Young’s double slit experiments express the mystery of quantum mechanics. To explore the mystery, varieties of the double slit and cross-double slit experiments were performed. In this article, we show novel universal phenomena: (1) the fringes of the interference patterns of the double slit/cross-double slit/triple slit experiments can be distributed along curves, and the curvatures depend on the orientations of the diaphragms; (2) the characteristics of the interference patterns of the double slit/cross-double slit/triple slit experiments depend on the orientation of the diaphragm, specifically, on which axis the diaphragm rotates around, the rotating angle and how to rotate, clockwise or counterclockwise; and (3) in the cross-double slit experiments, the interference patterns created by the tilt double slits tend to incline towards the axis that is perpendicular to the axis the diaphragm rotates around. The single slit experiments have the same phenomena that, due to the rotation of the diaphragm around different axis, either the patterns are curved or the patterns expanded. We show the novel universal phenomena of the single slit/double slit/cross-double slit/triple slit experiments, which may be utilized in the applications of, for example, the double slit.