entropy

noun
en·​tro·​py | \ ˈen-trə-pē How to pronounce entropy (audio) \
plural entropies

Definition of entropy

1 thermodynamics : a measure of the unavailable energy in a closed thermodynamic system that is also usually considered to be a measure of the system's disorder, that is a property of the system's state, and that varies directly with any reversible change in heat in the system and inversely with the temperature of the system broadly : the degree of disorder or uncertainty in a system
2a : the degradation of the matter and energy in the universe to an ultimate state of inert uniformity Entropy is the general trend of the universe toward death and disorder.— James R. Newman
b : a process of degradation or running down or a trend to disorder The deterioration of copy editing and proof-reading, incidentally, is a token of the cultural entropy that has overtaken us in the postwar years.— John Simon
4 statistical mechanics : a factor or quantity that is a function of the physical state of a mechanical system and is equal to the logarithm of the probability for the occurrence of the particular molecular arrangement in that state
5 communication theory : a measure of the efficiency of a system (such as a code or a language) in transmitting information, being equal to the logarithm of the number of different messages that can be sent by selection from the same set of symbols and thus indicating the degree of initial uncertainty that can be resolved by any one message

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Other Words from entropy

entropic \ en-​ˈtrō-​pik How to pronounce entropic (audio) , -​ˈträ-​pik \ adjective
entropically \ en-​ˈtrō-​pi-​k(ə-​)lē How to pronounce entropically (audio) , -​ˈträ-​ \ adverb

Did You Know?

With its Greek prefix en-, meaning "within", and the trop- root here meaning "change", entropy basically means "change within (a closed system)". The closed system we usually think of when speaking of entropy (especially if we're not physicists) is the entire universe. But entropy applies to closed systems of any size. Entropy is seen when the ice in a glass of water in a warm room melts—that is, as the temperature of everything in the room evens out. In a slightly different type of entropy, a drop of food coloring in that glass of water soon spreads out evenly. However, when a nonphysicist uses the word, he or she is usually trying to describe a large-scale collapse.

Examples of entropy in a Sentence

Recent Examples on the Web In a paper published in March in Physical Review Letters, Goon and Riccardo Penco broadened the lessons of the earlier work by proving a simple, universal formula relating energy and entropy. Quanta Magazine, "Black Hole Paradoxes Reveal a Fundamental Link Between Energy and Order," 28 May 2020 According to the second law of thermodynamics, the entropy of a closed, isolated system cannot shrink. Caroline Delbert, Popular Mechanics, "Quantum Steampunk Is a Real, Retrofuturistic Field of Physics," 21 Apr. 2020 Our own bad habits and the natural entropy of most systems has caused misery and burnout, and attendant self-help books. Penelope Green, New York Times, "As Economy Is Upended, Marie Kondo Drops a Workplace Book," 20 Mar. 2020 There is, in theory, at least one way to pump heat more efficiently, and that's to manipulate the entropy of solid materials. Scott K. Johnson, Ars Technica, "What if your refrigerator cooled your food by twisting wires?," 11 Oct. 2019 This tendency to equilibrate, like a cup of coffee cooling to room temperature, is the most familiar outcome of the second law of thermodynamics, which says that energy constantly spreads and the entropy of the universe always increases. Quanta Magazine, "First Support for a Physics Theory of Life," 16 June 2019 Information theorists quantify ignorance with entropy, just as thermodynamicists do. Nicole Yunger Halpern, Scientific American, "Quantum Steampunk: 19th-Century Science Meets Technology of Today," 18 Apr. 2020 As the our coronavirus isolation continues, assorted antidotes to the entropy, anomie and stress are thankfully becoming more available. Beth Segal, cleveland, "5 great recipes to spice up your virtual Happy Hour," 27 Mar. 2020 At that temperature, the resulting glass would have an entropy as low as that of a crystal. Quanta Magazine, "Ideal Glass Would Explain Why Glass Exists at All," 11 Mar. 2020

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'entropy.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of entropy

1867, in the meaning defined at sense 1

History and Etymology for entropy

International Scientific Vocabulary en- entry 2 + Greek tropē change, literally, turn, from trepein to turn

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Time Traveler for entropy

Time Traveler

The first known use of entropy was in 1867

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Statistics for entropy

Last Updated

16 Jun 2020

Cite this Entry

“Entropy.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/entropy. Accessed 3 Jul. 2020.

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More Definitions for entropy

entropy

noun
en·​tro·​py | \ ˈen-trə-pē How to pronounce entropy (audio) \
plural entropies

Medical Definition of entropy

: a measure of the unavailable energy in a closed thermodynamic system that is also usually considered to be a measure of the system's disorder and that is a property of the system's state and is related to it in such a manner that a reversible change in heat in the system produces a change in the measure which varies directly with the heat change and inversely with the absolute temperature at which the change takes place broadly : the degree of disorder or uncertainty in a system

Other Words from entropy

entropic \ en-​ˈtrōp-​ik How to pronounce entropic (audio) , -​ˈträp-​ How to pronounce entropic (audio) \ adjective
entropically \ -​i-​k(ə-​)lē How to pronounce entropically (audio) \ adverb

More from Merriam-Webster on entropy

Britannica English: Translation of entropy for Arabic Speakers

Britannica.com: Encyclopedia article about entropy

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