Ralph Hartley

Ralph Vinton Lyon Hartley, who lived from 30 November 1888 to 1 May 1970, was an American electronics researcher born in Sprucemont, Nevada. He studied at the University of Utah, graduating in 1909, and as a Rhodes Scholar at Oxford, receiving degrees in 1912 and 1913. At the Research Laboratory of Western Electric, whose research division later became Bell Laboratories, he developed the Hartley oscillator, for which a patent was filed in 1915 and awarded in 1920, and he is also credited with the Hartley transform. In 1928 he formulated the law that the total amount of information that can be transmitted is proportional to the frequency range transmitted and the time of the transmission, a paper described as the single most important prerequisite for Shannon's theory of information. The hartley, a unit of information equal to one decimal digit, is named after him. He received the IRE Medal of Honor in 1946 and retired from Bell Laboratories in 1950.