Re: computationalism and supervenience
Bruno wrote... KURTZ S. A., 1983, On the Random Oracle Hypothesis, Information and Control, 57, pp. 40-47. I recall reading this paper, and the followup entitled The Random Oracle Hypothesis is False by Chang et al. From recollection though, the claim was of superior algorithmic performance (ie solving NP problems in P time) rather than solving uncomputable problems. Cheers -- *PS: A number of people ask me about the attachment to my email, which is of type application/pgp-signature. Don't worry, it is not a virus. It is an electronic signature, that may be used to verify this email came from me if you have PGP or GPG installed. Otherwise, you may safely ignore this attachment. A/Prof Russell Standish Phone 8308 3119 (mobile) Mathematics0425 253119 () UNSW SYDNEY 2052 [EMAIL PROTECTED] Australiahttp://parallel.hpc.unsw.edu.au/rks International prefix +612, Interstate prefix 02 --~--~-~--~~~---~--~~ 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 [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~--~~~~--~~--~--~---
RE: Rép: ROADMAP (well, not yet really...
Peter Jones writes: Saying that there is a material substrate which has certain properties is just a working assumption to facilitate thinking about the real world. It may turn out that if we dig into quarks very deeply there is nothing substantial there at all, but solid matter will still be solid matter, because it is defined by its properties, not by some mysterious raw physical substrate. I am not using the Bare Substrate to explian solidity, which is as you say a matter of properties/behaviour. I am using it to explain contingent existence, and (A series) time. We could say that matter is that which feels solid, reflects light, distorts spacetime etc. and leave it at that. Having these properties is necessary and sufficient for what we call existence, and it doesn't add anything to postulate a bare substrate, any more than it adds anything to postulate an undetectable ether. Stathis Papaioannou _ Be one of the first to try Windows Live Mail. http://ideas.live.com/programpage.aspx?versionId=5d21c51a-b161-4314-9b0e-4911fb2b2e6d --~--~-~--~~~---~--~~ 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 [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~--~~~~--~~--~--~---
RE: Rép: ROADMAP (well, not yet really...
Peter Jones writes: By youur definitions, it's a straight choice between metaphysics and solipsism. I choose metaphsyics. We can posit the unobservable to expalint he observable. Solipsism is a metaphysical position. (BTW: it it is wrong to posit an unobserved substrate, why is it OK to posit unobserved worlds/branches ?) It's debatable, but perhaps MWI is a better and simpler explanation of the facts of quantum mechanics than is CI, for example. Similarly (but much more strongly) believing there is a world out there is a better explanation of the facts than solipsism. But some explanations of physical phenomena, such as an undetectable ether through which light propagates have been dropped as unnecessary. And perhaps the propertyless substrate is more like the ether than the many worlds, in that we can at least imagine travelling to other branches or detecting them in some way, whereas the ether and the propertyless substrate are undetectable as a part of their definition - i.e. if we found evidence of the propertyless substrate it wouldn't be a propertyless substrate any more. Stathis Papaioannou _ Be one of the first to try Windows Live Mail. http://ideas.live.com/programpage.aspx?versionId=5d21c51a-b161-4314-9b0e-4911fb2b2e6d --~--~-~--~~~---~--~~ 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 [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~--~~~~--~~--~--~---
RE: computationalism and supervenience
Brent Meeker writes: This may be coincidental, but I think not. Your PC is engineered to avoid the effects of chaos to prevent this very thing occurring. Why wouldn't nature do the same thing unless it were deliberately trying to exploit randomness? In nature there's no reason to depend on amplifying quantum randomness - there's plenty of random environmental input to keep our brains from getting stuck in loops. And even without environmental input, unlike digital computers, brains have enough noise to keep from going into loops. Poincare recurrence won't kick in until long after the brain has turned to dust. I'm not sure that's true. As I recall during the sensory-deprivation fad in the late 60's it was reported than people in a sensory-deprivation tank for an extended period (hour+) had their thoughts go into loops. Maybe so, but there is no theoretical reason why a brain could not run a very, very long time before it starts repeating physical states. Stathis Papaioannou _ Be one of the first to try Windows Live Mail. http://ideas.live.com/programpage.aspx?versionId=5d21c51a-b161-4314-9b0e-4911fb2b2e6d --~--~-~--~~~---~--~~ 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 [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~--~~~~--~~--~--~---
RE: Rép: ROADMAP (well, not yet really...
