Young’s double slit experiment was called as "a phenomenon […] has in it the heart of quantum mechanics. In reality, it contains the only mystery. We cannot make the mystery go away by ‘explaining’ how it works". To study the mystery, we perform the non-crossing-slit-experiments and crossing-slit experiments and show phenomena:
(1) in the same double slit or cross double slit experiments, the non-interference patterns gradually evolve to the interference patterns; (2) in the same single slit or cross single slit experiments, the non-diffraction patterns gradually evolve to the diffraction patterns; (3) in the same two-non-parallel-slits experiment, the non-wave patterns gradually evolve to the hybrid pattern (i.e., interference-pattern-embedded-in-diffraction-pattern); (4) in the same curved-double slit experiments, the non-interference patterns evolve to Seashell-shape interference patterns. The above phenomena show new mysteries that are more mysterious than that of the double slit experiments: it is challenge to consistently explain how they work. Those novel phenomena indicate that the standard theories of the double slit are incomplete. Novel experiments bring the search for the new theory of physical/quantum optics