially the atheistversion of christianism). I can appear clear only to people capableofacknowledging that science has not yet decided between Aristotle and Plato reality view. So when I am clear, I can look too much provocative for some.Having said that, I'm prepared to put effort in to learn something new if I have misunderstood something.OK. Nice attitude.You have misread my tone if you think it indicates bias against yourtheory. I have read your paper (at least the UDA part, not themachineinterview) several times, carefully, and presented it to my(informal)philosophy group, because I certainly find it intriguing.OK. Nice.I'll admit that step 8 is where I struggleHmm, from your post, it seemed to me that there remains some problem in UDA1-7.- it's not well explained in the paper yet contains the all the really sweeping and startling assertions.When I presented UDA at the ASSC meeting of 1995 (I think) a "famous"philosopher of mind left the room at step 3 (the duplication step).Hepretended that we feel to be at both places at once after a self- duplication experience. It was the first time someone told me this. Idon't know if he was sincere. It looks some people want to believeUDAwrong, and are able to dismiss any step.Theargument about passive devices activated by counterfactual changesinthe environment is opaque to me and seems devious - probablydefeatedin the details of implementation like Maxwell's demon - but that is obviously not a rebuttal. I will take a look at the additional information you've linked to.OK. Maudlin has found a very close argument. Mine is simpler (and older).I can see that you are actually right in asserting that the UDA's computations are not random,OK.but I'm not sure that negates the core of my objection. Actually what the UDA does is produce a bit field containing every possible arrangement of bits. Is this not correct?It generates old inputs of all programs, including infinite streams.Those can be considered as random. But what the program does withsuchinput is not random.Iam open to contradiction on this. If it doesn't, then it means ithasto be incapable of producing certain patterns of bits, but inprinciple every possible pattern of bits must be able to begenerated.As inputs, yes. As computation? No.Now a machine with infinite processing power and infinite statememorythat merely generates random bit sequences would eventually also generate every possible arrangement of bits. So the UDA and the ultimate random generator are indistinguishable AFAICS.Not really. In fact the random inputs might play a role in making possible to have a measure on the computational histories. It can entail also that the "winning computations" (= those being normal in the Gaussian sense) inherit a random background, which would make other feature of the usual (quantum) physics confirming comp. Everett QM makes such a random background unavoidable in any normal branch of the universe, like when we send a sheaf of electron prepared in the state (1/sqrt(2)(up + down), on a device measuring them in the {up, down} base. This should not be a problem, and if it proved to be an insuperable problem, then comp is refuted. I have no problem withthat, given that my goal consists in showing that comp is"scientific"in the popperian sense (refutable).I think what you are saying is that somehow this computationproducesmore pattern and order than a program which simply generates allpossible arrangements of bits. Why? If I were to select at randomsomealgorithm from the set of all possible algorithms, it would beprettymuch noise almost all the time. *Proving* it is noise is of courseimpossible, because meaning is a function of context. You'veselectedout "the program emulating the Heisenberg matrix of the Milky Way", but among all the other possible procedures will be a zillion morethat perform this operation, but also add in various otherquantitiesand computations that render the results useless from a physicist'spoint of view. There are certainly all kinds of amazing proceduresandunfound discoveries lying deep in the UDA's repertoire ofalgorithms,but only when we intelligently derive an equation by some othermeans(measurements, theory, revision, testing etc) can we find out which ones are signal and which ones noise.Suppose that you are currently in state S (which exist by the comp assumption). The UD generates an infinity of computations going through that state. All what I say is that your future is determined by all those computations, and your self-referential abilities. If from this you can prove that your future is more random than the one observed, then you are beginning to refute rigorously comp. But themath part shows that this is not easy to do. In fact the randominputsconfer stability for the programs which exploits that randomness, and again, this is the case for some formulation (à-la Feynman) of QM.Fine. But then we can simply dispense with the UD altogether and just gather up its final results,This does not make any sense. A non stopping program does notoutputanything.OK. I