Re: A thought on MWI and its alternative(s)
On 5/06/2017 12:19 pm, Bruce Kellett wrote: On 4/06/2017 10:05 pm, Bruno Marchal wrote: On 02 Jun 2017, at 03:01, Bruce Kellett wrote: Your claim appears to be that Bell's theorem is not valid in MWI. Bell's theorem is valid. His inequality does not even assume QM, but just locality. I agree, but that is not what you were implying above. It seems that now you agree that the Bell inequalities assume only locality. But these inequalities are violated by experiment. That can only mean that the assumption of locality was wrong -- whatever interpretation of QM you adopt. I think that this important part of recent exchanges might have got lost in the welter of to-and-fro. Bruno accepts: 1. Bell's theorem (and the associated inequalities) are valid in MWI. 2. Bell's theorem assumes only locality (not even QM -- it is valid in classical physics also). 3. The Aspect et al., and subsequent, experiments demonstrate that the Bell inequalities are violated. It seems to follow with the force of simple logic that: 4. Experiment shows that QM is non-local, even in MWI. Bruno appears to reject this conclusion. I conclude that Bruno's position is incoherent. Bruce -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: substitution level
On Sun, Jun 04, 2017 at 11:48:23AM -0400, John Clark wrote: > On Sat, Jun 3, 2017 at 9:48 PM, Russell Standish > wrote: > > > > > > > That is not the same thing. The largest prime number doesn't exist, so > > > > there's no answer to find there, but the halting problem always has an > > > > answer - a program either halts, or it does not. > > > > But that's not the Halting Problem, it's is there a general way, in a > finite number of steps, to separate all programs into these 3 categories? > > 1) Programs that will halt and there is a proof they will halt > 2) Programs that will not halt and there is a proof they will not halt > 3) Programs that will either halt or will not halt but have no proof they > will not halt. > > Turing gave us the answer to that 80 years ago and it's no. Yes a program > will either stop or it won't but the Halting Problem isn't about truth it's > about proof. Mathematicians worry that some important problems, like the > Goldbach Conjecture, may be in category #3, but if it is we will never know > that it is. Goldbach could be true but a proof it is true does not exist, > so a billion years from now, whatever hyper intelligent entities we will have > evolved into will still be deep in thought looking, unsuccessfully, for a > proof that it is true and still grinding away at numbers looking, > unsuccessfully, for a counterexample to show it is false. > > > > > > > In fact, there are a variety of hypercomputers that can solve the > > > > halting problem in finite time. > > > It sounds to me like you're talking about one of Bruno's very silly book > computers that are just ink squiggles on dried wood pulp that are unable to > calculate 2+2 even if an infinite amount of time were available. > Not at all. Bruno's ontology implicitly assumes such hypercomputers don't exist. It was David Deutsch who initially made the point, with a Hilbert Hotel computer. > > > > > > Basically, any machine capable of > > > > executing an infinite number of computational steps will be able to > > > > solve the halting problem in finite time. > > > > Right, > > executing an infinite number of computations in a finite number of seconds. > How hard can that be? > There are a number of proposals for for doing so, probably the most interesting is Malament-Hogarth spacetime, which is a solution to general relativity that permits such a possibility. It is similar to a Tipler cyclinder, which is a solution for a time machine that travels back in time, in the sense that a seemingly impossible physical situation is allowed by General Relativity. > > > > > > >> > > >> Anything that can be done a Turing Machine can do, if it can't be done > >> > >> then a Turing Machine can't do it, and neither can anything else. > > > > > > > > > That is a thesis about the physical world > > > > > > Yes. > > > > > > > > > It is quite a strong assumption about reality, and appears to be true > > > Yes, but it's no stronger than the assumption perpetual motion machines > can't be built, or that the Second Law of Thermodynamics is correct. It is > no stronger than > > the assumption everything we know about physics isn't complete bullshit. > I disagree. There is nothing in conventional physics that rules out the possibility of a hypercomputer. David Deutsch has proposed a principle that effectively says "hypercomputers are not possible", but the fact that hypercomputing solutions of General Relativity exist, such a principle would mean that something must be up the spout with that. But then, we know that QM is incompatible with GR, and I strongly suspect it is GR that will need modification, so it doesn't bother me if this is just something else that needs changing in Einstein's theory. But it may well be that the physical CT thesis is itself only some classical approximation. We just don't know at this stage. -- Dr Russell StandishPhone 0425 253119 (mobile) Principal, High Performance Coders Visiting Senior Research Fellowhpco...@hpcoders.com.au Economics, Kingston University http://www.hpcoders.com.au -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: A thought on MWI and its alternative(s)
On 4/06/2017 10:05 pm, Bruno Marchal wrote: On 02 Jun 2017, at 03:01, Bruce Kellett wrote: In QM, with or without collapse, decoherence and the transition from the pure state to a mixture gives a definite measurement result. In particular branches only. When looking at the whole wave including the observers, decoherence explain why it *looks*, to all observers in the different branches, that mixed states have been obtained, but that is not the case in the global description. The transition to the mixed state is essential for one to get a definite experimental result. Physicists realized a long time ago that the pure unreduced state of the MWI does not work. The difficulty is known as the 'basis problem'. If you retain the full superposition of the pure state, there is no preferred basis, and expanding this superposition in terms of different bases gives different -- usually nonsensical -- physical results. It is only when you reduce to a mixed state that the basis is fixed, and results are definite. This does not mean, as you appear to think, that you have lost the other branches. All the branches of the MWI are still present, except that now there is a different definite measurement result in each branch. Without collapse, different branches get different results, but once obtained, these results are fixed, and are not affected by whether Alice and Bob exchange information or not. I agree. That is used in the fact that in EPR like situation, when Alice and Bob are space-time