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This new research suggesting Debroglie/Bohm pilot wave theory may yet have legs sounded compelling and I would love to hear the thoughts of the PF community:
https://www.quantamagazine.org/20160517-pilot-wave-theory-gains-experimental-support
There is some discussion in the comments by Wiseman (one of the authors of the paper) and by the always entertaining Lubos Motl.
Howard Wiseman says: May 18, 2016 at 7:12 am
https://www.quantamagazine.org/20160517-pilot-wave-theory-gains-experimental-support
There is some discussion in the comments by Wiseman (one of the authors of the paper) and by the always entertaining Lubos Motl.
Howard Wiseman says: May 18, 2016 at 7:12 am
The two comments here (by Pradeep Mutalik and Lubos Motl) nicely illustrate the problem with terminology in this area, a problem I've addressed a number of times, most recently in https://arxiv.org/abs/1503.06413 "Causarum Investigatio and the two Bell's Theorems of John Bell" to be published in http://www.springer.com/us/book/9783319389851
For Mutalik, nonlocality is demonstrated whenever a Bell's inequality is violated for space-like separated events. I maintain we should call that a violation of *local causality* (a notion defined by Bell in 1976) rather than of locality. The "causality" element here is appropriate because this notion is built on the assumption that correlated events must have a common cause that explains the correlation. This is not the case in a purely operational interpretation of quantum mechanics.
For Motl, nonlocality means signalling faster than light. I maintain we should call that a violation of *signal locality* rather than of locality.
The nonlocality we address in this experiment is neither of these. It is the violation of *locality*, in the sense (I maintain) that Bell used it in 1964, and that various philosophers of physics (Jon Jarrett, Don Howard) have used it since. It is also known by the ugly name of "parameter independence". You could think of it as signalling at the hidden-variable level. Because we as experimenters don't have access to the hidden variable level, violation of locality does *not* mean we can signal faster than light.
For Mutalik, nonlocality is demonstrated whenever a Bell's inequality is violated for space-like separated events. I maintain we should call that a violation of *local causality* (a notion defined by Bell in 1976) rather than of locality. The "causality" element here is appropriate because this notion is built on the assumption that correlated events must have a common cause that explains the correlation. This is not the case in a purely operational interpretation of quantum mechanics.
For Motl, nonlocality means signalling faster than light. I maintain we should call that a violation of *signal locality* rather than of locality.
The nonlocality we address in this experiment is neither of these. It is the violation of *locality*, in the sense (I maintain) that Bell used it in 1964, and that various philosophers of physics (Jon Jarrett, Don Howard) have used it since. It is also known by the ugly name of "parameter independence". You could think of it as signalling at the hidden-variable level. Because we as experimenters don't have access to the hidden variable level, violation of locality does *not* mean we can signal faster than light.
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