At the end of his life he was an American, and a power behind the scenes
of American scientific policy and foreign policy. But that was only the
last of several equally distinguished identities in different countries
and fields of thought. Janos Neumann, known as "Jansci," was a
prodigious young chemical engineer turned mathematician and logician in
Hungary in the early 1920s. Johann von Neumann was one of the elite
quantum physics revolutionaries in Gottingen, Germany, in the late
twenties. And from 1933 until his death, he was John von Neumann of
Princeton, New Jersey; Los Alamos, New Mexico; and Washington, D.C.,
known to professors and Presidents as "Johnny."Ada and Babbage could
only dream of the day their device could be put to work. Turing was a
tragic victim of political events before he could get his hands on a
computer worth the name. Johnny, however, not only managed to get his
machines built and use them to create the first working principles of
software -- but he also ended up telling his government how to use the
new technology. He was responsible for much more than the first boost in
accelerating American effort to develop computer technology.
A combination of many different scientific and political developments
led to the invention of ENIAC. Electronic tube technology, Boolean
logic, Turing-type computation, Babbage-Lovelace programming, and
feedback-control theories were brought together because of the War
Department's insatiable hunger for raw calculating power.
John von Neumann was the only man who
not only knew enough about the scientific issues but moved comfortably
enough in the societies of Princeton and Los Alamos and Washington to
grasp the threads and weave them together in an elegant and powerful
design.
Von Neumann was a very important, probably indispensable, member of
the
Manhattan Project scientific team. Oppenheimer, Fermi, Teller, Bohr,
Lawrence, and the other members of the most gifted scientific gathering
of minds in history were as awed by Johnny's intellect as anyone else
who ever met him. More impressively, they were as reliant on his
mathematical judgment as anyone else. In that galactic cluster of
world-class physicists, chemists, mathematicians, and engineers, it was
a rare tribute that von Neumann was put in charge of the mathematical
calculations upon which all their theories -- and the functioning of
their "gadget" -- would depend.
As if his significant contributions to the development of the first
nuclear weapons and the first computers were not enough for one man, he
was also one of the original logicians who had posed the questions that
Turing and Kurt G�del answered in the 1930s. He was a cofounder of the
modern science of game theory (picking up where Babbage left off), one
of the founders of operational research (also, curiously, advancing a
field first explored by Babbage), an active participant in the creation
of quantum physics, one of the first people to suggest analogies and
differences between computer circuits and brain processes, and one of
the first scientists since Turing to examine the relationship between
the mathematics of code-making and the mystery of biological
reproduction.
Von Neumann ended up a key
policy-maker in the fields of nuclear power, nuclear weapons, and
intercontinental ballistic weaponry: he was the director of the
Atomic Energy Commission and an influential member of the ICBM
Committee. Generals and senators were lucky to get an appointment. Even
when he was dying, the most powerful men in the world gathered around
for a final consultation. According to Admiral Lewis Strauss, former
chairman of the Atomic Energy commission: "On one dramatic occasion near
the end, there was a meeting at Walter Reed Hospital where, gathered
around his bedside and attentive to his last words of advice and wisdom,
were the secretary of Defense and his Deputies, the Secretaries of the
Army, Navy, and Air Force, and all the military Chiefs of Staff."
John von Neumann's political views, undoubtedly rooted in his
upper-class Hungarian past, were unequivocal and extreme, according to
the public record and his biographers.
He not only used his scientific expertise to hasten and accelerate the
development of nuclear weapons and computer-guided missiles, but
counseled military and political leaders to think about using these new
American inventions against the USSR in a "preventive war." (In
an article in Life magazine, published shortly after he died, von
Neumann was quoted as saying: "If you say why not bomb them tomorrow, I
say, why not today. If you say at five o'clock, I say why not one
o'clock.")
In contrast to Turing, whom he knew from Turing's prewar stay at
Princeton and from their wartime work, von Neumann was a sophisticated,
worldly, and gregarious fellow, famous for the weekly cocktail parties
he and his wife hosted during his tenure at Princeton's Institute for
Advanced Study and up on the Mesa at Los Alamos. He had a substantial
private income and an additional $10,000 a year from the Institute. He
was widely known to have a huge repertoire of jokes in several
languages, a vast knowledge of risqu� limericks, and a casual manner of
driving so recklessly that he demolished automobiles at regular
intervals, always managing to emerge miraculously unscathed.
Despite his apparently charmed existence, von Neumann, like Ada
Lovelace and Alan Turing, died relatively young. Lovelace died of cancer
at thirty-six, Turing of cyanide at forty-two, and von Neumann of cancer
at fifty-three. Like many other Los Alamos veterans, he may have been a
victim of exposure to radiation during the early nuclear bomb tests. His
death came as a shock to all who knew him as a vital, lively,
peripatetic, seemingly invulnerable individual. Stanislaw Ulam, von
Neumann's mathematical colleague and lifelong friend, in a memorial to
Johnny published in a mathematical journal shortly after von Neumann's
death, described his physical presence
in loving detail:
Johnny's friends remember him in his characteristic
poses: standing before a blackboard or discussing problems at home.
Somehow his gesture, smile, and the expression of the eyes always
reflected the thought or the nature of the problem under discussion.
He was of middle size, quite slim as a young man, then increasingly
corpulent; moving in small steps with considerable random
acceleration, but never with great speed. A smile flashed on his
face whenever a problem exhibited features of a logical or
mathematical paradox. Quite independently of his liking for abstract
wit, he had a strong appreciation (one might almost say a hunger)
for the more earthy type of comedy and humor.
Everyone who knew him remembers to point out two things about von
Neumann -- how charming and personable he was, no matter what language
he was speaking, and how much more intelligent that other human beings
he always seemed to be, even in a crowd of near-geniuses. Among his
friends, the standard joke about Johnny
was that he wasn't actually human but was as skilled at imitating human
beings as he was at everything else.
Born into an upper-class Hungarian Jewish family, Jansci was fluent
in five or six languages before the age of ten, and he once told his
collaborator Herman Goldstine that at age six he and his father often
joked with each other in classical Greek. It was well known that he
never forgot anything once he read it, and his ability to perform
lightning fast calculations was legendary.
One night in the middle of the summer of 1944, von Neumann
encountered by happenstance a mathematician of past acquaintance in the
Aberdeen, Maryland, train station. History might have been far different
if one of their trains had been scheduled a few minutes earlier. That
accidental meeting in Aberdeen presented von Neumann with a nearly
completed approach to a problem the strategic significance of which he
was uniquely equipped to understand, the details of which were complex
and profound enough to attract his intellectual curiosity, the
successful completion of which could be hastened by the use of his
political clout.
Lieutenant Herman Goldstine, then associated with the U.S. Army
Ordnance Ballistic Laboratory at Aberdeen, Maryland, didn't know
anything about the other projects von Neumann was juggling at that time.
