cousin_it:

Have you actually tried to do the mental gymnastics and explain the linked experiment [the Elitzur-Vaidman bomb tester] using the Copenhagen interpretation?

Maybe I'm missing something, but how exactly does this experiment challenge the Copenhagen interpretation more than the standard double-slit stuff? Copenhagen treats "measurement" as a fundamental and irreducible process and measurement devices as special components in each experiment -- and in this case it simply says that a dud bomb doesn't represent a measurement device, whereas a functioning one does, so that they interact with the photon wavefunction differently. The former leaves it unchanged, while the latter collapses it to one arm of the interferometer -- eiher its own, in which case it explodes, or the other one, in which case it reveals itself as a measurement device just by the act of collapsing.

As far as I understand, this would be similar to the standard variations on the double-slit experiment where one destroys the interference pattern by placing a particle detector at the exit from one of the holes. One could presumably do a similar experiment with a detector that might be faulty, and conclude that an interference-destroying detector works even if it doesn't flash when several particles are let through (in cases where they all happen to go through the other hole). Unless I'm misunderstanding something, this would be a close equivalent of the bomb test.

The final conclusion in the bomb test is surely more spectacular, but I don't see how it produces any extra confusion for Copenhageners compared to the most basic QM experiments.