6 0 0 CALENDAR 1920
Queen Wilhelmina issues her decree confirming Einstein’s
appointment as Special Professor at the University of
1-page TLS from Vieweg publishing house. The missing
check for 14,400 M can be cashed only if one has an
account in a bank. They turned to the post office for infor-
mation about the registered letter containing the check.
September 22 Elected to membership of the Scientific Committee of the
GDNÄ (see 30 September, in Calendar).
1-page ALS from Friedrich Adler. Has to leave Bad Nau-
heim soon. Says good-bye and leaves a copy of Adler 1920,
the manuscript of which he discussed earlier with Einstein
(Vol. 8, Doc. 628). [6 014].
3-page ALS from P. R. Bennett. Proposes a method, differ-
ent from the one he found in the English translation of
Einstein 1917a, for determining simultaneity of distant
events. If two clocks are synchronized at the same point,
then carried apart from each other in the same frame of ref-
erence, and observers watching their own clock measure the
times of an event that prove to be the same after they meet
again, then the event can be stipulated as having happened
simultaneously. With this method, events can be simulta-
neous both in the frame of the rails and in the moving frame
of the train. [6 079].
September 23 Attends combined mathematical and physical sections of
the 86th meeting of the GDNÄ in Bad Nauheim dedicated
to relativity theory. Opens the session. Frankfurter Zeitung,
24 September 1920; Berliner Lokal-Anzeiger, 24 September
September 24 “A Confession” (Vol. 7, Doc. 37) is published.
Elsa Einstein joins him in Bad Nauheim.
September 26 Closing of the Bad Nauheim meeting.
4-page ALS from Ralph de Laer Kronig. When a new star is
born, it sends light in all directions. If the universe is quasi-
spherical, as general relativity maintains, these light waves
must meet again at their source star, increasing its actual
brightness. The periodicity in the brightness may prove the