Im trying to get a good physical picture of what is causing the interference pattern in single slit diffraction (Im using a water wave that goes through a slit and then hits a wall Im also ignoring reflections)... Let me know if I am on the right track... I am picturing a wave front approaching the slit and Im using Huygens model to picture the "point" sources for the plane wave... I picture waves spreading out from the slit....some from the middle "source" (meaning the middle of the slit) and some from the edge "sources" (meaning from the edge of the slit). The waves created by the different sources will reach various points on the wall at different times due to path length differences. My question is can I say that the waves created by the "edge sources" will interact at a certain point on the wall with, say, the waves created by the "middle source" of the next wave front?