Reading the recent Insight series on Block Universe, Blockworld and its Foundational implications Part 5, the second paragraph talks about an experiment where a photon detected earlier is affected by the position of a detector far away: First, let me round the focal length of the lens to 1 meter. The way I understood the article, I could install 2 detectors D1 (at 1m and at 2m), and by turning on one or the other, I'd be affecting the pattern at D2. But if I position myself midway between those detectors, I only need time 0.5/c to activate a detector, while D2 is 3.5 meters away. So I need time 0.5/c to send a message 3.5/c into the past? The message being, which of the 2 patterns are being detected. The article does not really go into details about the "Single counts Coincidences" and "Conditional counts in D2", perhaps the explanation is hiding there?