[TUHS] [TUHS} RIP Claude Shannon

[TUHS] [TUHS} RIP Claude Shannon

[Doug McIlroy]

So many memories. The "ultimate machine" (which was brought out and
demonstrated from time to time while I was at the Labs) was built in
collaboration with Ed Moore (he of Moore-model automata, who published
"Dijkstra's algorithm" for shortest paths a year before Dijkstra) and
(I believe) Dave Hagelbarger. Moore endowed the machine with a longevity
property seldom remarked on: majority logic so that any electrical
component can be removed without harming its observable behavior.

Shannon moved to MIT from Bell Labs some weeks before I moved the
other way, so I only met him much later when he visited the Unix room
(an excuse, albeit weak, for this distant detour from TUHS). By that
time Shannon was descending into Alzheimer's fog, but his wife who
accompanied him was a memorably curious and perceptive visitor. I have
wondered what role she may have played as a sounding board or more in
Shannon's research.

As a child, I used to ski on the 50-foot hill that was the lawn of the
mansion that Shannon would buy when he moved to Massachusetts. We kids
would ski down and climb back up. Not Shannon. He installed a chairlift.
One house separated mine from the ski hill. It belonged to John Trump,
another MIT prof who engineered the Van de Graaff generator into a
commercial product for generating million-volt x-rays and, yes, was uncle
of the Donald. John, as kind as he was bright, fortunately did not live
to see the apotheosis of his wayward nephew.

Doug


> 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.

[TUHS] [TUHS} RIP Claude Shannon

[Larry McVoy]

Just for the record, I love these memories.  A glimpse into history.
Detours like these are very welcome in my opinion.

I had forgotten about this: https://www.youtube.com/watch?v=Gw2Bq0HYu1M

On Sat, Feb 24, 2018 at 10:51:19AM -0500, Doug McIlroy wrote:
> So many memories. The "ultimate machine" (which was brought out and
> demonstrated from time to time while I was at the Labs) was built in
> collaboration with Ed Moore (he of Moore-model automata, who published
> "Dijkstra's algorithm" for shortest paths a year before Dijkstra) and
> (I believe) Dave Hagelbarger. Moore endowed the machine with a longevity
> property seldom remarked on: majority logic so that any electrical
> component can be removed without harming its observable behavior.
> 
> Shannon moved to MIT from Bell Labs some weeks before I moved the
> other way, so I only met him much later when he visited the Unix room
> (an excuse, albeit weak, for this distant detour from TUHS). By that
> time Shannon was descending into Alzheimer's fog, but his wife who
> accompanied him was a memorably curious and perceptive visitor. I have
> wondered what role she may have played as a sounding board or more in
> Shannon's research.
> 
> As a child, I used to ski on the 50-foot hill that was the lawn of the
> mansion that Shannon would buy when he moved to Massachusetts. We kids
> would ski down and climb back up. Not Shannon. He installed a chairlift.
> One house separated mine from the ski hill. It belonged to John Trump,
> another MIT prof who engineered the Van de Graaff generator into a
> commercial product for generating million-volt x-rays and, yes, was uncle
> of the Donald. John, as kind as he was bright, fortunately did not live
> to see the apotheosis of his wayward nephew.
> 
> Doug
> 
> 
> > 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.

-- 
---
Larry McVoy            	     lm at mcvoy.com             http://www.mcvoy.com/lm 

[TUHS] [TUHS} RIP Claude Shannon

[Otto Moerbeek]

On Sat, Feb 24, 2018 at 10:51:19AM -0500, Doug McIlroy wrote:

> So many memories. The "ultimate machine" (which was brought out and
> demonstrated from time to time while I was at the Labs) was built in
> collaboration with Ed Moore (he of Moore-model automata, who published
> "Dijkstra's algorithm" for shortest paths a year before Dijkstra) and
> (I believe) Dave Hagelbarger. Moore endowed the machine with a longevity
> property seldom remarked on: majority logic so that any electrical
> component can be removed without harming its observable behavior.

Keep the stories coming, much apprectaied.

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

http://www-m3.ma.tum.de/foswiki/pub/MN0506/WebHome/dijkstra.pdf
https://books.google.nl/books/about/The_Shortest_Path_Through_a_Maze.html?id=IVZBHAAACAAJ&redir_esc=y

But it is documented Dijkstra's algorithm has been invented and used
by him in 1956.  See e.g.
https://amturing.acm.org/award_winners/dijkstra_1053701.cfm

	-Otto