On Thursday, November 7, 2019 at 4:43:51 PM UTC-6, Brent wrote: > > > > On 11/7/2019 2:32 PM, Philip Thrift wrote: > > > > On Thursday, November 7, 2019 at 3:53:12 PM UTC-6, Brent wrote: >> >> >> >> On 11/7/2019 1:40 PM, Bruce Kellett wrote: >> >> On Fri, Nov 8, 2019 at 6:35 AM 'Brent Meeker' via Everything List < >> [email protected]> wrote: >> >>> On 11/7/2019 12:21 AM, Philip Thrift wrote: >>> >>> >>> >>> The mystery is: Why do (according to the science press in the wake of >>> Sean Carroll's book) so many people think Many Worlds is a good scientific >>> idea (or the best idea, according to the author). >>> >>> >>> Because it treats measurement as just another physical interaction of >>> quantum systems obeying the same evolution equations as other interactions. >>> >> >> But you can do that (viz. accept that people, and measuring instruments, >> and everything else are basically quantum mechanical) without adopting the >> "many worlds" philosophy. >> >> >> ISTM that creates problem for defining a point where one of the >> probabilities becomes actualized. MWI tries to avoid this by supposing >> that all probabilities are "actualized" in the sense of becoming orthogonal >> subspaces. There are some problems with this too, but I see the attraction. >> >> Brent >> >> >> I studied probability theory - and statistics - through the 70s - my > thesis was in random fields [ def: > https://en.wikipedia.org/wiki/Random_field ] - and T've read much on > 'interpretations' of probability and statistics. > > I'll just say that the vocabulary I see with 'probability' in the way some > are describing things like Many Worlds are just baffling to me - > probability theory-wise. > > I know one can have a Bayesian probabilities sense of 'a probability > becomes 1.0' as in a prior to posterior probability updating, but I don't > think the Many Worlds people are doing this. It's like a hybrid of QBI and > MWI maybe. > > > I think of probability as an abstract quantity like "energy". It's a > useful concept *because* it has different interpretations that can be > translated from one context to another. So the Born rule gives a measure > that satisfies the Kolmogorov axioms, and it's useful because in an > operational context it translates into the frequentist meaning, and that's > useful because it tells you how to bet in a decision theory problem. > > Brent >
As long as QMists are clear about what type of 'probabilities' they are referring from one day (or paragraph) to the next, It's OK I guess. (I always think first: What is the *sample space [ * https://en.wikipedia.org/wiki/Sample_space ]? What are the *elements* of the sample space?) I've always been a propensitist [ https://plato.stanford.edu/entries/probability-interpret/#ProInt ]. @philipthrift -- 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/612ece16-c6f1-4444-925a-940ee045b46c%40googlegroups.com.
