The physicist Hans-Peter Dürr (1929 – 2014), successor to Werner Heisenberg at the Max Planck Institute in Munich, in the field of tension between the physicists Edward Teller and Josef Rotblat. Teller and Rotblat belonged to the “Manhattan Project” in Los Alamos, where the bombs with which the USA destroyed Hiroshima and Nagasaki in 1945 were constructed under the direction of Robert Oppenheimer. Both went in opposite directions: Teller became known as the “father of the hydrogen bomb”, Rotblat received the Nobel Peace Prize for founding the “Pugwash movement”. In between is Dürr: as a doctoral student at Teller, without knowing his background, later an ardent admirer of Rotblat and supporter of Pugwash. Appointed as successor by Werner Heisenberg, he heads the Max Planck Institute for Astrophysics and at the same time participates in the peace movement. He makes enemies – and many new friends.