Stathis Papaioannou wrote: Brent Meeker writes: Saying that there is a material substrate which has certain properties is just a working assumption to facilitate thinking about the real world. It may turn out that if we dig into quarks very deeply there is nothing substantial there at all, but solid matter will still be solid matter, because it is defined by its properties, not by some mysterious raw physical substrate. But I don't think we ever have anything but working assumptions; so we might as well call our best ones real; while keeping in mind we may have to change them. That's just what I meant. If you say, this is *not* just a working assumption, there is some definite, basic substance called reality over and above what we can observe, that is a metaphysical statement which can only be based on something akin to religious faith. Stathis Papaioannou I put working assumption in scare quotes because I think the fact that we can create models of the world that are successful over a wide domain of phenomena is evidence for an underlying reality. It's not conclusive evidence, but reality is more than just an assumption. Brent Meeker There is good reason to believe that there is some sort of reality out there as opposed to the solipsistic alternative, but there is less reason to believe that there is some basic material substrate on which the various properties of physical objects are hung. The two ideas are not the same. Stathis Papaioannou _ Be one of the first to try Windows Live Mail. http://ideas.live.com/programpage.aspx?versionId=5d21c51a-b161-4314-9b0e-4911fb2b2e6d --~--~-~--~~~---~--~~ 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 [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~--~~~~--~~--~--~---
Re: Rép: ROADMAP (well, not yet really...
Stathis Papaioannou wrote: Peter Jones writes: Saying that there is a material substrate which has certain properties is just a working assumption to facilitate thinking about the real world. It may turn out that if we dig into quarks very deeply there is nothing substantial there at all, but solid matter will still be solid matter, because it is defined by its properties, not by some mysterious raw physical substrate. I am not using the Bare Substrate to explian solidity, which is as you say a matter of properties/behaviour. I am using it to explain contingent existence, and (A series) time. We could say that matter is that which feels solid, reflects light, distorts spacetime etc. and leave it at that. However, that is mere behaviour. I need a defiition which digs deeper than behaviour,and I have one. Having these properties is necessary and sufficient for what we call existence, and it doesn't add anything to postulate a bare substrate, Solidity and light-reflection are not instantiated at every point in space time. There is contingent existence, i.e materiality. any more than it adds anything to postulate an undetectable ether. Stathis Papaioannou _ Be one of the first to try Windows Live Mail. http://ideas.live.com/programpage.aspx?versionId=5d21c51a-b161-4314-9b0e-4911fb2b2e6d --~--~-~--~~~---~--~~ 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 [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~--~~~~--~~--~--~---
Re: Rép: ROADMAP (well, not yet really...
Stathis Papaioannou wrote: Peter Jones writes: By youur definitions, it's a straight choice between metaphysics and solipsism. I choose metaphsyics. We can posit the unobservable to expalint he observable. Solipsism is a metaphysical position. A minimal one, that refuses to posit anything beyond that for which there is direct evidence. (BTW: it it is wrong to posit an unobserved substrate, why is it OK to posit unobserved worlds/branches ?) It's debatable, but perhaps MWI is a better and simpler explanation of the facts of quantum mechanics than is CI, for example. Presumably for reason more complex than we cannot posit the unobservable. Similarly (but much more strongly) believing there is a world out there is a better explanation of the facts than solipsism. But some explanations of physical phenomena, such as an undetectable ether through which light propagates have been dropped as unnecessary. And perhaps the propertyless substrate is more like the ether than the many worlds, in that we can at least imagine travelling to other branches or detecting them in some way, whereas the ether and the propertyless substrate are undetectable as a part of their definition - i.e. if we found evidence of the propertyless substrate it wouldn't be a propertyless substrate any more. Since the propertyless substrate is needed to explain time and contingency, time and contingency are evidence for it. Stathis Papaioannou _ Be one of the first to try Windows Live Mail. http://ideas.live.com/programpage.aspx?versionId=5d21c51a-b161-4314-9b0e-4911fb2b2e6d --~--~-~--~~~---~--~~ 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 [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~--~~~~--~~--~--~---
Re: Rép: ROADMAP (well, not yet really...
