Zen wrote:ne question: have you changed your mind about this?
viewtopic.php?f=6&t=18#p151Do you agree that in all simulations (nicely written, by the way; long live to R!) discussed in this forum we are either making the distribution of the hidden variable depend on the detector settings or we are playing with the detectors efficiencies (standard detection loopholes)?
Another question: do
you believe that the description of the macroscopic parts of Aspect's apparatus cannot be made using good old Euclidean space?
Best,
Zen.
- No change of mind
- The simulations can be interpreted in two ways. Suppose we do N runs and we observe some "no shows", non-detections, so we only get say n < N pairs of both detected particles. There are two options.
Option 1: We can imagine that we are doing an N run experiment with ternary outcome (-1, 0, 1). Bell-CHSH is an inequality for binary outcomes. We need the CGLMP inequality for a ternary outcome experiment, or we can use CHSH after merging two of the three outcomes to one. Either of these kinds of inequalities are what we call "generalized Bell inequalities" and these two kinds are the only generalized Bell inequalities for a 2 party, 2 setting, 3 outcome experiment. See the section of my paper on generalized Bell inequalities
http://arxiv.org/abs/1207.5103 (the final revision just came out on arXiv today). None of the generalized Bell inequalities for a 2x2x3 experiment are violated, because the experiment satisfies "local realism" with no conspiracy loophole.
Option 2: there really are only n runs. The probability distribution of the local hidden variables in the model is the conditional distribution given both particles are accepted by the detectors. In order to pick a value of the hidden variable in the model, we need to know the settings (in effect, we are using rejection sampling: we just keep on picking a value, discard if it is rejected by the settings and try again). We now have n runs of a local realistic 2x2x2 experiment in which the hidden variables are chosen knowing in advance what the settings will be. Or you could call it not conspiracy, realist it is for sure, but non local. First there is communication from the settings to the source. Then the hidden variable is created. Then the particles fly to the detectors, knowing in advance what the settings will be.
- Good old Aspect's experiment operated at very very low detector efficiency and moreover with settings chosen according to a periodic deterministic scheme (with the ratio of the periods in the two arms of the experiment not close to small integers). So it did not prove anything. It is easy to give a local realist simulation which generates similar statistics. Weihs' experiment is a whole lot better but still far too low detector efficiency. It is easy to give a local realist simulation which generates similar statistics. We probably have to wait another five years for an experiment which *cannot* be simulated in a local realist way.