On Monday, June 11, 2018 at 7:39:45 PM UTC, [email protected] wrote: > > > > On Monday, June 11, 2018 at 4:19:34 PM UTC, Bruno Marchal wrote: >> >> >> On 11 Jun 2018, at 12:59, [email protected] wrote: >> >> >> >> On Monday, June 11, 2018 at 10:40:13 AM UTC, Bruno Marchal wrote: >>> >>> >>> On 11 Jun 2018, at 07:06, [email protected] wrote: >>> >>> >>> >>> On Monday, June 11, 2018 at 2:20:47 AM UTC, [email protected] wrote: >>>> >>>> >>>> >>>> On Monday, June 11, 2018 at 2:09:25 AM UTC, Bruce wrote: >>>>> >>>>> From: <[email protected]> >>>>> >>>>> On Monday, June 11, 2018 at 1:37:53 AM UTC, Bruce wrote: >>>>>> >>>>>> From: Bruno Marchal <[email protected] >>>>>> 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* >
*In the real world the cat is never isolated, nor can it be isolated insofar as it consists of a huge number of particles already entangled with its environment. This is the meaning of "macro" ! If you insist on imagining it as isolated for your thought experiment, you will generate a paradox, as Schroedinger did. 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 [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.
