ARMS-D-Request@MIT-MC.ARPA (Moderator) (10/24/85)
Arms-Discussion Digest Wednesday, October 23, 1985 5:12PM
Volume 5, Issue 4
Today's Topics:
Krytron data
Prof. Parnas resigns from antimissile defense panel
The Hundreth Monkey
Reading material
David Parnas Quits SDI Panel on Battle Management
Seminar on Computer Reliability and Nuclear War
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Date: Sat, 13 Jul 85 04:15:41 PDT
From: rimey%ucbmiro@Berkeley (Ken Rimey)
Message-Id: <8507131115.AA06114@ucbmiro.ARPA>
To: arms-d@mit-mc
Subject: krytron data
Date: Wed, 26 Jun 85 14:50:37 CDT
From: William Martin <control@ALMSA-1>
Subject: Krytrons
1) How much do these things cost, anyway? $1000 each? $10 each? If
they are cheap enough, maybe I'd like to buy one and sit it on my
mantelpiece as a curio...
Got one in front of me. It is a glass tube about 3/4" long and about
3/8" in diameter. It would look more appropriate in a transistor radio
than on a mantelpiece. It is not radioactive.
I also have data sheets from the manufacturer, EG&G. They describe
half a dozen models of Krytron and Sprytron. Suggested applications are
Exploding Bridge Wire Systems for missile stage separation,
motor ignition, arming and fusing
Nanosecond Pulse Generation
Radar Beacon Modulator
Trigger Transformer primary switch for triggering Xenon Flashtubes,
Triggered Spark Gaps, Ignitrons and spark chambers
Gallium Arsenide Cell Switch
The general description is
The Krytron is a 4 element (grid, anode, cathode and keep-alive),
cold-cathode, gas-filled switch tube designed to operate in an
arc discharge mode conducting moderately high peak currents for
short durations. ...
and the description of a Sprytron is
The Sprytron is a 3 electrode (anode, trigger and cathode) vacuum,
switch tube that does not require any keep-alive current. ...
KN-11B and 12 Sprytrons were developed to meet switching applications
where high intensity radiation environments are encountered.
The specifications for this one are:
Anode Voltage: 700V - 5000V
Max. Peak Current: 3000A
Pulse Duration: 10us
Trigger Voltage: 250V
Firing Delay: 0.25us
Firing Jitter: 0.03us
Pulses per Minute: 1
Total Firings: 35,000
It is suggestive that the total firings listed for the two models of
Sprytrons are 2,000 and 500. Some models of Krytron can provide
thousands of pulses per second and 10^7 firings.
Hope you find this data interesting. I am normally one to complain
about technology export controls, but then again, nuclear proliferation
is really bad to say the least.
Ken Rimey
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Date: 13 Jul 1985 0655-PDT
From: CAULKINS@USC-ECL.ARPA
Subject: Prof. Parnas resigns from antimissile defense panel
To: arms-d@MIT-MC
From the New York Times of 12 July 85, P7:
"Scientist Quits Antimissile Panel, Saying Task Is Impossible
by Charles Mohr
A computer scientist has resigned from an advisory panel on
antimissile defense, asserting that it will never be possible to
program a vast complex of battle management computers relaibly or to
assume they will work when confronted with a salvo of nuclear
missiles. ...
Professor [David L.] Parnas ... said ... it would never be possible to
test realistically the large array of computers ... Nor, he protested,
would it be possible to follow orthodox computer program-writing
practices in which errors and 'bugs' are detected and eliminated in
prolonged everyday use.
'Because of the extreme demands on the system and our inability to test it,
we will never be able to believe, with any confidence, that we have
succeeded', he wrote. 'Most of the money spent will be wasted.' ...
Professor Parnas took note of President Reagan's 1983 request to scientists
to work toward making nuclear weapons obsolete and impotent.
'I believe,' Professor Parnas said, 'that it is our duty, as scientists and
engineers, to reply that we have no technological magic that will
accomplish that. The President and the public should know that.'
'The worst thing is that we wouldn't trust the system if we did buld it' ...
