On Wed, Oct 26, 2022 at 9:00 AM John Clark <[email protected]> wrote:
> On Tue, Oct 25, 2022 at 5:31 PM Bruce Kellett <[email protected]> > wrote: > > *> One of the main troubles with this is that the Copenhagen >> Interpretation, insofar as there is any such thing, does not entail that >> the wave function collapses when the result enters consciousness. This was >> a mad idea put forward by Wigner, and it was soon realized that the idea >> was just silly, and could never work. So that idea has long been abandoned. >> Deutsch's attempted proof involves comparison with an abandoned idea of >> quantum mechanics, so it doesn't really prove anything. Besides, the whole >> set-up involves assumptions about quantum computers and consciousness that >> are far from obvious, and probably not even correct.* >> > > OK, so forget about consciousness, the fact remains that If you see > interference bands on Deutsch's photographic plate then that would prove a > universe can split and, provided the difference between them is very small, > can under the right conditions become identical again and thus merge back > together. That is the key part of the multiverse idea and if it's true > then there is no need to indulge in the mumbo-jumbo of Copenhagen quantum > complementarity. > That is as much mumbo-jumbo as anything in Copenhagen. For instance, what determines if the difference between the worlds is small 'enough'? You are using the result of no divergence between worlds to conclude something about a divergence that probably never occurred. It is simpler to state that no measurement was made in the Deutsch set-up. Measurement, after all, involves irreversible decoherence, and such cannot be 'quantum erased'. So no which-way measurement would have been made in the Deutsch experiment. "Measurement" requires the formation of permanent records in the environment (and many copies of the result can be formed as well). So if the experiment was actually performed, what is your guess > would happen, what would you place your money on, would there be > interference bands on that photographic plate or would there not be? My > guess is that you would see interference bands, I would not bet my life on > it or even my house, but I would be willing to bet a week's salary. > I, too, would expect to see interference bands, because no which-way measurement would have been made in that set-up. 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 [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/everything-list/CAFxXSLQxCDUwLp%2BROQu5Rk0ApAeqJqcFaKgDV2FSOtzkebNXFw%40mail.gmail.com.
