On Mon, Oct 14, 2019 at 6:22 PM 'Brent Meeker' < [email protected]> wrote:
>>This is physics not mathematics, the Born rule isn't derived it's >> observed, and it's observed to work. > > > * > But then MWI can't claim to be simpler and "purer" than CI. * > CI says the laws of physics work one way if a system is not observed and another way if it is observed, and it never makes clear what observed means. The MWI says the laws of physics only work one way and it makes crystal clear what observed means. And I don't know about purer but MWI is certainly simpler than interpretations that are compelled to add extra terms to Schrodinger's Equation that, other than get rid of other worlds, do nothing but complicate a already hideously complicated calculation. > >> I like Many Worlds because it gives me a little intuitive >> understanding why we can only make probabilistic predictions even though >> the underlying mathematics is completely deterministic, and I like it >> because it gives a precise definition of "measurement". > > *> That your consciousness becomes correlated with an eigenvalue of some > Hermitean operator?* > No. > > Does MWI define when a measurement has taken place or not? > It does. > > *What is this precise definition of which you write? * > Oh for christ sake! As I've said over and over, in Many Worlds a change, any change, is equivalent to a measurement and it doesn't make the slightest difference if that change involves consciousness or not. If Brent Meeker flips a coin and it comes out heads then obviously that Brent Meeker is not living in the world where it came out tails. In the same way if you do the two slit experiment and the photon goes through slit A then you are not living in the world where it went through slot B, but the 2 slit experiment can be a little different from the simple coin toss example. If after the photon makes its decision on which of the 2 slits to go through it then hits a photographic plate then both photons in both universes are destroyed and thus there is no longer any difference between the two, so the universes will merge back together. So in that newly re-merged universe there will be ambiguity about which slit the photon actually went through which is why that photon will contribute to the interference pattern that shows up on the photographic plate. The important thing is that the photographic plate destroys the photon in both universes so you could replace the plate with a brick wall and the same thing would happen, it would just be harder to tell that something funny was going on. However if you had a detector next to each slit and sent information on which slit the photon went through to your computer then there would still be a physical difference between universes even though the photon no longer exists in either, one universe would have computer in it with a few magnetic spots on its disk drive indicating the photon went through slot A but in the other universe the magnetic spots would be in a slightly different place indicating slot B, so the universes remain different, so they don't remerge, so there is no ambiguity in either universe, so neither universe will see a interference pattern. Universes don't usually merge back together because the differences between them usually accelerates so it's astronomically unlikely they will ever become identical again, however a skilled experimenter can make the change to be very small and then can gently nudge them back together. If you got rid of the film (or the brick wall) and let the photon head out into infinite space after it passed the slits then the universes, and you, will split and never recombine, and so of course you will see no interference effect. The beautiful part of the theory is that it doesn't have to explain what an observer is and that's why a brick wall will work just as well as a photographic plate. John K Clark -- 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/CAJPayv3r2rArz_2m4ydRK9oz1u87aGg4WChfPg1mcKdKHgEOGw%40mail.gmail.com.