Herbert Lin, a research fellow at the Massachusetts Institute of
Technology, said this month that the basic lesson was that 'no program
works right the first time' ... "
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Date: Sat 13 Jul 85 20:16:26-EDT
From: Fred Hapgood <SIDNEY.G.HAPGOOD%MIT-OZ@MIT-MC.ARPA>
Subject: The Hundreth Monkey
To: arms-d@MIT-MC.ARPA
cc: zbbs%MIT-OZ@MIT-MC.ARPA
. Re: potato washing
From: *Sociobiology*, by E.O. Wilson. p. 170
... Starting in 1952, the biologists (Kinji Imanishi and
Syunzo Kawamura) began to scatter sweet potatoes on the beach in an
attempt to supplement the diet of the monkeys (macaques). The troop
then ventured out of the forst to accept the gift, and in so doing
it extended its activities to an entirely new habitat. The following
year Kawamura observed the beginnings of a new behavior pattern...
washing sand off the potatoes by employing one hand to brush the
sand away and the other to dip the potato into water.
Potato washing was invented by a 2-year old female named
Imo. Within ten years the habit had been acquired by 90% of the
troop members in all age classes, except infants a year old or less
and adults older than 12 years. During the same period, the washing
was transferred from the fresh water of the brook to the salt water
of the sea. The behavior was most readily learned by juveniles
between 1 and 2 1/2 years old, Imo's own age class. By 1958, five
years after Imo invented it, potato washing was practised by 80% of
monkeys from 2 to 7 years in age. Older monkeys remained
conservative; only 18%, all of them females, learned the behavior.
Part of this conservatism is intrinsic to age and sex... Some... was
also a side product of the tendency of monkeys to learn from their
closest companions. When the tradition of potato washing first
spread, mothers learned from their children and juveniles from their
siblings. Older monkeys, and especially the subadult and adult males
who stayed near the periphery of the group, had fewer opportunities
to learn in this way.
In 1955 Imo, the monkey genius, invented another food
gathering technique. The biologists had originally given wheat to
the Koshima troop simply by scattering it onto the beach. The
monkeys were then required to pick out the grains singly from among
the particles of sand. Imo, now four years old, somehow learned to
scoop handfuls of the mixed sand and wheat, carry them to the edge
of the sea, and cast the mixture onto the water surface. When the
sand sank, the lighter wheat grains were skimmed off the surface and
eaten. The pattern by which this new tradition spread through the
troop resembled that for sweet-potato-washing. Juveniles passively
taught their mothers and age peers, and mothers their infants, but
adult males largely resisted learning the technique.
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From: rimey%ucbmiro@Berkeley (Ken Rimey)
Message-Id: <8507141008.AA08835@ucbmiro.ARPA>
To: arms-d@mit-mc
Subject: reading material
I want to advertise some reading material.
First, the June "Physics Today" has an article by Gerold Yonas, chief
scientist of SDI, outlining the research program, and one by Wolfgang
Panofsky on the politics of missile defense.
There is also a letter by our own Herb Lin. By the way, congratulations
on the publicity your paper has been getting. I spotted two references
to it in the NY Times.
Second, a few weeks ago the UCS finally mailed out the free technical papers
they promised in the preface of the "Fallacy of Star Wars" book. They
are packaged as "Some Technical Aspects of Space-Based Missile Defense"
papers 1 and 2. They are really
"How Many Orbiting Lasers for Boost-Phase Intercept?" by
Richard L. Garwin. (Pre-print of article to appear in "Nature".)
[32 pages; text is 20 pages]
"New BMD Technologies," by Hans A. Bethe and Richard L. Garwin.
(Chapter to appear in "Daedalus", a special issue dedicated to
the space-weapons study of the American Academy of Arts and
Sciences.) [51 pages]
The first presents various models for estimating the number of infrared
laser satellites needed to destroy a given number of ICBMs. It
concludes that the square root scaling law proposed by Canavan does
not hold in realistic situations. Canavan himself is acknowledged
for having commented on the draft, but of course that is no indication
as to whether he agrees with the new conclusions. This paper is really
dull, but it is a great source of convenient numbers and formulas useful
for impressing friends with mental calculations.
