He also has a classic result in measure theory that the French probabilist Le Cam called 'tightness'. For any probability measure and for any h > 0, there exists r > 0 such that the probability mass farther than r from the origin is less than h.

This result holds in spaces of considerable generality, but I'd have to look up the details now. Details are in P. Billingsley, 'Convergence of Probability Measures', 1999.

I used the result in a paper once. It's nice result and gets used occasionally in advanced work in probability.

It's Stanislaw, since he was Polish, Stanislav would be a Russian name. He is most importantly the co-inventor of the hydrogen bomb:

http://en.wikipedia.org/wiki/Thermonuclear_weapon

There is a great autobiography by him called "Adventures of Mathematician".

> There is a great autobiography by him called "Adventures of Mathematician".

A terrific book, still available but pricey (ca. $30 for a paperback). I have a dog-eared copy acquired 40 years ago in my library.

The closest Ulam comes to revealing atomic secrets in his book is to say the method he and Teller chose to produce a thermonuclear reaction requires the "repetition of certain arrangements." I always thought that was the perfection of obscurity.

Agreed, linking through Stanislaw Ulam turned out to be evermore interesting, even though the Ulam Spriral itself is a good starting point, given its relevance to the field of programming.

http://en.wikipedia.org/wiki/Stanislaw_Ulam

Wasn't he also involved in an early atmosphere on Earth simulation experiment?

Edit: sure not, it's Urey. Four letters, starts with U. Mental index hash fail :)