But he knew that von Neumann's security clearance was miles above his
and that he was a member of the Scientific Advisory Committee at the
Ballistic Research Laboratory. So Goldstine happened to mention that an
Army project at the Moore School of Engineering was soon to produce a
device capable of performing mathematical calculations at phenomenal
speeds.
Years later, Goldstine remembered that he was understandably nervous
upon meeting the world-famous mathematician on the platform at the
Aberdeen station. Goldstine recalled:
Fortunately for me, von Neumann was a warm friendly
person who did his best to make people feel relaxed in his presence.
The conversation soon turned to my work. When it became clear to von
Neumann that I was concerned with the development of an electronic
computer capable of 333 multiplications per second, the whole
atmosphere of our conversation changed from one of relaxed good
humor to one more like the oral examination for the doctor's degree
in mathematics.
Because he had all-important reasons for wanting a fast automatic
calculator, von Neumann asked for a demonstration. At the Moore School
of Engineering, he met the gadget's inventors, Mauchly and Eckert, and
the next years saw Johnny adding Aberdeen as a regular stop on his
Princeton-D.C.-Los Alamos shuttle. Like everything else he turned his
mind to, von Neumann immediately seemed to see more clearly than anyone
else the future potential of what was then only a crude prototype. While
the other principal creators of the first electronic computer were
either mathematicians or electrical engineers, von Neumann was also a
superb logician, which enabled him to understand what few others
did -- that these gadgets were in a class quite far beyond that of
superfast calculating engines.
From those early meetings in 1944 to the eras of ENIAC, EDVAC,
UNIVAC, MANIAC, and (yes) JOHNNIAC, the
problem of assigning legal and historical credit to the inventors of the
first electronic digital computers becomes a tangled affair in
which easy explanations are impossible and many conflicts are still
unresolved. Goldstine -- the other man on the platform with von Neumann
-- had his own version of the key events in early computer history.
Mauchly and Eckert had a distinctly different point of view. There was a
tale of Stibitz at Bell Labs. IBM's Thomas Watson, Senior, had yet
another story. And a man in Iowa named
Atanasoff eventually had the unexpected last laugh in a courtroom in
1973.
Monumental court cases have been fought over the issue of assigning
credit for the invention of the modern computer, and even the legal
decisions have been somewhat murky. Certainly it was a field in which a
few people all over the world, working independently, reached similar
conclusions. In the case of the ENIAC team, it was a case of several
determined minds working together.
It isn't hard to envision von Neumann coming onto the scene after
others have worked for years on the considerable engineering problems
involved in building
ENIAC
(Electronic Numerical Integrator and Calculator), then dominating
the voice of the group when they articulated their discoveries, not out
of self-aggrandizement, but because he undoubtedly had the most elegant
way of stating the conclusions that the group had arrived at, working in
concert. Because of von Neumann's prominence in other fields, and the
way his charm worked on journalists as well as generals, he was often
described by the mass media as the sole inventor of key concepts
like the all-important "stored program" -- a credit he never claimed
himself.
Although the matter of assigning credit for the earliest computer
hardware is a tricky business, there is no denying von Neumann's central
role in the history of software. His contributions to the science of
computation in the late forties and early fifties were preceded by even
earlier theoretical work that led to the notion of computation. He was
one of the principal participants in both of the lines of thought that
converged into the construction of ENIAC -- mathematical logic and
ballistics.
John von Neumann's role in the invention of computation began nearly
twenty years before the ENIAC project. In the late 1920s, between his
major contributions to quantum physics, logic, and game theory, young
Johann von Neumann of G�ttingen was one of the principal players in the
international game of mathematical riddles that started with Boole
seventy years prior and led to Turing's invention of the universal
machine a decade later.
The impending collision of philosophy and mathematics that was
becoming evident at the end of the nineteenth century made
mathematicians extremely uncomfortable. Slippery metaphysical concepts
associated with human thought might have appealed to minds like Boole's
or Turing's. But to David Hilbert of G�ttingen and others of the early
1900s, such vagueness was a grave danger to the future of an enterprise
that intended to reduce all scientific laws to mathematical equations.
The logical and metamathematical foundations of more "pure" forms of
mathematics, Hilbert insisted, could only be stated clearly in terms of
numerical problems and precisely defined symbols and rules and
operations. This was the doctrine of formalism that later spurred
Turing to make his astonishing discovery about the capabilities of
machines. Johann von Neumann, a student of Hilbert's, was one of the
stars of the formalists. In itself, von Neumann's metamathematical
achievement was remarkable. His work in formalism, however, was only
part of what von Neumann achieved in several disparate fields, all in
the same dazzling year.
In 1927, at the age of twenty-four,
von Neumann published five papers that were instant hits in the academic
world, and which still stand as monuments in three separate fields of
thought. It was one of the most remarkable interdisciplinary
triple plays in history. Three of his 1927 masterpieces were critical to
the field of quantum physics. Another paper established the new field of
game theory. The paper most directly to the future of computation was
about the relationship between formal logic systems and the limits of
mathematics.
In his last 1927 paper, von Neumann demonstrated the necessity of
proving that all mathematics was consistent, a critically important step
toward establishing the theoretical basis for computation (although
nobody yet knew that). This led, one year later, to a paper published by
Hilbert that listed three unanswered questions about mathematics that he
and von Neumann had determined to be the most important questions facing
logicians and mathematics of the modern era.
The first of these questions asked whether or not mathematics was
complete. Completeness, in the technical sense used by
mathematicians, means that every true mathematical statement can be
proven (i.e., is the last line of a valid proof).
The second question, the one that most concerned von Neumann, asked
whether mathematics (or any other formal system) was consistent.
Consistency in the technical sense means that there is no valid sequence
of allowable steps (or "moves" or "states") that could prove an untrue
statement to be true. If arithmetic was a consistent system, there would
never be a way to prove that 1 + 1 = 3.
The third question, the one that opened the side door to computation,
asked whether or not mathematics was decidable. Decidability
means that there is some definite method that is guaranteed to correctly
determine whether an assertion is provable.
It didn't take long for a shocking answer to emerge in response to
the first Hilbert-von Neumann question. In 1930, yet another young
mathematician, Kurt G�del, showed that arithmetic cannot be complete,
because there will always be at least one true assertion that cannot be
proved. In the course of demonstrating this, G�del crossed a crucial
threshold between logic and mathematics when he showed that any formal
system that is as rich as the number system (i.e., contains the
mathematical operators + and =) can be expressed in terms of arithmetic.
This means that no matter how complicated mathematics (or any other
equally powerful formal system) becomes, it can always be expressed in
terms of operations to be performed on numbers, and the parts of the
system (whether or not they are inherently numerical) can be manipulated
by rules of counting and comparing.
Von Neumann's and Hilbert's third question about the decidability of
mathematics led Turing to his 1936 breakthrough. The "definite method"
(of determining whether a mathematical assertion is provable) that was
demanded by the decidability question was formulated by Alan Turing as a
machine that could operate in definite steps on statements encoded as
symbols on tape. G�del had shown how numbers could represent the
operations of formal system, and Turing showed how the formal system
could be described numerically to a machine equipped to decode such a
description (e.g., translate the system's rules into the form "find a
number n, such that . . . ", "n" being expressible as a
string of ones and zeroes).
