On Wednesday, April 13, 2022 at 8:55:48 PM UTC+3 [email protected] (Brent) wrote:
Decoherence has gone part way in solving the when/where/what basis > questions, but only part way. > As I wrote at the end of my first reply to your message, I share your concern about decoherence but I see the glass as half-full; that is, with a little more subtlety I hope that the matter can be formulated in clear terms. Surely collapse is easier to handle as a general concept (except, on the other hand, that it requires new dynamics). I forgot to mention that *my argument for deriving the Born Rule works with collapse, too* -- so it is an alternative to Gleason's theorem. Here I define colapse as an irreversible process, violating unitarity of course, and I keep it separate from randomisation. The latter means that each outcome is somehow randomised -- an assumption we can do without. *Collapse can also be described in a many-world formulation!* It differs from the no-collapse MWI only in being irreversible. My argument in outline is 1. assessment that MWI-with-collapse is workable; 2. therefore, outcomes of small enough measure can be neglected in practice; 3. now Everett's argument can proceed, concluding that the Born Rule is a practically safe assumption (to put it briefly). So I have replaced two assumptions of Gleason's theorem, randomisation and non-contextuality, by the assessment of workability only. If you don't feel comfortable yet with formulating collapse in a many-world setting, let us also assume randomisation (God plays dice), for the sake of the argument, in a single-world formulation. That is, we ASSUME the existence of probability; then the previous argument just guarantees that this probability follows the Born Rule. Of course I favour the first version of the argument, using the many-world formulation of collapse, to avoid the "God plays dice" nightmare. Thanks for the comments so far, because they stirred my thinking and motivated fresh ideas, some of which I hope will prove helpful and worth discussing, if and when they mature. George K. -- 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/06930c0c-5537-4fb7-bf70-fd8c7d9859b0n%40googlegroups.com.
