On Wednesday, April 25, 2018 at 10:51:13 AM UTC, Bruce wrote: > > From: Bruno Marchal <[email protected] <javascript:>> > > On 22 Apr 2018, at 01:47, Bruce Kellett < <javascript:> > [email protected] <javascript:>> wrote: > > From: smitra <[email protected] <javascript:>> > > > On 22-04-2018 00:18, Brent Meeker wrote: > >> On 4/21/2018 12:42 PM, smitra wrote: >> >>> >>> That's then an artifact of invoking an effective collapse of the >>> wavefunction due to introducing the observer. The correlated two particle >>> state is either put in by hand or one has shown how it was created. In the >>> former case one is introducing non-local effects in an ad-hoc way in a >>> theory that only has local interactions, so there is then nothing to >>> explain in that case. In the latter case, the entangled state itself >>> results from the local dynamics, one can put ALice and Bob at far away >>> locations there and wait until the two particles arrive at their locations. >>> The way the state vectors of the entire system that now also includes the >>> state vectors of Alice and Bob themselves evolve, has no nontrivial >>> non-local effects in them at all. >>> >> >> Sure it does. The state vector itself is a function of spacelike >> separate events, which cause it to evolve into orthogonal >> components...whose statistics violated Bell's inequality. >> >> Brent >> > > There is no non-locality implied here unless you assume that the dynamics > as predicted by QM is the result of a local hidden variables theory. > > Saibal > > > There is no need to suggest local (or non-local) hidden variables. The > non-locality we are talking about is implied by the quantum state itself -- > nothing to do with the dynamics. > > > > But that type of non-locality has never been questioned, neither in the > MWI, or a fortiori in QM+collapse. But the MWI explains without the need of > “mysterious” influence-at-a-distance, which would be the case in the > mono-universe theory, or in Bohm-De Broglie pilot wave theory. Without > dynamic we have “only” d’Espagnat type of inseparability. > > Bruno > > > It seems that you are starting to see it from my perspective. Non-locality > is just another way of emphasizing the non-separablity of the quantum > singlet state. As you say, this is true in MWI as in collapse theories. In > my extended development of the mathematics in another recent post, I > demonstrated that there is actually no difference between MWI and CI in > this regard. All that we have is the non-separability of the state, which > means that a measurement on one particle affects the result of measurements > on the other -- they are inseparable. This is all that non-locality means, > and this is not changed by MWI. An awful lot of nonsense has been talked > about this -- people trying to find a "mechanism" for the inseparability -- > but that is not necessary. Quantum theory requires it, and it has been > totally vindicated by experiment. That is the way things are, in one world > or many. > > Bruce >
You place great faith in the singlet wf. But how can you legitimately treat the system quantum mechanically if you assume zero uncertainty in the total spin AM? AG -- 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.
