entropy: difference between revisions

From Wiktionary, the free dictionary
Jump to navigation Jump to search
Browse history interactively
← Go to previous editGo to next edit →
Content deleted Content added
VisualWikitext
Rukhabot (talk | contribs)
Bots
4,643,261 edits
m interwikis: +ca:entropy
→‎Noun: removing seemingly-prescriptive statement (Talk:entropy)
Line 18: Line 18:
## The capacity factor for thermal energy that is hidden with respect to [[temperature]] [http://arxiv.org/pdf/physics/0004055].
## The capacity factor for thermal energy that is hidden with respect to [[temperature]] [http://arxiv.org/pdf/physics/0004055].
## The dispersal of energy; how much energy is spread out in a process, or how widely spread out it becomes, at a specific temperature. [http://www.entropysite.com/students_approach.html]
## The dispersal of energy; how much energy is spread out in a process, or how widely spread out it becomes, at a specific temperature. [http://www.entropysite.com/students_approach.html]
# {{context|statistics|information theory|countable|lang=en}} A [[measure]] of the [[amount]] of [[information]] and [[noise]] [[present]] in a [[signal]]. Originally a [[tongue-in-cheek]] coinage, has fallen into disuse to avoid confusion with thermodynamic entropy.
# {{context|statistics|information theory|countable|lang=en}} A [[measure]] of the [[amount]] of [[information]] and [[noise]] [[present]] in a [[signal]].
# {{context|uncountable|lang=en}} The [[tendency]] of a system that is left to itself to descend into [[chaos]].
# {{context|uncountable|lang=en}} The [[tendency]] of a system that is left to itself to descend into [[chaos]].


Revision as of 21:42, 12 December 2015

English

Pronunciation

Etymology

First attested in 1868. From German (deprecated template usage) Entropie, coined in 1865 by Rudolph Clausius, from (deprecated template usage) [etyl] Ancient Greek (deprecated template usage) ἐντροπία (entropía), from (deprecated template usage) ἐν (en) + (deprecated template usage) τροπή (tropḗ).

Noun

English Wikipedia has an article on:
Wikipedia

entropy (countable and uncountable, plural entropies)

  1. (deprecated template usage) (thermodynamics, countable)
    1. strictly thermodynamic entropy. A measure of the amount of energy in a physical system that cannot be used to do work.
      The thermodynamic free energy is the amount of work that a thermodynamic system can perform; it is the internal energy of a system minus the amount of energy that cannot be used to perform work. That unusable energy is given by the entropy of a system multiplied by the temperature of the system.[1] (Note that, for both Gibbs and Helmholtz free energies, temperature is assumed to be fixed, so entropy is effectively directly proportional to useless energy.)
    2. A measure of the disorder present in a system.
      Ludwig Boltzmann defined entropy as being directly proportional to the natural logarithm of the number of microstates yielding an equivalent thermodynamic macrostate (with the eponymous constant of proportionality). Assuming (by the fundamental postulate of statistical mechanics), that all microstates are equally probable, this means, on the one hand, that macrostates with higher entropy are more probable, and on the other hand, that for such macrostates, the quantity of information required to describe a particular one of its microstates will be higher. That is, the Shannon entropy of a macrostate would be directly proportional to the logarithm of the number of equivalent microstates (making it up). In other words, thermodynamic and informational entropies are rather compatible, which shouldn't be surprising since Claude Shannon derived the notation 'H' for information entropy from Boltzmann's H-theorem.
    3. The capacity factor for thermal energy that is hidden with respect to temperature [2].
    4. The dispersal of energy; how much energy is spread out in a process, or how widely spread out it becomes, at a specific temperature. [3]
  2. (deprecated template usage) (statistics, information theory, countable) A measure of the amount of information and noise present in a signal.
  3. (deprecated template usage) (uncountable) The tendency of a system that is left to itself to descend into chaos.

Synonyms

Antonyms

Derived terms

Translations

The translations below need to be checked and inserted above into the appropriate translation tables. See instructions at Wiktionary:Entry layout § Translations.
Retrieved from "https://en.wiktionary.org/w/index.php?title=entropy&oldid=35696577"