Maxwell's demon

1. An imaginary creature who is able to sort fast-moving molecules from slow-moving molecules without adding any energy to the system. Such a creature could separate a gas into two containers, one containing hot gas and the other cold gas, bringing about a general decrease in entropy and violating the second law of thermodynamics; however, such a creature is impossible, since the act of observing the molecules to detect their speed must add energy to the system.

Example Sentences

No big deal — until you realize Maxwell’s Demon could violate the second law of thermodynamics, thereby rewinding the slow unspooling of the universe we call entropy.

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For Canales, devils like Descartes’ evil genius or Maxwell’s Demon cannot be explained away as “psychological delusions or simplistic heuristic fictions.”

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Meanwhile, Maxwell’s Demon appeared more real than perhaps even its most committed adherents had ever imagined.

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Wiener had greater ambitions for cybernetic concepts, however, and in The Human Use of Human Beings, he spells out his thoughts on its application to topics as diverse as the thought experiment Maxwell’s demon, human language, the brain, insect metabolism, the legal system, the role of technological innovation in government, and religion.

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Davies explains this connection by referring to Maxwell’s demon.

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