All of these questions were terribly important at the time they were
formulated -- to the few dozen people around the world who were equipped
to understand their significance. But in 1930, the rest of the
population had more important things to worry about that the
hypothetical machines of the metamathematicians. Even those who
understood that universal machines could in fact be built were in no
position to begin such a task. Making a
digital computer was an engineering project that would require the kind
of support that only a national government could afford.
John von Neumann was at the Institute
for Advanced Study at Princeton by the time young G�del and Turing
came along. Although he was keenly aware of the latest developments in
the "foundation crisis of mathematics" he had helped initiate in the
late 1920s, von Neumann's restless intellect was attacking half a dozen
new problems by the early 1930s. To Johnny, still in his twenties, the
most important thing in life was to find "interesting problems."
In particular, he was interested in mathematical questions involving
the phenomenon of turbulence, and the dynamics of explosions and
implosions happened to be one area where such questions could be
applied. He was also interested in new mathematical methods for modeling
complex phenomena like global weather patterns or the passage of
radiation through matter -- methods that were powerful but required such
enormous numbers of calculations that future progress in the field was
severely limited by the human inability to calculate the results of the
most interesting equations in a reasonable length of time.
Von Neumann seemed to have a kind of
"Midas Touch." The problems he tackled, no matter how abstruse
and apparently obscure they might have seemed at the time, had a way of
becoming very important a decade or two later. For example, he wrote a
paper in the 1920s on the mathematics underlying economic strategies. A
quarter of a century later it turned out to be a perfect solution to the
problem of how airplanes should search for submarines (as well as one of
the first triumphs of "operational research," one of the fields
pioneered by Babbage).
By the 1940s, von Neumann's expertise in the mathematics of
hydrodynamic turbulence and the management of very large calculations
took on unexpected importance because these two specialties were
especially applicable to a new kind of explosion that was being cooked
up by some of the old gang from G�ttingen, now gathered in New Mexico.
The designers of the first fission bomb knew that hellish mathematical
problems in both areas had to be solved before any of the elegant
equations of quantum physics could be transformed into the fireball of a
nuclear detonation. As von Neumann already suspected, the mathematical
work involved in designing nuclear and thermonuclear weapons created an
avalanche of calculations.
The calculating power needed in the quest for thermonuclear weaponry
ended up being one of the highest-priority uses for ENIAC -- top-secret
calculations for Los Alamos were the subject of the first official
programs run on the device when it became operational -- although
the reason the electronic calculator had
been commissioned in the first place was to generate the mathematical
tables needed for properly aiming conventional artillery.
The ENIAC project was started under the auspices of the Army
Ballistic Research Laboratory. Herman Goldstine, a historian of
computation as well as one of the key participants, took the trouble to
point out that the word ballistics is derived from the Latin
ballista, the name of a large device for hurling missiles.
Ballistics in the modern sense is the mathematical science of predicting
the path of a projectile between the time it is launched and the moment
it hits the target. Complex equations concerning moving bodies are
complicated further by the adjustments necessary for winds of different
velocities and for the variations in air resistance encountered by
projectiles fired from very large guns as they travel through the
atmosphere. The results of all possible distance, altitude, and weather
calculations for guns of each specific size and muzzle velocity are
given in "firing tables" which artillerymen consult as they set up a
shot.
The application of mass-production techniques to weapons meant that
new types of guns and shells were coming along at an unprecedented pace,
making the ongoing production of firing tables no easy task. During
World War I, such calculations were done by humans who were called
"computers." But even then it was clear that new methods of organizing
these large-scale calculations, and new kinds of mechanical calculators
to help the work of human computers, would be an increasingly important
part of modern warfare.
In 1918 the Ballistics Branch of the Chief of Ordnance set up a
special mathematical section at the Aberdeen Proving Ground in Maryland.
One of the early recruits was the young
Norbert Wiener,
who was to feature prominently in another research tributary of the
mainstream of ballistic technology -- the automatic control of
antiaircraft guns -- and who was later to become one of the creators of
the new computer-related discipline of cybernetics.
In the 1930s, both the Aberdeen laboratory and an associated group at
the University of Pennsylvania's Moore School of Engineering obtained
models of the automatic analog computer constructed by
Vannevar Bush at
MIT, a gigantic mechanical device known as the "differential analyzer."
It was a marvelous aid to calculation, but it was far from being a
digital computer, in either its design or its performance.
With the aid of these machines, the work of performing ballistic
calculations was somewhat relieved. Before World War II, the machines
were still second to the main resource -- mathematics professors emeriti
at the Moore School, who performed the calculations by hand, with the
aid of hand-cranked mechanical calculators. Shades of
Babbage's Cornish
clergymen!
When war broke out, it was obvious that the institutions in charge of
producing ballistic calculations for several armed services needed
expert help. It was for this reason that a mobilized mathematician,
Lieutenant Herman Goldstine, reported for duty at Aberdeen in August,
1942, and was assigned the task of streamlining ballistic computations.
He soon found the Moore School facilities inadequate, and started to
expand the staff of human "computers" by adding a large number of young
women recruited from the Women's Army Corps to the small cadre of
elderly ex-professors.
Goldstine's wife, Adele, herself a mathematician who was to play a
prominent role in the programming of early computers (she and six other
women were eventually assigned the task of programming the ENIAC),
became involved with recruiting and teaching new staff members. Von
Neumann's wife, Klara, performed a similar role at Los Alamos, both
before and after electronic computing machines became available. The
tradition of using women for such work was widespread -- the equivalent
roles in Britain's code-breaking efforts were played by hundreds of
skilled calculators whom Turing and his colleagues called "girls" as
well as "computers."
The expansion of the human computing staff at Aberdeen to nearly two
hundred people, mostly WACs, was a stopgap measure. The calculation of
firing tables was already out of hand. As soon as a new kind of gun,
fuse, or shell became available for combat, a new table had to be
calculated. The final product was either printed in a booklet that
gunners kept in their pockets, or was mechanically encoded in special
aiming apparatus called automata. (An entirely different
mathematical research effort by Julian Bigelow, Warren Weaver, and
Norbert Wiener was to concentrate on the characteristics of these
automatic aiming machines.)
The answer to the firing table dilemma, as Goldstine was one of the
first to recognize, was to commission the invention of an entirely new
kind of mechanical calculating aid. The Vannevar Bush calculators were
no longer the most efficient calculating devices. Faster machines, built
on different principles, had been built by Dr. Howard Aiken and an IBM
team at Harvard, and by a group led by a man named George Stibitz at
Bell laboratories. But Goldstine knew that what they really needed at
Aberdeen and the Moore School was an automatic calculator that was
hundreds, even thousands of times faster than the fastest existing
machines.
