The following is the obituary/eulogy that the NY Times wrote today
regarding the death of Claude Shannon. If you read it, you'll see how
much his ideas affect every aspect of your current lives.

I have never believed in the indispensibility of individuals,
particularly scientists. The truth is there to be discovered, and like
all truths, it's patient. There's almost an irrelevancy to who actually
gets to a new truth first. Climate and culture are undoubtedly more
important than the names of the individuals involved. If Einstein or
Newton or Darwin or Shannon had never lived, we would still know pretty
much everything we know now.

Nonetheless, Shannon ranked with Einstein and Newton and Darwin, and
that's no small thing.

Wirt Atmar


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February 27, 2001

Claude Shannon, Mathematician, Dies at 84

By GEORGE JOHNSON

Dr. Claude Elwood Shannon, the American mathematician and computer
scientist whose theories laid the groundwork for the electronic
communications networks that now lace the earth, died on Saturday in
Medford, Mass., after a long fight with Alzheimer's disease. He was 84.

Understanding, before almost anyone, the power that springs from
encoding information in a simple language of 1's and 0's, Dr. Shannon as
a young man wrote two papers that remain monuments in the fields of
computer science and information theory.

"Shannon was the person who saw that the binary digit was the
fundamental element in all of communication," said Dr. Robert G.
Gallager, a professor of electrical engineering who worked with Dr.
Shannon at the Massachusetts Institute of Technology. "That was really
his discovery, and from it the whole communications revolution has
sprung."

Dr. Shannon's later work on chess- playing machines and an electronic
mouse that could run a maze helped create the field of artificial
intelligence, the effort to make machines that think. And his ability to
combine abstract thinking with a practical approach — he had a penchant
for building machines — inspired a generation of computer scientists.

Dr. Marvin Minsky of M.I.T., who as a young theorist worked closely with
Dr. Shannon, was struck by his enthusiasm and enterprise. "Whatever came
up, he engaged it with joy, and he attacked it with some surprising
resource — which might be some new kind of technical concept or a hammer
and saw with some scraps of wood," Dr. Minsky said. "For him, the harder
a problem might seem, the better the chance to find something new."

Born in Petoskey, Mich., on April 30, 1916, Claude Elwood Shannon got a
bachelor's degree in mathematics and electrical engineering from the
University of Michigan in 1936. He got both a master's degree in
electrical engineering and his Ph.D. in mathematics from M.I.T. in 1940.

While at M.I.T., he worked with Dr. Vannevar Bush on one of the early
calculating machines, the "differential analyzer," which used a
precisely honed system of shafts, gears, wheels and disks to solve
equations in calculus.

Though analog computers like this turned out to be little more than
footnotes in the history of the computer, Dr. Shannon quickly made his
mark with digital electronics, a considerably more influential idea.

In what has been described as one of the most important master's theses
ever written, he showed how Boolean logic, in which problems can be
solved by manipulating just two symbols, 1 and 0, could be carried out
automatically with electrical switching circuits. The symbol 1 could be
represented by a switch that was turned on; 0 would be a switch that was
turned off.

The thesis, "A Symbolic Analysis of Relay and Switching Circuits," was
largely motivated by the telephone industry's need to find a
mathematical language to describe the behavior of the increasingly
complex switching circuits that were replacing human operators. But the
implications of the paper were far more broad, laying out a basic idea
on which all modern computers are built.

George Boole, the 19th-century British mathematician who invented the
two-symbol logic, grandiosely called his system "The Laws of Thought."
The idea was not lost on Dr. Shannon, who realized early on that, as he
once put it, a computer is "a lot more than an adding machine." The
binary digits could be used to represent words, sounds, images — perhaps
even ideas.

The year after graduating from M.I.T., Dr. Shannon took a job at AT&T
Bell Laboratories in New Jersey, where he became known for keeping to
himself by day and riding his unicycle down the halls at night.

"Many of us brought our lunches to work and played mathematical
blackboard games," said a former colleague, Dr. David Slepian. "Claude
rarely came. He worked with his door closed, mostly. But if you went in,
he would be very patient and help you along. He could grasp a problem in
zero time. He really was quite a genius. He's the only person I know
whom I'd apply that word to."

In 1948, Dr. Shannon published his masterpiece, "A Mathematical Theory
of Communication," giving birth to the science called information
theory. The motivation again was practical: how to transmit messages
while keeping them from becoming garbled by noise.

To analyze this problem properly, he realized, he had to come up with a
precise definition of information, a dauntingly slippery concept. The
information content of a message, he proposed, has nothing to do with
its content but simply with the number of 1's and 0's that it takes to
transmit it.

This was a jarring notion to a generation of engineers who were
accustomed to thinking of communication in terms of sending
electromagnetic waveforms down a wire. "Nobody had come close to this
idea before," Dr. Gallager said. "This was not something somebody else
would have done for a very long time."

The overarching lesson was that the nature of the message did not matter
— it could be numbers, words, music, video. Ultimately it was all just
1's and 0's.

Today, when gigabytes of movie trailers, Napster files and e-mail
messages course through the same wires as telephone calls, the idea
seems almost elemental. But it has its roots in Dr. Shannon's paper,
which may contain the first published occurrence of the word "bit."

Dr. Shannon also showed that if enough extra bits were added to a
message, to help correct for errors, it could tunnel through the
noisiest channel, arriving unscathed at the end. This insight has been
developed over the decades into sophisticated error-correction codes
that ensure the integrity of the data on which society interacts.

In later years, his ideas spread beyond the fields of communications
engineering and computer science, taking root in cryptography, the
mathematics of probability and even investment theory. In biology, it
has become second nature to think of DNA replication and hormonal
signaling in terms of information.

And more than one English graduate student has written papers trying to
apply information theory to literature — the kind of phenomenon that
later caused Dr. Shannon to complain of what he called a "bandwagon
effect."

"Information theory has perhaps ballooned to an importance beyond its
actual accomplishments," he lamented.

After he moved to M.I.T. in 1958, and beyond his retirement two decades
later, he pursued a diversity of interests — a mathematical theory of
juggling, an analog computer programmed to beat roulette, a system for
playing the stock market using probability theory.

He is survived by his wife, Mary Elizabeth Moore Shannon; a son, Andrew
Moore Shannon; a daughter, Margarita Shannon; a sister, Catherine S.
Kay; and two granddaughters.

In the last years of his life, Alzheimer's disease began to set in.
"Something inside him was getting lost," Dr. Minsky said. "Yet none of
us miss him the way you'd expect — for the image of that great stream of
ideas still persists in everyone his mind ever touched."


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