Recollections of physics community in 1920s and early 1930s; opportunities for physics work in Europe; awareness of political climate in Germany (1932); relationship with Werner Heisenberg at University of Leipzig; awarded Rockefeller Fellowship to study at University of Rome; contacts with physicists after Leipzig and before Rome; John Von Neumann's list of refugee physicists; offered appointment to position at Stanford University; visit to University of Copenhagen and Niels Bohr's advice to accept appointment; relinquishing of second half of fellowship; influenced by Bohr, Heisenberg and