[ExI] R: Re: Cramer on impossibility of FTL communication

[scerir at alice.it]

Ciao Giulio, 

Well, there is a general agreement we cannot use quantum 
entanglement
for FTL messaging. By definition we cannot use for FTL messaging 
the so called
"superquantum" correlations . These correlations are still under 
investigation, under 
the name of Popescu-Rohrlich correlations, or PR-boxes. 


Good papers about "superquantum" correlations are 
http://tinyurl.com/nw6h9n3
http://arxiv.org/pdf/quant-ph/9508009.pdf

Quantum mechanics and relativistic 
causality together imply nonlocality. 
Can we invert the logical order? Can we 
consider a conjecture that nonlocality  
and relativistic causality together 
imply quantum mechanics? 

See also 
http://arxiv.org/pdf/quant-ph/9709026v2.pdfand 
http://www.nature.com/nphys/journal/v10/n4/full/nphys2916.html
But (following 
Jarrett, Shimony, Ghirardi, Howard, Eberhard, Cushing, etc.) 
it is possible to 
show that a ***deterministic*** theory (i.e. one in which the 
range of any 
probability distribution of outcomes is the set 0 or 1) reproducing 
all the 
predictions of (the indeterministic) quantum mechanics would allow 
FTL 
signaling. That's important imo. 



----Messaggio originale----
Da: 
giulio at gmail.com
Data: 30-ago-2015 11.14
A: "scerir at alice.it"<scerir at alice.it>, 
"ExI chat list"<extropy-chat at lists.extropy.org>
Ogg: Re: [ExI] Cramer on 
impossibility of FTL communication

Thanks for posting! By pure synchronicity, 
I was reading the paper
when your post arrived!

The consensus, even among 
imaginative mavericks like Cramer and
Herbert, seems to be that quantum 
entanglement can't be used for
instant messaging. That's kind of intuitive 
because measurements are
random anyway, entanglement or not, and cheating 
breaks the
entanglement. Of course one can hope to find a cleaver way of

cheating... Any news about that?