Such dreams would have been akin to an Air Force officer wishing for
a ten-thousand-mile-per-hour airplane, except for the fact that another
new technology, one that only a few people even thought of applying to
mathematical problems, looked as if it might make such a machine
possible in theory, if only questionably probable in execution. Research
in the young field of electronics had been uncovering all sorts of
marvelous properties of the vacuum tube. Over in Great Britain, the whiz
kids at Bletchley Park were using such devices in Colossus, their
not-quite-computational code-breaking machine.
Until the war, electronic vacuum tubes had been used almost
exclusively as amplifiers. But they could also be used as very fast
switches. Since the rapid execution of a
large number of on/off impulses is the hallmark of digital computation,
and vacuum tubes could switch on and off as fast as a million times a
second, electronic switching (as opposed to the mechanical switching of
Vannevar Bush's machine) was an unbelievably good candidate for the key
component of an ultrafast computing machine.
By 1943, unknown to Goldstine and almost all of his superiors,
another, much higher-ranking scientist was also searching for an
ultrafast computing machine. Goldstine beat the other fellow to it.
Goldstine found Mauchly and Eckert in 1942. John von Neumann, and
chance, found Goldstine in 1944.
John W. Mauchly and J. Presper Eckert have been properly credited
with the invention of ENIAC, but before they implemented the key ideas
of electronic digital computing machines, a man named Atanasoff in Iowa,
in the 1930s, built small, crude, but functioning prototypes of
electronic calculating machines. His name has not been as widely known,
and his fortunes turned out differently from those of other pioneers
when computers grew from an exotic newborn technology to a powerful
infant industry. But in 1973 a Unites Stated district court ruled that
John Vincent Atanasoff invented the electronic digital computer.
It was a complicated decision, reached after years of litigation, and
was not as clear-cut as it might have been if both did not have such
strong cases. The core of the dispute centered around original work
Atanasoff did in the 1930s, and the influence that his work later had on
John Mauchly's design of ENIAC. Like the Hollerith-Billings story of the
invention of punched-card data processing, simple explanations of where
one man's ideas left off and another's began are difficult to
reconstruct at best.
Atanasoff was the last of the lone
inventors in the field of computation; after him, such projects
were too complicated for anything less than a team effort. Like Boole,
Atanasoff was the recipient of one of those sudden inspirations that
provided the solution to a problem he had been grappling with for years.
A theoretical physicist teaching at Iowa State in the early 1930s, he
came up against the same obstacle faced by other mathematicians and
physicists of his era. The approaches to the most interesting ideas were
blocked by the problems of performing large numbers of complex
calculations.
By 1935, Atanasoff was in hot pursuit of a scheme to mechanize
calculation. He was aware of Babbage's ideas, but he was an electronic
hobbyist as well as a physicist, and entire technologies that didn't
exist in Babbage's time were now showing great promise. Atanasoff was
gradually convinced that an electronic computing machine was a good bet
to pursue, but he had no idea how to go about designing one, and he
wasn't sure how to design a machine without working out a method of
programming it. In the late 1970s, Atanasoff told writer Katherine
Fishman:
I commenced to go into torture. For the next two
years my life was hard. I thought and thought about this. Every
evening I would go into my office in the physics building. One night
in the winter of 1937 my whole body was in torment from trying to
solve the problems of the machine. I got in my car and drove at high
speeds for a long while so I could control my emotions. It was my
habit to do this for a few miles: I could gain control of myself by
concentrating on driving. But that night I was excessively
tormented, and I kept on going until I had crossed the Mississippi
River into Illinois and was 189 miles from where I started. I knew I
had to quit; I saw a light, which turned out to be a roadhouse, and
I went in. It was probably zero outside, and I remember hanging up
my heavy coat; I started to drink and commenced to warm up and
realized that I had control of myself.
Nearly forty years later, when he testified in the patent case
concerning the invention of the electronic computer, Atanasoff recalled
that he decided upon several design elements and principles that night
in the roadhouse -- including a binary system for encoding input and
electronic tube technology for switching -- that would transform his
dream of an electronic calculator into a practical plan.
The state of each inventor's mind at the time of their discussions in
1940 and 1941 was the crux of the legal and historical conflict. There
is no dispute that John Mauchly had also devoted years of thought to the
idea of automated calculation. Thirty-three years old when he met
Atanasoff, Mauchly had worked his way through Johns Hopkins as a
research assistant, which gave him extensive experience with procedures
that involve detailed measurement and calculation. In 1933, as head of
the physics department at Ursinus College near Philadelphia, he began to
perform research in atmospheric electricity.
Mauchly was particularly interested in the long-disputed theory about
the effect of sunspots on the earth's weather. There was no obvious
connection between these huge storms on the sun and terrestrial weather
conditions, but that did not prove that such a connection did not exist.
In 1936, Mauchly arranged to have many parts of the government's
voluminous meteorological records shipped back to his office at Ursinus.
He intended to apply modern statistical analysis to the weather data in
an attempt to correlate them with records of sunspot activity, hoping
that this probe would reveal the previously undetected pattern.
As other mathematical meteorologists like von Neumann were also
quickly discovering, Mauchly found that any calculations involving data
based on weather quickly grew so complicated that it would take a
lifetime to calculate all the equations generated from even the shortest
periods of observation. So he found himself doing the same thing that
the ballistics experts did -- hiring a lot of people with adding
machines. A Depression-era agency, the National Youth Administration,
helped Mauchly pay students fifty cents an hour to tabulate his weather
data with hand calculators. Mauchly planned to obtain punched-card
machines, once he got his crew to tackle the first part of the data. But
when he watched a demonstration of the world's most advanced
punched-card tabulator at the 1939 World's Fair, he realized that even
scores of such machines in the hands of trained operators might take
another decade to go through the weather data.
In 1939 and 1940, Mauchly read in scientific journals about a new
measuring and counting system developed to assist cosmic-ray research.
The part of the system that caught his eye was the fact that this new
device, using electronic circuits, could count cosmic rays far faster
than a dozen of the fasted punched-card tabulators. Cosmic rays can be
detected at the rate of thousands per second, but all previous recorders
failed to keep pace beyond 500 times a second. Mauchly tried making a
few electronic circuits for himself, and he began to see a way that they
could be used for computation.
Mauchly took note of one circuit in particular that was developed by
the cosmic-ray researchers -- the coincidence circuit, in which a
switch would be closed only when several signals arrived at exactly the
same time, thus, in effect, rendering a decision. Would a machine
capable of making electronic logical operations be possible via some
variation of this circuit? Experimenting with his own vacuum-tube
circuits, Mauchly speculated that there might also exist circuits used
in other kinds of instruments that would enable him to build a machine
to add, subtract, multiply, and divide. At this point his speculations
were more grandiose than his hand-wired prototypes, but the clues he had
obtained from the cosmic-ray researchers were enough to put Mauchly's
weather-predicting machines on a collision course with a certain device
the U.S. Army had in mind, one that had nothing to do with sunspots or
the weather.
