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* [TUHS] RIP Claude Shannon
@ 2018-02-23 21:44 Dave Horsfall
  2018-02-25  0:03 ` Charles H Sauer
  0 siblings, 1 reply; 10+ messages in thread
From: Dave Horsfall @ 2018-02-23 21:44 UTC (permalink / raw)


We lost Claude Shannon on this day in 2001.  He was a mathematician, 
electrical engineer, and cryptographer; he is regarded as the "father" of 
information theory, and he pioneered digital circuit design.  Amongst 
other things he built a barbed-wire telegraph, the "Ultimate Machine" (it 
reached up and switched itself off), a Roman numeral computer ("THROBAC"), 
the Minivac 601 (a digital trainer), a Rubik's Cube solver, a mechanical 
mouse that learned how to solve mazes, and outlined a chess program 
(pre-Belle).  He formulated the security mantra "The enemy knows the 
system", and did top-secret work in WW-2 on crypto and fire-control 
systems.

-- 
Dave Horsfall DTM (VK2KFU)  "Those who don't understand security will suffer."


^ permalink raw reply	[flat|nested] 10+ messages in thread
* [TUHS] RIP Claude Shannon
@ 2018-02-24  7:28 Rudi Blom
  0 siblings, 0 replies; 10+ messages in thread
From: Rudi Blom @ 2018-02-24  7:28 UTC (permalink / raw)


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Never heard of Claude Shannon. So a good opportunity to do some
searching reading to 'catch up'.

Interesting person and this quota tends to make him my type of guy
"I just wondered how things were put together.
– C.E. Shannon"

http://themathpath.com/documents/ee376a_win0809_aboutClaudeShannon_willywu.pdf

Now wondering if I should register for this THORIAC project or just
read some more and do it. Not in the mood for learning Python I'd
probably do some fumbling in C.
https://www.engage-csedu.org/find-resources/shannons-throbac

Keeps me busy and amuzed,
uncle rubl


^ permalink raw reply	[flat|nested] 10+ messages in thread
* [TUHS] RIP Claude Shannon
@ 2018-02-25 13:16 Doug McIlroy
  2018-02-25 13:59 ` Otto Moerbeek
  0 siblings, 1 reply; 10+ messages in thread
From: Doug McIlroy @ 2018-02-25 13:16 UTC (permalink / raw)


> But a note on Dijkstra's algorithm: Moore and Dijsktra both published
> in 1959.

I was off by one on the year, but the sign of the error is debatable.

Moore's paper was presented in a conference held in early April, 1957,
proceedings from which were not issued until 1959. I learned about it
from Moore when I first I met him, in 1958. Then, he described the
algorithm in vivid, instantly understandable terms: imagine a flood
spreading at uniform speed through the network and record the
distance to nodes in order of wetting.

> But it is documented Dijkstra's algorithm has been invented and used
> by him in 1956.

Taking into account the lead time for conference submissions, one
can confidently say that Moore devised the algorithm before 1957.
I do not know, though, when it first ran on a Bell Labs computer.

That said, Moore's paper, which presented the algorithm essentially
by example, was not nearly as clear as the capsule summary he gave
me. It seems amateurish by comparison with Dijkstra's elegant treatment.
Dijkstra's name has been attached to the method with good reason.

Doug


^ permalink raw reply	[flat|nested] 10+ messages in thread
* [TUHS] RIP Claude Shannon
@ 2018-02-26 20:47 Doug McIlroy
  2018-02-26 21:16 ` Dave Horsfall
  0 siblings, 1 reply; 10+ messages in thread
From: Doug McIlroy @ 2018-02-26 20:47 UTC (permalink / raw)


> [Bob Fano}  still has a reverential photograph of Shannpn
> hanging in his office.

Alas, no, Fano died in 2016 at age 98.

More memories: Fano was among the grad students who came to 
ice-skating parties at our house in the mid-40s--the house near
Shannon's later abode. I did not really get to know him until
Multics days. His gravelly mafioso voice would scare you off--until
you saw the irrepressible twinkle in his eye. A beloved and
inspiring leader, worthy of Dave Horsfall's calendar.

Doug


^ permalink raw reply	[flat|nested] 10+ messages in thread

end of thread, other threads:[~2018-02-26 21:16 UTC | newest]

Thread overview: 10+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-02-23 21:44 [TUHS] RIP Claude Shannon Dave Horsfall
2018-02-25  0:03 ` Charles H Sauer
2018-02-25 12:44   ` Mike Markowski
2018-02-25 14:26     ` Charles H Sauer
2018-02-25 23:31   ` Bakul Shah
2018-02-24  7:28 Rudi Blom
2018-02-25 13:16 Doug McIlroy
2018-02-25 13:59 ` Otto Moerbeek
2018-02-26 20:47 Doug McIlroy
2018-02-26 21:16 ` Dave Horsfall

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