Dissipative system

The term dissipative structure (so called dissipative structure, dissipative structure ') is the phenomenon of self-organizing, dynamic, ordered structures called away to the thermodynamic equilibrium in nonlinear systems. Dissipative structures are formed only in open nonequilibrium systems that exchange energy, matter, or both with their environment. In the construction of ordered structures, the entropy decreases locally; this minimization of entropy of the system must be balanced by a corresponding exchange with the environment.

The occurrence of ordered structures is critically dependent on the system parameters, the transition from a disordered to ordered state takes place by leaps and bounds. Dissipative structures show a certain stability against external interference, decay, however, as soon as the exchange with the environment is interrupted or generally in case of major system parameters.

History

Already in 1950 Alan Turing was working on a new mathematical theory of morphogenesis, which shows the effects of non-linear chemical reaction and diffusion functions on spontaneous structure formation. The results of this work he published in 1952 under the title The chemical basis of morphogenesis. This work ( Turing mechanism) is considered crucial to the later discovery Dissipative structures.

The term dissipative structure itself was founded in 1967 suggested by the physical chemist Ilya Prigogine, who was involved, from the 1940s to the development of the theory of nonequilibrium thermodynamics. Prigogine examined with Grégoire Nicolis and R. Lefever later with the kinetics of open systems, which were held by energy and material throughput far from thermodynamic equilibrium. Based on the work of Alan Turing and Lars Onsagers he showed that. In open systems in which autocatalytic chemical reactions occur in the vicinity of thermodynamic equilibrium initially inhomogeneities occur, which may be maintained by diffusion or flow processes Upon reaching a transition point far from equilibrium, the system can show symmetry breakings by leading to the formation of a stationary orderly " dissipative structure ".

Ilya Prigogine was awarded the 1977 Nobel Prize in Chemistry for his contribution to irreversible thermodynamics, particularly the theory of " dissipative structures ".

" We have dealt with the fundamental conceptual problems did do arise from the macroscopic and microscopic aspects of the second law of thermodynamics. It is shown did non- equilibrium june become a source of order and did irreversible processes june lead to a new type of dynamic states of matter called " dissipative structures". "

Thermodynamic Description

In the construction of ordered structures, the entropy decreases locally, which is only in open systems possible (or likely). The change of the entropy of a time interval

Is divided into an inner () and outer (, exchange with the environment ) to share. In a closed system can not find a replacement instead of () and according to the second law is always ( equal to zero in equilibrium ), ie. In open systems, however, entropy can be exchanged with the environment, and there may be structures, ordered stationary (constant in time), provided ( it is in a steady state, according to the second law applies here as well )

Examples

Examples of dissipative structures are the formation of honeycomb cell structures in a heated liquid from below ( Bénard effect) or at phase boundaries on flow processes, flow equilibria in biochemistry, hurricanes, chemical clocks and candle flames. Dissipative structures have much in common with biological organisms, which is why living things are also usually counted among these.

The surface of the earth including the atmosphere forms an equilibrium distant energieumsetzendes ( dissipative ) system that absorbs energy through the sunlight and emits heat radiation into space. Within this system, a variety Dissipative structures can form, such as clouds, rivers or hurricanes.

Also, an economy is a dissipative system in which the increase in the degree of complexity increases the throughput of energy and the entropy. The so-called technical progress in the sense of the Solow residual can thus be explained by an increasing complexity to improve the performance, convert primary energy into useful work for the economic production process. Dissipative structures here are capital goods (machinery) and organization ( company ).