Relatively speaking, physics should be the most difficult, because the experimental tools and materials needed for modern physics research are huge, and some experimental environments simply can't do it. Theoretically, the "conflict" between quantum mechanics and relativity, the two cornerstones of modern physics, has not been completely solved until now; ? Mathematics is relatively unnecessary, and the experimental environment is slightly better. Physicists are basically mathematicians, such as Newton and Dirac. ; ? Chemistry is a highly experimental science, and the relevant theories of chemistry are not completely systematic at present, so it is difficult to make progress.