On 12/31/2013 7:22 PM, LizR wrote:
On 1 January 2014 13:54, meekerdb <meeke...@verizon.net <mailto:meeke...@verizon.net>> wrote:


    On 12/31/2013 3:24 PM, LizR wrote:
    On 1 January 2014 12:05, meekerdb <meeke...@verizon.net
    <mailto:meeke...@verizon.net>> wrote:

        Mark A. Rubin 
<http://arxiv.org/find/quant-ph/1/au:+Rubin_M/0/1/0/all/0/1>
        (Submitted on 14 Mar 2001 (v1 
<http://arxiv.org/abs/quant-ph/0103079v1>), last
        revised 10 May 2001 (this version, v2))

            Bell's theorem depends crucially on counterfactual reasoning, and is
            mistakenly interpreted as ruling out a local explanation for the
            correlations which can be observed between the results of 
measurements
            performed on spatially-separated quantum systems. But in fact the 
Everett
            interpretation of quantum mechanics, in the Heisenberg picture, 
provides an
            alternative local explanation for such correlations. 
Measurement-type
            interactions lead, not to many worlds but, rather, to many local 
copies of
            experimental systems and the observers who measure their properties.
            Transformations of the Heisenberg-picture operators corresponding 
to the
            properties of these systems and observers, induced by measurement
            interactions, "label" each copy and provide the mechanism which, 
e.g.,
            ensures that each copy of one of the observers in an EPRB or GHZM
            experiment will only interact with the "correct" copy of the other
            observer(s). The conceptual problem of nonlocality is thus replaced 
with a
            conceptual problem of proliferating labels, as correlated systems 
and
            observers undergo measurement-type interactions with 
newly-encountered
            objects and instruments; it is suggested that this problem may be 
resolved
            by considering quantum field theory rather than the quantum 
mechanics of
particles.
        Comments:       18 pages, no figures. Minor changes
        Subjects:       Quantum Physics (quant-ph)
        Journal reference:      Found. Phys. Lett. 14 (2001) 301-322
        Report number:  WW-10184
        Cite as:        arXiv:quant-ph/0103079 
<http://arxiv.org/abs/quant-ph/0103079>


        just moves the problem from FTL signaling to FTL labeling.


    Where is the FTL? I don't recall any suggestion that the "contagion" of 
entangled
    systems spreading themeselves in the MWI involves anything FTL.

    Of course in Hilbert space there's no FTL because the system is just one 
point and
    when a measurement is performed it projects the system ray onto a mixture of
    subspaces; spacetime coordinates are just some labels.


I thought there was no FTL in ordinary space, either? (I mean, none required 
for the MWI?)

Right, but the state in Hilbert space is something like |x1 y1 z1 s1 x2 y2 z2 s2> and when Alice measures s1 at (x1 y1 z1) then s2 is correlated at (x2 y2 z2). As I understand it the MWI advocates say this isn't FTL because this is just selecting out one of infinitely many results |s1 s2>. But the 'selection' has to pair up the spins in a way that violates Bell's inequality.

    In fact, it's generally assumed to be very, very STL (unless light itself is
    involved). At great distances from the laboratory, one imagines that the
    superposition caused by whatever we might do to cats in boxes would decay 
to the
    level of noise, and fail to spread any further.
    That's an interesting viewpoint - but it's taking spacetime instead of 
Hilbert space
    to be the arena.  If we take the cat, either alive or dead, and shoot it 
off into
    space then, as a signal, it won't fall off as 1/r^2.

No, but it will travel STL!

Sure. I was just commenting on the idea that the entanglement has a kind of limited range because of 'background noise'. An interesting idea, similar to one I've had that there is a smallest non-zero probability.

But if you want to get FTL, that's possible if Alice and Bob are near opposite sides of our Hubble sphere when they do their measurements. They are then already moving apart faster than c and will never be able to communicate - with each other, but we, in the middle will eventually receive reports from them so that we can confirm the violation of Bell's inequality.

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 everything-list+unsubscr...@googlegroups.com.
To post to this group, send email to everything-list@googlegroups.com.
Visit this group at http://groups.google.com/group/everything-list.
For more options, visit https://groups.google.com/groups/opt_out.

Reply via email to