Mauchly brought a small analog device to the AAAS meeting where he
met Atanasoff, and in June, 1941, he hitched a ride to visit Atanasoff
in Ames, Iowa. Atanasoff demonstrated the ABC, Mauchly stayed for five
days, and thirty-two years later a court decided that Mauchly's later
invention of the ENIAC relied upon key ideas of Atanasoff's that were
transferred from mind to mind those five days in June.
The 1973 legal decision (Honeywell versus Sperry Rand, U.S.
District Court, District of Minnesota, Fourth Division) did not state
that Mauchly stole anything, but did restore partial credit for the
invention of the electronic computer to a man whose name had been nearly
forgotten in all the publicity and honors heaped upon Mauchly and
Eckert. After the ruling, Mauchly said: "I feel I got nothing out of
that visit to Atanasoff except the royal shaft later." On Mauchly's
behalf, it must be noted that nobody has disputed the fact that the
sheer scale and engineering audacity of ENIAC was far beyond the ABC,
and that Mauchly was indeed on the right track at least as early as
Atanasoff.
Part of the reason for ENIAC's success and ABC's obscurity must be
attributed to the accidents of history. Legal issues aside, the
historical momentum shifted to Mauchly later in the summer of 1941, when
he signed up for an Army-sponsored electronics course at the Moore
School of Engineering. His instructor, J. Presper Eckert, was an
exceptionally bright Philadelphia blueblood twelve years younger than
Mauchly. When Eckert, the electronics wizard, learned of Mauchly's plan
to automate large-scale numerical calculations, a critical mass of
idea-power was reached. They were in exactly the right place at the
right time to cook up such an ambitious project.
Not long after thirty-four-year-old John Mauchly and
twenty-two-year-old Pres Eckert started to sketch out a plan for an
electronic computer, they became acquainted with Lieutenant Herman
Goldstine, both as a mathematician and as a liaison officer between the
Moore School and the Ballistic Research Laboratory. By the time he met
them, Goldstine was sufficiently
frustrated by the lack of ballistic computing power that he was
receptive to even a science-fiction story like the one presented to him
by these two whiz kids.
As wild as it sounded as an engineering feat, Goldstine knew that an
electronic device such as the one Mauchly and Eckert described to him
had the potential to perform ballistic calculations over 1000 times
faster than the best existing machine, the Aiken-IBM-Harvard-Navy device
called the Mark I. But it would cost a lot of money to find out if they
were right. Atanasoff and Berry built
their prototype for a
total of $6500. These boys would need hundreds of thousands of dollars
to lash together something so complicated and delicate that most
electrical engineers of the time would swear it could never work.
Goldstine later explained the risks associated with attempting the
proposed electronic calculator project:
. . . we should realize that the proposed machine
turned out to contain over 17,000 tubes of 16 different types
operating at a fundamental clock rate of 100,000 pulses per second.
. . . once every 10 microseconds an
error would occur if a single one of the 17,000 tubes operated
incorrectly; this means that in a single second there were 1.7
billion . . . chances of a failure occurring . . . Man has never
made an instrument capable of operating with this degree of fidelity
or reliability, and this is why the undertaking was so risky a one
and the accomplishment so great.
The two young would-be computer inventors at the Moore School, the
mathematician-turned-lieutenant who found them, and their audacious plan
for cutting through the calculation problem by creating the world's most
complicated machine were the subject of a high-level meeting on April 9,
1943. Attending was one of the original founders of the military's
mathematical research effort and President of the Institute for Advanced
Study at Princeton, Oswald Veblen, as well as Colonel Leslie Simon,
director of the Ballistic Research Laboratory, and Goldstine.
The moment when the United States War Department entered the age-old
quest for a computing machine, and thus made the outcome inevitable, was
recalled by Goldstine when he wrote, nearly thirty years later, that
Veblen, "after listening for a short while to my presentation and
teetering on the back legs of his chair brought the chair down with a
crash, arose, and said, 'Simon, give Goldstine the money.'" They got
their money -- eventually as much as $400,000 -- and started building
their machine.
ENIAC was monstrous -- 100 feet long,
10 feet high, 3 feet deep, weighing 30 tons -- and hot enough to keep
the room temperature up toward 120 degrees F while it shunted
multivariable differential equations through its more than 17,000 tubes,
70,000 resistors, 10,000 capacitors, and 6,000 hand-set switches. It
used an enormous amount of power -- the apocryphal story is that the
lights of Philadelphia dimmed when it was plugged in.
When it was finally completed, ENIAC was too late to use in the war,
but it certainly delivered what its inventors had promised: a ballistic
calculation that would have taken twenty hours for a skilled human
calculator could be accomplished by the machine in less than thirty
seconds. For the first time, the trajectory of a shell could be
calculated in less time than it took an actual shell to travel to its
target. But the firing tables were no longer the biggest boom on the
block by the time ENIAC was completed. The first problem run on the
machine, late in the winter of 1945, was a trial calculation for the
hydrogen bomb then being designed.
After his first accidental meeting with Goldstine at Aberdeen, and
the demonstration of a prototype ENIAC soon afterward, von Neumann
joined the Moore School project as a special consultant. Johnny's genius
for formal, systematic, logical thinking was applied to the logical
properties of this huge maze of electronic circuits. The engineering
problems were still formidable, but it was becoming clear that the
nonphysical component, the subtleties of setting up the machine's
operations -- the coding, as they began to call it -- was equally
difficult and important.
Until the transistor came along a few years later, ENIAC would
represent the physical upper limit of what could be done with a large
number of high-speed switches. In 1945, the most promising approach to
greater computing power was in improving the logical structure of the
machine. And von Neumann was probably the one man west of Bletchley Park
equipped to understand the logical attributes of the first digital
computer.
Part of the reason ENIAC was able to operate so fast was that the
routes followed by the electronic impulses were wired into the machine.
This electronic routing was the materialization of the machine's
instructions for transforming the input data into the solution. Many
different kinds of equations could be solved, and the performance of a
calculation could be altered by the outcome of subproblems,
but ENIAC was nowhere near as flexible
as Babbage's Analytical Engine, which could be reprogrammed to solve a
different set of equations, not by altering the machine itself, but by
altering the sequence of input cards.
What Mauchly and Eckert gained in
calculating power and speed, they paid for in overall flexibility. The
gargantuan electronic machine had to be set up for solving each separate
problem by changing the configuration of a huge telephone-like
switchboard, a procedure that could take days. The origins of the
device as a ballistics project were partially responsible for this
inflexibility. It was not the intention of the Moore School engineers to
build a universal machine. Their contract quite clearly specified that
they create an altogether new kind of trajectory calculator.
Especially after von Neumann joined the team, they realized that what
they were constructing would not only become the ultimate mathematical
calculator, but the first, necessarily imperfect prototype of a whole
new category of machine. Before ENIAC was completed, its designers were
already planning a successor. Von Neumann, especially, began to realize
that what they were talking about was a general-purpose machine,
one that was by its nature particularly well suited to function as an
extension of the human mind.
