Some straightforward problems I have encountered in QM; i'll post them gradually, otherwise it 'd be a little long, thanks 1a) Wave/particle Duality: A quantum wave as stated through Dirac and von Neumann is a probability wave expressed by Schrödinger equation and thus here implying a superimposed state. A first conceptual problem I encounter here is that the very being of superposition can never be observed. It can be derived from the interference of for example the double slit experiment. Logically, the superimposed wave function has encountered a "wave collapse" due to a certain form of measurement. Due to this wave collapse, the former probability wave will act as a single vector in Hilbert space, containing finite energy, thus being a point in Hilbert space. If we keep on using this definition of the quantum properties, I am very curious what that exactly causes the wave collapse. 1b) The notion of the "particle"- being of the quantum as a single vector in Hilbert space with finite energy thus implies a major problem explaining classical "rest mass". Thus if a classical observable particle,if being fundamentally different in some way of the quantum vector,is observed, it could never generate an interference pattern (if we do a gedankenexperiment containing two slits and bowling balls), just because the quantum properties of the propability wave needed for interference avoid the classical notion of matter. IF! on the other hand you don't make a difference of fundamental level between a single quantum system and a classical system, -what- does then "convert" your theoretical vector in Hilbert space to a classical observable system having a structural rest mass, in which E=mc² must play a major role? 1c) If indeed, you don't make a fundamental difference between a single quantum state and a "classical" system (as being build up by single quantum states), then what contains the information to collapse the wave function of a whole system, thus creating a logically structured classical system??