Entropy (disambiguation)

From Wikipedia, the free encyclopedia
Jump to: navigation, search

Additional relevant articles may be found in the following categories:

Entropy, in thermodynamics, is a state function originally introduced to explain why part of a thermodynamic system's total energy is unavailable to do useful work.

Entropy may also refer to:

Thermodynamics and statistical mechanics[edit]

  • Entropy (classical thermodynamics), thermodynamic entropy in purely 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 (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

Introductory articles[edit]

Other aspects[edit]

Information theory and mathematics[edit]

  • Entropy (information theory), also called Shannon entropy, a measure of the unpredictability or information content of a message source.
  • Algorithmic entropy an (incomputable) measure of the information content of a particular message.
  • Rényi entropies, a family of diversity measures generalising Shannon entropy; used to define fractal dimensions.
  • Measure theoretic entropy, a measure of exponential growth in dynamical systems; equivalent to the rate of increase of Shannon entropy of a trajectory in trajectory-space.
  • Topological entropy, a measure of exponential growth in dynamical systems; equivalent to the rate of increase of α->0 Renyi entropy of a trajectory in trajectory-space.
  • Volume entropy, a Riemannian invariant measuring the exponential rate of volume growth of a Riemannian metric
  • Maximum entropy (disambiguation)

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

Media[edit]

Film and television[edit]

Games[edit]

Literature[edit]

Music[edit]

Software[edit]