I'm reading: "What Is Real?" by Adam Becker, book mentioned Einstein's thought experiment:
At that 1927 conference Einstein made a short presentation during the general discussion session where he focused on problems of interpretation associated with the collapse of the wave function. He imagines a situation where electrons pass through a small hole and are dispersed uniformly in the direction of a screen of photographic film shaped into a large hemisphere that surrounds the hole.
I assume instead of the "uniformly distributed" we'd see some "diffraction pattern", produced by the stream of electrons, but it is not the point. The key here is: we will get some electrons deviated from the original trajectory.
Now let's simplify this experiment down to a single electron sent through a small hole in the isolated lab hanging in empty space in front of us (observers). See Fig. 1:
As you can see the vector of the "gun recoil" momentum can not be fully compensated by the "impact momentum" vector because the impact vector now has Y component! (see red Y component on the diagram). Who/when/how will compensate for this? Or does this mean that during the electron passage through the hole it will "push" the screen with the hole in the opposite direction (upwards)? But then we can accurately measure that "pressure" near the hole and tell in advance where the electron will land on the screen (spoils the whole wave f-n collapse surprise party:). But even in this case there will be clock-wise rotation moment applied to the lab because of the distance between "upward" and "downward" applied forces. I'm completely lost here.. :-)
