Weinberg takes a summer job in the Atomic Beam Group at Princeton, calculating the trajectories of beam particles through the experimental equipment. He describes the culture of close relations of graduate students in physics with the younger faculty and its emphasis on research rather than course work. He details the various courses he took, along with the personalities of the Princeton professors at the time. Sam Treiman agrees to be his PhD advisor for a thesis on strong interactions in decay processes.

Makers of history want historians to treat them favorably. Those who wield power often wish to influence the way in which history will view them. They are concerned about securing their place in history. This chapter explores how participants in the decision to use the bomb, provoked by criticism and worried about how historians would treat them, explained and justified their decision. The impact of John Hersey’s bestselling Hiroshima and other writing critical of the use of the bomb deeply troubled participants in the decision. They instigated Henry Stimson’s Harper’s 1947 article “The Decision to Use the Atomic Bomb,” which defended the decision as necessary to avoid an invasion, bring the war to an early end, and save American and Japanese lives. Despite its shortcomings, Stimson’s defense stood for two decades as the largely unchallenged interpretation of the use of the bomb and became the foundation of the “orthodox interpretation” which still remains a widely held view.

This chapter provides the background of the decision; it narrates the bare facts, which all historians of the decision would agree on. Albert Einstein’s letter to President Franklin Roosevelt in 1939 alerted him to the danger posed by possible German attempts to build an atomic bomb. We trace the origins of the Manhattan Project and the events leading to use of the atomic bomb on Hiroshima and Nagasaki. Japanese wartime strategy hoped to achieve a decisive battle that would compel the Allies to negotiate an end to the war. The bare facts don’t speak for themselves; they must be interpreted. “A catalogue of undoubted and indubitable information, even if arranged chronologically, remains a catalogue. To become a history, facts have to be put together into a pattern that is understandable and credible….” When historians explain the narrative of events which we tell in this chapter, they will differ in a host of ways depending on what facts they choose to emphasize, the questions they ask, their generational and national perspectives, and their personal background.