Stathis Papaioannou wrote: There is good reason to believe that there is some sort of reality out there as opposed to the solipsistic alternative, but there is less reason to believe that there is some basic material substrate on which the various properties of physical objects are hung. The two ideas are not the same. Materialism has stood up for centuries. --~--~-~--~~~---~--~~ 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 [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~--~~~~--~~--~--~---
Re: computationalism and supervenience
Le 27-aot-06, 17:49, 1Z a crit : Bruno Marchal wrote: Le 25-aot-06, 02:31, 1Z a crit : Of course it can. Anything can be attached to a bare substrate. It follows from the UDA that you cannot do that, unless you put explicitly actual infinite in the bare substrate, I don't see why. Because the UDA shows the mind-body relation cannot be one-one. You can attach a mind to a computation C based on your (putative) bare matter, but then that mind will correspond to an infinity of computations simulating sufficiently closely C, unless C is using non turing emulable property of that bare matter, but then the comp hyp is abandoned. an then attach your mind to it (how?). Why not ? A bare substrate can carry any property whatsoever. Just because it isn't a logically necessary truth doens't make it impossible. OK but one second after, the probability or the credibility that you are still in contact with that bare matter is negligible. I am not pretending this is obvious, and you can tell me where in the UDA you have troubles. If it were impossible to attach a class of properties to a substrate, that would constitute a property of the substrate, and so it would not be bare I am sorry but you lost me here. Especially when elsewhere you say the bare substrate can have subjective experiences. Think of a bare substrate as a blank sheet of paper. You can writhe anything on it, but what is written on it is no part of the paper itself. This looks like Colin Hales' conception of consciousness, which at least does not need bare substrate a priori. And then with numbers we don't have any of those trouble in the sense that numbers, although they play nicely the role of building blocks, they do have (relational) property of their own. (But I know that you don't believe in numbers, whatever that could mean ... A bare substrate can carry any properties, but it is bare in itself. I have no idea what you try to say here. Bare substrate is compatible with qualia. How? There is nothing to stop it being compatible with qualia. Nothing-but-numbers is not. Why? Becuase you would have to identify qualia with mathematical structures, which no-one can do. We can identify qualia with the truth about quantities and qualities that introspective machine can simultaneously measure and realise they cannot communicate the result to any machine. The logic of credibility one bearing of those qualia is then describe by the logic of the statement which are provable (in the logician sense), true (in Tarski sense) and consistent (again in the logician sense). I have been able to deduce that such a credibility one defines a canonical notion of arithmetical quantization. I can formulate precisely questions like does the comp-nature violate Bell's inequality, does the comp-physical laws allows irreversibility, etc. Unfortunately, this leads to hard mathematical questions. But my initial goal was not to solve those problems, just to show that if we take comp seriously enough, then such questions can be put in precise mathematical shapes. If Platonia is not real in any sense, it cannot contain observers, persons, appearances, etc. To exist Platonically is to exist eternally and necessarily. There is no time or changein Plato's heave. All partial recursive solutions of Schroedinger or Dirac equation exists in Platonia, and define through that block description notion of internal time quite analogous to Everett subjective probabilities. The A-series cannot be reduced to the B-series. All the point is that with Church thesis you can do that. How ? By 1) distinguishing truth (G*) and provability (G) for lobian machine which are simpler than us. 2) defining the first person by true-provability (Theaetetus, Plotinus), or true-consistent-provability. 3) isolating the temporal logic of the 1-person, which appears naturally. 4) by showing how those logics does reduce, at the G* level, the *appearances of A series to the B-series (that is technical of course) 5) We can at this stage explain why the machine will not been able to make this reduction about herself. The machine can consistently believe what you say! 6) by using the comp bet to lift what the simpler than us lobian machine say to us about herself and applying it to us in some interrogative mode (here we need to bet in a subtle (interrogative) way on our own local consistency). A program is basically the same as a number. No it isn't. You don't know which programme is specified by a number without knowing how the number is to be interpreted, ie what hardware it is running on. Not necessarily. The numbers can be interpreted by other numbers. The closure of the Fi for diagonalization makes this possible. No need for more than numbers and their additive and multiplicative behavior. I don't pretend this is obvious. A process or a
Re: Rép: ROADMAP (well, not yet really...
Le 27-août-06, à 19:36, 1Z a écrit : Bruno Marchal wrote: Le 26-août-06, à 22:44, Brent Meeker a écrit : I understand Peters objection to regarding a mere bundle of properties as existent. But I don't understand why one needs a propertyless substrate. Why not just say that some bundles of properties are instantiated and some aren't. I guess Peter needs it for having a notion of (absolute) instantiation. If you think, as I do, that there is a difference between logical and physical posibility, you need to explain instantiation. I do think indeed that there is a difference between logical and physical possibility. The logico-arithmetical possibility for a machine are given by the G and G* logics of self-reference. G is for what the machine can tell us about that, and G* is for the whole truth (unexpectedly, at the propositional level, this is completely captured by G*). The physical possibilities are given by the box and diamond of the Z(*) and X(*) logics, The COMP physical possibilities are given by the box and diamond of the Z1(*) and X1(*) logics. A case can still be given that S4Grz1 plays some role there too, but that would make physics closer to the David Lyman, George Levy conception; this is testable in principle, but for some reason I doubt that this could be possible). If you think, as I do, that there is a difference between phsyical actuality and physical posibility, you need to explain instantiation. The difference belongs to the person views. if you think, as rationalists do, that everything possible is also necessary and actual, you don't need those distinctions. It is grosso modo, the motto of the everything list! Of course the comp hyp put restriction on what we can take as possible, and it is mainly given by the true or consistent or both restriction. This leads naturally to the hypostases. If Peter takes the relative notion of instantiation, which is number theoretical in nature, then he would loose any motivation for his bare matter. I don't think something can exist in relation to what does not exist. Nor do I. if that is what you mean. I guess you are doing the confusion I describe in my preceding post. Anyway, current physical theory is that there is a material substrate which has properties, e.g. energy, spin, momentum,... I doubt this. Yes current *interpretations* of physical theories do suppose a material substrate, but only for having peaceful sleep (like the collapse non-answer in QM). All theories assume contingency. ? (very vague, I can agree, disagree ...) Anyway, the theories does not presuppose it. They presuppose only mathematical structure and quantitative functor between those mathematical structure and numbers that we can measure in some communicable ways. No physical theory needs to presuppose numbers as having an existence of their own. Formalists can do physics. But they cannot interpret their theory. Now, you can be formalist with respect to the lobian interview, but then you should try to understand formally the theory (at least). But frankly I have no clues about how a formalist can apply any theory without accepting some interpretation of the formula in the theory. Bruno http://iridia.ulb.ac.be/~marchal/ --~--~-~--~~~---~--~~ 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 [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~--~~~~--~~--~--~---
Re: Rép: ROADMAP (well, not yet really...
