On Sun, Jul 4, 2021 at 9:18 PM 'Brent Meeker' via Everything List < [email protected]> wrote:
> > On 7/4/2021 6:13 PM, Jason Resch wrote: > > > > On Sun, Jul 4, 2021, 8:54 PM 'Brent Meeker' via Everything List < > [email protected]> wrote: > >> >> On 7/4/2021 5:14 PM, Jason Resch wrote: >> >> >> >> On Sun, Jul 4, 2021, 6:54 PM 'Brent Meeker' via Everything List < >> [email protected]> wrote: >> >>> >>> On 7/4/2021 5:17 AM, Tomas Pales wrote: >>> >>> >>> On Sunday, July 4, 2021 at 1:51:51 PM UTC+2 Bruce wrote: >>> >>>> >>>> And in the two-outcome experiment, how do you ever get a probability >>>> different from 0.5 for each possible outcome? >>>> >>>> You would seem to be looking for a branch counting explanation of >>>> probability (self-locating uncertainty). But there is no mechanism in >>>> Everett or the Schrodinger equation to give anything other than a 50/50 >>>> split when only two outcomes are possible. This is wildly at variance with >>>> experience. >>>> >>> >>> In the classical example with balls you may have a collection of blue >>> and red balls so there are only two possible outcomes of a random selection >>> of a ball: blue and red. This doesn't mean that the proportion of blue and >>> red balls in the collection must be 50/50. Why would the proportion of >>> branching worlds necessarily be 50/50 if there are only two possible >>> outcomes? >>> >>> >>> It's not that it's necessarily 50/50; it's that there's no mechanism for >>> it being the values in the Schroedinger equation. In one world A happens. >>> In the other world B happens. How does, for example, a 16:9 ratio get >>> implemented. There's nothing in Schroedinger's equation that assigns one >>> of those numbers to one world or the other. You can just make it an >>> axiom. Or equivalently, if you can show these are odds ratios, you can >>> invoke Gleason's theorem as the only consistent probability measure. But >>> all that is extra stuff that MWI claims to avoid by just being pure >>> Schroedinger equation evolution. >>> >>> Brent >>> >> Is this question unique to MW? >> >> Do Copenhagen/GRW/QBism/Transactional/Bohm have any advantage(s) in >> explaining the Born rule? >> >> Yes. They don't pretend that all you need is the Schroedinger equation >> and linear evolution of the state. They explicitly recognize that you need >> a probability interpretation to connect with observations. >> > > But if all (including MW) require a 'probability interpretation', then I > don't see the disadvantage of MW here. > > What additional assumptions are needed by MW that aren't needed by the > others? > > > It needs the assumption that the splitting or the selection of split is > random per the Born rule. True this, or equivalent is needed in the other > interpretations. But given that you need this interpretation, why keep all > those worlds. > All QM interpretations are "many-component" theories. It's just that some posit that, at certain (often not well-defined) times, all but one of those many-components stop existing. So as to "Why keep those components?" I think it leads to a simpler theory, and one is more in the spirit of all other physical theories: it's reversible, linear, local, deterministic, and avoids the fuzzy definitions around measurement, observation, consciousness, etc. MW doesn't add the many-components, rather it subtracts the step of "deleting all but one of them." > You've already committed to a probability interpretation: So instead of: > > MWI axiom: Everything happens in proportionate number of worlds per Born > and then one is selected per self-locating uncertainty in accordance with a > uniform random distribution. > > You can have > > CI: The possible worlds have probabilities of being realized per Born and > one of them is. > > > I see. Thanks that is helpful. Though I don't see it as a big downside for a physical theory to require assuming a theory of probability. Physical theories already require the assumption of theories of logic, theories of arithmetic, theory of geometry, and so on. And even if you start with Copenhagen, once one entertains theories like eternal inflation, with potentially infinite ensembles of duplicate universes/observers/experiments, you are back to the same sorts of probability questions that MW introduced. Jason > > -- > 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/5dcbf0d0-69fc-93d7-1cff-794e05cc8503%40verizon.net > <https://groups.google.com/d/msgid/everything-list/5dcbf0d0-69fc-93d7-1cff-794e05cc8503%40verizon.net?utm_medium=email&utm_source=footer> > . > -- 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/CA%2BBCJUjCoMQCU5j9v%2B9qN%3DKJGSwJ-qZTaO3fwaJaAeoGcGNXMA%40mail.gmail.com.
