Akeida in Parallel Universes

Michael Frayn’s 1998 play, Copenhagen, concerns a meeting between two great physicists, Niels Bohr and Werner Heisenberg, in 1941 in Copenhagen. In this play, the spirits of Heisenberg, Bohr, and Bohr’s wife, Margrethe, come together in the afterlife to answer Margrethe’s question, “Why did Heisenberg come to Copenhagen?” Bohr and Heisenberg worked closely together in Copenhagen in the 1920s while developing atomic physics, resulting in the formulation of quantum mechanics. Bohr was already an accomplished scientist when the young German Heisenberg joined his group, and Bohr began mentoring him. Heisenberg became one of the leading figures in formulating the new quantum mechanics. Later, Heisenberg joined the group of German physicists developing nuclear weapons for Nazi Germany. Why did Heisenberg return to Copenhagen in 1941? Denmark was at that time already occupied by Germany. [...]