Wissenschaft am Abgrund: Weltkrieg und Revolution
Einstein’s Friendship with Paul Ehrenfest
Einstein’s postcard from 4 February 1917, reproduction
To Paul Ehrenfest, Einstein can speak out freely about the attitude of the Germans and about his desperation in the face of war. In times of crisis he finds comfort in humorous distance and the fact that he is always welcome in neutral foreign countries. Even in the 1920s, his friend Ehrenfest’s house in Leiden is a sanctuary when the climate in Berlin gets too dangerous for him.