I just posted this as a reply, but i figured Id open a new thread for discussion. correct me if im wrong here. according to the double slit experiment, a photon takes every possible path to it's destination, causing it to interfere with itself, right? My first question is, does each separate path have a different probability of occuring, or do they all have the same probability? and if they do have the same probability, how would a photon know it's destination if more than one path intersects with an object? Couldnt the photon just as easily have appeared on the double slit cover rather than the photosensitive sheet? This would sort of signify that a photon knows it's destination before it get's there. otherwise, we might observe the same photon hitting more than one object, and therefore being at multiple places at one time. am i looking at this completely wrong here? add-on question: since only one path can be a straight line, the other paths would be larger, whch would mean the photon would take longer on those paths. "Every possible path", to me, means even the one that travels in 9 loops across the galaxy just to go three feet away. Wouldnt we observe that a photon arrives someplace more than once? none of this makes sense to me.