separated, what we have is "only" an infinity of Alices and Bobs, This is wrong. There is no "infinity of Alices and Bobs". all with their spin correlated, and when Alice makes her measurement, at any angle, she will know Bob's possible result, Bobs possible results, as far as Alice knows, is 50/50 for '+' or '-'. without needing any action at a distance. She just localize herself, and her corresponding Bob, in which branch they belong. That is not correct. You keep saying it, but you offer no proof or mechanism whereby such a thing could happen. There is no influence at a distance, although we would need it to talk of token unique Alice and Bob in case there would be only one universe. That is a total misunderstanding as well. All branches might exist (two for Alice in this case, one where she got '+' and one where she got '-'), but we need consider only one typical branch to get the general result -- that is how things are done in physics when you have superpositions. But there is non-locality -- non-local influence -- in all interpretations since it is inherent in the quantum formalism. I don't see any non-locality in the MWI. EPR, Bell, assumes always one Alice and Bob, and as Everett shows, decoherence explains the manitenance of coherent first person plural description, and the absence of collapse prevent any non-local influence. That is not the case either. Bell does not assume a necessary collapse. Bell's theorem is a mathematical theorem, it is true whatever interpretation of QM you adopt. You seem to be suggesting (and you are more explicit in this suggestion elsewhere) that Bell's theorem is invalid for MWI. 1. That is not true -- Bell's theorem is valid in all interpretations. 2. Even if you did find an error in Bell's theorem, all that that would get you is the possibility of a local hidden-variable account of the correlations. If you think such a local hidden variable account is possible, then give it - in full mathematical detail - and we might begin to think that you know what you are talking about. You cannot get away by reversing the onus of proof. Bell's theorem is independent of whether or not a collapse is assumed, To interpret the experimental violation, you need to identify the Alice and Bob you talk about. But EPR and Bell talk of Alice and Bob like if they were in a definite universe all along the experience, when that is never the case. They do assume implicitly one physical universe. Not true. See above. Even if this were the case so that the theorem was not valid in MWI, that actually does not get you anywhere -- non-locality would still exist, except that now you could give a local hidden variable account. I see no sign that you are actually doing this. so if you want to argue that MWI removes the non-locality proved by Bell, then the onus of proof is very much on you: you have to demonstrate how this can be possible. It is a trivial consequence of the linear differential shroedinger equation. Or of the fact that the evolution is a rotation (unitary) in Hilbert space. Rubbish. If you remain with the linear Schrödinger equation, you cannot get definite results for experiments. Once you have definite results, as you need to calculate correlations, the non-locality is evident. You say that Bell's theorem relies on the unicity of outcomes. By this, I presume you mean that Bell assumes counterfactua
Re: A thought on MWI and its alternative(s)
On Thu, Jun 1, 2017 at 8:19 AM, Bruno Marchal wrote: > > I was juste arguing against John Clarks idea that the Bell's inequality > violation introduce physical action at a distance, even with the MWI. That's not exactly correct, what I actually said was *at least* one of the following 3 things must be untrue: 1) Determinism 2) Locality 3) Realism Einstein thought all 3 were true but he died 10 years before Bell's inequality had even been discovered and 30 years before experiments had shown it was violated. You can't have everything and I think Einstein would have been least horrified if #1 was untrue and most horrified if #3 was. John K Clark -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Proof and truth are not the same thing (was: substitution level)
On Sun, Jun 4, 2017 at 1:15 PM, Bruno Marchal wrote: >> >> Anything that can be done a Turing Machine can do, if it can't be done >> then a Turing Machine can't do it, and neither can anything else. > > > > If "can be done" means "can compute or emulate", I am OK. That is > basically Church's Thesis. > > If by "can be done" mean solve a problem, or prove a theorem, then it is > an entirely different story. > If you were bound and determined to prove that the Halting Problem had a solution you could certainly find starting axioms that would allow you to construct that conclusion, but then you could also prove there was a one to one correspondence between the integers and the Real Numbers. Perhaps that doesn't frighten you but a proof is only as good as the axioms it starts with , so I want to be very very conservative with my choice of axioms because I'd rather there be true statements that have no proof they are true than false statements that do have a proof they are true. In the fist case you can't know everything for certain and that's a shame, but in the second case you can't know anything for certain and that's worse. John K Clark -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: A thought on MWI and its alternative(s)
On 04 Jun 2017, at 08:52, Telmo Menezes wrote: Sure, we can take the same drug and talk about our experiences, and conclude that they were similar. And they probably were. But ultimately, there is a language grounding problem. We have no way of comparing qualia, private experience. I cannot even verify experimentally that you are indeed conscious. I assume it heuristically, that's all. OK. Let me tell you how I think about it, heuristically at least, as you say. From my first-personal perspective, 'you' - that is your body - can only ever be said to be "conscious' in the brutely covariate sense. For that matter, the same goes for my observation of my own body. As you say, there's no conceivable objective test that could establish more than this. Nor - and this is telling - would anything more than neurocognition, at least in principle, be required to account for your, or my own, observable behaviour. I agree. I think we need to accept that this is indeed telling us something. But what? In my view it's telling us to stop thinking of consciousness as being 'explained' exclusively with reference to its observable physical correlates. IOW this is possibly a paradigm case of the distinction between correlation and causation. Yes, this is all I'm saying too! The alternative - shorn of its uniquely a posteriori relation with one's own consciousness - would be in effect simply to accept that physical behaviour is its own 'explanation'. This is the conclusion Brent urges