(08-01-2016, 07:14 PM)secur Wrote: On further reading, I see this loophole is apparently called the "synchronization" loophole - if I understand correctly. In fact, you probably already know that Hess and Philipp must be based on this idea. But it's not at all obvious from reading the paper, and (I thought) worth pointing out.

I call it the coincidence loophole https://arxiv.org/abs/quant-ph/0312035. I agree that is not at all obvious from reading the Hess and Philipp papers that this is what they were thinking of. Their paper did inspire Jan-Ake Larsson and myself to think about and analyse the loophole and show that it is worse than the well-known efficiency loophole.

The mathematics of the Hess-Philipp papers has not got anything to do with the coincidence loophole at all. They believed that they had built a genuine local hidden variables model which violated Bell inequalities. It was very difficult to track down the mistake in the mathematics, it was hidden very deeply and came down to forgetting an index (one of many) and forgetting to renormalise a measure to get a probability distribution, in the heart of their construction.

The latest experiments are not afflicted with either the detection loophole nor the coincidence loophole. A strict timing schedule means that the experimental unit is not "particle pair" but "time window". Per time window there are always two new settings and there are always two binary outcomes.