[drudman]

In retrospect, I didn't really do justice with my explanation. There is weirder stuff involved in it that I can't really explain too well. I know the gist... the idea is that the interference is caused because the electrons are going through both slits at the same time. There is something that the experimenter can do, however, to detect which slit the electron goes through... when this detection is used, all of a sudden the electron only goes through one slit. By making the observation, we collapse the wave-function, and the electron again behaves like a particle. This is kind of related to EPR paradox, or nonlocality. Hugely fascinating stuff, and I hope that Daryn or someone else with an extensive background in physics will do a better job of explaining what we know about nonlocality.