Maxwell's Demon
A tiny creature sorting fast molecules from slow ones appears to make heat flow the wrong way, for free, forever.
1867 (letter to Tait), 1871 (published in Theory of Heat)18 min read
American physics of information
Charles H. Bennett
1943
IBM researcher, co-inventor of quantum key distribution (1984, with Gilles Brassard) and quantum teleportation (1993). In 1973 he showed that computation can in principle be made logically reversible, and in 1982 he used that result to close the Maxwell's-demon problem: the demon's measurement need cost nothing, but clearing its memory to measure again must pay Landauer's bill.