> On 7 Aug 2019, at 02:19, Bruce Kellett <[email protected]> wrote: > > On Wed, Aug 7, 2019 at 10:04 AM smitra <[email protected] > <mailto:[email protected]>> wrote: > On 07-08-2019 00:45, Bruce Kellett wrote: > > > The trouble with that argument is that in any simulation, you get to > > set the rules of physics that obtain. There is then no guarantee that > > the results of your simulation have any relation to physics in the > > real (unassimilated) world. For decoherence to work, all that is > > required is a sufficient number of environmental degrees of freedom > > for multiple copies of the result to be recorded by the "environment > > as witness", in Zurek's words. Quantum Darwinism then ensures that the > > result is permanent and irreversible. > > If you measure the z-component of a spin polarized in the x-direction, > then however astronomically large the number of environmental degrees of > freedom there are that get entangled with the spin, it's still a finite > number. One minute after the measurement all the degrees of freedom that > can be entangled are within one light-minute of the experimental set-up. > So, the recording of the result in the environment are going to be a > superposition of the two possible recordings. > > It is called the "relative state" interpretation for a reason. The > entanglement with the environmental degrees of freedom that leads to the > recording of the result in the environment is relative to each possible > experimental outcome. Within the decoherence time (typically of the order of > a few nanoseconds or less) these "relative states" become effectively > orthogonal, and the measurement becomes irreversible. Because there is no > longer any possibility of interference between the results, there is no > longer any superposition.
That does not follow. There is no more a possibility to detect the interference. That does not make the other terms of the wave vanishing, they become just inaccessible, or … you introduce something non linear in QM. > You guys seems so desperate to hold on to a superposition that no longer has > any practical consequences. Yes, because we are not interested in practical matter, but in conceptual understanding. > Get used to it -- measurements have definite outcomes. That is the fact that > has to be incorporated into your theory. That’s like coming back to collapse, if not to 'shut up and calculate', frankly. Bruno > > 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] > <mailto:[email protected]>. > To view this discussion on the web visit > https://groups.google.com/d/msgid/everything-list/CAFxXSLR8CTLwit7B-y2WTzBdA0Pph2wpa4ZnTUhTCxNtab5vOQ%40mail.gmail.com > > <https://groups.google.com/d/msgid/everything-list/CAFxXSLR8CTLwit7B-y2WTzBdA0Pph2wpa4ZnTUhTCxNtab5vOQ%40mail.gmail.com?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/78B8C02E-9051-45E6-82C7-510BF2623D01%40ulb.ac.be.