If one thing was sacred to Johnny, it was the power of human thought
to penetrate the mysteries of the universe, and the will of human beings
to apply that knowledge to practical ends. He had other things on his
own mind at the time -- from the secrets of H-bomb design to the
structure of logic machines -- but he appeared to be most keen on the
idea that these devices might evolve into some kind of intellectual
extension. How much more might a thinker like himself accomplish with
the aid of such a machine? One biographer put it this way:
Von Neumann's enthusiasm in 1944 and 1945 had first
been generated by the challenge of improving the general-purpose
computer. He had been a proponent of using the latest in computing
machines in the atomic bomb project, but he realized that for the
impending hydrogen bomb project still better and faster machines
were needed. In the theoretical level he was intrigued by the fact
that there appeared to be organizational parallels between the brain
and computers and that these parallels might lead to formal-logic
theories encompassing both computers and brains; moreover, the
logical theories would constitute interesting abstract logics in
their own right. He was cautious in assuming similarity between a
computer and the awesome functioning of the human brain, especially
as in 1944 he had little preparation in physiology.
Rather he regarded the computer as a
technical device functioning as an extension of its user; it would
lead to an aggrandizement of the human brain, and von Neumann wanted
to push this aggrandizement as far and as fast as possible.
There is no dispute that Mauchly, Eckert, Goldstine, and Von Neumann
worked together as a team during this crucial gestation period of
computer technology. The team split up in 1946, however, so the matter
of accrediting specific ideas has become a sticky one. Memoranda were
written, as they are on any project, without the least expectation that
years later they would be regarded as historical or legal documents.
Technology was moving too fast for the traditional process of peer
review and publication: the two most important documents from these
early days were titled "First Draft . . ." and "Preliminary Report . .
."
By the time they got around to sketching the design for the next
electronic computer, the four main ENIAC designers had agreed that the
goal was to design a machine that would use the same hardware technology
in a more efficient way. The next step, the invention of stored
programming, is where the accreditation controversy comes in. At the
end of June, 1945, the ENIAC team prepared a proposal in the form of a
"First Draft of a Report on the Electronic Discrete Variable Calculator"
(EDVAC). It was signed by von Neumann, but reflected the conclusions of
the group. Goldstine later said of this: "It has been said by some that
von Neumann did not give credits in his First Draft to others.
The reason for this was that the document was intended by von Neumann as
a working paper for use in clarifying and coordinating the thinking of
the group and was not intended for publication." (Mauchly and Eckert,
however, took a less benign view of von Neumann's intentions.) The most
significant innovations articulated in this paper involved the logical
aspects of coding, as well as dealing with the engineering of the
physical device that was to follow the coded instructions.
Creating the coded instructions for a new computation on ENIAC was
nowhere near as time consuming as carrying out the calculation by hand.
Once the code for the instructions needed to carry out the calculation
had been drawn up, all that had to be done to perform the computation on
any set of input data was to properly configure the machine to perform
the instructions. The calculation, which formerly took up the most time,
had become trivial, but a new bottleneck was created with the resetting
of switches, a process that took an unreasonable amount of time compared
with the length of time it would take to run the calculation.
Resetting the switches was the most worrisome bottleneck, but not the
only one. The amount of time it took for the instructions to make use of
the data, although greatly reduced from the era of manual calculation,
was also significant -- in ballistics, the ultimate goal of automating
calculation was to be able to predict the path of a missile before
it landed, not days or hours or even just minutes later. If only there
was a more direct way for the different sets of instructions -- the
inflexible, slow-to-change component of the computing system -- to
interact with the data stored in the electronic memory, the more quickly
accessible component of computation. The solution, as von Neumann and
colleagues formulated it, was an innovation based upon a logical
breakthrough.
The now-famous "First Draft" described the logical properties of a
true general-purpose electronic digital computer. In one key passage,
the EDVAC draft pointed out something that Babbage, if not Turing, had
overlooked: "The device requires a considerable memory. While it appears
that various parts of this memory have to perform functions which differ
somewhat in their nature and considerably in their purpose, it is
nevertheless tempting to treat the entire memory as one organ." In other
words, a general-purpose computer should be able to store instructions
in its internal memory, along with data.
What used to be a complex configuration of switchboard settings could
be symbolized by the programmer in the form of a number and read by the
computer as the location of an instruction stored in memory, an
instruction that would automatically be applied to specified data that
was also stored in memory. This meant
that the program could call up other programs, and even modify other
programs, without intervention by the human operator. Suddenly, with
this simple change, true information processing became possible.
This is the kernel of the concept of stored programming, and although
the ENIAC team was officially the first to describe an electronic
computing device in such terms, it should be noted that the abstract
version of exactly the same idea was proposed in Alan Turing's 1936
paper in the form of the single tape of the universal Turing machine.
And at the same time the Pennsylvania group was putting together the
EDVAC report, Turing was thinking again about the concept of stored
programs:
So the spring of 1945 saw the ENIAC team on one
hand, and Alan Turing on the other, arrive naturally at the idea of
constructing a universal machine with a single "tape." . . .
But when Alan Turing spoke of "building a brain," he
was working and thinking alone in his spare time, pottering around
in a British back garden shed with a few pieces of equipment
grudgingly conceded by the secret service. He was not being asked to
provide the solution to numerical problems such as those von Neumann
was engaged upon; he had been thinking for himself. He had simply
put together things that no one had put together before: his one
tape universal Turing machine, the knowledge that large scale pulse
technology could work, and the experience of turning cryptanalytic
thought into "definite methods" and "mechanical processes." Since
1939 he had been concerned with little but symbols, states, and
instruction tables -- and with the problem of embodying these as
effectively as possible in concrete forms.
With the EDVAC design, ballistics calculators took the first step toward
general-purpose computers, and it became clear to a few people that such
devices would surely evolve into something far more powerful.
The kind of uses the inventors
envisioned for the future of their technology was a cause for one of
several major theoretical disagreements that were to surface soon
thereafter among the four ENIAC principals. Von Neumann and Goldstine
saw the opportunity to build an incredibly powerful research tool for
scientists and mathematicians. Mauchly and Eckert were already thinking
of business and government applications outside military or research
institutions.The first calculation run on ENIAC in December, 1945,
six months after the "First Draft," was a problem posed by scientists
from Los Alamos Laboratories. ENIAC was formally dedicated in February,
1946. By then, the patriotic solidarity enforced upon the research team
by wartime conditions had faded away. Von Neumann was enthusiastic about
the military and scientific future of the computer-building enterprise,
but the two young men who had dreamed up the computer project before the
big brass stepped in were getting other ideas about how their
brain-child ought to mature. The tensions between institutions, people,
and ideas mounted until Mauchly and Eckert left the Moore School on
March 31, 1946, over a dispute with the university concerning patent
rights to ENIAC. They founded their own group shortly thereafter,
eventually naming it The Eckert-Mauchly Computer Corporation.