realised after I posted that this was wrong, actually hasty shorthand for what I was trying to say - didn't have time for anamendment. By 'results' I mean the machine's state. It seems thatforthe UDA to work, we have to assume that the simulation has'finished',even though from a 3p perspective it never can.I don't think so. The terminating computation are on the contraryrarecompared to the non terminating, and so might have a null measure. To "appear" in the UD*, all we need is that some program go through your state, not that a program has to stop on that state, or output that state.What I mean is, if the UDA had just started running, it wouldn't have any complex representations in its trace yet. And since the UDA exists purely mathematically, platonically, how can it be subject to time at all?The UD generate all "times" in relation with its own internal time, which can be defined by the steps of its own computation. This gives a block mindscape, no more threatening subjective time or physical time than any physicalist bloc-universe conception ofreality, which in physics is already necessary with specialrelativity.It has no processing limitations, so any notion of time as a factor can be disregarded. Otherwise you'd have to say that to process an instruction takes t amount of time, and where would such a constant come from?Just imagine the trace of the UD. You have many notion of time. The most basic one is given, as I said, by the number of step of the UD itself. Then, for each program generated, you can take the number of steps ofthat particular program. Those are sub-step of the preceding one.If aself-aware creature appears on that particular computation, he will not be aware of the UD step, but might be aware of the step of "its own" program. There many other times notion. The subjective time (à-la Bergson) is recovered by the logic of knowledge of the self-aware entity themselves, and handled by the logic of self-reference.The time taken to compute something in the physical worldis a function of the fact that all computation we know of is boundtothe manipulation of physical substrates that are embedded in the constraints of time, space and energy. Sequentiality in the UDA is purely conceptual.Perhaps, but it is better to remain neutral about the primary or not nature of the physical time. No physical theories is assumed, beyond the fact that we need some physical reality (but not necessarily a primitive one). If not, you beg the question.And because my 1-p moments could be anywhere in the UD's record of histories, I can't speak about where the UD is upto in its work 'now', but just have to take it as all somehow'done',Right. And you next 1p moment, results from the statistical indeterminacy in UD*.even though it can 'never' be done. I'm granting this, even thoughitis itself problematic. 'Results' was my clumsy shorthand for theUD'sinfinite record of states.OK.If this is a misunderstanding, I'm sure you'll point it out!It is correct, but the states are connected. From the 3p descriptionof each computation, they are connected by the program leading tosuchcomputation. From the 1-p views, it is quite different, they are connected by all programs leading to such states. It is a bit like there is a competition among infinities of (universal) programs for defining your private 1p history.Actually I'm not sure why you have to resort to the dovetailing inthefirst place. Since you grant your machine infinite computational resources, why not grant it parallelism? Just to make it a Turing machine? The Turing machine is just an idea, there's no reason tothink the universe (whatever the hell that is) has to be serial initsworkings.The UD is not the universe. To be sure, there is no physical primary universe at all (unless some number conspiracy is at play, which cannot be entirely excluded, but this would mean my brain is the physical universe, which I doubt). Physical reality is defined by the way infinitely many computations define normal and lawful shared "dreams". Dovetailing assure that the set of all computations is a well define effective set. Parallelism is defined from this. If I postulateparallelism, this will be difficult, and ambiguous. The work reliesonChurch thesis, for making "universal" mathematically and precisely definable.The existence of the UD is already a theorem of Peano Arithmetic.Robinson arithmetic *is* a UD.Huh? You've inverted ontological priority completely. Any form of arithmetic is a product of human intelligence.For a logician, a theory is just a number, relatively to another number. They exist independently of us, like the number 17 exists independently of us. Human wiill use richer alphabet, but axiomatizable theories are really machine or program, or recursively enumerable set (this can been made precise by a theorem of Craig). In AUDA I use Robinson arithmetic as defining the basic ontology. It is just a logician rendering of a sigma_1 complete theory/machine, that is a Turing universal machine. Then, the more richer theories (like the infinitely richer