Le 27-août-06, à 19:41, 1Z a écrit : But you don't really address the existence question. You just loosely assume it is the same thing as truth. I just assume that the existence of a number is equivalent with the intended truth of an existential proposition written in a theory about numbers. I identify propositions like there exist a perfect number with it is true that there exist a perfect number. I am dialoguing with PA (Peano Arithmetic theorem prover). When PA tells me there exist perfect numbers, I take it as an existential proposition. It is a way, for PA, to make an ontological commitment, which I do too. Of course, I don't interpret this as there exist a physical world, and numbers exist there physically. I don't assume there is a physical world, and I doubt very much there is a physical primary world. Indeed the UDA shows such an assumption to be useless concerning the possible explanations of both quanta and qualia. Bruno http://iridia.ulb.ac.be/~marchal/ --~--~-~--~~~---~--~~ 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 [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~--~~~~--~~--~--~---
Re: computationalism and supervenience
Le 27-août-06, à 19:56, 1Z a écrit : Bruno Marchal wrote: Come on, I have already insist on this. Understanding what really means surviving through the yes doctor = understanding that, in *that* case, we survive without doctor. Without the doctor is computationalism+Platonism, not computationalism. I guess it is our major disagreement. See my preceding posts of today. Bruno http://iridia.ulb.ac.be/~marchal/ --~--~-~--~~~---~--~~ 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 [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~--~~~~--~~--~--~---
Re: Rép: ROADMAP (well, not yet really...
Le 27-août-06, à 21:41, Brent Meeker a écrit : I put working assumption in scare quotes because I think the fact that we can create models of the world that are successful over a wide domain of phenomena is evidence for an underlying reality. It's not conclusive evidence, but reality is more than just an assumption. I agree that reality is more than an assumption. I agree even that physical reality is more than an assumption. I have few doubt about the existence of a physical reality. Now to assume the existence of a primary physical reality, or to believe that physics is obviously or necessarily the fundamental science, well that is a big assumption, and I would say that such an assumption is even unclear in front of QM, and then useless in front of comp. I realize that even Aristotle, in his metaphysics, is much more prudent on this, than the standard Christian (especially catholic) interpretation of Aristotle. Bruno http://iridia.ulb.ac.be/~marchal/ --~--~-~--~~~---~--~~ 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 [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~--~~~~--~~--~--~---
Arithmetical Realism
Le 27-août-06, à 23:17, David Nyman wrote to Peter (1Z) : 1Z: But you don't really address the existence question. You just loosely assume it is the same thing as truth. Could I appeal to Bruno at this juncture to address this point directly?! At several places in our own dialogues, Bruno, you've implied that your 'number theology' was an 'as if' postulate, because (if I've understood) you are concerned to see how much can be explained by starting from this particular set of assumptions. I don't believe that you are claiming they are 'true' in an exclusive sense, rather that they are enlightening. Is this a correct interpretation of your position, or is there further nuance? As a scientist, or if you prefer as a willing to be a consistent scientist (you never know), I would say that *all* theories are third person discourses which have to be taken with an as if proviso. Even the grandmother physics (with propositions like 'objects fall', or 'the sun rise in the morning', etc.) is like that. Even our unconscious theories that we have probably inherited from our ancestors are like that. Of course, given a theory, we can harbor doubts about it, and we can harbor those doubts differentially, that is more or less doubts on some part of it. My theory is a digital version of the very old mechanist theory, saying that we are sort of natural machine. It is already explained by Nagarjuna in the Milinda's Questions for example, or by Plato in some place, and it has been developed by Descartes concerning animals (and perhaps concerning humans too in some hidden way, if you take the context of Descartes epoch). I make that digital version more precise so as to be able to drive precise conclusions. I have called in this list that more precise version: COMP (but I called it digital mechanism in some places). Note that what you call number theology belongs to the conclusion of comp (I don't assume it). The precise comp version is given by a) the yes doctor act of faith YD b) Church (Hypo) Thesis CT c) Arithmetical Realism hypothesis AR Now I can imagine a) to be false. In three ways actually: For example I say yes to the doctor but the digital reconstitution of me remains inanimate, or, I say yes to the doctor, and the digital reconstitution is a zombie, or I say yes to the doctor, and the reconstitution is alive but is not me. This I can logically conceived, and that would make a) wrong. Note that in the lobian interview we do not need anymore the yes doctor, except for giving a general sense to the *goal* of the interview. It