When Mauchly and Eckert later suggested that they were, in fact, the
sole originators of the EDVAC report, they were, in Goldstine's phrase,
"strenuously opposed" by Goldstine and von Neumann. The split turned out
to be a lifelong feud. Goldstine, writing in 1972 from his admittedly
partial perspective, was unequivocal in pointing out von Neumann's
contributions:
First, his entire summary as a unit constitutes a
major contribution and had a profound impact not only on the EDVAC
but also served as a model for virtually all future studies of
logical design. Second, in that report he introduced a logical
notion adapted from one of McCulloch and Pitts, who used it in a
study of the nervous system. This notation became widely used, and
is still, in modified form, an important and indeed essential way
for describing pictorially how computer circuits behave from a
logical point of view.Third, in the famous
report he proposed a repertoire of instructions for the EDVAC, and
in a subsequent letter he worked out a detailed programming for a
sort and merge routine. This represents a milestone, since it is
the first elucidation of the now famous stored program concept
together with a completely worked-out illustration.
Fourth, he set forth clearly the serial mode of
operation of the modern computer, i.e., one instruction at a time is
inspected and then executed. This is in sharp distinction to the
parallel operation of the ENIAC in which many things are
simultaneously performed.
While Mauchly and Eckert set forth to establish the commercial
applications of computer technology, Goldstine, von Neumann, and another
mathematician by the name of Arthur Burks put together a proposal and
presented it to the Institute for Advanced Study at Princeton, the Radio
Corporation of America, and the Army Ordnance Department, requesting one
million dollars to build an advanced electronic digital computer. Once
again, some of the thinking in this project was an extension of the
group creations of the ENIAC project. But this "Preliminary Discussion,"
unquestionably dominated by von Neumann, also went boldly beyond the
EDVAC conception as it was stated in the "First Draft."
Although the latest proposal was aimed at the construction of a
machine that would be more sophisticated than EDVAC, the authors went
much farther than describing a particular machine. They very strongly
suggested that their specification should be of the general plan for the
logical structure and fundamental method of operation for all future
computers. They were right: it took
almost forty years, until the 1980s until anyone made a serious attempt
to build "non-von Neumann machines."
"Preliminary Discussion of the Logical Design of an Electronic
Computing Instrument," which has since been recognized
as the founding document of the modern
science of electronic computer design, was submitted on June 28,
1946, but was available only in the form of mimeographed copies of the
original report to the Ordnance Department until 1962, when a condensed
version was published in Datamation magazine. The primary
contributions of this document were related to the logical use of the
memory mechanism and the overall plan of what has been come to be known
as the "logical architecture." One aspect of this architecture was the
ingenious way data and instructions were made to be changeable during
the course of a computation without requiring direct intervention by the
human operator.
This changeability was accomplished by treating numerical data as
"values" that could be assigned to specific locations in memory. The
basic memory component of an EDVAC-type computer used collections of
memory elements known as "registers" to store numerical values in the
form of a series of on/off impulses. Each of these numbers was assigned
an "address" in the memory, and any address could contain either data or
an instruction. In this way, specific data and instructions could be
located when needed by the control unit. One result of this was that a
particular piece of data could be a variable -- like the x in
algebra -- that could be changed independently by having the results of
an operation stored at the appropriate address, or by telling the
computer to perform an operation on whatever was found at that location.
One of the characteristics of any series of computation instructions
is a reference to data: when the instructions tell the machine how to
perform a calculation, they have to specify what data to plug into the
calculation. By making the reference to data a reference to the contents
of a specific memory location, instead of a reference to a specific
number, it became possible for the data to change during the course of a
computation, according to the results of earlier steps. It is in this
way that the numbers stored in the memory can become symbolic of
quantities other than just numerical value, in the same way that algebra
enables one to manipulate symbols like x and y without
specifying the values.
It is easier to visualize the logic of this schema if you think of
the memory addresses as something akin to numbered cubbyholes or
post-office boxes -- each address is nothing but a place to find a
message. The addresses serve as easily located containers for the
(changeable) values (the "messages") to be found inside them. Box #1,
for example, might contain a number; box #2 might contain another
number; box #3 might contain instructions for an arithmetic operation to
be performed on the numbers found in boxes #1 and #2; box #4 might
contain the operation specified in box #3. The numbers in the first two
boxes might be fixed numbers, or they might be variables, the values of
which might depend on the result of other operations.
By putting both the instructions and the raw data inside the same
memory, it became possible to perform computations much faster than with
ENIAC, but it also became necessary to devise a way to clearly indicate
to the machine that some specific addresses contain instructions and
other addresses contain numbers for those instructions to operate on.
In the "First Draft," von Neumann specified that each instruction
should be designated in the coding of a program by a number that begins
with the digit 1, and each of the numbers (data) should begin with the
digit 0. The "Preliminary Report" expanded the means of distinguishing
instructions from data by stating that computers would keep these two
categories of information separate by operating during two different
time cycles, as well.
All the instructions are executed according to a timing scheme based
on the ticking of a built-in clock. The "instruction" cycles and
"execution" cycles alternate: On "tick," the machine's control unit
interprets numbers brought to it as instructions, and prepares to
execute the operations specified by the instructions on "tock," when the
"execution" cycle begins and the control unit interprets input as data
to operate upon.
The plan for this new category of general-purpose computer not only
specified a timing scheme but set down what has become known as the
"architecture" of the computer -- the division of logical functions
among physical components. The scheme had similarities to both Babbage's
and Turing's models. All such machines, the authors of the "Preliminary
Report" declared, must have a unit where arithmetic and logical
operations can be performed (the processing unit where actual
calculation takes place, equivalent to Babbage's "mill"), a unit where
instructions and data for the current problem can be stored (like
Babbage's "store," a kind of temporary memory device), a unit that
executes the instructions according to the specified sequential order
(like the "read/write head" of Turing's theoretical machine), and a unit
where the human operator can enter raw information or see the computed
output (what we now call "input-output devices").
Any machine that adheres to these
principles -- no matter what physical technology is used to implement
these logical functions -- is an example of what has become known as
"the von Neumann architecture." It doesn't matter whether you
build such a machine out of gears and springs, vacuum tubes, or
transistors, as long as its operations follow this logical sequence.
This theoretical template was first implemented in the Unites States at
the Institute for Advanced Study. Modified copies of the IAS machine
were made for the Rand Corporation, an Air Force spinoff "think tank"
that was responsible for keeping track of targets for the nation's new
but fast-growing nuclear armory, and for the Los Alamos Laboratory.
Against von Neumann's mild objections, the Rand machine was dubbed
JOHNNIAC. The Los Alamos machine assigned to nuclear weapons-related
calculations was given the strangely uneuphemistic name of MANIAC.
(Neither EDVAC, the IAS machine, the Los Alamos machine, nor the Rand
machine was the first operational example of a fully functioning
stored-program computer. British computer builders, who had been
pursuing parallel research and who were aware of Von Neumann's ideas,
beat the Americans when it came to constructing a machine based on the
logical principles enunciated by von Neumann. The first machine that was
binary, serial, and used stored-program memory was EDSAC -- the
Electronic Delay Storage Automatic Calculator, built at the University
Mathematical Laboratory, University of Cambridge, England.)
