One of the key themes in FotC is that all known physics (with the exception of certain exotic meson decay paths) are time reversible (if you mirror charge, etc. at the same time). This includes the Schrödinger 'probability waves' that define how a wave/particle travels.

The only thing that isn't is the waveform collapse when a measurement takes place. And to this day no-one seems to to know why, how, or even what defines a measurement.