I am not going to argue for MWI particularly, though I will say a bit next paragraph. The idea there are retro-causal influences that underlie apparent quantum nonlocality is simply wrong. The Kochen-Specker theorem illustrates limits on hidden variables, which means a measurement of an observable must be context dependent. In other words the orientation of a Stern-Gerlach apparatus is something determined by a classical observer and not by quantum mechanics. The four dimensional version of the KS theorem involves the 24-cell and its associated Lie group F4. It is curiously less complicated than the standard 3 dimensional version of the KS theorem. The 4-dim version illustrates why it is not possible to replace QM with some subquantal wiring in four dimensions --- such as retrocausality. To assume a retrocausal structure is to say that an 8 dimensional manifold is equivalent to that manifold embeded in one dimension larger. In other words 8 = 9, which is a contradiction.
The MWI may have connections to the multiverse. Susskind and others have speculated on this. It is not clear though whether this is that solid in its conclusion --- even just on a theoretical level. The type-I multiverse has regions on a flat spatial surface that replicates other regions, where there could be other Earths with all of us, but with differences that are associated with MWI eigenbranching of histories. These regions must of course be causally isolated from each other, lest we admit quantum cloning. This might extend to type II multiverse with different cosmologies entirely that are related to our world by MWI eigenbranching. I am not so sure about these things, though I don't dismiss them. I have some issues with all quantum interpretations, and they all appear incomplete. With MWI the problem is there is no mechanism for assigning the point of an eigenbranch event. If you have the quantum amplitude for the decay of a radioactive isotope there is nothing in that process to indicate where a decoherent event should occur that in MWI corresponds to this eigenbranching. In MWI there is then this yggdrasillian branched world, corresponding potentially to the multiverse, but there is nothing in QM which tells us how the observer or the phenomenological frame of the world is split onto different paths. LC On Saturday, November 25, 2017 at 11:00:46 PM UTC-6, [email protected] wrote: > > > > On Sunday, November 26, 2017 at 2:33:16 AM UTC, [email protected] wrote: >> >> >> >> On Saturday, November 25, 2017 at 11:24:36 PM UTC, John Clark wrote: >>> >>> >>> > The quantum concept of "things only exist when I look at them" originates > in the double slit experiment, and is sort-of limited to situations of this > type. To calculate the probabilities correctly as Feynman clearly explains > in his Lectures, one must calculate |A + B|^2, not (|A|^2 + |B|^2), the > latter being OK for classical physics, where A and B are the wf's or > amplitudes entering slits A and B respectively. Think of the electron or > photon as waves when we don't look, going through both slits and as > particles when observed. One way to interpret the first term is to say, > "The system is in both A and B states simultaneously, not in either state > exclusively." But regardless of the words chosen, one must use the first > calculation to make correct quantum predictions. Moreover, AFAIK, the MWI > does not avoid this conclusion even if it uses different words. In sum, to > make the general claim that QM says "things only exist when I look at them" > is misleading, and for most situations like macro events, simply wrong. AG > >> >> >>> But it really doesn't matter, >>> as long as there is no logical self contradiction there is nothing >>> wrong with bizarre >>> . >>> Occam's razor doesn't say we should embrace the least bizarre theory >>> , >>> it says we should embrace the simplest theory >>> , >>> and >>> one that doesn't need to explain the collapse is simpler than one that >>> does. >>> >>> Unlike Copenhagen Many Worlds has no need to to explain how when or why >>> the wave function collapse >>> s >>> because the hypothesized collapse has no observable consequences. The >>> wave collapse is a needless complication that does nothing but get rid of >>> the multiverse for people who don't like the idea of a multiverse, its >>> wheels within wheels rather like the epicycles of old for people who didn't >>> like the idea of the planets going around the Sun rather than the Earth. >>> >>> The wave function says the multiverse exists, to get rid of it >>> additional complications are needed and those complications do not improve >>> the ability to predict experimental results one bit >>> , so they have no point. >>> >>> >> >> You keep ignoring the obvious 800 pound gorilla in the room; introducing >> Many Worlds creates hugely more complications than it purports to do away >> with; multiple, indeed infinite observers with the same memories and life >> histories for example. Give me a break. AG >> >>> >>> 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 [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
