At the beginning of his visiting professorship at the Reichs-Universität of Leiden, on May 5, 1920, Albert Einstein gave this lecture with the title “Ether and Relativity Theory.” This copy, in his own handwriting, contains numerous corrections and deletions. The lecture was published in the same year. Einstein later often returned to the concepts set forth in this lecture. (fri)

Online Since: 12/17/2015