The world's first hydrogen bomb design was developed in 1951 by a team of scientists working for the US government in a secret project "Manhattan". Stanisław Ulam, a Polish mathematician and graduate of Lvov Technical University, was among the scientists working on this project. In the USA, this project is still named "Teller-Ulam" project - after Edward Teller, the team leader, and Ulam. The hydrogen bomb has a huge destructive force: it is estimated that if a city with 3 million inhabitants was attacked, half of the population would die within a few minutes or suffer serious injuries. Stanislaw Ulam was also the creator of the first numerical methods, including Monte Carlo method.