It took less than seven years from the discovery of nuclear fission in 1938 to the ignition of the first atomic bomb in the summer of 1945 and its subsequent use against the cities of Hiroshima and Nagasaki. In this course, we will take a deep dive into this development, which forever changed the dynamics of global politics — as well as our views on science. In addition to the Manhattan project, the course will also cover the nuclear weapon programs in other countries, in particular Nazi Germany. We will place the rapid development of the war years in a wider historical context, from the first anticipations of atomic weapons to the rise of “big science” in the postwar years. In this way, we will be able to address the pressing ethical questions (and their continuing relevance to scientists today) in a nuanced, historically informed way.