is much harder for me to conceive that Church thesis could be false, but this is due to more than many years of reflection on it. I am not so much impress by the empirical evidence (all attempt to define computable function lead to the same class of function, despite completely different definitions and motivations), but I am infinitely impressed by the closure for the diagonalization of the class of partial computable functions. This is a quite convincing argument for CT, as I try to explain periodically on this list. Still I can logically doubt about CT. It is enough that someone comes up with a function and a way to explain me how to compute and a proof that the function cannot be programmed in Java (say), and CT would be refuted. I would say that this is unlikely. Now, it is still much more harder for me to doubt about AR. It is about AR that I often say that I would have the feeling to lie to myself in case I would pretend harboring doubt about it. AR just says that elementary number theoretical statements (including existential one) are true or false in a way which does not depend on me. Actually I am even using a weaker version of AR, in the sense that for the ontic part of the theory, I need only the independent truth of the formula with the shape ExP(x), i.e. it exist a number verifying the property P, where P is an easily verifiable statement (like being prime, being odd, etc.). I don't need universal (with the for all quantifier) independent truth, only the simpler formula among the existential one. (of course I don't believe at all in Peter Jones heavy form of magical platonism). I have also never met someone doubting about AR, although I met regularly people who pretend to doubt AR, but like Peter, they put in it things which I don't put in it at all. Somehow, to believe in NON-AR you have to believe in the possibility that there is a proposition of arithmetic, stating the existence of a number having some verifiable property, which truth value is capable of changing according to the fact that you are alive or not. You need to make a stronger and much weirder ontological commitment to get it. Some people ask me: but if AR is so obvious, why do you postulate it? I postulate it for reason of completeness, but also because I am aware of contradicting 1500 years of implicit theological aristotelian
Re: computationalism and supervenience
Le 28-août-06, à 05:37, Stathis Papaioannou a écrit : It *has* been proved (by diagonalization) that there exist some problem in number theory which are soluble by a machine using a random oracle, although no machine with pseudorandom oracle can sole the problem. That's interesting: does this imply it is possible to test a number sequence to see if it is random? Alas No. That would contradict other theorems in computer science. So we can infer that Kurtz diagonalization is non constructive. I will check Kurtz's paper to verify. KURTZ S. A., 1983, On the Random Oracle Hypothesis, Information and Control, 57, pp. 40-47. But it is not relevant given that self-duplication is already a way to emulate true random oracle. Do you mean by this an algorithm that explores every possible branch, by analogy with the MWI of QM? Yes. Just think about the UD. It generates all the possible computational branches (if you accept CT, and AR. No need for YD here). Bruno http://iridia.ulb.ac.be/~marchal/ --~--~-~--~~~---~--~~ 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 [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~--~~~~--~~--~--~---
Re: A question about the Uncertainty Measure
Hi Stephen, Le 28-août-06, à 04:31, Stephen Paul King a écrit : Hi Folks, I have been reading Bruno's wonderful Elsavier paper Thanks for saying so. and have been wondering about this notion of a Uncertainty measure. Does not the existence of such a measure demand the existence of a breaking of the perfect symmetry that is obvious in a situation when all possible outcomes are equally likely? In both comp and the quantum, a case can be made that the irreversibility of memory (coming from usual thermodynamics, or big number law) can explain, through physical or comp-physical interactions, the first person feeling of irreversibility. But with comp we do start from a basic irreversibility: 0 has a successor but no predecessors. And we do get physical symmetries (perhaps not enough: open problem), and then we get a temporal logic directly from the theaetetical definition of the first person (the knower). Consider an infinite Hilbert space and a normed state vector on it. What is the analogue of a sense of direction? I don't understand. Best regards, Bruno http://iridia.ulb.ac.be/~marchal/ --~--~-~--~~~---~--~~ 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 [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~--~~~~--~~--~--~---
Re: computationalism and supervenience
Le 27-août-06, à 12:43, Russell Standish a écrit : I recall reading this paper, and the followup entitled The Random Oracle Hypothesis is False by Chang et al. Have you the reference? Do you know if Chang has found a math error, or a conceptual mishandling? I would be interested to know. From recollection though, the claim was of superior algorithmic performance (ie solving NP problems in P time) rather than solving uncomputable problems. I doubt this very much, but I will check and let you know, Bruno http://iridia.ulb.ac.be/~marchal/ --~--~-~--~~~---~--~~ 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 [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~--~~~~--~~--~--~---
