Disordered movement

As a disordered movement is called the random , in the sense of unpredictable motion of one or more particles. One observes them in nature, for example in the Brownian movement . In statistical physics , these phenomena are described mathematically with the help of the theory of stochastic processes . The Langevin equation and the Fokker-Planck equation are often used to describe the continuous disordered movement .

Individual molecules in gases move in a disorderly manner and thus generate mechanical pressure through elastic collisions on the walls . Although the microscopic movement of individual particles is disordered, macroscopic measured quantities are not affected. This always follows from the central limit theorem of statistics.

An ordered movement becomes a disordered movement either through thermal coupling to a heat bath , as is the case with Brownian movement, or through the achievement of unstable paths in phase space , which generate unpredictable trajectories that appear disordered, chaotic . (see also strange attractor )

The transition from the ordered to the disordered state of motion is always associated with a production of entropy .