Home › Forums › 2015 International Workshop on Quantum Foundations › Panel Discussion › Are there any pressing problems? › Reply To: Are there any pressing problems?
in my study I only tried to analyze the nonrealism option using the concrete model. The nonrealism possibility exists already 50 years, but it was not explored. Thus the question is old, only the proposed solution is new.
The realism is equivalent to the von Neumann axiom (the wave function represents the individual state) hence in each nonrealism model the von Neumann axiom must be false and then also individual superposition principle must be false. I did not take the psi-epistemic position but the psi-hybrid position (some wave functions represent individual systems). In my analysis I have found the suprising fact that many old problems can be relatively simply solved in the modified QM (as expected, nobody believes that this is possible).
Your expectation that this needs the new empirical evidence cannot be satisfied in this case since the modified QM and the standard QM give the same predictions. The fact that two very different theories can give the same prdictions is strange but it seems that it is true (i.e. these theories are empirically indistinguishable). This implies that neither the von Neumann axiom nor the anti-von Neumann axiom have some empirical consequences – but the explanation power of these theories is different.
There is a question if the psi-epistemic variant can be realized (no-go theorems). If modified QM is consistent (I hope it is) then this is an example of the psi-epistemic model.
Your opinion that the wave function is nonlocal (I agree) is the kernel of the classical argument against von Neumann: the nonlocal wave function cannot represent the individual cat which is local (it can perhaps represent the ensemble of cats). The classical argument is, of course, the old Einsten`s example.
I think that the nonrealism option should be studied seriously since the opposite option, the nonlocality, was not fruitful.