The discussion revolves around the distinction between measurement and preparation in the context of the double slit experiment. Participants explore theoretical implications, definitions, and the roles of different apparatuses in quantum mechanics, focusing on how states are prepared and measured.
Participants express differing views on the definitions and implications of measurement versus preparation, with no consensus reached on the nature of measurement apparatuses or the certainty of results in quantum mechanics.
Participants highlight limitations in their discussions, such as the dependence on specific experimental setups and the challenges of idealized conditions in quantum mechanics.
And of spin states, not of position states!vanhees71 said:Ok, that's still a superposition of states, not of "position".
Then your notation |u> and |d> stands for two spherical waves, not for two position eigenstates! And nothing at all is measured at the slits (if not energy), just prepared. There are no clicks anywhere. (Except perhaps in a detector later, which does a measurement (of the energy at the detector surface).naima said:It has nothing to do with spin!
|u> is for the upper slit.