From: helbig@asclothestro.multivax.de   
      
   In article , Sylvia Else   
    writes:   
      
   > On 22-Oct-22 7:12 am, Nicolaas Vroom wrote:   
   >> Op maandag 17 oktober 2022 om 09:10:38 UTC+2 schreef Tom Roberts:   
   >>   
   >>> Consider a generic experiment on quantum entanglement: Two particles   
   >>> are created at event A in an entangled state, they are separated and   
   >>> transported to events B and C, where their individual properties are   
   >>> measured; B and C are spacelike-separated events.   
      
   >> It is also important to understand that as a result of this specific   
   >> reaction, it is not required to perform any measurement to assume that   
   >> the two particles are correlated. Based on this concept, when any   
   >> particle is measured the spin of the other particle is known.   
   >> No physical process, or action, or link is involved.   
      
   > You've assumed that the only situations of interest are the cases where   
   > the measurement of spin are in the same axis or perpendicular axes. The   
   > results of such measurements can be explained by a simple hidden   
   > variable model.   
   >   
   > However, once measurements are made on axes at other angles to each   
   > other, the correlations are no longer explainable that way, and locality   
   > is brought into question.   
      
   Reality is complex, but examples---sometimes even from professional   
   physicists---such as a disk broken in a "random" way (the jagged edges   
   of each are "correlated"---yes, I really did see that used as an   
   example) are too simple and misleading and don't grasp the essential   
   concept.   
      
   Here is something in-between.  It's wrong, but more involved than the   
   simple examples.  Showing why real correlation is "more" than this might   
   help to understand it.   
      
   Imagine that a vector can have any orientation between 0 and 360   
   degrees.  If it is between 270 and 90, the measurement result is "up".   
   If between 0 and 180, "right", 90 and 270 "down" and 180 and 360 "left".   
      
   Two correlated vectors have opposite directions.   
      
   If I measure one to have "up", then I know that the other is "down", but   
   can't say whether it is "left" or "right".  And so on.  But if I measure   
   it to be "right", I know that the other is "left", but can't say whether   
   it is "up" or "down".  I am also free to choose which 90 degrees   
   correspond to, say, "up".   
      
   That model explains many popular presentations of quantum correlation,   
   but what is the "more" which is actually observed?  Is such a model the   
   simple hidden-variable model mentioned above?   
      
   --- SoupGate-Win32 v1.05   
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