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. :) - 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.
