Martin Gardner writes, “Ulam’s spiral grids have added a touch of fantasy to speculations about the enigmatic blend of order and haphazardry in the distribution of primes….Ulam’s doodlings in twilight zone of mathematics are not to be taken lightly. It was he who made the suggestion that led him and Edward Teller to think of the ‘idea’ that made possible the first thermonuclear bomb.”
In addition to his mathematical contributions and his work on the Manhattan Project to develop the first nuclear weapon during World War II, Ulam is also famous for his work on spacecraft propulsion system. He had escaped with his brother from Poland on the eve of the Second World War, but the rest of his family died in the Holocaust.