on us and I can respect this position without being content with it myself. Right, I can also understand Brent's positions. One of the reasons why I am not satisfied with such a position is that consciousness appears to be unnecessary from an intelligence / Darwinian standpoint. It appears that Darwinism + neuroscience/computer science can explain the emergence of our behaviour in non-conscious zombies. It has been argued that it could be a spandrel, a by-product of the evolutionary process. I have no problem with that -- in fact I am betting this is the case, because I doubt that a non-conscious human-level intelligence is possible. But I still want to know why. Every time a problem baffles us, and people suggest that: "look, it's just a brute fact", I can't help but feel that this stance is very akin to saying "the gods did it". One of the things I like about Bruno's work is that I fell that he, at least, provides a theory on why it looks so mysterious to us. What also baffles me is why some people can't see the mystery. I don't think this is the case with Brent though, I think he is a pragmatist -- which is a perfectly reasonable thing to be. To go beyond this, as for example Bruno is attempting to do with the comp theory, requires an explanatory schema that somehow manages both to transcend and encapsulate the explication of conscious phenomena in exclusively reductive terms. And to strip this move of any sense of arbitrariness or avoidance of the problem we also need to show that this is a necessary consequence of situating those phenomena adequately within a tractable theory of knowledge. Such a theory will then focus on explicating a characteristic logic of consciousness in terms of what is perceptible or not, what is doubtable or not, what is communicable or not, and so forth. And of course a crucial component of this must be the relation of these categories to the dynamics of the necessarily correlated 'physics of the observable'. Yes, this is something I would like to see Bruno talk about more: how he hopes to derive physics from his theory. By convincing courageous people to pursue the extraction of the quantum logics from the arithmetical "material hypostases". This means, notably, to optimize the theorem prover for G and G*, and the variants. We need "only" an army of mathematicians working in a department of theology in some science academy ... By UDA, the physical is given by, either Bp & p, or Bp & Dt, or Bp & Dt & p. (anything giving Bp -> Dp, so that we have a notion of bet). Normally the first person plural one should be the one given by Bp & Dt. p is for sigma_1 proposition, the "leaves" of the universal dovetailing, and B is for Gödel's beweisbar predicate, where all those nuances are enforced by incompleteness theorem for any machine betting on computationalism and trying to predict its consistent extension in arithmetic. We do have the three quantum logics, and their corresponding quantization (the logic of []<>p, to "reverse" Goldblatt's translation of the modal logic into quantum logic) gives the quantum relations, from which it is hoped we get enough (we know we do get something complete, in some sense) to get either Gleason theorem, or a corresponding one. The qualia should be given by S4Grz1 and X1* minus X1. But the quanta are sort of qualia, partially sharable and seems to appear in the three physics we get.
Re: substitution level
On 04 Jun 2017, at 03:20, John Clark wrote: Anything that can be done a Turing Machine can do, if it can't be done then a Turing Machine can't do it, and neither can anything else. If "can be done" means "can compute or emulate", I am OK. That is basically Church's Thesis. If by "can be done" mean solve a problem, or prove a theorem, then it is an entirely different story. This does not mean that "prove", above some complexity threshold, will not obey common laws and principle, but proving is always relative to the prover, and the things proved can be very different, unlike computability, which defines the same class of functions, even of algorithm, (again above a unique mathematically well defined threshold: Turing completeness, sigma_1 completeness, ...). Bruno http://iridia.ulb.ac.be/~marchal/ -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: substitution level
On Sun, Jun 4, 2017 at 3:05 AM, Telmo Menezes wrote: > > There is nothing that a quantum > > computer can do that a classical computer cannot do, There are problems a classical computer can't solve in polynomial time that a quantum computer can. > > given sufficient > > time. Besides that Mrs. Lincoln how did you like the play? John K Clark -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: substitution level
On Sat, Jun 3, 2017 at 9:48 PM, Russell Standish wrote: > > > That is not the same thing. The largest prime number doesn't exist, so > > there's no answer to find there, but the halting problem always has an > > answer - a program either halts, or it does not. > But that's not the Halting Problem, it's is there a general way, in a finite number of steps, to separate all programs into these 3 categories? 1) Programs that will halt and there is a proof they will halt 2) Programs that will not halt and there is a proof they will not halt 3) Programs that will either halt or will not halt but have no proof they will not halt. Turing gave us the answer to that 80 years ago and it's no. Yes a program will either stop or it won't but the Halting Problem isn't about truth it's about proof. Mathematicians worry that some important problems, like the Goldbach Conjecture, may be in category #3, but if it is we will never know that it is. Goldbach could be true but a proof it is true does not exist, so a billion years from now, whatever hyper intelligent entities we will have evolved into will still be deep in thought looking, unsuccessfully, for a proof that it is true and still grinding away at numbers looking, unsuccessfully, for a counterexample to show it is false. > > > In fact, there are a variety of hypercomputers that can solve the > > halting problem in finite time. It sounds to me like you're talking about one of Bruno's very silly book computers that are just ink squiggles on dried wood pulp that are unable to calculate 2+2 even if an infinite amount of time were available. > > > Basically, any machine capable of > > executing an infinite number of computational steps will be able to > > solve the halting problem in finite time. > Right, executing an infinite number of computations in a finite number of seconds. How hard can that be? > > >> > >> Anything that can be done a Turing Machine can do, if it can't be done >> >> then a Turing Machine can't do it, and neither can anything else. > > > > > That is a thesis about the physical world > > Yes. > > > > It is quite a strong assumption about reality, and appears to be true Yes, but it's no stronger than the assumption perpetual motion machines can't be built, or that the Second Law of Thermodynamics is correct. It is no stronger than the assumption everything we know about physics isn't complete bullshit. > > > but there is > > no really good reason why it should be true, ISTM. It just appears to > be a brute fact. > And it is in their very nature that if X is a brute fact you will never be able to prove X is a brute fact. John K Clark -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: A thought on MWI and its alternative(s)
