The word chaos originally refers to the chaotic state before the formation of the universe. Both China and ancient Greek philosophers hold the theory that the universe began with chaos, and think that the universe gradually formed an orderly world from chaos. In the orderly universe, western natural scientists have discovered many laws in nature one by one after a long discussion, such as gravity, lever principle, relativity and so on. These natural laws can be described by a single mathematical formula, according to which the behavior of objects can be accurately predicted.