Communication, Shannon and data
13
Mar
Born in the small town of Gaylord, Claude
Shannon watched the creation of telegraphs using the barbed wire of the mountain farms in his region from an early age. He soon built his own telegraph, unlike the telephone companies of the time, in the countryside they continued to use barbed wire to send messages as telegraphs.
Shannon went to study at the University of Michigan, interested in mathematics and communication, where he discovered an advertisement asking for monitors for Vannevar Bush’s famous MIT Laboratory, where students finishing their theses were looking for a machine to tabulate data, unlike Charles Babbage’s historic English computer, this was just a machine to tabulate data, we could say a nascent data science.
The MIT laboratory was where “professors and students turned to the Differential Analyzer in moments of desperation, and when it was possible to solve equations with a margin of error of 2%, the operator of the Claude Shannon Machine was happy” (Gleick, 2013, p. 181).
The circuits of this machine were made up of ordinary switches and special switches called relays, direct descendants of the telegraph and predecessors of the logic of 0 and 1, whose logic was known to Bush, called Boole’s Algebra, which Shannon learned there.
This was where the data processed by Bush’s differential analyzer and the new logic of 0 and 1 came together, the other point we made in the previous post, the concern with an intelligible language for the machine and the problem of coding and decoding messages modified into electrical signals in the logic of 0 and 1.
Claude Shannon’s important point and great collaboration, expressed in his Mathematical Theory of Communication, determined how many coded signals would be needed to maintain the integrity of the message before the coding process.
The so-called Shannon Theorem determines that a number of signals twice the highest frequency communicated through the channel are required between the sender, who precedes the message sent, and the receiver, who decodes the signal and reconstructs the message. In order for this message to remain unchanged, the number of signals in Shannon’s Theorem must be observed.
The noise problem depends exclusively on the distance and the way the signal is captured and sampled (segmented into a quantity that complies with the theorem) while the sender and receiver problem depend on the transformation of the message into a signal (i.e. the transformation of an analog signal into a digital signal and vice versa).
The message sent and the message received depend only on human sources, as the sender and receiver are electrical, digital or photonic devices. Quantum devices are already being developed and could represent greater speed and signal integrity.
Gleick. (2013) Informação: uma história, uma teoria e uma enxurrada. (Information: a history, a theory and a flood). Trad. Augusto Cali. Brazil, São Paulo: ed. Companhia das Letras.
