On Monday, November 11, 2019 at 5:45:45 AM UTC-6, Bruce wrote: > > On Mon, Nov 11, 2019 at 8:18 PM Bruno Marchal <[email protected] > <javascript:>> wrote: > >> On 10 Nov 2019, at 22:24, Bruce Kellett <[email protected] <javascript:>> >> wrote: >> >> On Sun, Nov 10, 2019 at 11:22 PM Bruno Marchal <[email protected] >> <javascript:>> wrote: >> >>> On 7 Nov 2019, at 22:58, Bruce Kellett <[email protected] <javascript:>> >>> wrote: >>> >>> On Fri, Nov 8, 2019 at 8:53 AM 'Brent Meeker' via Everything List < >>> [email protected] <javascript:>> wrote: >>> >>>> ISTM that creates problem for defining a point where one of the >>>> probabilities becomes actualized. MWI tries to avoid this by supposing >>>> that all probabilities are "actualized" in the sense of becoming >>>> orthogonal >>>> subspaces. There are some problems with this too, but I see the >>>> attraction. >>>> >>> >>> You can always find problems with any approach. What I particularly >>> dislike about MW advocates (like Sean Carroll) is that they are dishonest >>> about the number of assumptions they have to make to get the SWE to "fly". >>> Particularly over the preferred basis problem and Born rule. Zurek comes >>> closer, and he effectively dismisses the "other branches" as a convenient >>> fiction. If these other branches play no effective role in explaining our >>> experience, then why have them there? >>> >>> >>> How could some terms in a wave expansion disappear without assuming some >>> non unitary collapse of some sort? >>> >> >> I did not say that they disappeared: merely that they do not play any >> role in explaining our experience. >> >> >> Then you agree with the, or some, form of the Many-Histories/World theory. >> >> If you can point to any such role, then fine. But I doubt that you can do >> this. >> >> >> That is the whole point of realism. To believe in things despite we can >> not access to them. The belief that reality is bigger than the reality we >> can personally observe. >> > > That is not scientific realism -- that is metaphysical mysticism. > >> >> >>> There is no preferred basis, only personal basis to be able to interact >>> locally in between us. >>> >> >> Again you appear to ignore the primary role of science is in explaining >> our experience. In our experience, there most certainly is a preferred >> basis -- the world around us has not dissolved into the "mush" that >> Schroedinger feared so much. If there is only a "personal basis", explain >> to me why your personal basis does not include superpositions of live and >> dead cats. >> >> >> For exactly the same reason that when I am duplicated in Washington and >> Moscow, I don’t feel personally to be in both cities at once. >> > > So you are in the Washington/Moscow basis -- not the( W+/- M) basis. That > is a preferred basis. > >> The linearity of the evolution of the wave + the linearity of the tensor >> product entails that if a robot observe a cat in the state a + d, and this >> with a ad-measuring device, he ends up into a robot observing the evolution >> of a cat which is alive, and a robot observing the evolution of a cat which >> is dead. >> > > That is exactly the definition of a preferred basis -- which you appear to > want to deny even exists. > >> Once we have a body, evolution has chosen the “preferred base”, but it >> does not play a fundamental role in the fundamental equation. >> > > Evolution has precisely nothing to do with it. The preferred basis is > determined by quantum Darwinism acting on the normal physical interactions > between quantum objects. Being human or sentient is totally irrelevant.. > The preferred basis plays a fundamental role in the explanation of the > world as we perceive it -- we do not directly perceive Hilbert space. And > explaining our experience is the aim of science -- other things fall into > the realm of metaphysics, which is not science. > > Bruce > > We need some base to have a perspective, like in Mechanist philosophy of >> mind we need some universal machinery to be able to talk on all of them. >> >> Bruno >> >
*Journal of Quantum Information Science* *No Quantum Process Can Explain the Existence of the Preferred Basis:* *Decoherence Is Not Universal* Hitoshi Inamori https://file.scirp.org/Html/3-1300204_70108.htm Environment induced decoherence, and other quantum processes, have been proposed in the literature to explain the apparent spontaneous selection―out of the many mathematically eligible bases―of a privileged measurement basis that corresponds to what we actually observe. This paper describes such processes, and demonstrates that―contrary to common belief―no such process can actually lead to a preferred basis in general. The key observation is that environment induced decoherence implicitly assumes a prior independence of the observed system, the observer and the environment. However, such independence cannot be guaranteed, and we show that environment induced decoherence does not succeed in establishing a preferred measurement basis in general. We conclude that the existence of the preferred basis must be postulated in quantum mechanics, and that changing the basis for a measurement is, and must be, described as an actual physical process. @philipthrift -- 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/0c8fd1f8-c0e8-4a5d-bb16-63e7b637c0cb%40googlegroups.com.
