On Tuesday, November 27, 2018 at 8:43:55 PM UTC, Philip Thrift wrote: > > > > On Tuesday, November 27, 2018 at 2:05:04 PM UTC-6, [email protected] > wrote: >> >> >> >> On Tuesday, November 27, 2018 at 6:49:51 PM UTC, Philip Thrift wrote: >>> >>> >>> >>> On Tuesday, November 27, 2018 at 12:17:08 PM UTC-6, [email protected] >>> wrote: >>>> >>>> >>>> >>>> On Tuesday, November 27, 2018 at 6:00:50 PM UTC, Philip Thrift wrote: >>>>> >>>>> >>>>> >>>>> On Tuesday, November 27, 2018 at 8:43:35 AM UTC-6, [email protected] >>>>> wrote: >>>>>> >>>>>> >>>>>> >>>>>> On Tuesday, November 27, 2018 at 9:27:46 AM UTC, Philip Thrift wrote: >>>>>>> >>>>>>> >>>>>>> >>>>>>> On Monday, November 26, 2018 at 3:43:14 PM UTC-6, >>>>>>> [email protected] wrote: >>>>>>>> >>>>>>>> >>>>>>>> *I checked the postulates in Feynman's Sums Over Histories (in link >>>>>>>> provided by Phil) and I see nothing related to waves, as expected, and >>>>>>>> thus >>>>>>>> nothing about collapse of anything. I would suppose the same applies >>>>>>>> to >>>>>>>> Heisenberg's Matrix Mechanics; no waves, no collapse. I suppose you >>>>>>>> could >>>>>>>> say they just produce correct probabilities, and imply nothing about >>>>>>>> relative states other than their probabilities (which wave mechanics >>>>>>>> does), >>>>>>>> but certainly nothing about consciousness. To summarize: you're right >>>>>>>> that >>>>>>>> they are "no collapse" theories, but IMO they say nothing about >>>>>>>> consciousness. AG* >>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>> >>>>>>> >>>>>>> In terms of the path-integral (PI) interpretation [ interesting >>>>>>> lecture: >>>>>>> https://www.perimeterinstitute.ca/videos/path-integral-interpretation-quantum-mechanics >>>>>>> >>>>>>> ], there is in effect no waves or wave function, just paths, or >>>>>>> histories, >>>>>>> in the sum-over-histories (SOH) terminology. >>>>>>> >>>>>>> There is still "decoherence" in the SOH (a single history is >>>>>>> ultimately "realized"), but it could be called "selection": a single >>>>>>> history is selected from the total ensemble of multiple and interfering >>>>>>> histories. E.g. a single point on a screen is "hit" by a photon in the >>>>>>> double-slit experiment. >>>>>>> >>>>>> >>>>>> *Does "selection" add any insight to the measurement problem; that >>>>>> is, why do we get what we get? And if not, what is its value? TIA, AG * >>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>> If you look at it as a "selection of the fittest" (one history >>>>> surviving from an ensemble of histories), then it's like a form of >>>>> quantum >>>>> Darwinism. The quantum substrate is a cruel world where all histories >>>>> (but >>>>> one) die. >>>>> >>>> >>>> That's not an explanation; rather, a vacuous statement of the result. >>>> AG >>>> >>>>> >>>>> >>> But that is a criticism of Darwinism (*natural selection*) in general. >>> >> >> *Ridiculous comparison IMO. Darwinism posits a changing environment and >> competition among species for niches. Nothing comparable in Quantum >> Darwinism other than all outcomes fail except for one which succeeds in >> each single trial, which we knew from the get-go. AG* >> >>> >>> *Quantum Darwinism* is a theory claiming to explain the emergence of >>> the classical world <https://en.wikipedia.org/wiki/Classical_physics>from >>> the quantum world <https://en.wikipedia.org/wiki/Quantum_mechanics> as >>> due to *a process of **Darwinian >>> <https://en.wikipedia.org/wiki/Charles_Darwin> natural selection >>> <https://en.wikipedia.org/wiki/Natural_selection>*; where the many >>> possible quantum states <https://en.wikipedia.org/wiki/Quantum_states> are >>> selected against in favor of a stable pointer state >>> <https://en.wikipedia.org/wiki/Pointer_state>. >>> [ https://en.wikipedia.org/wiki/Quantum_Darwinism ] >>> >>> - pt >>> >>> >> > > > As for "competition for niches", the histories are in a sense competing. > Perhaps there is some conservation principle at work, so only one history > can win. > > I don't know. Physicists don't know. We're even. :) >
*Darwin had a theory or proposal to explain why some changes occur and persist, but Quantum Darwinism doesn't, as far as I can tell. AG * > > - 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 [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
