On Sun, Feb 23, 2020 at 7:17 AM 'Brent Meeker' via Everything List < [email protected]> wrote:
> On 2/21/2020 10:31 PM, Bruce Kellett wrote: > > On Sat, Feb 22, 2020 at 4:50 PM 'Brent Meeker' via Everything List < > [email protected]> wrote: > >> Yes, Zurek is hard to follow since he seems to use unusal terminology >> sometimes. Attached is a good discussion of his method by Schlosshauer and >> Fine which I find useful >> > > Yes, Zurek is sometimes quite opaque, and I found the Schlosshauer-Fine > discussion of Zurek's additional, hidden, assumptions useful. In their > conclusions, they state: "We cannot derive probabilities from a theory that > does not already contain some probabilistic concept; at some stage, we need > to 'put probabilities in to get probabilities out'." > > This is perhaps my basic worry with Zurek, as with other attempts to > derive the Born rule from the SWE. Zurek simply assumes that probabilities > are relevant, and necessarily a property of the quantum state -- the > amplitudes are then an obvious place for these probabilities to reside. > Everything else then follows. But this is not a derivation without > additional assumptions: where did the probability notion creep in? If you > take the SWE straight, the amplitudes (coefficients) just go along for the > ride and have no influence at all on the final state after measurement. > > I have always found this a worrying aspect of Everett. > > > But isn't that just a matter of it's proponents overselling it. If you > say, well it's a probabilistic theory, then that the Born rule is the way > to get a probability is fairly compelling. > Many-world proponents certainly oversell Everett. I have not seen anybody admit openly that there is a problem with getting probability into a deterministic theory so it just has to be put in by hand. If, as you say, people admit that what they really want is a probabilistic theory, even if they have to force it in by hand, then at least some of the arguments for the Born rule make sense. But if you insist that your theory is pure SWE/Everett, then all attempts at deriving the Born rule from this deterministic position fail. The arguments that I have developed here, based on Kent's insight, take Many-worlds at face value. Then the theory is clearly incoherent, or at least incompatible with observation. However, if you take a classical deterministic theory, such as Bruno's WM-duplication thought experiment, then there is no way you can sensibly interpret such a theory probabilistically. 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/CAFxXSLSBAiF0P%2BLUAZSpS4m2QabhjKUy7jLsEXhwQ6Esaw%3DiGQ%40mail.gmail.com.
