National Geographic : 1967 Feb
This man is not smiling The headline you've just read is information less. It tells you nothing you haven't already learned from looking at the picture. If someone tells you your own name, he again transmits no information: you already know it. He doesn't resolve any uncertainty for you. This idea-that whatever resolves uncertainty is information-was used by Dr. Claude E. Shan non during his years at Bell Telephone Labora tories to define and measure information for the first time in a way that was usable to scientists. Starting from such basic concepts, Shannon built a theory which has many applications to problems in communication and in other fields. In 1948, he published his classic paper, "A Mathematical Theory of Communication." Before this there was no universal way of measuring the complexities of messages or the capabilities of circuits to transmit them. Shannon gave us a mathematical way of making such mea surements in terms of simple yes-or-no choices conveniently represented by binary digits, which Dr. John W. Tukey of Bell Labs and Princeton University named "bits." As a result, we now have a benchmark. We know how much information a business machine, for example, can theoretically produce. We have a means for comparing this with the information of a telephone call or a television program. We have tools to help us design for high quality and high efficiency at the lowest possible cost. Shannon's quantitative measurement of in formation is not only invaluable to the Bell System but to scientists and engineers the world over. It is exciting much interest among psychologists and workers in other fields in which information han dling is so vital.