Le mar. 19 avr. 2022 à 09:27, Bruce Kellett <bhkellet...@gmail.com> a écrit :
> On Tue, Apr 19, 2022 at 5:19 PM Quentin Anciaux <allco...@gmail.com> > wrote: > >> Le mar. 19 avr. 2022 à 09:14, Bruce Kellett <bhkellet...@gmail.com> a >> écrit : >> >>> On Tue, Apr 19, 2022 at 4:52 PM Quentin Anciaux <allco...@gmail.com> >>> wrote: >>> >>>> Le mar. 19 avr. 2022 à 03:20, Bruce Kellett <bhkellet...@gmail.com> a >>>> écrit : >>>> >>>>> On Tue, Apr 19, 2022 at 11:09 AM Brent Meeker <meekerbr...@gmail.com> >>>>> wrote: >>>>> >>>>>> On 4/17/2022 1:45 PM, George Kahrimanis wrote: >>>>>> >>>>>> Just as in Schroedinger's famous example with the cat, you need a >>>>>> "box" and an observer outside, in order to make sense of the cat being in >>>>>> an entangled superposition. Instead of a superobserver, we can do with an >>>>>> impersonal quantum description (in any chosen frame of reference), if you >>>>>> prefer. >>>>>> >>>>>> >>>>>> The only purpose of the box in Schroedinger's thought experiment was >>>>>> to put off the observers perception. Really the thought experiment is >>>>>> over >>>>>> when the radioactive decay occurs. That atom has transitioned to a >>>>>> different nuclear state which is entangled with and recorded in the >>>>>> environment. >>>>>> >>>>> >>>>> Yes. Schrodinger had the cat in a box to emphasize the idea that the >>>>> cat was in a macro-superposition of alive/dead. This misled Wigner to the >>>>> extent that he thought the state collapsed only when the box was opened. >>>>> All of this was made redundant when it was realized that decoherence >>>>> rendered the state definite almost instantaneously. Saibal makes the same >>>>> mistake when he claims that Alice, after her measurement, is still in a >>>>> superposition until Bob sees her result. The idea that the superposition >>>>> still exists since decoherence is only FAPP is something of a red herring >>>>> -- in MWI, Alice has branched according to her result into up and down >>>>> branches that no longer interfere. There is no macro-superposition. >>>>> >>>>> Bruce >>>>> >>>> >>>> It's because Saibal sees observers as "machine"... so until anything is >>>> recorded in the machine available memory... it's in a superposed state. >>>> >>> >>> I think you are referring to consciousness in quantum computers where >>> there is no decoherence. The trouble with this idea is that without >>> decoherence, no permanent memories can be formed, so it is difficult to >>> know what "observe" means in that context. In any ordinary machine, >>> decoherence is everywhere, so no superposition ever endures. Observers >>> cannot be in superposed states (observation requires the formation of >>> records, and that in turn requires decoherence, which destroys >>> superpositions.) Saibal refers to observation as "an algorithm". But >>> without specifying what runs the algorithm, his claim is devoid of meaning. >>> >>> Bruce >>> >> >> No I'm referring to consciousness as a "program" that can run on a turing >> machine... the consciousness is well defined and finite at each steps and >> can be represented as a big integer... and until the information from the >> "outside" reach the memory of that program, it's unique... even if the >> experiments has already been done and splitted the environment, the actual >> consciousness split occurs once the memory of the "consciousness program" >> is modified... until it actually records that fact. >> > > What use is that? > I'm explaining to you what Saibal is saying... an observer for Saibal is a machine. > You don't know that anything has happened until it has decohered and is > recorded. Being in a superposition is nothing special. everything that can > be represented as a vector (or ray) in Hilbert space is in an infinite > number of different superpositions all the time. There are an infinite > number of possible bases for the Hilbert space, and the state is a > superposition in all of these bases, except the one basis that is stable > against environmental decoherence. > > 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. > To view this discussion on the web visit > https://groups.google.com/d/msgid/everything-list/CAFxXSLRTDyBURgdHpVJ4v_%2BAYhVCLhKGd4vVg-bZji_su3EtNg%40mail.gmail.com > <https://groups.google.com/d/msgid/everything-list/CAFxXSLRTDyBURgdHpVJ4v_%2BAYhVCLhKGd4vVg-bZji_su3EtNg%40mail.gmail.com?utm_medium=email&utm_source=footer> > . > -- All those moments will be lost in time, like tears in rain. (Roy Batty/Rutger Hauer) -- You received this message because you are subscribed to the Google Groups "Everything List" group. 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