A little rusty on my QM but I believe the key to demonstrating when the collapse happens is that while doing a measurement will collapse the wave function, appl

A little rusty on my QM but I believe the key to demonstrating when the collapse happens is that while doing a measurement will collapse the wave function, applying a transformation won't necessarily. An experiment can work something like this. Produce 1000 state that you think are undecided. Apply a transformation that you know will turn the uncollapsed 50/50 state to 1 and the collapsed 0 and 1 states to the uncollapsed 50/50 state. Then measure all 1000 states. If they all yield 1, with high probability they were were indeed undecided to begin with. If they yield random results, with high probability they were collapsed 0 or 1 to begin with.