Hello, folks - The descriptions I read for laymen say that once a particle is measured or observed, it's wave function collapses and it becomes a well defined, deterministic object. Then if that same particle remains unobserved after the intitial measurement, the wave function re-emerges and the particle becomes indeterminate again. My questions are: What kind of time scale doe this return to indeterminacy happen on? How long does the particle remain in a well defined state before we need to describe it with a wave function again? Is there some period of time after a particle is measured and its wave function collapses when we can accurately measure both it's position and momentum? Have there ever been any experiments where we have seen the wave function of a measured particle return? For instance, imagine a double version of the 2 slit experiment. We detect the particle at the slits of a first screen, making it's wave function collapse - but then it speeds on not to a detector, but to a second screen with two slits, with the detector behind the second screen. If the particle regains its wave function after measurement at the first screen, we would see interference patterns on the detector behind the second screen. Has anything like this been tried? Thanks!