On 4 Jun 2017 1:05 p.m., "Bruno Marchal" wrote: On 02 Jun 2017, at 03:01, Bruce Kellett wrote: On 1/06/2017 10:19 pm, Bruno Marchal wrote: > >> On 01 Jun 2017, at 02:26, Bruce Kellett wrote: >> On 1/06/2017 4:43 am, Bruno Marchal wrote: >> >>> On 31 May 2017, at 04:01, Bruce Kellett wrote: > On 30/05/2017 9:35 pm, Bruno Marchal wrote: > >> On 30 May 2017, at 11:28, Telmo Menezes wrote: >> >> I get your point with decoherence. >>> Again, I would say that it all depends on theories of mind. What does >>> mind supervene on? Perhaps it is true that every single coupling with >>> the environment prevents the current observer state to become >>> compatible with other branches. But can we be sure? I feel that such >>> certainties come from a strong belief in emergentism (which I cannot >>> disprove, but find problematic). >>> >> >> It is impossible to recohere the past, FAPP. >> >> But only FAPP. To make the blue T-rex interfereing with the >> red-T-rex, we must erase the trace of particle interaction between the >> T-rex in its whole light-cone, and this without forgetting the particles >> "swallowed" by the black-holes, etc. It is just completely impossible, >> but >> to derive from that the unicity of the past, is, it seems to me (and you >> if >> I understood well) is invalid. >> > > I think the recoherence of paths that have completely decohered is > more than just FAPP impossible, I think it is impossible in principle. One > major problem with recoherence in general is that information leaks from > the paths at the speed of light (as well as less slowly for other > interactions). Since this vital information goes out along the light cone, > it can never be recaptured and returned to the original interaction. > In QM + special relativity OK. (note that to me QM + special relativity => no collapse (and even the Many dreams, but we have agreed to disagree on this if I remember well). >>> >>> Reasoning in QM without SR is not very profitable. Besides, QM + SR does >>> not particularly imply MWI -- it is perfectly possible to have a consistent >>> collapse model of QM+SR. I know you don't agree because of the non-locality >>> implied by EPR, but this non-locality is not removed in MWI, regardless of >>> what you might say. >>> >> >> I don't see it, and the mast time we discuss this, we conclude on some >> vocabulary problem. When there is no collapse, measurement tells to people >> light separated in which branch theiy belongs, but to exploits that >> information, they need to come into contact. >> > > Last time we discussed this, no resolution was achieved. > That is not what I remembered, but I will not insist. In QM, with or without collapse, decoherence and the transition from the > pure state to a mixture gives a definite measurement result. > In particular branches only. When looking at the whole wave including the observers, decoherence explain why it *looks*, to all observers in the different branches, that mixed states have been obtained, but that is not the case in the global description. Without collapse, different branches get different results, but once > obtained, these results are fixed, and are not affected by whether Alice > and Bob exchange information or not. > I agree. That is used in the fact that in EPR like situation, when Alice and Bob are space-time separated, what we have is "only" an infinity of Alices and Bobs, all with their spin correlated, and when Alice makes her measurement, at any angle, she will know Bob's possible result, without needing any action at a distance. She just localize herself, and her corresponding Bob, in which branch they belong. There is no influence at a distance, although we would need it to talk of token unique Alice and Bob in case there would be only one universe. > Consequently, indispensable phase information is lost *in principle*, so > the recoherence is, in general, impossible. > OK. (I was reasoning in naive classical QM) Of course, with carefully constructed systems, where the loss of > information along the light cone is prevented, recoherence is possible in > special circumstances, but not in general. > > From this, the uniqueness of the past of any decoherent history is > assured. So deriving the unicity (if I understand this use of the word) is > by no means invalid -- it is proved. > In QM + SR. OK. Even if one encounters one of those rare situations in which > recoherence is achieved, that still does not invalidate the uniqueness of > the past history -- recoherence, if it occurs, simply means that no new > branches are formed at that point, so the decoherent history remains > unique. > OK. That might suggest that we identify our indistinguishible past in
Re: A thought on MWI and its alternative(s)
On 02 Jun 2017, at 04:06, Bruce Kellett wrote: (answered in my previous post). In quantum mechanics, this change is brought about by the unitary processes of decoherence, As Everett explains well, and suggest already this makes any influence at a distance only apparent, but never real. Einstein can sleep well. and the non-unitary trace over the environmental degrees of freedom. Which reflects only, in the MWI, the contagion of the superposition to the environment. This is an essential difference between classical and quantum physics, and the necessity for this non-unitary reduction of the pure state to a mixture is ultimately why MWI is actually no better at explaining quantum measurement than are the collapse models. Only if you interpret the decoherence as a physical phenomenon, but then we get non unitary evolution in Nature, and -quantum mechanics- without collapse is false. Are you suggesting that decoherence is *not* a physical phenomenon? I am saying that the first person seeing mixed states is a first person valid seeing from its "personal branch" perspective, but there is no definite outcome in the third person view we can have on the wave or the formalism. Decoherence and the pure-to-mixed transition do indeed say that MWI is strictly false -- you need non-unitary additions. ? Only the collapse, if real, needs to falsify the unitarity of the evolution. The question is, what determined (from the 3p view) that the universe followed that particular path and not any of the others? Why do you reject out of hand that the universe might be probabilistic? It is possible 'nothing' determined which path from the possibilities was actually followed. All that is known are the probabilities for each path. We do not know that the other paths are followed, either 1p or 3p. In QM, we do have evidences that many path are taken all together. if only the two slits. That is not really a relevant comment. Quantum mechanics is characterized by the presence of superpositions -- that is what makes the theory work, and why it is so different from classical physics. Superpositions generally represent pure states, and these must be reduced to mixed states by the measurement process. Without collapse, that never happens. So your non-collapse theory is immediately falsified by every quantum experiment ever performed. It is falsified only if you take a definite outcome as being absolute and not branch relative. Bruno http://iridia.ulb.ac.be/~marchal/ -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