The second paper is a technically oriented survey of BMD technologies.
It is much better reading than the usual watered-down stuff, and it
contains some technical information I have not seen elsewhere. On first
reading of Yonas's paper, I didn't find anything that contradicts what
Bethe and Garwin say here. That leaves me impressed with both Yonas and
Bethe and Garwin.
Ken Rimey
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Date: 15 Jul 85 00:16 EDT
From: Andy.Hisgen@CMU-CS-A.ARPA
To: ARMS-D@MIT-MC.ARPA
Subject: David Parnas Quits SDI Panel on Battle Management
Message-Id: <15Jul85.001616.AH20@CMU-CS-A.ARPA>
Below are excerpts from a story in the New York Times, Friday,
June 12, 1985:
Scientist Quits Antimissile Panel, Saying Task is Imposssible
By Charles Mohr
Washington, July 11 -- A computer scientist has resigned from an
advisory panel on antimissile defense, asserting that it will never
be possible to program a vast complex of battle management computers
reliably or to assume they will work when confronted with a salvo
of nuclear missiles.
The scientist, David L. Parnas, a professor at the University of
Victoria, British Columbia, who is a consultant to the Office of Naval
Research in Washington, was one of nine scientists asked by the Strategic
Defense Initiative Office to serve at $1,000 a day on the "panel on
computing in support of battle management."
Professor Parnas, an American citizen with secret military clearances,
said in a letter of resignation June 28 and in 17 pages of accompanying
memorandums that it would never be possible to test realistically the large
array of computers that would link and control a system of sensors,
antimissile weapons, guidance and aiming devices, and battle management
stations.
...
In his letter to Commander Offutt [of the SDI office], Professor Parnas
took note of President Reagan's 1983 request to the scientists to work
toward making nuclear weapons obsolete and impotent.
"I believe," Professor Parnas said, "that it is our duty, as scientists
and engineers, to reply that we have no technological magic that will
accomplish that. The President and the public should know that."
...
[end of excerpts from article]
Has anybody seen Parnas's letter & 17 pages of memorandums? Does
anybody have it on-line?
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Date: Tue, 16 Jul 85 20:28:13 EDT
From: Steven A. Swernofsky <SASW@MIT-MC.ARPA>
Subject: [BERLIN: SEMINAR]
To: ARMS-D@MIT-MC.ARPA, SOFT-ENG@MIT-MC.ARPA
Message-ID: <[MIT-MC.ARPA].578525.850716.SASW>
MSG: *MSG 4297
Date: 07/16/85 13:14:03
From: BERLIN at MIT-XX.ARPA
Re: SEMINAR
Received: from MIT-XX.ARPA by MIT-MC.ARPA.ARPA; 16 Jul 85 13:14:02 EDT
Date: Tue 16 Jul 85 13:10:10-EDT
From: Steve Berlin <BERLIN@MIT-XX.ARPA>
Subject: SEMINAR
To: bboard@MIT-MC.ARPA
Computer System Reliability
and
Nuclear War
Wednesday, July 17th, 7:30
545 Tech Square, 8th floor lounge
Speaker: Professor Alan Borning, University of Washington
On several occasions, the NORAD early warning system has mistakenly
indicated that Soviet missiles were headed for the United States. These
incidents raise questions of the following sorts: Could a computer failure,
in either the U.S. or the Soviet warning systems, start an accidental
nuclear war? What risks are associated with placing the nuclear forces of
one or both powers on alert? Would it be responsible for a country to adopt
a policy of launch-on-warning, in which missiles would be fired based on
warnings that an attack was imminent?
In this talk, in addition to discussing these questions, I will look
more generally at problems of reliability in complex systems, and at the
prospects for fighting limited nuclear wars and of future computer
controlled military systems.
Sponsored by Computer Professionals for Social Responsibility, CPSR/Boston
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End of Arms-Discussion Digest
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