The two-slit experiment is an extremely important experiment as it demonstrates electrons behaving as waves, rather than as classical particles (like bullets or stones). It also reveals a very important property of the "unknowable" behaviour of quantum particles.
We will start off by looking at the two slit experiment for an ideal wave. There is no "quantum wierdness" in this description - it is a classical wave superposition problem, and has been observed for light since about 1800, when Thomas Young performed the experiment.