Re: A thought on MWI and its alternative(s)
On 02 Jun 2017, at 03:01, Bruce Kellett wrote: On 1/06/2017 10:19 pm, Bruno Marchal wrote: On 01 Jun 2017, at 02:26, Bruce Kellett wrote: On 1/06/2017 4:43 am, Bruno Marchal wrote: On 31 May 2017, at 04:01, Bruce Kellett wrote: On 30/05/2017 9:35 pm, Bruno Marchal wrote: On 30 May 2017, at 11:28, Telmo Menezes wrote: I get your point with decoherence. Again, I would say that it all depends on theories of mind. What does mind supervene on? Perhaps it is true that every single coupling with the environment prevents the current observer state to become compatible with other branches. But can we be sure? I feel that such certainties come from a strong belief in emergentism (which I cannot disprove, but find problematic). It is impossible to recohere the past, FAPP. But only FAPP. To make the blue T-rex interfereing with the red- T-rex, we must erase the trace of particle interaction between the T-rex in its whole light-cone, and this without forgetting the particles "swallowed" by the black-holes, etc. It is just completely impossible, but to derive from that the unicity of the past, is, it seems to me (and you if I understood well) is invalid. I think the recoherence of paths that have completely decohered is more than just FAPP impossible, I think it is impossible in principle. One major problem with recoherence in general is that information leaks from the paths at the speed of light (as well as less slowly for other interactions). Since this vital information goes out along the light cone, it can never be recaptured and returned to the original interaction. In QM + special relativity OK. (note that to me QM + special relativity => no collapse (and even the Many dreams, but we have agreed to disagree on this if I remember well). Reasoning in QM without SR is not very profitable. Besides, QM + SR does not particularly imply MWI -- it is perfectly possible to have a consistent collapse model of QM+SR. I know you don't agree because of the non-locality implied by EPR, but this non-locality is not removed in MWI, regardless of what you might say. I don't see it, and the mast time we discuss this, we conclude on some vocabulary problem. When there is no collapse, measurement tells to people light separated in which branch theiy belongs, but to exploits that information, they need to come into contact. Last time we discussed this, no resolution was achieved. That is not what I remembered, but I will not insist. In QM, with or without collapse, decoherence and the transition from the pure state to a mixture gives a definite measurement result. In particular branches only. When looking at the whole wave including the observers, decoherence explain why it *looks*, to all observers in the different branches, that mixed states have been obtained, but that is not the case in the global description. Without collapse, different branches get different results, but once obtained, these results are fixed, and are not affected by whether Alice and Bob exchange information or not. I agree. That is used in the fact that in EPR like situation, when Alice and Bob are space-time separated, what we have is "only" an infinity of Alices and Bobs, all with their spin correlated, and when Alice makes her measurement, at any angle, she will know Bob's possible result, without needing any action at a distance. She just localize herself, and her corresponding Bob, in which branch they belong. There is no influence at a distance, although we would need it to talk of token unique Alice and Bob in case there would be only one universe. Consequently, indispensable phase information is lost *in principle*, so the recoherence is, in general, impossible. OK. (I was reasoning in naive classical QM) Of course, with carefully constructed systems, where the loss of information along the light cone is prevented, recoherence is possible in special circumstances, but not in general. From this, the uniqueness of the past of any decoherent history is assured. So deriving the unicity (if I understand this use of the word) is by no means invalid -- it is proved. In QM + SR. OK. Even if one encounters one of those rare situations in which recoherence is achieved, that still does not invalidate the uniqueness of the past history -- recoherence, if it occurs, simply means that no new branches are formed at that point, so the decoherent history remains unique. OK. That might suggest that we identify our indistinguishible past in arithmetic, if we assume mechanism. I use the Y = II principle, or the "quantum" linearity of the tensor product "@": we have that a @ (b + c) = (a @ b) + (a @ c). That makes sense. Linearity is the heart of QM. It is linearity that allows superpositions, and leads to all the "quantum weirdness". I agree. Both "linearities" (the quantum evolution, and the tensor product
Re: Answers to David 4
On 4 June 2017 at 11:47, Bruno Marchal wrote:
>
> On 02 Jun 2017, at 00:29, David Nyman wrote:
>
> On 1 June 2017 at 18:00, Bruno Marchal wrote:
>
>>
>> On 01 Jun 2017, at 16:42, David Nyman wrote:
>>
>>
>>
>> On 1 Jun 2017 15:20, "Bruno Marchal" wrote:
>>
>>
>> On 01 Jun 2017, at 15:59, David Nyman wrote:
>>
>>
>>
>> On 1 Jun 2017 14:01, "Bruno Marchal" wrote:
>>
>>
>> On 01 Jun 2017, at 12:44, David Nyman wrote:
>>
>>
>>
>>
>> Yes, but doesn't the comp theory itself assume the relation as if true,
>> in order for mechanism to make sense (which was my caveat)?
>>
>>
>>
>> The point here is very subtle. We cannot assume Mechanism is true, we can
>> only assume Mechanism. We can assume it as a sort of meta-level hypothesis.
>> It is indeed the reason why I insist on an act of faith, and why it is a
>> theology.
>>
>> Now, you might ask me what is the difference between assuming X, and
>> assuming X is true. The difference is that when we assume X, but don't
>> invoke the full semantic of X, and we can preserve our consistency. By
>> saying "mechanism is true", even in an hypothesis, you refer to the God of
>> mechanism at a place that is impossible.