Re: computationalism and supervenience
Le 28-août-06, à 07:42, Stathis Papaioannou a écrit : Bruno marchal writes: Le 26-août-06, à 16:35, 1Z a écrit : And since the computer may be built and programmed in an arbitrarily complex way, because any physical system can be mapped onto any computation with the appropriate mapping rules, That is not a fact. It would make sense, indeed, only if the map is computable, and in this case I agree it has not been proved. Again UDA makes such question non relevant, given that the physical is secondary with respect to the intelligible. Any computation that can be implemented on a physical system A can be mapped onto another physical system B, even if B has fewer distinct states than A, since states can be reused for parallel processing. If B is some boring sysstem such as the ticking of a clock then the work (not sure what the best word to use here is) of implementing the computation lies in the mapping rules, not in the physical activity. The mapping rules are not actually implemented: they can exist written on a piece of paper Honestly I am not sure about that. so that an external observer can refer to them and see what the computer is up to, or potentially interact with it. And if the computer is conscious because someone can potentially talk to it using the piece of paper, ther is no reason why it should not also be conscious when the piece of paper is destroyed, or everyone who understands the code on the piece of paper dies. In the limiting case, the platonic existence of the mapping rule contains all of the computation and the physical activity is irrelevant - arriving at the same position you do. OK, in the case the mapping rule can be coded in a finite way. For example I can code the computation of any partial recursive function by using a n-body problem. But a slight change in the initial position of one of the body would destroy the information, and it is not clear why some other *finite* working mapping rule would appear, even in Platonia. Computation is a much constrained notion than people usually realize. You may be right, but I have never seen any proof. The probable reason for this is that such a proof would need a much more formal approach to physics, including what happens in the bottom, but nobody knows what happens there, and current theories makes big simplification there (renormalization, etc.). I think that what you say is not totally excluded by string theory, but would be false with loop gravity, for example (in loop gravity everything is quantized, and I can build, if only by diagonalization, computation non mappable to any finite piece of loop-gravity-matter (if I can say). Bruno http://iridia.ulb.ac.be/~marchal/ --~--~-~--~~~---~--~~ 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 [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~--~~~~--~~--~--~---
Re: Arithmetical Realism
Bruno Marchal wrote: AR eventually provides the whole comp ontology, although it has nothing to do with any commitment with a substantial reality. If it makes no commitments about existence,. it can prove nothing about ontology. --~--~-~--~~~---~--~~ 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 [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~--~~~~--~~--~--~---
Re: A question about the Uncertainty Measure
Bruno Marchal wrote: In both comp and the quantum, a case can be made that the irreversibility of memory (coming from usual thermodynamics, or big number law) can explain, through physical or comp-physical interactions, the first person feeling of irreversibility. But with comp we do start from a basic irreversibility: 0 has a successor but no predecessors. ...among the natural numbers. Does COMP really prove that negative numebrs don't exist ? --~--~-~--~~~---~--~~ 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 [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~--~~~~--~~--~--~---
Re: Rép: ROADMAP (well, not yet really...
Stathis Papaioannou wrote: Peter Jones writes: By youur definitions, it's a straight choice between metaphysics and solipsism. I choose metaphsyics. We can posit the unobservable to expalint he observable. Solipsism is a metaphysical position. (BTW: it it is wrong to posit an unobserved substrate, why is it OK to posit unobserved worlds/branches ?) It's debatable, but perhaps MWI is a better and simpler explanation of the facts of quantum mechanics than is CI, for example. Multiple-worlds are a consequence of dropping the collapse of the wave function, which was inexplicable and ad hoc. I'm not fond of it either, but it does have the support of being based on an good empirical model. Similarly for multiple-universes; they are implied by our best theory. Similarly (but much more strongly) believing there is a world out there is a better explanation of the facts than solipsism. But some explanations of physical phenomena, such as an undetectable ether through which light propagates have been dropped as unnecessary. The lumineferous aether was not only undetectable, it had to have contrdictory properties to remain undetected in both Michelson-Morley and stellar aberration. Brent Meeker --~--~-~--~~~---~--~~ 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 [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~--~~~~--~~--~--~---
Re: Rép: ROADMAP (well, not yet really...
