‎"SZILARD, LEO.‎
‎Über die Entropieverminderung in einem thermodynamischen System bei Eingriffen intelligenter Wesen. [On the Decrease of Entropy in a Thermodynamic System by the Invention of intelligent Beings). - [""THE EARLIEST KNOWN PAPER IN WHAT BECAME THE FIELD OF ""INFORMATION THEORY""""]‎

‎Berlin, Julius Springer, 1929. 8vo. Bound in contemporary halfcloth. In ""Zeitschrift für Physik"", Vol. 53, 1929. Entire volume offered. Library stamp to title page, otherwise fine and clean. Pp. 840-856. [Entire volume: VII,(1),889,(1) pp.]‎

Reference : 49819

‎First edition of the landmark paper in which Szilard solved the puzzle of Maxwell's demon and discovered a theoretical model that serves both as a heat engine and information engine, establishing the connection between entropy and information. ""This work is now considered to be the earliest known paper in what became the field of ""information theory"". (Lanouette, Genius in the Shadows: A Biography of Leo Szilard, the Man Behind the Bomb). In the philosophy of thermal and statistical physics, Maxwell's demon is a thought experiment created by Maxwell to show that the Second Law of Thermodynamics has only a statistical certainty. ""Maxwell's demon was first mentioned in a letter written to Tait in 1867. Maxwell was one amongst a number of researchers in the developing field of thermodynamics who was interested in seeking an understanding of thermal phenomena in terms of an underlying atomic physics. However, unlike Boltzmann and Clausius, who were attempting to prove the law of entropy increase from such atomic physics, Maxwell had realised that if thermodynamics was ultimately grounded in atomic theory, then the second law of thermodynamics could have only a statistical validity."" (SEP). Szilard (In the present paper) attempted to investigate this special case of intelligently operated devices by considering a box containing only a single molecule. He argued that in order to achieve the entropy reduction, the intelligent being must acquire knowledge of which fluctuation occurs and so must perform a measurement. The second law would not be threatened provided there was a compensating cost to performing this measurement, regardless of the character of the intelligent being.""Claude E. Shannon, who spelled out detailed relationship between information and entropy in the 1950s, also later acknowledged that Szilard's paper had proposed the basis for his new field study."" (Lanouette, Genius in the Shadows: A Biography of Leo Szilard, the Man Behind the Bomb).‎