>>
>> We have something similar, but slightly simpler, for the notion of
>> self-consistency. Take PA. It has 6 axioms + the infinity of induction
>> axioms
>>
>> 1) Ax (0 ≠ s(x))
>> 2) AxAy (s(x) = s(y) -> x = y)
>> 3) Ax (x+0 = x)
>> 4) AxAy (x+s(y) = s(x+y))
>> 5) Ax (x*0=0)
>> 6) AxAy (x*s(y)=(x*y)+x)
>> 7) the infinity) (F(0) & Ax(F(x) -> F(s(x -> AxF(x)
>>
>> PA is consistent (I hope you are OK with this, as all mathematicians are,
>> except nelson)
>>
>> Imagine I add to PA the axiom 8) PA is consistent. That is
>>
>> 8) consistent(1+2+3+4+5+6+7)
>>
>> In that case there is no problem that new theory, PA+con(PA) is
>> consistent, and even much more powerful than PA. It proves new theorems and
>> it shorten many proofs.
>>
>> But imagine we add the following to PA
>>
>> 8') consistent(1+2+3+4+5+6+7+8')
>>
>> That is self-referential, but using the diagonal lemma (the D'X' = 'X'X''
>> trick), we can build that formula in arithmetic and add it to PA as axiom.
>>
>> In that case, we get a theory which can prove, indeed in one line proof,
>> its own consistency, and so, by Gödel II, that theory is inconsistent.
>>
>> The case above is more complex to describe, because it refers to
>> "arithmetical truth", which cannot even be defined in arithmetic. It is
>> almost the nuance between (Bp & p), and (Bp & V(p)). For each partuclar p,
>> you can write Bp & p, but you cannot define knowledge by a general (Bx &
>> x). It is the nuance between assuming that x + 0 = x, and using only that,
>> and assuming True('x + 0 = x'), which cannot be express in the arithmetical
>> language.
>> Mechanism is awkward on this. Yet, this
>>
>> sustains your intuition that the ultimate 3p, the outer God view, is a 0p
>> pov.
>>
>
> "Out of sight, out of mind" as the proverb has it.
>
>
> "Loin des yeux, loin du coeur", we say in french (which has not exactly
> the same intent).
>
>
>
>
>
>> It works well with Plotinus idea that God does not exist, as it is the
>> ultimate reason why everything exists without mentioning ever itself in the
>> creation (making the idea that God can talk with us in a direct public way
>> nonsensical). Only the first person has access to this, but can only stay
>> mute.
>>
>
>
> Another example is that even if someone survives the classical
>> teleportation experience, he/she cannot claim that he/she knows that
>> mechanism is true.
>>
>
> OK
>
>
>> Still another example, even closer to what is alluded above is the case
>> of the notion of sigma_1 truth, or simply sigma-truth. The notion of
>> sigma-truth *is* definable in arithmetic, and the self-referential
>> sentences saying that she is sigma-true appears to be a sigma proposition,
>> yet it can be shown to be ... false! This is very unlike the sigma
>> proposition saying "I am provable", which is always true! All this despite
>> G* proves (sigma-true <-> sigma provable), but again, only G* says this,
>> the machine has to be mute.
>>
>
> The machine would appear to take Wittgenstein's dictum to heart. But its
> guardian angel is able nonetheless to intuit a truth in what it cannot say.
>
>
> I would not use "intuit" for the guardian angel. he is not a subject. just
> a machinery who knows everything about the machine(s). At the propositional
> level, he knows/proves the whole truth about the self-referential sentence.
> We know it is true, only because we limit ourselves to true machine, by
> decision.
>
So the angel is not conceived as self-referential, hence cannot be said to
possess intuition. Is that it?
>> I cannot say "if mechanism is true then the truth of mechanism go without
>> saying", but I can say at the meta-level "If mechanism then the truth of
>> mechanism go without saying". I think.
>>
>
> Perhaps "if mechanism is true" is close to what Brent calls a
> reifica
Re: A thought on MWI and its alternative(s)
On 4 Jun 2017 7:53 a.m., "Telmo Menezes" wrote: > Sure, we can take the same drug and talk about our experiences, and > > conclude that they were similar. And they probably were. But > ultimately, there is a language grounding problem. We have no way of > comparing qualia, private experience. I cannot even verify > experimentally that you are indeed conscious. I assume it > heuristically, that's all. > > > OK. Let me tell you how I think about it, heuristically at least, as you > say. From my first-personal perspective, 'you' - that is your body - can > only ever be said to be "conscious' in the brutely covariate sense. For that > matter, the same goes for my observation of my own body. As you say, there's > no conceivable objective test that could establish more than this. Nor - and > this is telling - would anything more than neurocognition, at least in > principle, be required to account for your, or my own, observable behaviour. I agree. > I think we need to accept that this is indeed telling us something. But > what? In my view it's telling us to stop thinking of consciousness as being > 'explained' exclusively with reference to its observable physical > correlates. IOW this is possibly a paradigm case of the distinction between > correlation and causation. Yes, this is all I'm saying too! > The alternative - shorn of its uniquely a > posteriori relation with one's own consciousness - would be in effect simply > to accept that physical behaviour is its own 'explanation'. This is the > conclusion Brent urges on us and I can respect this position without being > content with it myself. Right, I can also understand Brent's positions. One of the reasons why I am not satisfied with such a position is that consciousness appears to be unnecessary from an intelligence / Darwinian standpoint. It appears that Darwinism + neuroscience/computer science can explain the emergence of our behaviour in non-conscious zombies. It has been argued that it could be a spandrel, a by-product of the evolutionary process. I have no problem with that -- in fact I am betting this is the case, because I doubt that a non-conscious human-level intelligence is possible. But I still want to know why. Every time a problem baffles us, and people suggest that: "look, it's just a brute fact", I can't help but feel that this stance is very akin to saying "the gods did it". One of the things I like about Bruno's work is that I fell that he, at least, provides a theory on why it looks so mysterious to us. What also baffles me is why some people can't see the mystery. I don't think this is the case with Brent though, I think he is a pragmatist -- which is a perfectly reasonable thing to be. > To go beyond this, as for example Bruno is attempting to do with the comp > theory, requires an explanatory schema that somehow manages both to > transcend and encapsulate the explication of conscious phenomena in > exclusively reductive terms. And to strip this move of any sense of > arbitrariness or avoidance of the problem we also need to show that this is > a necessary consequence of situating those phenomena adequately within a > tractable theory of knowledge. Such a theory will then focus on explicating > a characteristic logic of consciousness in terms of what is perceptible or > not, what is doubtable or not, what is communicable or not, and so forth. > And of course a crucial component of this must be the relation of these > categories to the dynamics of the necessarily correlated 'physics of the > observable'. Yes, this is something I would like to see Bruno talk about more: how he hopes to derive physics from his theory. > I have no problem with theories of mind, > but I am not sure that we can expect them to be validated or refuted > in the some way that other theories can be. > > > That's right. Not in the same way, but perhaps nonetheless, in principle and > with justification, to the extent that it can be said to be explained at > all. Yes. In the end, some weirdness is to be expected. After all, the attempt to understand consciousness amounts to something creating theory on itself. After all, we only have the first-person view. The third-person view of reality is an abstraction. Independently of one's position on MWI, comp, physicalism, idealism, etc, one only knows reality in the 1p. Trying to understand consciousness is trying to understand 1p from the 1p. If logic has taught me anything, it's that once you apply something to itself, strange things happen... > >>> Indirect measures of consciousness entail hidden >>> assumptions, and it becomes easy to beg the question. >> >> >> Which particular question did you have in mind? > > For example: does consciousness in humans supervene only on brain > activity? > > > Well, in the terms I've set out: Yes if you you mean the indispensable > necessity of covariance with the observable physics, which is to say the > spectrum of perceptible externality and its theoretical ontology.