Brent Meeker wrote: Stathis Papaioannou wrote: Peter Jones writes: By youur definitions, it's a straight choice between metaphysics and solipsism. I choose metaphsyics. We can posit the unobservable to expalint he observable. Solipsism is a metaphysical position. (BTW: it it is wrong to posit an unobserved substrate, why is it OK to posit unobserved worlds/branches ?) It's debatable, but perhaps MWI is a better and simpler explanation of the facts of quantum mechanics than is CI, for example. Multiple-worlds are a consequence of dropping the collapse of the wave function, which was inexplicable and ad hoc. It's neither. If anything there is an embarassment of explanations for it, and number of motivations for positing it. A genuine problem with MWI: it starts with the assumption that the universe is in a 'pure' state. However, unitary evolution under the SWE is unable to fully transform a pure state into a genuine mixture. It can generate (by mechanisms similar to environmental decoherence) an approximate mixture -- For All Practical Purposes. Since collapse does, by stipulation, produce orthogonal states, there is a difference between collapse interpretations and MW. The residual interferences could be detectable. (It is also believed by many that collapse itself is detectable). In fact it turns out that in the general case , there will be a unique pair of orthogonal perception states accompanying a pair of orthogonal cat states. This is something known as the Schmidt decomposition of an entangled state. However this is not much use for resolving the measurement paradox (...) because gernerally this mathematically preferred pair of cat states (..) would not be the desired |live cat + | dead cat at all, but some linear superposition of these! [...] Since the mathematics alone will not single out the |live cat and |dead cat states as being in any way 'preferred' we still need a theory of perception before we can make sense of [MWI] and such a theory is lacking.Moreover the onus on such a theory would be not only to explain why superpositions of dead and alive cats (or anything else macroscopic) occur in do not occur in the physical world but also why the wonderous and extraordinarily precise squared-modulus rule actually gives the right answers for probabilities in quantum mechanics! R. Penrose, Road to Reality p809 Is MWI a complete solution to the paradoxes of QM? Is an Universal Wave Function feasible ? A genuine problem with MWI: Reasonableness of all-embracing unitary evolution. MWI-ers claim that the unitary evolution of the SWE (or some variation) is the single all-embracing law of the universe -- the other main part of the QM universe, the process of collapse (AKA reduction) is not needed. However, QM itself is not an all-encompassing physical theory because it does not include gravity and relativity. It might be possible to include gravity in an extended WE, but the conventional SWE requires a derivative against time, wich is difficult to achieve in a way that is compatible with the requirements of relativity. There is also a more conceptual argument against large-scale branching; since all branches co-exist in the same space-time, and since the disposition of matter determines how space bends in general relativity, large-scale differences between the branches would leave space not knowing which way to bend. --~--~-~--~~~---~--~~ 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 [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~--~~~~--~~--~--~---
Re: Rép: ROADMAP (well, not yet really...
1Z wrote: Brent Meeker wrote: Stathis Papaioannou wrote: Peter Jones writes: By youur definitions, it's a straight choice between metaphysics and solipsism. I choose metaphsyics. We can posit the unobservable to expalint he observable. Solipsism is a metaphysical position. (BTW: it it is wrong to posit an unobserved substrate, why is it OK to posit unobserved worlds/branches ?) It's debatable, but perhaps MWI is a better and simpler explanation of the facts of quantum mechanics than is CI, for example. Multiple-worlds are a consequence of dropping the collapse of the wave function, which was inexplicable and ad hoc. It's neither. If anything there is an embarassment of explanations for it, and number of motivations for positing it. A genuine problem with MWI: it starts with the assumption that the universe is in a 'pure' state. However, unitary evolution under the SWE is unable to fully transform a pure state into a genuine mixture. It can generate (by mechanisms similar to environmental decoherence) an approximate mixture -- For All Practical Purposes. Since collapse does, by stipulation, produce orthogonal states, there is a difference between collapse interpretations and MW. The residual interferences could be detectable. (It is also believed by many that collapse itself is detectable). In fact it turns out that in the general case , there will be a unique pair of orthogonal perception states accompanying a pair of orthogonal cat states. This is something known as the Schmidt decomposition of an entangled state. However this is not much use for resolving the measurement paradox (...) because gernerally this mathematically preferred pair of cat states (..) would not be the desired |live cat + | dead cat at all, but some linear superposition of these! [...] Since the mathematics alone will not single out the |live cat and |dead cat states as being in any way 'preferred' we still need a theory of perception before we can make sense of [MWI] and such a theory is lacking.Moreover the onus on such a theory would be not only to explain why