Maxwell's demonMax·well's demon
An imaginary creature who is able to sort hot molecules from cold molecules without expending energy, thus bringing about a general decrease in entropy and violating the second law of thermodynamics.
Origin of Maxwell's demonAfter James Clerk Maxwell.
(plural Maxwell's demons)
- A hypothetical creature created for a thought experiment. Maxwell's demon, if it existed, would act as a sort of gate guard by sorting between higher-energy molecules and lower-energy molecules within an enclosed space. Because such a sorting process would tend to decrease entropy, it would violate the second law of thermodynamics.