In everyday speech, chaos means disorder, crowd, unpredictability, etc. In philosophy, chaos is used in the terms of pro-matter, primordial space, that is, what became before order was brought into our world. In psychology, the word chaos raises fears that order will disappear and disorder will reign again. Chaos is a new field of science, but also a new way of observing the world. So, for physicists, engineers, economists, doctors, biologists, sociologist, psychologists, psychiatrists etc., chaos means an incentive to re-examine their equations, data, knowledge and beliefs. Chaos enabled a systematic approach to phenomena and systems of great internal complexity as well as an understanding of seemingly extremely simple phenomena. Many (but not all) scientists agree that after the theory of relativity and quantum physics, chaos is the third scientific revolution.Is theory of chaos the third scientific revolution?