On Thu, Mar 5, 2020 at 10:50 AM 'Brent Meeker' via Everything List < [email protected]> wrote:
> On 3/4/2020 2:43 PM, Bruce Kellett wrote: > > On Thu, Mar 5, 2020 at 9:15 AM 'Brent Meeker' via Everything List < > [email protected]> wrote: > >> >> Whether MWI is a satisfactory interpretation or not; do you have a >> preferred proposal for getting rid of the unobserved macroscopic states >> that are predicted by the formalism with a collapse postulate, e.g. >> gravitationally induced collapse, transactional interpretation, or what? >> > > I do not think the problem is solved at the moment. Penrose's > gravitational induced collapse still lacks a dynamical mechanism for the > collapse when the gravitational superposition become unwieldy. > > > Have you looked at Laloe's paper which fills this in using some Bohmian > ideas. arXiv:1905.12047v3 [quant-ph] 6 Sep 2019 > > Cramer's (Kastner's) transactional interpretation introduces a whole new > "possibility world", and relies on the failed absorber theory of radiation. > > > I think the function of the possibility space is to avoid the problems of > the absorber theory. The absorbtion is "transacted" in possibility space. > I'm note sure how it handles free radiation (e.g. the CMB) since nothing > happens except by an exchange of energy/information between an emitter and > absorber. > > > No-go there. Bohm is the preferred option of many philosophers of QM, but > I think Flash-GRW is growing in plausibility. At least it does give an > underlying stochastic dynamics, so doesn't suffer the problems of > introducing probability that other approaches have. > > It is still an open question, as far as I can see. The clear thing is that > Everett plainly fails to make any sense of probability when all outcomes > occur for any measurement. > > > I don't see that as particularly damning. I just means you need another > postulate of the form "And *this* is a probability measure." > But that does not get around the problem that the set of possible results from N trials on the state |psi> = a|0> and b|1> for non-zero coefficients a and b, is independent of the coefficients a and b. So any experimental test of any probability idea, whether imposed by hand or not, is going to show that the probabilities are not related to the coefficients or branch weights. > For example, if you take Zurek's quantum Darwinism to provide an > objective pointer basis then you can say, in this basis, off-diagonal terms > in the reduced density matrix that are so small they will never be observed > can be set to zero and then the diagonal terms are just the probability of > the (one) world that will be actual. > That is still a probabilistic assertion. And no derivation of probabilities for cases in which all outcomes occur is going to be successful. The arguments for probability assignments given by Zurek (and Carroll and Wallace, among others) all rely, at some point, on the "intuition" that equal amplitudes equate to equal probabilities. It is that assumption that I have shown to be false. 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/CAFxXSLQyeUey%2B4cj%3Dv%2BwGm%2BYKQubpgQ-SGeLk19iD1FXkCJbpw%40mail.gmail.com.
