On Thu, Oct 27, 2022 at 5:05 PM Brent Meeker <[email protected]> wrote:
*> as pointed out by Carroll in his explication of the delayed choice > quantum experiment, "...make the measurement you program it to produce a > document saying it has knowledge of which slit the electron went > through..." this can't be a real measurement, because that would imply a > record of it. * But there *WAS* a record of which slit the electron went through when the document was written, that is how the machine got the information that enabled it to say it knew which way the electron went. It was only after that the information was erased. *> If it done just by correlating with a quantum variable that can be > erased it's not a measurement. * Then why did the computer that you programmed say a measurement had been done? Any information can be stored quantum mechanically and if a computer stores that information quantum mechanically, which conventional computers do not do, then that information can be erased. * > Deutsch's whole idea depends on it being conscious of this measurement > because that obfuscates what can and can't be erased. * No. The only reason Deutsch mentions consciousness is that some rival theories to Many Worlds think consciousness has something to do with the question at hand, but if you're like Deutsch and me and believe consciousness is irrelevant when talking about the foundations of quantum mechanics then forget about consciousness and think about the computer as just a scientific instrument that works on quantum mechanical principles. *> It's trivial to hook up a machine that just prints out "I measured it."* Obviously, but do you really think that's what Deutsch was proposing, do you really think he's that stupid? Instead you program the computer to perform the best measurement possible, and if it is able to determine which slit the electron went through the machine writes a document saying it knows which way the electron went through, but of course it does not specify which slit that was; and if for some reason it is unable to make the measurement it writes a document saying it was unable to make that measurement. Then after the electron passes through the slits but before it hits the photographic plate the witch-way information is erased. So when the photographic plate is developed and if you see interference bands then you know there must be other worlds than this one, and if you don't see interference bands then the Many Worlds idea is bullshit. *> You forget things and so you could measure something and then remember > you measured it but forget the value, but you can't quantum erase the value > measured...it just got decohered.* Decoherence usually spreads with enormous speed but if things are arranged very carefully, if only one electron in the universe got decohered, then it's possible the electron could become re-cohered because in the Many Worlds theory it makes no sense to talk about two identical universes, so if the witch-way information of that electron has been erased then there's no longer any difference between the two universes and they merge back together. John K Clark See what's on my new list at Extropolis <https://groups.google.com/g/extropolis> u6g > -- 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 view this discussion on the web visit https://groups.google.com/d/msgid/everything-list/CAJPayv2-Rf6%2B%2BXFPuRdbU3M2oVK2ov8D9CwFTeaEknfR6Utb%2Bw%40mail.gmail.com.