Löbian observers) are simulated by Robinson arithmetic. That is a particularity of comp: the ontology is much less rich than the epistemology on the internal observer, like the UD is dumber than an infinity of the programs that it will run.Just because someone has mentally constructed a mathematics with the structure of the UD does not instantiate a UD that actually 'runs' and creates the whole universe!The expression "whole universe" is ambiguous, and far more complex to define than the elementary arithmetical truth needed. Also, we should better be agnostic on the primary existence of that universe. Its primary existence is not a scientific fact. All you need to "believe", to give sense to the comp hyp. is that elementary arithmetical truth are not dependent of humans. In case you believe that, "17 is prime" does depend on humans, then I will ask you to define human, and to explain me the dependence in a theory which does not assume its independence. Actually, logicians have proved that this is not possible. Elementary arithmetic, or equivalent, have to be postulated.That is a vast mathematical hubris - akin to the way anyperson tends to over-apply their dominant metaphors. As a writerit'svery easy to see the universe as a vast story.Comp implies that the phsyical reality will appear to be deep (very long, perhaps infinitely long) from the internal observers point ofview. To stabilize sharable computations, we need deep computation(inthe Bennett sense of deep), and linearity at the botton, which has already been isolated from self-reference logics (I skip the nuance for not being too much long and technical).As a programmer, I see algorithms everywhere. But I'm not so inflated as to think it's more than a metaphor.The key point here, is that if you say "yes to a doctor", he will put in your skull a computer, and this, in case you survive (the comp case) is not a metaphor.If you want, no digital machine can distinguish a mathematicalrealityfrom a primary physical one. And the mathematical definition of reality by physicist are also given by particular universal machine. Who run those machine. Comp gives an answer: they are run by the laws of addition or multiplication of numbers, or by the laws of abstraction and application of lambda term. Eventually, physics is shown to not depend on the choice of the initial universal system. In a sense, physics is treachery: it postulate the simplest universal machine that we observe. But comp explain that the physical universe cannot be such a machine, and that if we want to extract both qualia and quanta, we have to derived the physical laws from any universal machine.I can invent my own logically consistent set ofaxioms right here and now, but I wouldn't presume it was anythingmorethan a set of mental relations.Don't take the mental granted. Don't take the physical granted.Oh, and :A proof is only something presented as a proof. You can only say: here is the flaw, (in case you have found one). I guess that is what you did, or thought you did.That's kind of pedantic. You know what I'm doing.Unfortunately I don't have time to continue my response/questionsnow- I'm amazed and impressed you can find the time for such detailed responses to random ignorants such as me!If ever you understand AUDA, you will understand that UDA is understandable by any Löbian universal machine. The only problem with the "old" humans, is that they are not always aware of their millenary assumption/prejudices, especially when they are experts, curiously enough. I like to share my questioning with people having a personal sincere interest.I'm more than prepared to concede my naivete and have my eyes opened to the revelation of UDA.Lol. You can follow UDA on the entheogen forum. Ah but I see you just send a post there too. Good. Ask there, because I don't want to bore too much the people of the everything list with a nth explanation ofUDA. Unless other insist, I prefer to link people to the UDA treadsofthe entheogen forum.On the other hand, the intelligent naive person has some advantages (hence the emperor's clothes reference).Some universities (not all, not all departments 'course) are often as much rotten than some political government. The diploma sometimesmeasure only the ability to lick the shoes of bosses, and in therightorder, please. Human are still driven by the gene: "the boss is right". Useful in war, and in hard life competition, but a bullet for free exploration. Layman have often a more genuine interest, and they are less blinded by their expertise, and narrow specialities. We live a sad period for knowledge, education, science, and even art. The "publish or perish" dicto has transformed some researcher into cut and paste machine, searching only funding and nothing else.Whether I'm the child in the story or merely ignorant is the question. I remain open the discovering the latter.It is up to you, BrunoOn Sep 26, 3:20 am, Bruno Marchal <marc...