Entropy (disambiguation)

From Wikipedia, the free encyclopedia

Entropy, in thermodynamics, is a property originally introduced to explain the part of the internal energy of a thermodynamic system that is unavailable as a source for useful work.

Entropy may also refer to:

Thermodynamics and statistical mechanics[edit]

  • Entropy (classical thermodynamics), thermodynamic entropy in macroscopic terms, with less emphasis on the statistical explanation
    • Entropic force. The product of temperature and the gradient of the entropy density is viewed an effective force, yielding a gradient in the energy density of a system.
    • Entropy production. Development of entropy in a thermodynamic system.
  • Entropy (statistical thermodynamics), the statistical explanation of thermodynamic entropy based on probability theory
    • Configuration entropy, the entropy change due to a change in the knowledge of the position of particles, rather than their momentum
    • Conformational entropy, the entropy change due to a change in the "configuration" of a particle (e.g. a right-handed vs. a left-handed polyatomic molecule)
  • Tsallis entropy, a generalization of Boltzmann-Gibbs entropy
  • von Neumann entropy, entropy in quantum statistical physics and quantum information science

Introductory articles[edit]

Other aspects[edit]

Information theory and mathematics[edit]

Other uses in science and technology[edit]

  • Entropy encoding, data compression strategies to produce a code length equal to the entropy of a message
  • Entropy (computing), an indicator of the number of random bits available to seed cryptography systems
  • Entropy (anesthesiology), a measure of a patient's cortical function, based on the mathematical entropy of EEG signals
  • Entropy (ecology), measures of biodiversity in the study of biological ecology, based on Shannon and Rényi entropies
  • Social entropy, a measure of the natural decay within a social system


Film and television[edit]