Re:Hrm (Score 1)

Its another example of the interference of probability waves. The reason you see fringes (constructive/destructive interference) with these sorts of experiments seems to be that the probability for a single particle (photon, electron, whatever) to follow one path interferes with its probabilities to follow other paths. In this case you set up a detector that sees an ionization event that is potentially caused by one of two sources ... each has its own probability, giving rise to the sort of interference we're familiar with from the traditional double-slit experiment. Incidentally, I think its a bit misleading to call it a double-slit in time instead of space. Point is, its a new way to arrange probabilities that interfere.