On Monday, June 11, 2018 at 4:19:34 PM UTC, Bruno Marchal wrote: > > > On 11 Jun 2018, at 12:59, agrays...@gmail.com <javascript:> wrote: > > > > On Monday, June 11, 2018 at 10:40:13 AM UTC, Bruno Marchal wrote: >> >> >> On 11 Jun 2018, at 07:06, agrays...@gmail.com wrote: >> >> >> >> On Monday, June 11, 2018 at 2:20:47 AM UTC, agrays...@gmail.com wrote: >>> >>> >>> >>> On Monday, June 11, 2018 at 2:09:25 AM UTC, Bruce wrote: >>>> >>>> From: <agrays...@gmail.com> >>>> >>>> On Monday, June 11, 2018 at 1:37:53 AM UTC, Bruce wrote: >>>>> >>>>> From: Bruno Marchal <mar...@ulb.ac.be >>>>> Everett prove the contrary, and he convinced me when I read it. I >>>>> found “his proof” used in many books on quantum computing, although with >>>>> different motivation. Thee result of an experiment, obviously depend of >>>>> what you measure, but when you embed the observer in the wave, you get >>>>> that >>>>> what they find is independent of the choice of the base used to describe >>>>> the “observer” and the “observed”. If not, the MW would already be >>>>> refuted. >>>>> >>>>> >>>>> In that case, MW is refuted. Clearly, what the observer finds is >>>>> dependent on the basis in which he is described. Or else experiments >>>>> would >>>>> not have definite results when described in the laboratory from the 1p >>>>> perspective. Even if you take the 'bird' view of the whole multiverse -- >>>>> which is, I agree, independent of the basis in which it is described -- >>>>> the >>>>> view of any observer embedded in the multiverse is totally >>>>> basis-dependent. >>>>> That is, after all, what we mean by 'worlds' -- the view from within, or >>>>> the 1p view. But that view depends on how you describe it: the way in >>>>> which >>>>> you partition the multiverse itself. Only certain very special bases are >>>>> robust against environmental decoherence -- how else do you resolve the >>>>> Schrödinger cat issue? >>>>> >>>>> Bruce >>>>> >>>> >>>> *So you find the resolution in the fact that according to decoherence >>>> theory, the cat is simultaneously alive and dead for only short time? AG* >>>> >>>> >>>> Decoherence has resolved the basis question long before the cyanide has >>>> hit the cat. >>>> >>>> Bruce >>>> >>> >>> *I don't think you've answered the question. Isn't the cat in a >>> superposition of alive and dead before the cyanide hits? Did Schroedinger >>> write an incorrect wf? If so, what is the correct one IYO? AG * >>> >> >> *I surmise your position is that decoherence happens so quickly, that the >> superposition Schroedinger wrote was really a mixed state. If so, I don't >> see this as a solution to the paradox, unless you want to allow the >> existence of a simultaneously alive and dead cat for a very, very short >> time. AG* >> >> >> >> That is why I prefer Bohm’s version of the cat, where the cat alive/dead >> state is corrupted with the up/down state of some particles. It ease the >> mind by showing that the time is not an issue. If you can completely >> isolate the cat from the environment (which is technically impossible), you >> can maintain the cat in the dead + alive superposition state as long as you >> want. If you isolate successfully the entire laboratory including you, >> Then, someone else can resurrect the cat, relatively to himself, despite >> you saw it dead. >> >> The reason why we cannot do this in principle, is that we cannot isolate >> the cat, and if the cat, when the cat is dead+alive, interact with some >> particles in the environment, you can no mare factorize the cat state, >> without tracking that particles. >> >> I don’t think it make sense to confine the superposition in the >> microscopic domain, nor in the short-time domain. If the SWE is correct, >> the superposition never disappear, unless a collapse assumption is made, >> but then it cannot be described by QM. Only by QM + exception rules for the >> observer or the measuring apparatus, but there are no evidences for that. >> >> Bruno >> > > *See my solution to the S Cat on the other thread. Since the cat can > never be isolated, it can never be in a superposition, which generates the > paradox. And since coherence can never occur, no need to apply > decoherence! AG* > > > > I am not sure this make sense (with the SWE). The cat is always isolated, > in some sense. >
*IMO totally wrong. In fact now you're contradicting what you wrote in a recent post. The cat is NEVER ISOLATED, VIRTUALLY BY DEFINITION OF WHAT MACRO MEANS. NEVER ISOLATED IMPLIES NEVER IN A SUPERPOSITION. AG*[snip] -- 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.
