On Sunday, December 2, 2018 at 8:17:54 PM UTC-6, Brent wrote: > > > > On 12/2/2018 5:14 PM, Philip Thrift wrote: > > > > On Sunday, December 2, 2018 at 4:25:04 PM UTC-6, Brent wrote: >> >> >> >> On 12/2/2018 11:42 AM, Philip Thrift wrote: >> >> >> >> On Sunday, December 2, 2018 at 8:13:48 AM UTC-6, agrays...@gmail.com >> wrote: >>> >>> >>> *Obviously, from a one-world perspective, only one history survives for >>> a single trial. But to even grossly approach anything describable as >>> "Darwinian", you have to identify characteristics of histories which >>> contribute positively or negatively wrt surviving but I don't see an >>> inkling of that. IMO, Quantum Darwinism is at best a vacuous restatement of >>> the measurement problemt; that we don't know why we get what we get. AG* >>> >>>> >>>> >>>> >> >> In the *sum over histories* interpretation - of the double-slit >> experiment, for example - each history carries a unit complex number - like >> a gene - and this gene reenforces (positively) or interferes (negatively) >> with other history's genes in the sum. >> >> >> But I thought you said the ontology was that only one history "popped out >> of the Lottery machine"? Here you seem to contemplate an ensemble of >> histories, all those ending at the given spot, as being real. >> >> Brent >> > > > > > All are real until all but one dies. > RIP: All those losing histories. > > > The trouble with that is the Born probability doesn't apply to histories, > it applies to results. So your theory says nothing about the probability > of the fundamental ontologies. > > Brent >
The probability distribution on the space of histories is provided by the path integral. *Backward causation, hidden variables and the meaning of completenes*s [ https://www.ias.ac.in/article/fulltext/pram/056/02-03/0199-0209 ] *Feynman’s path integral approach, calculation of the probability of the outcome in question depends on an integration over the possible individual paths between the given initial state and the given final state, each weighted by a complex number. The fact that the weights associated with individual paths are complex makes it impossible to interpret them as real valued probabilities, associated with a classical statistical distribution of possibilities.* *However, there is no such difficulty at the level of the entire ‘bundle’ of paths which comprise the path integral. If we think of the hidden reality as the instantiation not of one path rather than another but of one entire bundle rather than another, then the quantum mechanical probabilities can be thought of as classical probability distributions over such elements of reality. (For example, suppose we specify the boundary conditions in terms of the electron source, the fact that two slits are open, and the fact that a detector screen is present at a certain distance on the opposite side of the central screen. We then partition the detector screen, so as to define possible outcomes for the experiment. For each element O_i of this partition, there is a bundle B_i of Feynman paths, constituting the path integral used in calculating the probability of outcome O_i . We have a classical probability distribution* *over the set of such B_i .* One could stop at *history bundles* as the sample space, or the "hidden reality" could be that *one history* is selected at random from the history bundle. That could occur with t*ime symmetry* (retrocausality): The one path is chosen at random from a history bundle at the source in the present from the distribution determined on the history bundles in the future. - pt -- 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 everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
