>>13443315Daily reminder that the wavefunction is NOT an observable, hence questions whether a particle can be "at two places at the same time" and other questions that stem from the linearity of QM are ill-posed.
You see, most of the "mysterious" stuff of QM comes from people who try to give non-physical quantities a physical meaning. Of course you then end up with shit like this. If one wants to avoid such confusion, he or she should carefully think about which objects in the mathematical formulation of QM are actual physical observables.
That's also what Schrödinger's cat was originally about. Of course, the cat is NOT simultaneously dead or alive -- it's either dead OR alive. But the system (cat + poison or some shit) is a source of an ensemble, and a measurment picks out one specific realization of such an ensemble, highlighting the intrinsic, probabilistic nature of QM.
The same holds for particles. If you make a measurment, e.g. a photon on a screen, the photon will always appear at a single place -- and such a physical realization is all that counts, everything else is just a mathematical framework.