@ulb.ac.be> wrote:On 25 Sep 2011, at 04:20, Pierz wrote:OK, so I've read the UDA and I 'get' it,Wow. Nice!but at the moment I simply can't accept that it is anything like a 'proof'.Hmm... (Then you should not say "I get it", but "I don't getit"). Aproof is only something presented as a proof. You can only say:hereis the flaw, (in case you have found one). I guess that is what you did, or thought you did.I keep reading Brunomaking statements like "If we are machine-emulable, then physicsisnecessarily reducible to number psychology", but to me thereremainserious flaws, not in the logic per se, but in the assumptions.Bruno says that "no science fiction devices are necessary, other than the robust physical universe".To get the step-7. But that robust universe assumption isdischargedin the step 8. Which I have explained with more details (than in sane04) on this very list:http://www.nabble.com/MGA-1-td20566948.html#a20566948He also claims that to argue that the universe may not be large or robust enough (by robust I assume hemeans stable over time) to support his Universal Dovetailer is"adhoc and disgraceful". I think it is anything but.By robust I mean expanding enough to run the UD.It is disgraceful with respect to the reasoning. But if for some reason, you believe that there are evidence that the physical universedoes develop the infinite running of a UD, then you can skip thelast(and most difficult) step 8. Physics is already a branch ofcomputerscience/number theory, in that case.This is funny: if we have evidence that the physical universe has anever ending running UD, then we can from step 7 alone concludethatphysics is a branch of number theory. And by Occam, we don't needtoassume the primitive physical universe. But we don't, and I doubt we can, have such an evidence. The UD running is very demanding. Not only the universe must expandinfinitely, but in a way which connect solidly all its parts.Betterto grasp the step 8 (the movie graph argument).To describe such anargument as "disgraceful" is to dismiss with a wave of the handtheentirety of modern cosmology and physics, disciplines which after all have managed to produce a great deal more results in the way ofprediction, explanation and tangible benefits than Bruno'stheory (Iinsist it is a theory and not a 'result').Yes, it is the theory known as "mechanism". The theory that thebrainis a natural machine. The result is that physics emerges from numbers, or combinators, or from any first order specification of a universal machine, in the sense of theoretical computer science (branch of math).As a computer science expert, I assume Bruno is aware of modern computational approaches to physics. Such approaches explicitly forbid any kind of 'infinite informational resolution' as is required by Bruno's theory.Where is this required?Note that as a corollary of UDA we can show that the physical universe is not a computable object, a priori. The computational approach to physics can have many interesting application, but it can't tackle the mind body problem. But to get this, it is better to grasp UDA first.The information content of the universe is seen as being a fundamental quantity much like energy, constantly transforming but conserved over the whole system in the same way energy is.There is no assumption about the universe in the theory. We assumeonly that the brain (or the generalized brain, that is theportion ofobservable things needed to be emulated for my consciousness to be preserved) is Turing emulable.UDA assumes the existence of brains and doctors, and thus on some physical reality, but not on a primitive physical reality. At the start of the UDA, we are neutral on the nature of both mind and universes.This computational approach indeed seems to be the *basis* for much of Bruno talks about (computability, emulability and so on are all fundamental ideas), butthen he flies in the face of it by proposing some kind ofautomated,Platonic computation devoid of any constraints in terms of state memory or time.Computation is a mathematical notion, discovered by Post, Turing, etc.It is based on the notion of state memory, time steps, etc. It isnotbase on physical implementation of those notion (unlikeengineering).Let's take a look at the UD. Obviously this is not an'intelligent'device,You are right. It is very dumb. It is not even Turing universal,andit computes in the most complex possible way the empty function (it has no input, it has no output).beyond the intelligence implicit in the very simple base algorithm. It just runs every possible computer program.Yes.Random computer programs are made of and produce *static*, they are a random arrangement of bits.There is no randomness in the work of the UD.Now clearly, we know that if you look at a largeenough field of static, you will find pictures in it, assembliesofdots that happen to form structured, intelligible images.OK. But they are not related by computations. Neither in the first person views, nor in the third person views.Likewise inthe field of random computed algorithms, very very occasionallyonewill make some kind of 'sense', although the sense willnaturally beentirely accidental and