D O C U M E N T 2 2 5 D E C E M B E R 1 9 2 0 5 1 7
Born [8 157], attached to the present document, is omitted.
In a reorganization of the Mathematische Annalen at the end of 1919, Einstein had become a
member of its editoral board, and Born a member of its scientific advisory committee (see David Hil-
bert to Einstein, 20 December 1919 [Vol. 9, Doc. 225]). The committee members were kept up to date
about ongoing business by means of messages that circulated from one member to the next, and to
which each was asked to make brief comments (see Felix Klein to Einstein, 28 April 1920 [Vol. 9,
Sergei Boguslavsky. For his letter to Born, see Einstein/Born 1969, pp. 75–77. Born first men-
tioned Boguslavsky’s desperate situation to Einstein in Doc. 185.
Max Planck; Felix Klein (1849–1925), Professor Emeritus of Mathematics at the University of
Göttingen; David Hilbert.
Hans Bolza (1889–1986) was an entrepreneur in Würzburg. He had taken his Ph.D. with David
Hilbert in Göttingen in 1913.
Paul Epstein. Gilbert N. Lewis (1875–1946) was Professor of Chemistry at the University of
California at Berkeley. Born made his acquaintance through Fritz Haber (see Einstein/Born 1969,
Epstein was Privatdozent at the University of Zurich.
Otto Stern; Friedrich Wachsmuth; Erwin Madelung (1881–1972), Privatdozent in theoretical
physics at the University of Göttingen; Walther Kossel. For Wachsmuth’s opposition, rooted in his
anti-Semitism, see Doc. 95.
Alfred Landé (1888–1975) was Privatdozent in theoretical physics at the University of Frank-
Carl W. Ramsauer (1879–1955) was Professor of Physics at the Technical University of Danzig.
He took his doctorate under Philipp Lenard at Heidelberg.
The delay in the time that passed between observations of eclipses of Jupiter’s moons was
expected to be longer if the light coming from Jupiter had to travel against an ether wind, due to a
motion of the solar system with respect to the ether. In Born 1920a (p. 94), it was emphasized that no
such effect had been observed. In the second edition of his book, however, Born stated that the accu-
racy attained in observations only excluded the possibility that the velocity of the solar system with
respect to the ether would be any greater than the greatest known velocity of stars relative to each
other (Born 1921, p. 99).
225. From Paul Ehrenfest
[Leiden,] 8 XII 1920
Vielen Dank für Deinen lieben
Ich sende Dir anbei zwei Briefe und zwei Zeitungsausschnitte— Die Brochure
von Fr. Bauer, von der in dem Brief von ihm die Rede ist geht gleichzeitig mit einer
Sendung von Separata von
an Dich ab.—
Ich habe soeben wieder Briefe von den Physikern aus Petrograd erhalten. Es ist
sehr wahrscheinlich, dass meine Freunde Prof. Joffe und Roschdjestwensky nun
selber auf ein paar Wochen nach Holland
Vielleicht habe ich dann Dei-
ne Hülfe nöthig für Visum für Deutschland. Ich garantiere Dir dass Ihre Reise rein
wissenschaftl. Zwecken dient.
Ich freue mich sehr, dass Dein Aufenthalt hier trotz der endlosen Discutiererei