> On 7 Jul 2018, at 01:54, Bruce Kellett <bhkell...@optusnet.com.au> wrote: > > From: Bruno Marchal <marc...@ulb.ac.be <mailto:marc...@ulb.ac.be>> >> >> On 6 Jul 2018, at 14:18, Bruce Kellett <bhkell...@optusnet.com.au >> <mailto:bhkell...@optusnet.com.au>> wrote: >>> >>> From: Bruno Marchal <marc...@ulb.ac.be <mailto:marc...@ulb.ac.be>> >>>> On 5 Jul 2018, at 17:20, Lawrence Crowell >>>> <goldenfieldquaterni...@gmail.com >>>> <mailto:goldenfieldquaterni...@gmail.com>> wrote: >>>> >>>>> John Bell proved that any objective theory giving experimental >>>>> predictions identical to those of quantum theory is necessarily nonlocal. >>>> >>>> Assuming a unique reality. I prefer the term “inseparable”, because >>>> “non-locality” is often interpreted the existence of FTL influence (even >>>> if they cannot be used to transmit information), but such FTL influence >>>> seems to me suspicious. Some might disagree, but I have not yet seen a >>>> proof that any FTL subsists when we abandon the collapse postulate. Bell >>>> assumes that experiments gives univocal results. >>> >>> You might not have seen a proof that non-locality remains when we abandon >>> the collapse postulate, but that does not mean that no such proof can be >>> given. >>> >>> Consider the following scenario. Alice and Bob are given a large number of >>> entangled pairs, which they measure when they are at large spacelike >>> separation. Each measurement is made at some angle, and gives a '1' for >>> 'up' or 'passed', and '0' for the opposite result. Both record the sequence >>> of such results that they obtain in their individual lab books, together >>> with the corresponding polarizer orientations. Their lab books then contain >>> a random sequence of say N, '1's and '0's. There are 2^N possible such >>> sequences in the many-worlds case, but since each observer keeps the same >>> lab book for the whole sequence, each series of measurements is necessarily >>> made in the same one world. >> >> I am not sure I understand the idea of being in the same world when >> space-like separated. > > Who said anything like that?
You it seems to me, if only to say that Bob and Alice (but which one) will measure correlated spins, by sharing an EPR channel. But with Everett pr even just with computationalism you have first person aches only to your the Alice (res. Bob) you can access in the future. You would need a very special decoherence to be able to meet the “physically” original Bob (which I am not sure is not even definable). That is why in quantum teleportation of one qubit, they still need the information on which partition of the multiverse they are in, and this requires at least two classical bits. In Everett + any reasonable quantum theory of space, states are relative, not to the environment, which makes no sense, but to the locally accessible environment. A wave is always the sum of its front local wave, similarly, withe universal wave, our current worlds get shared by the accessible others at the speed of light. > They end up in the same world when they meet. I have some doubt that this makes sense. > Or do you disagree with that as well? Yes. > >> Each time one of them makes a measurement, they are localising themselves in >> different worlds. The pair state only entails that their measurement will >> fit accordingly, > > How? Because they have to share information at at least one “space-time” point. They don’t which branch they share, but they know they share it for sure. > You are just assuming the non-local result that you are claiming is local. > You are not consistent. The point is that the apparent non-locality is an illusion because we think that Alice and Bob are “world-identifiable”, but with the relative sate theory (in QM or arithmetic) that does not make sense. You are using a mind-brain identity thesis too strong, for both QM or or just Mechanism. > >> but Alice will meet the Bobs she is correlated with, and vice versa. It does >> not make sense to say that Alice will meet the original Bob, or something >> like that. > > Who is the original Bob? You are starting to sound like John Clark in > refusing to accept the consequences of duplication. In your duplication > thought experiments (as in step 3 of the UDA) you talk about each duplicate > keeping a diary and recording W or M as appropriate. OK. > After a long sequence of duplications, each resulting copy will have a diary > with a long sequence of Ws and Ms at random. Nice to ear that. > This is exactly what is happening with the lab books in my example above. One > copy of Alice meets with one copy of Bob. But when they meet, they are in the > same world, and their lab books record the experiences of that particular > realization of the long chain of Alices and Bobs. You should remember that > there are 2^N such chains of experiences, and after the 2^N runs of the > experiment, when any Alice copy meets the corresponding Bob copy, the same > argument holds-- they are in the same world, and their lab books record the > sequence of results that the obtained in the world that they happen to > inhabit. I know it is shocking, because this leads to a short-timed solipsism. But some experience by hardy, mixing temporal and spatial violation of Bell’s inequality suggest this has to happen, to