From Wikipedia, the free encyclopedia

This article or section is in need of attention from an expert on the subject. WikiProject Physics or the Physics Portal may be able to help recruit one. If a more appropriate WikiProject or portal exists, please adjust this template accordingly.

Chaos in physics is often considered analogous to thermodynamic entropy. Chaos is a poetic or metaphysical concept evoking a sense of discord, whereas entropy is a concretely defined function of a physical system. See entropy for the mathematical quantification of the disorder in a system. The term "chaos", as commonly used, denotes utter confusion, an incomprehensible and heterogeneous mess. This intuitive notion is at odds with the famous Second Law of Thermodynamics, which states that entropy cannot decrease in a closed system. Maximized entropy always corresponds to apparent homogeneity in a system. Any random disturbance of a homogeneous system results in no meaningful change, therefore scientists will say the randomness, i.e. chaos, is maximized. Such systems are observed as being isotropic.

As with any scientific concept or mathematical abstraction, entropy may not be equally applicable in every situation. For example, it is unknown whether protons may remain forever free and unchanged, or whether they are subject to destruction by cosmological randomness.

Chaos theory describes the behavior of certain nonlinear dynamical systems that under certain conditions exhibit a phenomenon known as chaos. Among the characteristics of chaotic systems, described below, is sensitivity to initial conditions (popularly referred to as the butterfly effect). As a result of this sensitivity, the behavior of systems that exhibit chaos appears to be random, even though the system is deterministic in the sense that it is well defined and contains no random parameters.

However, chaos as defined in physics is strongly contrasted with the common definition of chaos. Chaotic systems, with no central control, are able to create "order"; that is to say, they may form a pattern that humans recognize. Biological systems are well-known examples. Potential applications are found in nanotechnology, where self-assembling systems have been developed.

• Self-organization
• Evolutionary theory.
• Attractor