How exactly does which-slit information destroy interference?
I've seen in so many places online claiming:
"which-slit information destroys interference pattern"..."the act of observing which-slit causes the object to behave as a particle"... "by erasing the which-slit information, the object returns to behaving as a wave"
As if particles magically know to behave differently when somebody is watching. There is so much false information and I want to know if this is really correct. I feel like there must be a disturbance caused by measurement, or some other explanation as to why phenomena changes depending on how we measure it.
I'm OK with the double slit single-particle experiments. A single particle still produces an interference pattern, meaning it interferes with itself, the thing goes through both slits at once, is in superposition of states until collapsing according to wavefunction probability. OK. It's a quantum object. Fine. But the which-slit detectors trouble me.
I've looked at which-way interferometer experiments, polarization analyzer experiments, Stern-Gerlach experiments, quantum eraser experiments. I can't say I understand them completely. I'm not expecting a full answer, but hoping somebody can enlighten me, or point me in the right direction to get started. I've realised that it's probably impossible to understand this stuff without grasp some of the other quantum concepts, which I probably lack.