entropy English · revision 1117

+ ==Pronunciation==

+ * IPA: /ˈɛntɹəpi/^(Wiktionary)

+

+ ==Etymology==

+ It is [[bor|de|Entropie]],^(AHD)^(Barnhart 1995)^(Etymonline)^(RHWU) coined in 1865 by the physicist Rudolf Clausius on the analogy of ''Energie'',^(Etymonline)^(RHWU) from [[grc|ἐν|tr=en|t=in]] and [[grc|τροπή|tr=tropḗ|t=a turning, transformation]].^(AHD)^(Barnhart 1995)^(Etymonline)^(MW Collegiate)^(RHWU) Clausius intended the meaning “transformation content”.^(Etymonline)

+

+ ==Earliest recorded meaning==

+ In thermodynamics, a quantity that determines the condition of a body of matter, measuring the energy not available for work (1868).^(Barnhart 1995)^(Etymonline)^(OED 1989)

+

+ ==Semantic evolution==

+ Clausius used the word to state the second law of thermodynamics: “the entropy of the universe tends toward a maximum”.^(Etymonline) In statistical mechanics it became a measure of randomness or disorder,^(AHD)^(RHWU)^(MW Collegiate) and in communication theory, from 1948, a measure of the information in a message.^(OED 1989)^(AHD) By extension it means the tendency of the universe toward inert uniformity, and the steady decline of any system into disorder.^(AHD)^(MW Collegiate)^(Wiktionary)

+

+ ==Timeline==

+ * 1865 – German ''Entropie'' coined by Clausius.^(Etymonline)^(RHWU)

+ * 1868 – in English.^(Barnhart 1995)^(Etymonline)^(OED 1989)

+ * 1948 – in communication theory.^(OED 1989)

+ * 1951 – in mathematics generally.^(OED 1989)

+

+ ==Modern meaning==

+ ===Noun===

+ # In [[thermodynamics]], a measure of the [[energy]] in a closed system that is not available to do work.^(AHD)^(MW Collegiate)^(RHWU)^(Wiktionary)

+ # A measure of the disorder or randomness of a system.^(AHD)^(MW Collegiate)^(RHWU)^(Wiktionary)

+ # In [[information theory]], a measure of the information in, or loss of information from, a transmitted message.^(AHD)^(RHWU)^(OED 1989)^(Wiktionary)

+ # The supposed tendency of all matter and energy to reach a state of inert uniformity.^(AHD)^(MW Collegiate)

+ # Steady, inevitable deterioration of a system or society.^(AHD)^(Wiktionary)

+

+ ==Word family==

+ * [[entropic]]

+ * [[entropically]]

+

+ ==Related words==

+ * [[negentropy]]

+ * [[trope]]

+ * [[energy]]

+

+ ==References==

+ {{reflist}}