更改

'''Maxwell's demon''' is a [[thought experiment]] created by the physicist [[James Clerk Maxwell]] in 1867 in which he suggested how the [[second law of thermodynamics]] might hypothetically be violated.<ref>{{cite book |author=Cargill Gilston Knott |title=Life and Scientific Work of Peter Guthrie Tait |publisher=[[Cambridge University Press]] |year=1911 |pages=213–215 |chapter=Quote from undated letter from Maxwell to Tait | chapter-url=https://archive.org/stream/lifescientificwo00knotuoft#page/212/mode/2up}}</ref> In the thought experiment, a [[Demon (thought experiment)|demon]] controls a small door between two compartments of gas. As individual gas molecules approach the door, the demon quickly opens and shuts the door so that only fast molecules are passed into one of the chambers, while only slow molecules are passed into the other. Because faster molecules are hotter, the demon's behaviour causes one chamber to warm up and the other to cool down, thereby decreasing [[entropy]] and violating the second law of thermodynamics.  This thought experiment has provoked debate and theoretical work on the relation between thermodynamics and [[information theory]] extending to the present day, with a number of scientists arguing that theoretical considerations rule out any practical device violating the second law in this way.

'''Maxwell's demon''' is a [[thought experiment]] created by the physicist [[James Clerk Maxwell]] in 1867 in which he suggested how the [[second law of thermodynamics]] might hypothetically be violated.In the thought experiment, a [[Demon (thought experiment)|demon]] controls a small door between two compartments of gas. As individual gas molecules approach the door, the demon quickly opens and shuts the door so that only fast molecules are passed into one of the chambers, while only slow molecules are passed into the other. Because faster molecules are hotter, the demon's behaviour causes one chamber to warm up and the other to cool down, thereby decreasing [[entropy]] and violating the second law of thermodynamics.  This thought experiment has provoked debate and theoretical work on the relation between thermodynamics and [[information theory]] extending to the present day, with a number of scientists arguing that theoretical considerations rule out any practical device violating the second law in this way.

Maxwell's demon is a thought experiment created by the physicist James Clerk Maxwell in 1867 in which he suggested how the second law of thermodynamics might hypothetically be violated. In the thought experiment, a demon controls a small door between two compartments of gas. As individual gas molecules approach the door, the demon quickly opens and shuts the door so that only fast molecules are passed into one of the chambers, while only slow molecules are passed into the other. Because faster molecules are hotter, the demon's behaviour causes one chamber to warm up and the other to cool down, thereby decreasing entropy and violating the second law of thermodynamics.  This thought experiment has provoked debate and theoretical work on the relation between thermodynamics and information theory extending to the present day, with a number of scientists arguing that theoretical considerations rule out any practical device violating the second law in this way.

Maxwell's demon is a thought experiment created by the physicist James Clerk Maxwell in 1867 in which he suggested how the second law of thermodynamics might hypothetically be violated. In the thought experiment, a demon controls a small door between two compartments of gas. As individual gas molecules approach the door, the demon quickly opens and shuts the door so that only fast molecules are passed into one of the chambers, while only slow molecules are passed into the other. Because faster molecules are hotter, the demon's behaviour causes one chamber to warm up and the other to cool down, thereby decreasing entropy and violating the second law of thermodynamics.  This thought experiment has provoked debate and theoretical work on the relation between thermodynamics and information theory extending to the present day, with a number of scientists arguing that theoretical considerations rule out any practical device violating the second law in this way.

== 思想的起源和历史 ==

== 思想的起源和历史 ==

The [[thought experiment]] first appeared in a letter [[James Clerk Maxwell|Maxwell]] wrote to [[Peter Guthrie Tait]] on 11 December 1867. It appeared again in a letter to [[John William Strutt]] in 1871, before it was presented to the public in Maxwell's 1872 book on [[thermodynamics]] titled ''Theory of Heat''.<ref name=Leff>[[#Leff Rex 02|Leff & Rex (2002)]], p. 370.</ref>

The [[thought experiment]] first appeared in a letter [[James Clerk Maxwell|Maxwell]] wrote to [[Peter Guthrie Tait]] on 11 December 1867. It appeared again in a letter to [[John William Strutt]] in 1871, before it was presented to the public in Maxwell's 1872 book on [[thermodynamics]] titled ''Theory of Heat''.

