[SIGCIS-Members] ENIAC and the Cold War

[Thomas Haigh]

Fortuitously, I am about to mark up the final changes on the page proofs of
ENIAC In Action: Making and Remaking the Modern Computer by Haigh, Priestley
& Rope and ftp them back to MIT Press. The book should be out very early
next year and it has a great deal to say in answer to your question. We have
some explicit discussion of ENIAC as an artifact that bridges the transition
from WWII to the Cold War, and explore in detail its use for atomic bomb and
artillery calculations.

 

Artillery trajectory calculations: these were, as you might expect given
that the machine was being funded explicitly to perform them, absolutely
vital to the design of ENIAC. Contrary to previous claims that ENIAC
programming was an afterthought tackled only in late-1945 they were treated
in detail very early in the design process, playing a vital role in shaping
the machine's ultimate configuration. This includes sketches of a suitable
configuration in the initial proposal and detailed diagrams of how the
problem would be tackled produced in late-1943. This has been a sensitive
topic because discussion of early machines is very partisan. ENIAC-bashers
have liked to claim it was a "special purpose" and very limited machine. In
response, ENIAC boosters have downplayed the importance of the trajectory
application to shaping the machine's design. The truth is that ENIAC was
extremely flexible, but the archival records clearly show that key new
developments such as the conditional branch sprang from consideration and
generalization of the very specific requirements encountered when planning
the trajectory calculations. (Rather than, as some writers imply, from the
computer builders of the 1940s having read Turing's paper and then rushed
down to the machine shop to try and build a universal machine). We also give
a nice clear explanation of what the computations actually were, and how
they fit into the larger process of creating firing tables (which began with
the gathering and analysis of data from actual test firings). One of the
many things that Walter Isaacson gets wrong about ENIAC is his claim that it
was never actually used to compute trajectories.  In fact ENIAC was already
doing real work on this problem by August 1946, still at the Moore School,
and once running smoothly at Aberdeen Proving Ground from 1949 to 1955 spent
about 20% of its time calculating trajectories.

 

ENIAC's very first application, from December 1945 into the spring of 1946,
was to check the validity of Teller's basic approach to a hydrogen bomb, the
Super. This work does remain classified, but fortunately is covered in some
depth from the Los Alamos perspective in an excellent dissertation written
with access to classified sources: Fitzpatrick, Anne. Igniting  the Light
Elements: The Los Alamos Thermonuclear Weapon Project, 1942-1952
(LA-13577-T). Los Alamos, NM: Los Alamos National Laboratory, 1999. In the
book we draw on this heavily to make up for the inaccessibility of Los
Alamos sources.

 

Many other problems run on ENIAC were also concerned with atomic weapons,
include the first computerized Monte Carlo computations, which receive two
chapters in the book. Monte Carlo programs were run between 1948 and 1950,
and included fission weapon simulations for Los Alamos, fission power
simulations for Argonne, and a second wave of fusion calculations for
Teller. An earlier version of the section discussing the initial 1948
fission Monte Carlos in an already published article, "Los Alamos Bets on
ENIAC" which is available online at
http://eniacinaction.com/the-articles/3-los-alamos-bets-on-eniac-nuclear-mon
te-carlo-simulations-1947-8/. From the same page you can access some
supporting materials, including a report written by Klara von Neumann, the
full flow diagram, and an annotated version of the original code. This is of
particular historical interest because it is not only the first computerized
Monte Carlo program but also the first modern code to be run on any
computer. (By that, we mean a program expressed as a series of instructions
run from addressable memory with jumps, subroutines, and the other features
of EDVAC-style programs). There may well be material related to these in the
Metropolis papers, which were not accessible to us, but even without that
they appear to be the best documented programs run on any computer in the
1940s as surviving materials include a succession of flow diagrams that
serve as a window into the design process.

 

Best wishes,

 

Tom

 

 

 

 

 

From: Members [mailto:members-bounces at lists.sigcis.org] On Behalf Of Daniel
Ferrell
Sent: Thursday, August 27, 2015 12:41 PM
To: members at sigcis.org
Subject: [SIGCIS-Members] ENIAC and the Cold War

 

SIGCIS members:

   I have an inquiry into ENIAC. I understand that one of its purposes was
to track and calculate artillery trajectories. I am looking for resources
that emphasize the development of ENIAC against the backdrop of the Cold War
era, including the role ENIAC had in analyzing the hydrogen bomb. Are there
any suggestions?



-Daniel Ferrell

 

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65 S. Outer Rd.
P.O. Box 72
Benton, MO 63736

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