Animation of plane waves passing through a single slit, resulting in interference patterns. Various parameters are colour-coded here. The amplitude of the resulting waves varies from white (highest) through yellow and red to black (lowest). At the bottom of the screen, the intensity parallel to the apertures varies from black (lowest) through blue to pink (highest). Superimposed on that, the intensity distribution at that location is represented by the green line. The width of the slit increases over time, producing different patterns.