In a von Neumann machine, the arithmetic and logic unit is where the
basic operations of the system are wired in. All the other instructions
are constructed out of these fundamentals. It is possible, in principle,
to build a device of this type with very few, extremely simple, built-in
operations. Addition, for example, could be performed over and over
again whenever a multiplication operation is requested by a program. In
fact, the only two operations that are absolutely necessary are "not"
and "and." The problem with using a few
very simple hardwired operations and proportionally complex software
structures built from them is that it slows down the operation of the
computer: Because instructions are executed one at a time ("serially")
as the internal clock ticks, the number of basic instructions in a
program dictates how long it takes a computer to run that program.
The control unit specified by the "Preliminary Report" -- the
component that supervises the execution of instructions -- was the
materialization of the formal logic device created by Emil L. Post and
Turing, who had proved that it was possible to devise codes in terms of
numbers that could cause a machine to solve any problem that was clearly
statable. This is where the symbol meets the signal, where sequences of
on and off impulses in the circuits, the Xs and Os on the cells of the
endless tape, the strings of numbers in the programmer's code, marry the
human-created computation to the machine that computes.
The input-output devices were the parts of the system that were to
advance the most slowly while the switch-based memory, arithmetic, and
control components ascended through orders of magnitude. For over a
decade after ENIAC, punched cards were the main input devices, and for
over two decades, teletype machines were the most common output devices.
The possibility of future breakthroughs in this area and their
implications were not overlooked. In a memorandum written in November,
1945, concerning one of the early proposals for the IAS machine, von
Neumann anticipated the possibility of creating a more visually oriented
output device:
In many cases the output really desired is not
digital (presumably printed) but pictorial (graphed). In such
situations the machine should graph it directly, especially because
graphing can be done electronically and hence more quickly than
printing. The natural output in such a case is an oscilloscope,
i.e., a picture on its fluorescent screen. In some cases these
pictures are wanted for permanent storage . . . in others only
visual inspection is desired. Both alternatives should be provided
for.
But a personal interactive computer, helpful as such a device might be
to a mind such as von Neumann's, was not an interesting enough problem.
After solving interesting problems about the processes that take place
in the heart of stars, a scientific-technological tour de force that
also became a historical point of no return when the scientists'
employers demonstrated their creation at Hiroshima, and then solving
another set of problems concerned with the creation of computing
machinery, all the while pontificating about the most potent aspects of
foreign policy to the leaders of the most powerful nation in history,
John von Neumann was aiming for nothing less than the biggest secret of
all. In the late 1940s and early 1950s, the most interesting scientific
question of the day was "what is life?"To someone who had been at
Alamogordo and the Moore School, it would not have been too farfetched
to believe that the next intellectual conquest might bring the secret of
physical immortality within reach. Certainly he would never know whether
he could truly resolve the most awesome of nature's mysteries until
he set his mind to decoding the secret
of life. And that he did. Characteristically, von Neumann focused
on the aspect of the mystery of life that appealed to his dearest
instincts and most powerful capacities -- the pure, logical,
mathematical underpinnings of nature's code. He was particularly
interested in the logical properties of the theoretical devices known as
automata, of which Turing's machine was an example.
Von Neumann was especially drawn to the idea of self-reproducing
automata -- mathematical patterns in space and time that had the
property of being able to reproduce themselves. He was able to draw on
his knowledge of computers, his growing understanding of neurophysiology
and biology, and make particularly good use of his deep understanding of
logic, because he saw self-replicating automata as essentially logical
beasts. The way the task was accomplished by living organisms of the
type found on earth was only one way it could be done. In principle, the
task could be done by a machine that could follow a plan, because the
plan, and not the mechanism that carried it out, was a part of the
system with the special, heretofore mysterious property that
distinguished life from nonliving matter.
Von Neumann approached "cellular automata" on an abstract level, just
as Turing did with his first machines. As early as 1948, he showed that
any self-replicating system must have raw materials, a program that
provides instructions, an automaton that follows the instructions and
arranges the symbols in the cells of a Turing-type machine, a system for
duplicating instructions, and a supervisory unit -- which turned out to
be an excellent description of the DNA direction of protein synthesis in
living cells.
Another thing that interested Johnny was the gamelike aspect of the
world. Accordingly, he thought about the way his self-reproducing
automaton was like a game:
Making use of the work done by his colleague
Stanislav Ulam, von Neumann was able to refine his calculations and
make them more generally applicable. Von Neumann's mental
experiment, which we can easily present in the form of a game, makes
use of a homogeneous space subdivided by cells. We can think of
these cells as squares on a playing board. A finite number of states
-- e.g., empty, occupied, or occupied by a specific color -- is
assigned to a square. At the same time, a neighborhood is defined
for each cell. This neighborhood can consist of either the four
orthogonally bordering cells or the eight orthogonally and
diagonally bordering cells. In the space divided up this way,
transition rules are applied simultaneously to each cell. The
transition any particular cell undergoes will depend on its state
and on the states of its neighbors. Von Neumann was able to prove
that a configuration of about 200,000 cells, each with 29 different
possible states and each placed in a neighborhood of 4 orthogonally
adjacent squares, could meet all the requirements of a
self-reproducing automaton. The large number of elements was
necessary because von Neumann's model was also designed to simulate
a Turing machine. Von Neumann's machine can, theoretically, perform
any mathematical operation.
In 1950, when it was evident to all that the engineering phase of
computer technology was accomplishing impressive tasks,
von Neumann postulated one such system
in terms of a factory that contains within it the machinery and the
detailed blueprints for making identical factories (and identical
blueprints) from raw materials provided to it. Take that a step
up in complexity, and the details can include a specification for
subsystems that find raw materials for the factory from the environment,
with no human intervention.
If one fantasizes one step farther on the complexity spectrum, the
instructions and capabilities could specify factories capable of
building spaceships to send more spaceships to other planets, where the
raw materials found would be shaped into more factory-spaceship-launchpad
systems, and if you could build factories that could build two or
more such complexes, you could have a counterforce to the generally
disorderly trend of the cosmos, in the
form of a (mindless?) horde of factory-building factories, munching
outward through the galaxies like an anti-entropic swarm of logical
locusts.
While it definitely sounds like a science-fiction story, and many
would add that it could be interpreted to be an idea of such inhuman
coldness as to be termed "fiendish" such scenarios are legitimate topics
in the field of automata, and are still known as "von Neumann machines"
(as distinguished from "the von Neumann machine," the logical
architecture he created for digital computers).
Von Neumann died in 1957, before he could achieve a breakthrough in
the field of automata. Like Ada, he died of cancer, and like Ada, he was
said to have suffered terribly, as much from the loss of his
intellectual facilities as from pain. But the world he left behind him
was powerfully rearranged by what he had accomplished before he failed
to solve his last, perhaps most interesting problem.