The thought experiment first appeared in a letter Maxwell wrote to Peter Guthrie Tait on 11 December 1867. It appeared again in a letter to John William Strutt in 1871, before it was presented to the public in Maxwell's 1872 book on thermodynamics titled Theory of Heat.

The thought experiment first appeared in a letter Maxwell wrote to Peter Guthrie Tait on 11 December 1867. It appeared again in a letter to John William Strutt in 1871, before it was presented to the public in Maxwell's 1872 book on thermodynamics titled Theory of Heat.

In his letters and books, Maxwell described the agent opening the door between the chambers as a "finite being". [[William Thomson, 1st Baron Kelvin|William Thomson (Lord Kelvin)]] was the first to use the word "demon" for Maxwell's concept, in the journal ''[[Nature (journal)|Nature]]'' in 1874, and implied that he intended the mediating, rather than malevolent, connotation of the word.<ref>{{cite journal |author=William Thomson |year=1874 |title=Kinetic theory of the dissipation of energy |journal=[[Nature (journal)|Nature]] |volume=9 |issue=232 |pages=441–444 |doi=10.1038/009441c0 |bibcode=1874Natur...9..441T|author-link=William Thomson, 1st Baron Kelvin |doi-access=free }}</ref><ref>{{cite journal |year=1879 |title=The sorting demon Of Maxwell |journal=Nature |volume=20 |issue=501 |pages=126 |bibcode=1879Natur..20Q.126. |doi=10.1038/020126a0 |doi-access=free }}</ref><ref name=Weber>{{cite book |author=Alan S. Weber |year=2000 |title=Nineteenth Century Science: a Selection of Original Texts |publisher=[[Broadview Press]] |page=300}}</ref>

In his letters and books, Maxwell described the agent opening the door between the chambers as a "finite being". [[William Thomson, 1st Baron Kelvin|William Thomson (Lord Kelvin)]] was the first to use the word "demon" for Maxwell's concept, in the journal ''[[Nature (journal)|Nature]]'' in 1874, and implied that he intended the mediating, rather than malevolent, connotation of the word.

In his letters and books, Maxwell described the agent opening the door between the chambers as a "finite being". William Thomson (Lord Kelvin) was the first to use the word "demon" for Maxwell's concept, in the journal Nature in 1874, and implied that he intended the mediating, rather than malevolent, connotation of the word.

In his letters and books, Maxwell described the agent opening the door between the chambers as a "finite being". William Thomson (Lord Kelvin) was the first to use the word "demon" for Maxwell's concept, in the journal Nature in 1874, and implied that he intended the mediating, rather than malevolent, connotation of the word.

== 最初的假想实验 ==

== 最初的假想实验 ==

The second law of thermodynamics ensures (through statistical probability) that two bodies of different [[temperature]], when brought into contact with each other and isolated from the rest of the Universe, will evolve to a thermodynamic equilibrium in which both bodies have approximately the same temperature.<ref name="Bennett87">{{cite journal

The second law of thermodynamics ensures (through statistical probability) that two bodies of different [[temperature]], when brought into contact with each other and isolated from the rest of the Universe, will evolve to a thermodynamic equilibrium in which both bodies have approximately the same temperature.{{cite journal

The second law of thermodynamics ensures (through statistical probability) that two bodies of different temperature, when brought into contact with each other and isolated from the rest of the Universe, will evolve to a thermodynamic equilibrium in which both bodies have approximately the same temperature. The second law is also expressed as the assertion that in an isolated system, entropy never decreases.

The second law of thermodynamics ensures (through statistical probability) that two bodies of different temperature, when brought into contact with each other and isolated from the rest of the Universe, will evolve to a thermodynamic equilibrium in which both bodies have approximately the same temperature. The second law is also expressed as the assertion that in an isolated system, entropy never decreases.

Maxwell构想了一个假想实验，作为进一步理解第二定律的方法。他对实验的描述如下:

Maxwell构想了一个假想实验，作为进一步理解第二定律的方法。他对实验的描述如下: