1 4 6 D O C . 1 8 L U N A R L O N G I T U D E
Published in Königlich Preußische Akademie der Wissenschaften (Berlin). Sitzungsberichte (1919):
433–436. Submitted 24 April 1919, published 8 May 1919.
For a historical discussion of this paper and its sequel, Einstein 1919c (Doc. 22), see Martins
1999, pp. 33–36.
The fluctuations of lunar longitude (position of the moon in its orbit) are described in Newcomb
1909. The quoted values for the amplitude and period of the short-term fluctuation seem to be based
on Bottlinger’s work (see next note).
Bottlinger 1912b. A paper based on Bottlinger’s dissertation was published as Bottlinger 1912a.
Kurt F. Bottlinger (1888–1934) was Assistant Astronomer at the Babelsberg Observatory. See Mar-
tins 1999, sec. 7, for a discussion of Bottlinger’s theory.
Hugo Hans von Seeliger (1849–1926) was Professor of Astronomy at the University of Munich
and Director of its Observatory. Bottlinger was a student of Seeliger’s.
Seeliger 1909. This paper contains a discussion of problems in Newtonian cosmology, which the
author first pointed out in Seeliger 1895, 1896. Essentially the same problems were used in Einstein
1917b (Vol. 6, Doc. 43) to illustrate the need for a cosmological term in the field equations of general
relativity. For historical discussion of these problems, see Norton 1999. Einstein had become aware
of Seeliger’s work in this area by November 1917 (see Einstein to Rudolf Förster, 16 November 1917
[Vol. 8, Doc. 400]). Seeliger is explicitly mentioned in a discussion of cosmology in Einstein’s notes
for a course on general relativity in Zurich in 1919 (see Doc. 20, note 10).
Albert von Brunn (1880–1940), Professor of Astronomy at the Technische Hochschule Danzig
and Director of the local observatory of the Naturforschende Gesellschaft, showed in Brunn 1919 that
Einstein’s idea about the role played by the rotation of the earth in the astronomers’ way of measuring
the position and revolution of the moon was wrong. Einstein accepted von Brunn’s criticism in Ein-
stein 1919c (Doc. 22).