Jeroen van Dongen, Utrecht University, Holland
Communicating the Heisenberg relations: Niels Bohr and the forgotten Einstein-Rupp experiments

In 1926, Albert Einstein collaborated with Emil Rupp on a set of experiments that were to probe the wave versus particle nature of light. The experiments have now been forgotten, even though their history is quite surprising: after it was established that Rupp had committed fraud, they have been eradicated from the collective memory of the physics community. Niels Bohr is one of the physicists who was closely following the development of these experiments, and proposed his own interpretation of them to Einstein using Heisenberg's new relations; yet, he would not mention them in his later reminiscenses on discussions with Einstein. In this talk, I will discuss the Einstein-Rupp experiments, their interpretationby Bohr and their role in the discussions between Bohr and Einstein.