Figure 1
Wikimedia Commons/Htkym

Law breaker. Maxwell’s demon opens and closes the door between two sides of a box containing a gas (top) in order to allow one side to accumulate the colder molecules and the other side the warmer ones (bottom), in apparent violation of the second law of thermodynamics. A proposed device would mimic the demon and explicitly respect the second law by generating entropy from the information content in a stream of bits.