Einstein on "Theory of Relativity" to Scientist Who Hosted His 1st Public Lecture on Same. Also Discusses Clock to Illustrate His Theory!
Albert Einstein (1879-1955). Typed Letter Signed, “A. Einstein”, in German, 1p, 8.75" x 11", Berlin, February 9, 1920. Expected mailing folds with minor separation. A few scattered pencil notations. Punch holes with small tear at left margin, not affecting text, backed with paper at verso. Light soiling and foxing. In very good plus condition.
Einstein writes to astronomer Dr. Friedrich Simon Archenhold (1861-1939) in full: "I read with interest your kind article and the manuscript you sent. The error of the latter is that a pendulum clock alone is not a 'clock' in the sense of the theory of relativity, but merely the combination of a pendulum clock with a gravitating celestial body. The error of the authors arises from the disregard of this circumstance."
At his eponymous observatory, Archenhold was able to attract numerous well-known scientists and researchers for guest lectures. Perhaps the most famous of these was Albert Einstein, who gave his first public lecture on the theory of relativity at the Archenhold Observatory in Berlin on June 2, 1915. From then on, a friendly relationship grew between Einstein and Archenhold, leading to a permanent connection between the Observatory and Einstein's achievement. The Archenhold Observatory is the oldest and largest public observatory in Germany.
This item comes with a Certificate from John Reznikoff, a premier authenticator for both major 3rd party authentication services, PSA and JSA (James Spence Authentications), as well as numerous auction houses.
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