> On 7 Aug 2019, at 20:06, 'Brent Meeker' via Everything List > <[email protected]> wrote: > > > > On 8/7/2019 2:23 AM, Bruno Marchal wrote: >> >>> On 6 Aug 2019, at 20:00, 'Brent Meeker' via Everything List >>> <[email protected] >>> <mailto:[email protected]>> wrote: >>> >>> >>> >>> On 8/6/2019 6:38 AM, Bruno Marchal wrote: >>>>> If the QC does its task effectively, the output basis qbits will be put >>>>> into definite states, >>>> >>>> Relatively to the observer, but in the global state, the observer will >>>> inherit the superposition state, by linearity of the tensor products and >>>> of the evolution. >>> >>> In something like Shor's algorithm there is only one final state with >>> non-vanishing probability. Yet this is the kind of algorithm that Deutsch >>> cites as proving there must be many worlds. >> >> Can you wrote a classical emulator of the algorithm of Shor which does not >> emulate the “parallel computation”? >> >> I have never succeeded. I agree that this proves nothing, but QM without the >> superposition (the parallel histories) does not (yet) make any sense to me. >> That there is only one final state does not explain how shor’s algorithm >> works without the intermediate superposed states. > > Do you not see that there is only one intermediate state and the > superposition is an artifact of expressing the state relative to a certain > basis?
If it was an artfifact, one photon would not been able to interfere with itself, and there would be no Bell’s violation. An interesting video explaining (among other ideas) that the two slit experience is just entanglement is Susskind's talk on "Everett, Copenhagen and the ER = EPR" idea: https://www.youtube.com/watch?v=LndrOIXG3i8 The explanation I allude to is at 1:08:32 (but the whole talk is interesting! Notably on locality/non-locality). Earlier, he shows that GHZ + black hole entails experimental difference between Copenhagen and Everett, but in my opinion, you don’t need the black holes. Bruno > > Brent > >> >> It is the same with Deutsch Josza problem, and some others. In fact, as >> Deutsch said and explain well, even the two slits experiment is hard to >> explain without attributing a physical existence to the superposed state. >> The difference of the behaviour between pure sate and mixture seems to >> impose some notion of parallel histories. >> >> Bruno >> >> >> >> >>> >>> Brent >>> >>> -- >>> 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] >>> <mailto:[email protected]>. >>> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/everything-list/10717b73-00cf-2353-0415-42497db85c3e%40verizon.net >>> >>> <https://groups.google.com/d/msgid/everything-list/10717b73-00cf-2353-0415-42497db85c3e%40verizon.net?utm_medium=email&utm_source=footer>. >> >> -- >> 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] >> <mailto:[email protected]>. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/everything-list/6103D4C6-F077-4486-BF45-3D1C0336D1A8%40ulb.ac.be >> >> <https://groups.google.com/d/msgid/everything-list/6103D4C6-F077-4486-BF45-3D1C0336D1A8%40ulb.ac.be?utm_medium=email&utm_source=footer>. > > > -- > 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] > <mailto:[email protected]>. > To view this discussion on the web visit > https://groups.google.com/d/msgid/everything-list/2dd5ca9f-6b31-b3f7-0876-b7b6e2d00b3b%40verizon.net > > <https://groups.google.com/d/msgid/everything-list/2dd5ca9f-6b31-b3f7-0876-b7b6e2d00b3b%40verizon.net?utm_medium=email&utm_source=footer>. -- 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/612A5C64-DF40-4634-8739-577AA9379653%40ulb.ac.be.