in the vast, vast majority of cases will give way a moment later to nonsense again.The only randomness which might appear comes from the first person indterminacy, and the fact that we acnnot know in which computation we are. This leads to the "white rabbit" problem, but the computationthemselves are not random at all, and the WR problem is basicallytheproblem to which physics is reduced too, at the conclusion of the reasoning.So when the UD runs through its current sequence of programs, what it is really doing is just generating a vast random field of bits.I have not the slightest clue why you say that. It is provablyfalse.No program can generate randomness in this third person way. Therandomness ¨possible* can only appear from the first person(emulatedin the UD) perspective.The UD generates, to give an example, the program emulating the Heisenberg matrix of the Milky Way, at the level of string theory, and this with 10^(10^(10^(10^(10^9999999))))) digits. Notably. Actually it does it also with 10^(10^(10^(10^(10^9999999))))) + 1 digits, and 10^(10^(10^(10^(10^9999999))))) + 2 digits, etc. The point here is that all those running are not random structures. In fact, there is no randomness at all.Nonetheless, each of theseindividual programs needs to have potentially infinite statememoryavailable to it (the Turing machine tape). Now the list of of programsrun by the machine continues to grow with each iteration as itaddsnew algorithms, so it takes longer and longer to return toprogram 0to run the next operation.Right. Note that such delays are not perceptible for the emulated observers.As it needs to run *all* programs, anecessarily infinite number, it requires infinite time, but forsomereason Bruno thinks this is not important.It is utterly important.This why the first person indeterminacy bears on a continuum,despitethe digitalness of all present factors.You attribute me things which I never say, here. n the contrary,thefact that the UD never stops is crucial.Either it has infinite processing speed as well as memory, or it has infinite time on its hands.The UD* (the infinite trace or running of the UD) is part of a tiny part of arithmetical truth (the sigma_1 arithmetical truth). Step 8 makes the physical running of the UD irrelevant. UD and UD* are mathematical notion (indeed arithmetical relations).Fine. But then we can simply dispense with the UD altogether and just gather up its final results,This does not make any sense. A non stopping program does notoutputanything.which is an infinite field of static, a giant digital manuscript typed by infinite monkeys. Everything capableof being represented by information will exist in this field,whichmeans it is capable of "explaining" everything. And nothing.I think you miss the step 3: the first person indeterminacy. Ithinkyou miss also the arithmetical non random dynamic of the UD. Youareconfusing an infinite set of information, with an infinite nonrandomand well defined particular computation.We have to deconstruct the notion of "computation" here.Computationis the orderly transformation of information.I can agree, although information is more an emerging notion. It is not used in the definition of computation.But the UD's orderliness is the orderliness of the typing monkey.Not at all. It is the orderliness of the computations. Or the orderliness of the sigma_1 sentences and the logic of theirprobability/consistency (as it is made completely transparent intheAUDA: the translation of the UDA in arithmetic, or in thelanguage ofthe Löbian machine).If it is orderly at all, it is by mistake.It is 100% orderly.By talking about it the UD as performing computation more intelligence is implicitly imputed than this hypothetical device possesses.Where? The existence of the UD is already a theorem of Peano Arithmetic. Robinson arithmetic *is* a UD. You need only the intelligence for grasping addition and multiplication. The UD has been implemented:http://iridia.ulb.ac.be/~marchal/bxlthesis/Volume4CC/4%20GEN%20%26%20 ...And besides, the physical and psychological (theological, biological,..) order are brought by the machines from inside the running of the UD. The UD's intelligence is not needed.Yes, it would generate every possible information state, and...read more »-- You received this message because you are subscribed to the Google Groups "Everything List" group.To post to this group, send email to everything-list@googlegroups.com.To unsubscribe from this group, send email to everything-list+unsubscr...@googlegroups.com . For more options, visit this group athttp://groups.google.com/group/everything-list?hl=en .http://iridia.ulb.ac.be/~marchal/--You received this message because you are subscribed to the GoogleGroups "Everything List" group.To post to this group, send email to everything-list@googlegroups.com.To unsubscribe from this group, send email to everything-list+unsubscr...@googlegroups.com.For more options, visit this group at http://groups.google.com/group/everything-list?hl=en.

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