Some reflections on quantum measurement

Quantum measurement is a thorny problem without which the quantum theory cannot be taken as complete. Whether a measurement in laboratory is quantum measurement is a matter that needs be justified. Notably, not the eigenvalues of all the mechanical operators have realistic meaning. The role of intervention at the‘cut’between classical and quantum worlds in the quantum measurement postulates can be rephrased as a requirement that statistical principles should be incorporated therein, which are more fundamental in comparison with the quantum principles.That macroscopic measurements, such as the Stern—Gerlach experiment, the double-slit interference and alike, are well reconciled with quantum measurement postulates may just reveal the historic route and psychological basis of the development of those postulates. With this essay we want to call attention to the quantum measurement problem, and we’re sure that serious discussions over this problem may be helpful for further development of quantum mechanics.