Projection Evolution of Quantum States—the Delayed Choice Puzzle

We discuss the problem of the time variable in the nearly standard formulation of the quantum mechanics. In order to be able to describe the outcome of some of the experiments, we have used a novel formulation of the time evolution of quantum states called the projection evolution. As an example a delayed-choice experiment is described. We show that this description recreates the experimental results without relaying on the spatial parts of the wave functions. © 2018, Pleiades Publishing, Ltd.