On Sun, Jun 17, 2018 at 6:42 AM, Bruce Kellett <bhkell...@optusnet.com.au> wrote:
> From: Jason Resch < <jasonre...@gmail.com>jasonre...@gmail.com> > > On Sun, Jun 17, 2018 at 12:12 AM, < <agrayson2...@gmail.com> > agrayson2...@gmail.com> wrote: > >> >> >> * why do you prefer the MWI compared to the Transactional Interpretation? >> I see both as absurd. so I prefer to assume the wf is just epistemic, >> and/or that we have some holes in the CI which have yet to be resolved. AG * >> > > > 1. It's the simplest theory: "MWI" is just the Schrodinger equation, > nothing else. (it doesn't say Schrodinger's equation only applies > sometimes, or only at certain scales) > > > Well no, it is an interpretation of the SE, involving the reification of > the wave function. So it is not 'just' the Schrödinger equation. > It is a theory, in that it is fully mathematical and makes predictions. Other so called interpretations CI etc. are not mathematical theories because they don't say when or why or under what circumstances Schrodinger's equation stops working. As Max Tegmark said: “I disagree that the distinction between Everett and Copenhagen is ‘just interpretation’. The former is a mathematical theory, the latter is not. The former says simply that the Schrödinger equation always applies. The latter says that it only applies sometimes, but doesn't given an equation specifying when it doesn't apply (when the so-called collapse is supposed to happen). If someone were to come up with such an equation, then the two theories would be mathematically different and you might hope to make an experiment to test which one is right.” You speak of reification of the wave function as if it is something special. In what other physical theory is something postulated one theory, and a different theory is when that same thing is postulated, but is also "really real"? Is the theory of quarks distinct from another theory of quarks that holds them to be really real? David Deutsch comments on the absurdity of this: “Schrödinger also”, David Deutsch notes, “had the basic idea of parallel universes shortly before Everett, but he didn't publish it. He mentioned it in a lecture in Dublin, in which he predicted that the audience would think he was crazy. Isn't that a strange assertion coming from a Nobel Prize winner—that he feared being considered crazy for claiming that his equation, the one that he won the Nobel Prize for, might be true.” > > 2. It explains more while assuming less (it explains the appearance of > collapse, without having to assume it, thus is preferred by Occam's razor) > > > Maybe the collapse is real. > But to assume this is like assuming there are invisible and undetectable "motive demons" operating within a car engine that are necessary to make the car engine work, when we have another perfectly valid way of explaining everything the car engine does without having to assume these motive demons. I don't see the point when we have a theory that explains all the facts before us. > > > 3. Like every other successful physical theory, it is linear, reversible > (time-symmetric), continuous, deterministic and does not require faster > than light influences nor retrocausalities > > > MWI is still a non-local theory. FTL influences or not, QM is > intrinsically non-local. > When you say non-local what type of non-locality do you mean? It is a local theory in the sense that physical objects interact only with other physical objects in their proximity, and carry information only at luminal or subluminal speeds. See Q12 on http://www.anthropic-principle.com/preprints/manyworlds.html > > > 4. Unlike single-universe or epistemic interpretations, "WF is real" with > MWI is the only way we know how to explain the functioning of quantum > computers (now up to 51 qubits) > > > Rubbish. The functioning of quantum computers is not dependent on MWI. > Many worlds is, after all, only an interpretation. Not the reality of > anything at all. > How do you explain the finite computational resources of a table-top quantum computer factoring a prime number in seconds when it would take a classical computer the size of the solar system 10^100 years to do the same calculation? David Deutsch notes that quantum computers present a strong challenge to defenders of single-universe interpretations, saying “When a quantum computer delivers the output of such a computation, we shall know that those intermediate results must have been computed somewhere, because they were needed to produce the right answer. So I issue this challenge to those who still cling to a single-universe world view: if the universe we see around us is all there is, where are quantum computations performed? I have yet to receive a plausible reply.” > > > 5. Unlike copenhagen-type theories, it attributes no special physical > abilities to observers or measurement devices > > > Which version of the CI are you referring to? There are as many > "Copenhagen Interpretations" as there are citizens of Copenhagen. Bohr's > original theory did not refer to observers or make experiments central. He > merely thought that quantum phenomena were understandable only in the > context of a classical world. > By CI theories here, I mean those that include collapse of the wave function (an irreversible, random, instantaneous event) being triggered by some nebulously defined measurement, observation, consciousness, etc. > > > 6. Most of all, theories of everything that assume a reality containing > all possible observers and observations lead directly to laws/postulates of > quantum mechanics (see Russell Standish's Theory of Nothing > <http://www.hpcoders.com.au/theory-of-nothing.pdf>, Chapter 7 and > Appendix D). > > > Unfortunately, Russell's attempt to derive quantum mechanics from the > plenum of all possible bit strings failed at the first step. So you don't > have much support from this. > I would be very interested to see this, do you recall the subject or time frame of this discussion? In any case, if Russell's derivation failed, there are other results that are other clues (e.g. from Bruno's UDA) which from the assumption of an infinite reality predicts several quantum phenomenon, including apparent randomness, non-clonability of matter, and evidence of infinite computations at work when we look at sufficiently small scales. > > > Given #6, we should revise our view > > > But we don't have #6. See the discussion I had with Russell on this list > some time ago. He had to admit that his derivation of QM failed. > > It is not MWI and QM that should convince us of many worlds, but rather > the assumption of many worlds (an infinite and infinitely varied reality) > that gives us, and *explains *all the weirdness of QM. > > > No, the weirdness of the violation of the Bell inequalities and > non-locality remains, even in MWI. > Bell had an implicit assumption in his reasoning, which is that only a single definite result is obtained by all parties for any given measurement (including those not performed). This is not true under MWI so Bell's reasoning that there must be non-locality fails for MWI, as many-worlds lacks contra-factual definiteness. Again from: http://www.anthropic-principle.com/preprints/manyworlds.html *To recap. Many-worlds is local and deterministic. Local measurementssplit local systems (including observers) in a subjectively randomfashion; distant systems are only split when the causally transmittedeffects of the local interactions reach them. We have not assumed anynon-local FTL effects, yet we have reproduced the standard predictionsof QM.* *So where did Bell and Eberhard go wrong? They thought that all theoriesthat reproduced the standard predictions must be non-local. It has beenpointed out by both Albert [A] and Cramer [C] (who both supportdifferent interpretations of QM) that Bell and Eberhard had implicityassumed that every possible measurement - even if not performed - wouldhave yielded a *single* definite result. This assumption is calledcontra-factual definiteness or CFD [S]. What Bell and Eberhard reallyproved was that every quantum theory must either violate locality *or*CFD. Many-worlds with its multiplicity of results in different worldsviolates CFD, of course, and thus can be local.* > > > This should overwhelmingly convince us of MWI-type everything theories > over any single-universe interpretation of quantum mechanics, which is not > only absurd, but completely devoid of explanation. With the assumption of a > large reality, QM is made explainable and understandable: as a theory of > observation within an infinite reality. > > > I think other possibilities are still available, and generally more > acceptable. > > MWI has problems of its own. Particularly with the preferred basis problem > and the derivation of Born's rule from within many worlds in a non-circular > way. > > Other theories don't even offer an explanation for Born's rule. MWI at least offers several plausible answers, such as Gleason's Theorem. Regarding preferred bases, both of the papers I provided which began this thread address that question: https://arxiv.org/pdf/1104.2324.pdf > * Note that quantum interferences between different terms in Eq. (39) are > extremely small, since overlaps between macroscopically different > configurations, such as and , are suppressed by the huge dimensionality of > the corresponding Hilbert space. In fact, for any observables constructed > out of local operators, matrix elements between macroscopically distinct > states are highly suppressed, This, therefore, provides preferred bases for > any macroscopic systems.* and https://arxiv.org/pdf/1105.3796.pdf > *Decoherence Decoherence1 explains why observers do not experience > superpositions of macroscopically distinct quantum states, such as a > superposition of an alive and a dead cat. The key insight is that > macroscopic objects tend to quickly become entangled with a large number of > “environmental” degrees of freedom, E, such as thermal photons. In practice > these degrees of freedom cannot be monitored by the observer. Whenever a > subsystem E is not monitored, all expectation values behave as if the > remaining system is in a density matrix obtained by a partial trace over > the Hilbert space of E. The density matrix will be diagonal in a preferred > basis determined by the nature of the interaction with the environment* *This preferred basis is picked out by the apparatus configurations that > scatter the environment into orthogonal states. Because interactions are > usually local in space, ρSA will be diagonal with respect to a basis > consisting of approximate position space eigenstates. This explains why we > perceive apparatus states |0iA (pointer up) or |1iA (pointer down), but > never the equally valid basis states |±iA ≡ 2 −1/2 (|0iA±|1iA), which would > correspond to superpositions of different pointer positions.* Jason -- 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.
