Werner Heisenberg is an interesting historical figure, in addition to being a great physicist. During World War II, he was one of the few leading world scientists to remain behind in Germany. Hitler gave Heisenberg the task of developing a nuclear weapon. The story behind this event is controversial and unclear. It has never been established with certainty whether Heisenberg did not know how to make a nuclear weapon, or whether he resisted following Hitler's orders to make a weapon out of fear for what the Nazis would do with such a weapon. Anybody interested in pursuing information about this period of history should read Heisenberg's War, or The Catcher Was a Spy.