superpositions of dead and alive cats (or anything else macroscopic) occur in do not occur in the physical world but also why the wonderous and extraordinarily precise squared-modulus rule actually gives the right answers for probabilities in quantum mechanics! R. Penrose, Road to Reality p809 Is MWI a complete solution to the paradoxes of QM? Is an Universal Wave Function feasible ? A genuine problem with MWI: Reasonableness of all-embracing unitary evolution. MWI-ers claim that the unitary evolution of the SWE (or some variation) is the single all-embracing law of the universe -- the other main part of the QM universe, the process of collapse (AKA reduction) is not needed. However, QM itself is not an all-encompassing physical theory because it does not include gravity and relativity. It might be possible to include gravity in an extended WE, but the conventional SWE requires a derivative against time, wich is difficult to achieve in a way that is compatible with the requirements of relativity. There is also a more conceptual argument against large-scale branching; since all branches co-exist in the same space-time, and since the disposition of matter determines how space bends in general relativity, large-scale differences between the branches would leave space not knowing which way to bend. I'm well aware of the problems of MWI. But I think Roger is too pessimistic about the potential of a theory of einselection. There's an excellent review paper available on arXiv.org: Decoherence, the measurement problem, and interpretations of quantum mechanics Authors: Maximilian Schlosshauer Comments: 41 pages. Final published version Journal-ref: Rev. Mod. Phys. 76, 1267-1305 (2004) DOI: 10.1103/RevModPhys.76.1267 Environment-induced decoherence and superselection have been a subject of intensive research over the past two decades, yet their implications for the foundational problems of quantum mechanics, most notably the quantum measurement problem, have remained a matter of great controversy. This paper is intended to clarify key features of the decoherence program, including its more recent results, and to investigate their application and consequences in the context of the main interpretive approaches of quantum mechanics. It discusses the sucesses and problems of the decoherence program and their relation to other intepretations. I think you are wrong in saying the are plenty of explanations for collapse of the wave-function. Penrose's is the only one that comes close to being an explanation, i.e. something with a physical basis that could be tested. The others are just hueristic models. Decoherence is experimentally tested and provides collapse FAPP; but the FAPP still leaves some problems. Personally, I like Omnes' viewpoint, which is that QM is a probabilistic
Re: computationalism and supervenience
On Mon, Aug 28, 2006 at 03:41:00PM +0200, Bruno Marchal wrote:
Le 27-août-06, à 12:43, Russell Standish a écrit :
I recall reading this paper, and the followup entitled The Random
Oracle Hypothesis is False by Chang et al.
Have you the reference? Do you know if Chang has found a math error, or
a conceptual mishandling? I would be interested to know.
The ref is
@Article{Chang-etal94,
author = {Richard Chang and Benny Chor and Oded Goldreich and Juris
Hartmanis and Johan H\aa{}stad and Desh Ranjan and Pankaj Rohatgi},
title ={The Random Oracle Hypothesis is False},
journal = {Journal of Computer and System Sciences},
year = 1994,
volume = 49,
pages ={24-39}
}
Google it - its on the web.
From recollection though, the claim was of superior algorithmic
performance (ie solving NP problems in P time) rather than solving
uncomputable problems.
I doubt this very much, but I will check and let you know,
There is also the classic Leeuw et al paper (1957) demonstrating that
probabilistic TMs are no more powerful than the regular thing.
Anyway, I appreciate you checking - such a claim as you're saying
would be very interesting.
Bruno
http://iridia.ulb.ac.be/~marchal/
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RE: evidence blindness
-Original Message- From: everything-list@googlegroups.com [mailto:everything- [EMAIL PROTECTED] On Behalf Of David Nyman Sent: Monday, August 28, 2006 7:33 AM To: Everything List Subject: Re: evidence blindness [EMAIL PROTECTED] wrote: We all (excuse me to use 1st pers form) are well educated smart people and can say something upon everything. It is a rarity to read: I was wrong you are right - period. John You're right! Every time I post on these topics I *know* I'm wrong: I just don't know how specifically, but I keep doing it in the hope that someone will show me. Trouble is, there's something about this area that resists us - we seem doomed to come at it all wrong (particularly in those moments when we think we've got it right!) It's the struggle that fascinates us, I suppose. David Yeah! I actually believe this is more fundamental to the whole process of creativity I have a saying (the only one I have ever coined!): Insight is the serendipity born of the failure to make a mistake i.e. ready fire (shite!...missed)... then aim. Eventually you hit the bullseye by failing to miss everything that is not the bullseye voila!an answer... btw...I'm thinking of writing a short paper on the long overdue death of the solipsism argument and the 'no evidence for subjective experience' dogma I'd like to erect a grave-stone here on the everything list! R.I.P. :-) cheers, colin hales --~--~-~--~~~---~--~~ 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 [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~--~~~~--~~--~--~---
