From Cave Paintings to the Internet A Chronological and Thematic Database on the History of Information and Media Communication / Information Theory Timeline

In “Certain Factors Affecting Telegraph Speed,” Bell System Technical Journal 3 (1924) 324–346, Harry Nyquist analyzes factors affecting telegraph transmission speed, presenting the first statement of a logarithmic law for communication, and the first examination of the theoretical bounds for ideal codes for the transmission of information.

Ralph V. R. Hartley publishes “Transmission of Information,” in which he proves "that the total amount of information that can be transmitted is proportional to frequency range transmitted and the time of the transmission."

Hartley's law eventually became one of the elements of  Claude Shannon's  mathematical theory of communication.

In "Über die Entropieverminderung in einem thermodynamischen System bei Eingrffen intelligenter Wesen," Zeitschrift für Physik 53 (1929) 840-856 physicist Leo Szilard describes a theoretical model that serves both as a heat engine and an information engine, establishing the relationship between thermodynamics (manipulation and transfer of energy and entropy,) and information (manipulation and transmission of bits).

Szilard was one of the first to show that "Nature seems to talk in terms of information" (Seife, Decoding the Universe, 77).

Claude Shannon writes Communication in the Presence of Noise.

Because of World War II censorship the report was not published until 1949.

"The sampling theorem was implied by the work of Harry Nyquist in 1928 ('Certain topics in telegraph transmission theory'), in which he showed that up to 2B independent pulse samples could be sent through a system of bandwidth B; but he did not explicitly consider the problem of sampling and reconstruction of continuous signals. About the same time, Karl Küpfmüller showed a similar result, and discussed the sinc-function impulse response of a band-limiting filter, via its integral, the step response Integralsinus; this bandlimiting and reconstruction filter that is so central to the sampling theorem is sometimes referred to as a Küpfmüller filter (but seldom so in English).

"The sampling theorem, essentially a dual of Nyquist's result, was proved by Claude E. Shannon in 1949 ('Communication in the presence of noise'). V. A. Kotelnikov published similar results in 1933 ('On the transmission capacity of the 'ether' and of cables in electrical communications', translation from the Russian), as did the mathematician E. T. Whittaker in 1915 ('Expansions of the Interpolation-Theory', 'Theorie der Kardinalfunktionen'), J. M. Whittaker in 1935 ('Interpolatory function theory'), and Gabor in 1946 ('Theory of communication')" (Wikipedia article on Nyquist-Shannon Sampling Theorem, accessed 01-04-2010).

Having collaborated with Julian Bigelow, an engineer, Norbert Wiener publishes, as a classified document, The Extrapolation, Interpretation and Smoothing of Stationery Time Series.

According to Claude Shannon , this work contained “the first clear-cut formulation of communication theory as a statistical problem, the study of operations on time series.”

Claude Shannon publishes his Mathematical Theory of Communication. The theory determined how much information could be sent per unit of time in a system with a given, limited amount of transmission power. Shannon also introduced the term "bit" into the literature, and provided its current meaning in the context of information. (See Reading 12.2.)

Claude Shannon's report, originally issued as a classified document entitled A Mathematical Theory of Cryptography, Memorandum MM 45-110-02, September 1, 1945,  is formally published as "Communication Theory of Secrecy Systems" in Bell System Technical Journal, 28(4), 656–715.  This paper, discussing cryptography from the viewpoint of information theory, contained a proof that all theoretically unbreakable ciphers must have the same requirements as the one-time pad.

Noam Chomsky publishes "Three Models for the Description of Language" in IRE Transactions on Information Theory IT-2  113-24.

In this work read at a symposium on information theory held at MIT a few months before the publication of his Syntactic Structures (1957), Chomsky introduced two key concepts— 'Chomsky's hierarchy' of syntactic forms, and transformational-generative grammar theory.  The latter attempts to define rules that can generate the infinite number of grammatical (well-formed) sentences possible in a language, and works to identify rules (transformations) that govern relations between parts of a sentence, on the assumption that beneath such aspects as word order a fundamental deep structure exists.

Hook & Norman, Origins of Cyberspace (2002) no. 531.

Leonard Kleinrock publishes his 1962 PhD thesis in book form as Communication Nets: Stochastic Message Flow and Delay, providing a technology and mathematical theory of data communications. (See Reading 13.4.)

American mathematician and researcher in artificial intelligence Ray Solomonoff publishes "A Formal Theory of Inductive Inference, Part I" Information and Control, 7, No. 1, 1-22,  and  "A Formal Theory of Inductive Inference, Part II," Information and Control, 7, No. 2,  224-254.

This two-art paper is considered the beginning of algorithmic informatiion theory.

Solomonoff first described his results at a Conference at Caltech, 1960, and in a report of February, 1960: "A Preliminary Report on a General Theory of Inductive Inference."