# Has maxwells demon really been proved impossible

**URL:** <https://boards.straightdope.com/t/has-maxwells-demon-really-been-proved-impossible/796347>\
**Category:** Factual Questions\
**Created:** [September 14, 2017, 9:24pm UTC](https://boards.straightdope.com/t/has-maxwells-demon-really-been-proved-impossible/796347 "2017-09-14T21:24:03Z")\
**Posts on this page:** 2\
**Page:** 4

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**Author:** ![DPRK](https://avatars.discourse-cdn.com/v4/letter/d/4491bb/32.png) [@DPRK](https://boards.straightdope.com/u/DPRK)\
**Post date:** [September 20, 2017, 10:49pm UTC](https://boards.straightdope.com/t/has-maxwells-demon-really-been-proved-impossible/796347/61 "2017-09-20T22:49:55Z")

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I guess you could talk about the (Kolmogorov) complexity of a given string, versus the entropy of a dynamical system, but the two notions amount to the same thing if the string is generated by the system, as explained [here](http://www.loria.fr/~hoyrup/random_ergodic.pdf). There is always the possibility that you flip a fair coin 100 times and it lands on Heads each time, thus producing a string with a short description, but the point is that this is unlikely.

ETA this is a purely mathematical statement and has nothing to do with physical entropy specifically.

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**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\
**Post date:** [September 21, 2017, 1:49am UTC](https://boards.straightdope.com/t/has-maxwells-demon-really-been-proved-impossible/796347/62 "2017-09-21T01:49:00Z")

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Except that the purely mathematical statement pretty much is the modern description of physical entropy.

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