Re: Answers to David 4
On 02 Jun 2017, at 00:29, David Nyman wrote:
On 1 June 2017 at 18:00, Bruno Marchal wrote:
On 01 Jun 2017, at 16:42, David Nyman wrote:
On 1 Jun 2017 15:20, "Bruno Marchal" wrote:
On 01 Jun 2017, at 15:59, David Nyman wrote:
On 1 Jun 2017 14:01, "Bruno Marchal" wrote:
On 01 Jun 2017, at 12:44, David Nyman wrote:
Yes, but doesn't the comp theory itself assume the relation as if
true, in order for mechanism to make sense (which was my caveat)?
The point here is very subtle. We cannot assume Mechanism is true,
we can only assume Mechanism. We can assume it as a sort of meta-
level hypothesis. It is indeed the reason why I insist on an act of
faith, and why it is a theology.
Now, you might ask me what is the difference between assuming X, and
assuming X is true. The difference is that when we assume X, but
don't invoke the full semantic of X, and we can preserve our
consistency. By saying "mechanism is true", even in an hypothesis,
you refer to the God of mechanism at a place that is impossible.
We have something similar, but slightly simpler, for the notion of
self-consistency. Take PA. It has 6 axioms + the infinity of
induction axioms
1) Ax (0 ≠ s(x))
2) AxAy (s(x) = s(y) -> x = y)
3) Ax (x+0 = x)
4) AxAy (x+s(y) = s(x+y))
5) Ax (x*0=0)
6) AxAy (x*s(y)=(x*y)+x)
7) the infinity) (F(0) & Ax(F(x) -> F(s(x -> AxF(x)
PA is consistent (I hope you are OK with this, as all mathematicians
are, except nelson)
Imagine I add to PA the axiom 8) PA is consistent. That is
8) consistent(1+2+3+4+5+6+7)
In that case there is no problem that new theory, PA+con(PA) is
consistent, and even much more powerful than PA. It proves new
theorems and it shorten many proofs.
But imagine we add the following to PA
8') consistent(1+2+3+4+5+6+7+8')
That is self-referential, but using the diagonal lemma (the D'X' =
'X'X'' trick), we can build that formula in arithmetic and add it to
PA as axiom.
In that case, we get a theory which can prove, indeed in one line
proof, its own consistency, and so, by Gödel II, that theory is
inconsistent.
The case above is more complex to describe, because it refers to
"arithmetical truth", which cannot even be defined in arithmetic. It
is almost the nuance between (Bp & p), and (Bp & V(p)). For each
partuclar p, you can write Bp & p, but you cannot define knowledge
by a general (Bx & x). It is the nuance between assuming that x + 0
= x, and using only that, and assuming True('x + 0 = x'), which
cannot be express in the arithmetical language.
Mechanism is awkward on this. Yet, this sustains your intuition
that the ultimate 3p, the outer God view, is a 0p pov.
"Out of sight, out of mind" as the proverb has it.
"Loin des yeux, loin du coeur", we say in french (which has not
exactly the same intent).
It works well with Plotinus idea that God does not exist, as it is
the ultimate reason why everything exists without mentioning ever
itself in the creation (making the idea that God can talk with us in
a direct public way nonsensical). Only the first person has access
to this, but can only stay mute.
Another example is that even if someone survives the classical
teleportation experience, he/she cannot claim that he/she knows that
mechanism is true.
OK
Still another example, even closer to what is alluded above is the
case of the notion of sigma_1 truth, or simply sigma-truth. The
notion of sigma-truth *is* definable in arithmetic, and the self-
referential sentences saying that she is sigma-true appears to be a
sigma proposition, yet it can be shown to be ... false! This is very
unlike the sigma proposition saying "I am provable", which is always
true! All this despite G* proves (sigma-true <-> sigma provable),
but again, only G* says this, the machine has to be mute.
The machine would appear to take Wittgenstein's dictum to heart.
But its guardian angel is able nonetheless to intuit a truth in what
it cannot say.
I would not use "intuit" for the guardian angel. he is not a subject.
just a machinery who knows everything about the machine(s). At the
propositional level, he knows/proves the whole truth about the self-
referential sentence. We know it is true, only because we limit
ourselves to true machine, by decision.
I cannot say "if mechanism is true then the truth of mechanism go
without saying", but I can say at the meta-level "If mechanism then
the truth of mechanism go without saying". I think.
Perhaps "if mechanism is true" is close to what Brent calls a
reification.
Hmm... Brent does not use "reification" correctly. He accused me of
reifying arithmetic, when I said that he reified primary matter. but
arithmetic is assumes, not reified in anyway. Primary matter is
reifed, as it is an appearance only, and its assumption is uded to
avoid solving a question. It is like "God made it".
To say "mechanism is true" is more a l
Re: substitution level
On 01 Jun 2017, at 19:38, Telmo Menezes wrote: On Thu, Jun 1, 2017 at 12:43 PM, Bruno Marchal wrote: On 31 May 2017, at 12:44, Telmo Menezes wrote: Creating a new thread to avoid causing decoherence on the other one :) What if the substitution level turns out to be at a higher level than quantum? E.g. at the level of the neurons and their connections and activations levels? That would enlarge the uncertainty spectrum on the realities we can access without losing anything subjective. It would help the doctor to build the artificial brain. It could also make more difficult to justify the smallness of Planck constant, and to explain why the quantum seems more obviously present in the micro-states, Decoherence would be easier to fight against, and quantum computing would be more easy to be realized. This lakes me think that the quantum level is boundary of the substitution level. This appears to be a testable hypothesis. I know that Penrose proposed a theory on the quantum effects inside neurons that turned ou to be problematic because of decoherence, but of course that doesn't mean that quantum mechanics might not play a much more holistic role in brain activity. I remember a presentation perhaps a decade ago by a neuroscientist at an artificial life conference, where she showed that neurons can operate in a chaotic regime. In fact, she claimed at the time that we did not have the computational power to accurately simulate a single neuron. To me, this suggests that the activation of neurons might be governed by much subtler phenomena than simple threshold effects. Perhaps it is conceivable that small scale quantum effects could propagate to the macro level of the brain. On the other hand, it is also true that artificial neural network models with just simple threshold neurons are already Turing complete, provided that one allows for recurrence. This proves nothing, but purely when worrying about neuroscince / artificial intelligence, I am a it weary of going for more complicated models when there is still so much to explore in the simpler ones... I say this while completely disregarding the hard problem. I have perhaps the unusual intuition that intelligence and consciousness are quite different issues -- I share that intuition when intelligence is used in the sense of competence. Ok. When I say intelligence I am thinking about systems that can increase, with some degree of success, the future value of an utility function. I came to believe that what people usually call intelligence is something that is fundamentally linked to Darwinian dynamics. In that case, consciousness, or conscience, might be at the antipode of intelligence. That feeling is strengthened when reading the news... I agree. We became the apex predator on this planet, and so competent in your sense of the word that we are effectively cancer. I believe we have the potential to transcend biology, but at the moment it seems that we are taking steps backwards. Society is becoming increasingly insane. Perhaps it's just how it works, some steps back are unavoidable. I share with you the ideia that prohibition is central to the disease, and I think that it is no coincidence that its current incarnation came out of fear of the hippies and their program -- in our sick society, being anti-war and pro-love is the most subversive stance that can be conceived. I take the liberty of sharing a very short video showing a guy that realised the fallacy of utility functions (perhaps with some chemical help :) https://youtu.be/vMhiDCZXU2k?t=7 although I doubt that it is possible to build a sophisticated AI that is not conscious (or even a simple one, I don't know). We have to distinguish Hameroff from Penrose. Hameroff believes/ assumes that the brain operates at the quantum level,. He assumes that it is a quantum computer. But a quantum computer does not violate the classical Church's thesis, and his hypothesis does not change the conclusion of Mechanism (although it makes more complex the derivation of physics a priori). I have to revisit OR and both Hameroff and Penrose on this. Apparently there is now some evidence for mcrotubules being shielded from decoherence? Regarding the quantum computer, I understand that it is still a classical computer, I guess you mean that it does not violate Church thesis. Of course, it can "do" things impossible to do in real time, or without emulating the subject, that a classical computer cannot do. For example, it can generate a genuine random bit. To do emulate this with a non-quantum computer, you need to emulate the duplication of the observer, like in the WM duplication. but with comp it would have consequences regarding our "insertion" in reality, so to say. Correct? I am not sure of what you mean exactly. It would not change the physics, but allow us to exploit more directly the FPI. I am completely agnostic on t
Re: substitution level
On Sun, Jun 4, 2017 at 1:20 AM, John Clark wrote: > On Thu, Jun 1, 2017 Telmo Menezes wrote: > >> > >> Regarding the quantum computer, I understand that it is still a >> classical computer > > > If a Human being like you, or any computer in existence today, > had a telephone number and tried to match it up with a name in a telephone > book that had one mullion entries you or the computer would have to go > through half a million operations before there was a 50% chance of finding a > match, but a quantum computer would only need a thousand ; it goes as the > square root of N not N/2. That ain't classical. > > In areas other than search, such as predicting the chemical properties of > large molecules, the advantage a quantum computer would have over a > conventional computer or the human mind would be even greater. Russell already replied and I agree with what he says. I am also very excited about quantum computers, and there's no doubt that more computational power leads to exciting things. For example, Google started a neural network renaissance mostly by employing models that were already known for some time, but adding a lot of computational power and large datasets to them. My point was simply that one cannot expect something qualitatively different from quantum computers. There is nothing that a quantum computer can do that a classical computer cannot do, given sufficient time. Telmo. > > John K Clark > > > > > > -- > You received this message because you are subscribed to the Google Groups > "Everything List" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to everything-list+unsubscr...@googlegroups.com. > To post to this group, send email to everything-list@googlegroups.com. > Visit this group at https://groups.google.com/group/everything-list. > For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