keep up covariance and locality, indeed. It is shocking, but computatdnalism simply predict this, and quantum mechanism, once we abandon the collapse and all attempt to add something to avoid the simplest explanation, we might accept that hard to avoid, and somehow experienced short-timed solipsism. The difficulties disappears if you abandon the notion of worlds, use notions like partial sharable histories, and distinguish between the sharable and non sharable histories. > > >>> Basically, this is because the worlds are disjoint, and the observers >>> and/or lab books cannot move between worlds. >> >> Any measurement entails new differentiation. >> >> >>> When Alice and Bob meet up at the end of the run of N trials, >> >> Each of Alice and Bob will meet only the Bob and Alice prescribed by the >> result of their measurement. You need to look at the entire wave function. > > Why? An Alice copy meets a Bob copy and they compare notes. Any time this > happens the results in their lab books must confirm the quantum correlations. > Or do you not agree with this? I agree. But the correlation comes from the fact that alla Alice and Bob share the same set of relative sates, which spend the whole multiverse, the share the same relative ignorance; but this means Alice and Bob are undetermined on some infinite sets, and no “absolute measurement” will ever set the question, the continuations are set by the local interactions only, in each of those histories where they share the ignorance, but resolves it locally only by multiplying themselves in the covariant (and computationally consistent) continuations. > The trick is to understand how this happens. You are not giving an > explanation -- you are relying on some unspecified magic! I am relaying only on the SWE + special relativity. Here. But with mechanism, the observable is also, at first sight, a locally local things, which means that the physical is mainly only determined by the ignorance of which computations we belong among those below our substitution level. I am not sure if this does not entail that the substation level is Planck length or not. > > >>> they take their lab books with them. When they meet they are clearly in the >>> same Everettian branch. >> >> “They” is ambiguous here. > > Think about it and the ambiguity will disappear. "They" are any of the 2^N > copies of Alice and Bob. (But the copies are, themselves correlated.) Nice. That is what I am talking about. It is only their consciousness which locally decoder all this from their relative state point of view. The quantum vacuum is a quantum universal dovetailer, the question is why the exceptional group, why unitary matrices. Better to extract this from self-references in all computations, because it helps to distinguish what is sharable and what is not. > > >>> And since their lab books cannot have jumped between branches, the sequence >>> of results that they each bring must also have all been recorded in this >>> same one branch. So when they come to use their data to calculate the >>> correlations between the measurements on their individual particles of the >>> entangled pairs, they are in exactly the same situation as they would be if >>> they had assumed a collapse model from the outset. >> >> It is like they find themselves in the relevant partition of the mutilverse, >> but as there has not been any collapse, nothing has needed to propagate >> after than light. The non-locality, or better inseparability, > > You are choking on words. Non-locality just means that the state is not > separable, so what happens at one end affects the other end. If there is a > FTL interaction, that is a non-local hidden variable. But as Saibal points > out, there is no proof that there must be hidden variables -- there is just a > proof that there is non-locality, whether or not you want to explain that > with hidden variables. I prefer to not introducing hidden variable other than our local ignorance on which computations or “branches of the universal wave” our consciousness differentiate upon. As long as you don’t invoke events without cause, that is a god, I will follow you. If you agree that there is no FTL, there is no problem at all. I certainly believe in non-locality, and unless a number conspiration, such observable/testable non locality is virtually a prediction of computationalism, as you can bet when translating the simplest Bell inequality in the orthormodular lattice we have already n the material hypostases. > > >> just assures that whatever differentiation will occur locally, they will >> have the correlated spin, > > That is what the non-locality or non-separability gives you. I think you are > just choking on the word "non-local". It doesn't have to mean FTL, Then OK. I thought all along that you were saying that there are FTL in single world.branch.history. > you know -- it could just be magic. ? It is what QM predicts for the average relative state of physical Turing machine observers. And probably QM itself is retro-predicted by the sum on all computations, not just the quantum one. The quantum is only elementary arithmetic or elementary thought self-applied. > Or space and time are not what we think them to be. You can say that. > > >> but at no point are we assured that Alice meet something