On Fri, 28 Feb 2020 at 08:40, Bruce Kellett <[email protected]> wrote:
> On Fri, Feb 28, 2020 at 4:21 AM 'Brent Meeker' via Everything List < > [email protected]> wrote: > >> On 2/27/2020 3:45 AM, Bruce Kellett wrote: >> >> >> That is probably what all this argument is actually about -- the maths >> show that there are no probabilities. Because there are no unique >> probabilities in the classical duplication case, the concept of probability >> has been shown to be inadmissible in the deterministic (Everettian) quantum >> case. The appeal by people like Deutsch and Wallace to betting quotients, >> or quantum credibility measures, are just ways of forcing a probabilistic >> interpretation on to quantum mechanics by hand -- they are not derivations >> of probability from within the deterministic theory. There are no >> probabilities in the deterministic theory, even from the 1p perspective, >> because the data are consistent with any prior assignment of a probability >> measure. >> >> >> The probability enters from the self-location uncertainty; which is other >> terms is saying: Assume each branch has the same probability (or some >> weighting) for you being in that branch. Then that is the probability that >> you have observed the sequence of events that define that branch. >> > > I think that is Sean Carroll's approach. I am uncertain as to whether this > really works or not. The concept of a 'weight' or 'thickness' for each > branch is difficult to reconcile with the first-person experience of > probability: which is obtained within the branch, so is independent of any > overall 'weight'. But that aside, self-locating uncertainty is just another > idea imposed on quantum mechanics and, like decision-theoretic ideas, it is > without theoretical foundation -- it is just imposed by fiat on a > deterministic theory. It makes probability a subjective notion imposed on > a theory that is supposedly objective: there is an objective probability > that a radioactive nucleus will decay in a certain time period -- > independent of our subjective impressions, or self-location. (I can develop > this thought further, if required, but I think it shows Sean's approach to > fail.) > Probability derived from self-locating uncertainty is an idea independent of any particular physics. It is also independent of any theory of consciousness, since we can imagine a non-conscious observer reasoning in the same way. To some people it seems trivially obvious, to others it seems very strange. I don’t know if which group one falls into correlates with any other beliefs or attitudes. > -- Stathis Papaioannou -- 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/CAH%3D2ypWb-n24FgchakZWNBw9ifk7HYdtz5LQnDENstYM_0xVaw%40mail.gmail.com.
