## FLUCTUATION (Critical)
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I. PRIGOGINE states: "We have shown that it is only in the case of linear systems that the small fluctuation can be described by POISSON's formula… For nonlinear systems farfrom equilibrium, the distribution law of the fluctuations of the reacting substances is not that of POISSON… the fluctuations are local events, and one must consider a supplementary parameter scaling the extension of the fluctuations. This will be a new characteristic length determined by the intrinsic dynamics of the system and independent of the dimensions of the reacting volume. Thus, there is an essential difference in the behavior of the fluctuations depending on their spatial extension… This… implies that… only fluctuations of a sufficient extension can attain enough importance to compromise the stability of the macroscopic state considered.

"Thus our recently developped theory leads quite naturally to the notion of a critical fluctuation as a perequisite for the appearance of an instability" (1976, p.117).

PRIGOGINE also states: "It is the fluctuation that can force the system to leave a given macroscopic state and lead it on to a new state which has a different one" (1976, p.39).

In still another paper, I. PRIGOGINE et al. write: "In dissipative structures,… the macroscopic order which arises after an instability is determined by the fastest growing fluctuation" (1975, p.38).

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Bertalanffy Center for the Study of Systems Science(2020).

To cite this page, please use the following information:

* Bertalanffy Center for the Study of Systems Science (2020).* Title of the entry. In Charles François (Ed.), International Encyclopedia of Systems and Cybernetics (2). Retrieved from www.systemspedia.org/[full/url]

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