Chaos, an English word, originated from Greek. Its original meaning is the scene before the beginning of the universe, and its basic meaning mainly refers to the chaotic state. As a scientific term, the word chaos refers to a form of motion.
The certainty of dynamic system is a mathematical concept, which means that the state of the system at any moment is determined by the initial state. Although the motion state at any time in the future can be calculated according to the initial state data and motion law, the prediction result is bound to be wrong or even unpredictable because the initial data cannot be completely accurate.
The predictability of motion is a physical concept. Even if a motion is deterministic, it can still be unpredictable, which is not contradictory. The success of Newtonian mechanics, especially the success of predicting Neptune, has caused misunderstanding to some extent, equating certainty with predictability, and holding that deterministic motion must be predictable.
The research after 1970s shows that although the system is deterministic, the chaotic motion which is extremely sensitive to the initial value of the motion state, seemingly random and unpredictable generally exists in a large number of nonlinear systems. Chaos refers to a seemingly irregular and complex form of motion that exists in the real world.
The significance of chaos research;
The discovery of chaotic motion makes people see a form of motion that is ubiquitous in nature and has been neglected for a long time, thus understanding many phenomena that were difficult to understand in the past.
The discovery of chaotic motion provides a new angle to consider this problem. For example, the problem of long-term weather forecast, the discovery of Lorentz attractor and the sensitivity of the solution of atmospheric dynamic equations to initial values have shaken the original idea that long-term weather forecast can only be solved by improving the calculation accuracy.
(3) The study of chaotic motion has important implications for the study of complex life phenomena by precise scientific methods such as physics and mathematics. Such as various biological rhythms, are neither completely periodic nor completely random.