# Entropy (disambiguation)

Entropy is a scientific concept that is most commonly associated with a state of disorder, randomness, or uncertainty.
Entropy may also refer to:

## Science and technology
### Physics

* Entropy (classical thermodynamics), thermodynamic entropy in macroscopic terms, with less emphasis on the statistical explanation
* 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
* Entropy (order and disorder), the relationship of disorder with heat and work
* Entropy in thermodynamics and information theory, the relationship between thermodynamic entropy and information (Shannon) entropy
* Entropy (energy dispersal), dispersal of energy as a descriptor of entropy
* Entropy (astrophysics), the adiabatic constant

### Information theory and mathematics

* Entropy (information theory), also called Shannon entropy, a measure of the unpredictability or information content of a message source
* Differential entropy, a generalization of Entropy (information theory) to continuous random variables
** Entropy of entanglement, related to the Shannon and von Neumann entropies for entangled systems; reflecting the degree of entanglement of subsystems
* Algorithmic entropy an (incomputable) measure of the information content of a particular message
* Rényi entropy, a family of diversity measures generalising Shannon entropy; used to define fractal dimensions
* 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
* Graph entropy, a measure of the information rate achievable by communicating symbols over a channel in which certain pairs of values may be confused

### Other uses in science and technology

* 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

## Arts and entertainment
### Film and television

* Entropy (film), a 1999 film by Phil Joanou
* "Entropy" (Buffy episode), 2002
* "Entropy", an episode of Criminal Minds season 11

### Games

* Entropy (board game)
* Entropy (video game)
* Entropy or Alchemiss, a character in Freedom Force vs the 3rd Reich
* N. Tropy, a character from Crash Bandicoot: Warped
* Entropy: Zero, a Source mod for Half-Life 2 released in 2017 developed by Breadman
* Entropy: Zero 2, a sequel to Entropy: Zero released in 2022
* Entropy: Zero - Uprising, a mod of Entropy: Zero developed by Employee8 and Filipad

### Literature

* Entropy: A New World View, a book by Jeremy Rifkin and Ted Howard
* "Entropy", a 1960 short story by Thomas Pynchon
* "Entropy", a 1995 short story by Leanne Frahm
* Entropy (journal), a scientific journal published by MDPI
* Entropy (magazine), an online literary magazine

### Music

* Entropy, a 2005 album by Anathallo and Javelins
* Entropy / Send Them, an EP by DJ Shadow and the Groove Robbers
* "Entropy", a song by Bad Religion from Against the Grain
* "Entropy", a song by Kelly Osbourne from Sleeping in the Nothing
* "Entropy", a song by VNV Nation from Matter + Form
* "Entropy", a song by Moxy Früvous from The 'b' Album
* "Entropy", a song by Brymo from Oṣó
* "Entropy", a song by Daniel Caesar from Case Study 01
* "Entropy", a song by MC Hawking
* "Entropy", a song by Grimes and Bleachers
* Entropia (album), an album by Pain of Salvation
* Entropy, a track by Nigel Stanford
* The Book Of Us: Entropy, an album by DAY6

### Other uses in arts and entertainment

* Entropy (choreography), the difference between a transcription and a performance

## Other uses

* Entropy (package manager), a Sabayon Linux package manager
* Information entropy, relating to disruptive actions taken in Internet vigilantism