This process occurs due to distinct gravitational potentials caused by different geometrical conformations in the Diósi–Penrose model. This process is characterized by a namesake rate and the correlation length in the continuous spontaneous localization model, which is a dynamical reduction model of this process. Choosing to perform a certain action appears to make this process occur retroactively in Wheeler’s delayed-choice experiment. This mathematical process does not occur because of the existence of a certain universal quantity in Hugh Everett’s many-worlds interpretation. Decoherence is a theory explaining this process, which involves a single random eigenvalue being measured. For 10 points, name this process in which an observation causes a quantity representing quantum states, and denoted by psi (“sigh”), to take a single value. ■END■