Information Technology Reference
In-Depth Information
the use of 'cyber' as a modish prefix, as in 'Cyberculture' or 'Cyber-
feminism'. Such usage demonstrates how deeply the ideas of the
post-war cybernetic era are embedded in our current digital culture.
Information Theory was developed by Claude Shannon, an elec-
trical engineer trained at the University of Michigan and the
Massachusetts Institute of Technology. Before the War he had
worked with Vannevar Bush on the Differential Analyser. A summer
internship at AT & T's Bell Laboratories helped formulate the ideas
behind his thesis for his master's degree in electrical engineering,
'A Symbolic Analysis of Relay and Switching', which looked at the
application of boolean logic using telephone relays. This generated
far more interest than his thesis for his PhD in mathematics and, in
light of the development of digital technology, has been described as
one of the most significant master's theses of the twentieth century.
His interest in communications continued in the War with work in
cryptography, and on developing ways of scrambling audio signals
with Project X at the Bell Labs, as well as his research into anti-
aircraft missile control systems. These experiences led him to write
a memorandum at Bell, entitled 'Communication Theory of Secrecy
Systems', which outlined a mathematical analysis of communica-
tions systems. These ideas were expanded and made public in
1949
when Shannon published his topic, written in collaboration with
mathematician Warren Weaver, entitled
A Mathematical Theory of
Communication
,
1
which built on the work of other researchers at
Bell Labs, including Harry Nyquist and R.V.L. Hartley. In this
canonical work Shannon developed a linear schema of the commu-
nication process consisting of the following elements: the source of
a message; the device that encodes the message for transmission; the
channel along which the message is sent; the device that decodes the
message; and the message's destination. In the case of a telephone
call these elements would be represented by the person speaking
into the phone; the telephone itself; the cable that transmits the
