Suppose that instead of two slits for the classical experiment, we use three slits. First what pattern would appear? I tried drawing it out, but without a protractor to draw proper curves, it's hugely inaccurate and I'm too lazy right now. Anyway, to the actual meat of the question, I was wondering. If you were to put a detector at only one of the slits, what would happen to the resultant pattern on the screen detector? With two slits, detecting one meant detecting the other (because we're only given two choices), and so for whatever reason, the wave function of the particles collapse (correct me if I'm wrong). With a detector at only one of the three slits however, there would still be an uncertainty as to which of the two remaining holes the particle could go through. So would the final product be a "wave collapse" from 3-wave interference to a 2-wave interference superimposed on a single slit pattern? Or would the whole thing just collapse to a particle "pattern" just like the collapse of the 2 slit experiment?