Higher, directed forms of energy (e. g., mechanical, electric, chemical) are dissipated, that is, progressively converted into the lowest form of energy, i. e., undirected heat movement of molecules; chemical systems tend toward equilibria with maximum entropy; machines wear out owing to friction; in communication channels, information can only be lost by conversion of messages into noise but not vice versa, and so forth.

p. 75 as cited in: Jan Kåhre (2002) The Mathematical Theory of Information. p. 175-6 - Robots, Men and Minds' (1967)