Everything about Stanislaw Ulam totally explained
Stanisław Marcin Ulam (
April 13,
1909 –
May 13,
1984) was a
Polish mathematician who participated in the
Manhattan Project and proposed the
Teller–Ulam design of
thermonuclear weapons. He also invented
nuclear pulse propulsion and developed a number of mathematical tools in
number theory,
set theory,
ergodic theory, and
algebraic topology.
Biography
Stanislaw Ulam was born to a
Polish Jewish family in
Lwów (
German: Lemberg;
Ukrainian: Lviv),
Galicia, then in
Austria-Hungary; since 1918 in
Poland and since 1939 in
USSR. He was part of the city's large Jewish minority population; when he grew up in the city, it was in the
Second Polish Republic. His mentor in mathematics was
Stefan Banach, a great Polish mathematician and one of the moving spirits of the
Lwów School of Mathematics and more broadly of the remarkable
Interbellum Polish School of Mathematics.
Ulam went to the
United States in 1938 as a
Harvard Junior Fellow. He visited Poland in summer 1939 and together with his brother,
Adam, escaped from Poland on the eve of the
Second World War; the rest of their family died in
The Holocaust. When his fellowship wasn't renewed, he served on the faculty of the
University of Wisconsin-Madison. While in U.S., in the midst of the war, his friend
John von Neumann invited him to a secret project in
New Mexico. Ulam researched the invitation by checking out a book on New Mexico from the university library. There he found a list, on the library check-out card, of all those who had successively disappeared from the campus at the UW. Ulam then joined the
Manhattan Project at
Los Alamos.
While there, he suggested the
Monte Carlo method for evaluating complicated mathematical
integrals that arise in the theory of nuclear
chain reactions (not knowing that
Fermi and others had used a similar method earlier). This suggestion led to the more systematic development of Monte Carlo by Von Neumann,
Metropolis, and others.
Ulam — in collaboration with
C.J. Everett, who did the detailed calculations — showed
Edward Teller's early model of the
hydrogen bomb to be inadequate. Ulam then went on to suggest a better method. He was the first to realize that one could place all the H-bomb's components inside one casing, put a
fission bomb at one end and thermonuclear material at the other, and use mechanical shock from the fission bomb to compress and detonate
fusion fuel. This idea was probably an outcome of Ulam's initial ideas for 'staging' a conventional fission device, in which the neutron flux from one fission bomb would compress the fuel in another one, thus increasing its efficiency.
Teller at first resisted this idea, then saw its merit and suggested the use of a plutonium "spark plug", located at the center of the fusion fuel, to initiate and enhance the fusion reaction. Teller also modified Ulam's idea of compression by realizing that radiation from the fission bomb would compress the thermonuclear fuel much more efficiently than mechanical shock. This design, generally referred to as staged radiation implosion, has been the standard method of creating H-bombs ever since. Although this approach was worked out independently by Soviet physicist
Andrei Sakharov, it's often referred to as the "
Teller–Ulam design". Ulam and Teller jointly applied for a patent on the hydrogen bomb.
Ulam also invented
nuclear pulse propulsion and, at the end of his life, declared it the invention of which he was proudest.
He was an early proponent of using computers to perform "mathematical experiments." His most notable contribution here may have been his part in the
Fermi–Pasta–Ulam experiments, an early numerical study of a
dynamical system.
Another
dynamical system he introduced is the well-known
Fermi–Ulam model (FUM), that's a variant of
Fermi's primary work on acceleration of
cosmic rays, namely
Fermi acceleration.
FUM became over the years a prototype model for studying non-linear dynamics and
coupled mappings.
In pure mathematics, he worked in
set theory (including
measurable cardinals and abstract
measures),
topology,
ergodic theory, and other fields. After World War II he largely turned from rigorous pure mathematics to speculative and imaginative work, posing problems and making conjectures (which had always been specialties of his) that often concerned the application of mathematics to
physics and
biology. His friend
Gian-Carlo Rota ascribed this change to an attack of
encephalitis in 1946 that Rota claimed changed Ulam's personality (though detail had never been Ulam's strong point). This suggestion is believed by many but rejected by Ulam's widow,
Françoise, among others.
In May 1958, while referring to a conversation with von Neumann, Ulam said what would later become a foundation of the
technological singularity theory:
One conversation centered on the ever accelerating progress of technology and changes in the mode of human life, which gives the appearance of approaching some essential singularity in the history of the race beyond which human affairs, as we know them, couldn't continue.
Ulam took a position at the
University of Colorado in 1965. As he remained a consultant at Los Alamos, he divided his time between
Boulder,
Colorado,
USA and
Santa Fe,
New Mexico, from which he commuted to Los Alamos. Later he and his wife spent winters in
Gainesville,
Florida, where he'd a position with the
University of Florida. He died in Santa Fe on
May 13,
1984.
Bethe on Ulam
- "After the H-bomb was made, reporters started to call Teller the father of the H-bomb. For the sake of history, I think it's more precise to say that Ulam is the father, because he provided the seed, and Teller is the mother, because he remained with the child. As for me, I guess I'm the midwife." (Hans Bethe, 1968, as quoted by Schweber, p.166.)
Further Information
Get more info on 'Stanislaw Ulam'.
|
External Link Exchanges
Do you know how hard it is to get a link from a large encyclopaedia? Well we're different and will prove it. To get a link from us just add the following HTML to your site on a relevant page:
<a href="http://stanislaw_ulam.totallyexplained.com">Stanislaw Ulam Totally Explained</a>
Then simply click through this link from your web page. Our crawlers will verify your link, extract the title of your web page and instantly add a link back to it. If you like you can remove the words Totally Explained and embed the link in article text.
As long as your link remains in place, we'll keep our link to you right here. Please play fair - our crawlers are watching. Your site must be closely related to this one's topic. Any kind of spamming, dubious practises or removing the link will result in your link from us being dropped and, potentially, your whole site being banned. |