like the original >> Bob. The differentiation of the universe develops locally. Once Alice and >> Bob are space-light separated, they will never meet again after they made >> local measurement. > > What utter and complete twaddle. You force me to look for some translation. What means “twaddle”? Hmm I see "trivial or foolish speech or writing; nonsense”, or, in French “fadaise”. Let me tell you that the physicist in me assume covariance. Then, this, or something like this, when all terms are disambiguated, comes to the same things. > You are spacelike separated from your wife when you each get up in the > morning. Do you really think that this means that you can never meet her > again? It means I don’t know her, really. > > >> Each will meet only the corresponding (correlated) person, but there is no >> reason we can identify them in any single word. > > So your wife is a different person each time you meet her? You are lost in > word salad again. Maybe, or it is you which is in the world salad. Note the “l”. > >> >>> The correlations they observe are necessarily single-world correlations. >> >> That comes true after their measurement. But the world have differentiated >> before. >> >>> So the conditions of Bell's theorem are exactly satisfied, >> >> I don’t think so. All outcomes are realised (assuming the singlet state, and >> measurement in any direction). Each Bob and Alice have localised themselves >> in the corresponding branches, and will met only their corresponding >> partners, due to the local further separation obtained by their local >> measurement. That is inseparability. It does not require simultaneous action >> at a distance. > > Who said it did? Non-separability is the same as non-locality. Neither > implies FTL transfer of a physical messenger. That is not what where saying in many previews post. I said only this; quantum mechanics + collapse entails FTL, and. Without collapse, nor addition like potential guides of “particles", there is no more FTL. It looks like we agree completely, and I think this is not the first time. You did use once non-locality as implying FTL. > > >>> and since the correlations violate the Bell inequalities, their experiment >>> has demonstrated the impossibility of a local hidden variable account. >> >> I agree with this. That is indeed why a world or an entire history is more >> like a global “hidden variable”, making sense of those correlation in a >> local way, with differentiation occurring locally, but always ensuing the >> existence of the correlation. > > You just claim that it is local because you have not understood what is > really going on. Playing with words, yet again. > > >>> They have demonstrated that the quantum correlations require non-locality, >>> even with Everett's many-worlds, just as Bell proved. >> >> I can be OK with this conclusion, unless you imply that in Everett there is >> still something travelling faster than light. > > Where do I claim such a thing? You should remember that Maudlin wrote a whole > book on the reconciliation of non-locality with special relativity. Everett's > many worlds does not achieve this reconciliation. ? It does, completely, unless you keep nonsensical person-body identity theses. You come back with Everett is still FTL? You begin to loss me. > >>> >>> And all this happens whether they assume many-worlds or a collapse model. >> >> The collapse, if taken in its usual non local (instantaneous) sense, that >> Einstein criticised already in 1927, would need to act FTL to explain the >> correlation. But that is not needed in Everett. The states are relative to >> each others, and further measurement are themselves propagating locally, >> ensuring than all the many Alices and Bobs will have their spins correlated, >> but they are no more necessarily related to the original Bob and Alice in >> any univocal way. > > It is always accepted that information is transmitted by classical means at > less than the speed of light. Decoherence means that entanglements spread at > the speed of light or less. And, as explained in Everett; decoherence is only relative entanglement. > This is true, that is why the correlations of non-separable, non-local states > are hard to understand. Many worlds does not resolve the issue. Because you stick to an identity thesis which does not make sense already with just computationalism. I think. > Everett has not solved anything, as my account of the experiment proves > beyond doubt. Only by invoking some magical world, which might indeed not make sense with QM and/or Indexical Digital Mechanism. Bruno PS I read the sequel of Posts. I am, and computationalism “well understood” is, closer to Brent’s understanding of Zurek than yours Bruce. This should be clear from this post. > > 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 > <mailto:everything-list+unsubscr...@googlegroups.com>. > To post to this group, send email to everything-list@googlegroups.com > <mailto:everything-list@googlegroups.com>. > Visit this group at https://groups.google.com/group/everything-list > <https://groups.google.com/group/everything-list>. > For more options, visit https://groups.google.com/d/optout > <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. 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