Claude Shannon’s Information theory

1. Claude Shannon’sInformation theory Carlos V. Martinez • Professor Shannon, a distant relative of Thomas Edison, was affiliated with Bell Laboratories from 1941 to 1972, during which time he wrote the landmark A Mathematical Theory of Communication (1948). • The information content of a message, he theorized, consists simply of the number of 1s and 0s it takes to transmit it.

2. Describing the Invention • One of the basic postulates of information theory is that information can be treated like a measurable physical quantity, such as density or mass. • Information Theory regards information as only those symbols that are uncertain to the receiver. For years, people have sent telegraph messages, leaving out non-essential words such as "a" and "the." In the same vein, predictable symbols can be left out, like in the sentence, "only infrmatn esentil to understandn mst b tranmitd." Shannon made clear that uncertainty is the very commodity of communication. • Information theory identified the critical relationships among the elements of a cumminication system-the power at the source of a signal; the bandwidth or frequency range of an information channel through which the signal travels; and the noise of the channel, such as unpredictable static on a radio, which will alter the signal by the time it reaches the last element o the system, the reciever which must decode the signal.

3. Desribing the invention (cont.) • Shannon’s theory information told engineers how much information could be transmitted over the channels of an ideal system. He also spelled out mathematicially the principles of “data compression,” which recongnize what the end of this sentence demonstrates, that “only infrmatn esentil to understadn mst b tranmitd.” And he showed how we could transmit information over noisy channels at error rates we could control.

4. Why is the Information Theory Important? • Thanks in large measure to Shannon's insights, digital systems have come to dominate the world of communications and information processing. • Modems • satellite communications • Data storage • Deep space communications • Wireless technology

5. Why is the Information Theory Important? (cont.) • Shannon inspired an explosion of creative ways for compressing bits (extracting only the "real" information), encoding them for sending over a channel, and interpreting them later or elsewhere with any desired level of accuracy. • With Shannon's insight in mind, engineers and others continue to develop ways to maximize another communications breakthrough— the invention of the transistor.

6. Claude Shannon’s life • Claude Elwood Shannon was born in Gaylord, Michigan, on April 30, 1916, to Claude Elwood and Mabel Wolf Shannon. • Shannon's grandfather was an inventor and a farmer. He invented the washing machine along with many others farming machinery. • soon after his ground-breaking work, Claude Shannon stopped working actively in Information Theory relatively. He left a lot of unplowed ground that many of us were able to develop. Had he kept working in the field, he might have put many of us out of business.

7. Shannon’s life cont.(toy room) • Shannon’s toy room consisted of chess-playing machines include one that moves the pieces with a three-fingered arm, beep and makes wary comments. A chair lift that he built to take his three children 600 feet down to the lakeside has been taken down now that they are grown. Shannon's lifelong fascination with balance and controlled instability has led him to design a unicycle with an off-center wheel to keep the rider steady while juggling. Shannon love to juggle since he was a kid. In his toy room is a machine with soft beanbag hands that juggle steel balls. His juggling masterpiece is a tiny stage on which three clowns juggle 11 rings, 7 balls, and 5 clubs, all driven by an invisible mechanism of clockwork and rods.

8. Story around the invention • Shannon received his BS degrees in mathematics and electrical engineering from the University of Michigan in 1936. • Upon graduation, he became a research fellow at the Institute for Advanced Study in Princeton, New Jersey, and joined Bell Laboratories in New Jersey in 1941. • While at Bell Labs, he met Mary Elizabeth "Betty" Moore, a numerical analyst, whom he married in 1949. In 1956, Dr. Shannon became a visiting professor at MIT and the family settled on Mystic Lake in Winchester, Mass. He was MIT's Donnor Professor of Science from 1958-78, when he became professor emeritus. • During World War II, Dr. Shannon, a noted cryptographer, worked on secrecy systems at Bell Labs. His team's work on anti-aircraft directors--devices that observe enemy planes or missiles and calculate the aim of counter missiles--became crucial when German rockets were used in the blitz of England. His 1949 paper entitled "Communication Theory of Secrecy Systems" is generally credited with transforming cryptography from an art to a science.

9. How the invention was brought up • He came to MIT as a graduate student. As a part-time job, he worked on Professor Vannevar Bush's differential analyzer. His master's thesis, "A Symbolic Analysis of Relay and Switching Circuits," used Boolean algebra--in which problems are solved by manipulating two symbols, 1 and 0--to establish the theoretical underpinnings of digital circuits. This work was the beginning of modern switching theory. Harvard University Professor Howard Gardner called it "possibly the most important, and also the most famous, master's thesis of the century." Which ultimately led to the development of Information Thesis.

10. Claude Shannon landmark • Claude Shannon was a curious man, a juggler who rode his unicycle in the hallways of AT&T Bell Laboratories and the mathematician who laid the foundation for all digital communications back when the biggest pipes could carry only 1,800 voice conversations at a time. He died Feb. 24 at the age of 84. • In the 1990's, he developed Alzheimer's disease, and slowly withdrew from public life. He was unable to attend a statue dedication in his hometown of Gaylord, Michigan in 2000, and he died in 2001, at the age of 84.