Maxwell's demon 

a hypothetical being that could separate a mixture of hot and cold water into two compartments: hot and cold water, letting the hotter-than-average portion through a trapdoor between the compartments. Maxwell's demon challenges the second law of thermodynamics: when hot and cold water are mixed, it will reach an equilibrium middling temperature.

It has emerged that Maxwell's demon can covert information into energy.

Maxwell's demon by uttam maharjan November 19, 2010