D O C U M E N T 2 8 1 J A N U A R Y 1 9 2 0 3 8 3
Mit den herzlichsten Grüssen für Sie und Ihre liebe Frau, auch von meiner Frau,
bin ich Ihr
ALS. [17 169]. There are perforations for a loose-leaf binder at the left margin of the document. Writ-
ten on Meyer’s personal letterhead of “Physikalisches Institut der Universität Zürich.”
Docs. 235 and 247.
Meyer was member of a selection committee searching for a candidate for the vacant chair of
theoretical physics; see note 9 for a list of the other members.
Einstein declined the offer of a full-time professorship at the University of Zurich in Doc. 235.
In September he had already announced to his mother his decision not to give any more lectures in
Zurich; see Doc. 99, and its note 16.
Einstein proposed nominating both Simon Ratnowsky and Paul Epstein as extraordinary profes-
sors with shared teaching responsibilities, and each with a salary equivalent to that of a cantonal
teacher (see Doc. 247).
Peter Debye accepted the terms of his appointment at the Swiss Federal Institute of Technology
a week earlier. Final approval of his appointment by the Swiss Federal Council was given on 2 Feb-
ruary (see the telegram, Schulratspraesidium to Departement des Innern, and Auszug aus dem Pro-
tokoll der Sitzung des schweizerischen Bundesrates, 9 January 1920, Sz-Ar, E 80/829 Debye).
Traditionally, theoretical physics was taught at the University of Zurich in a sequence of five to
six lecture courses, comprising four hours per week and one hour of exercises. In Meyer’s detailed
report in March on the position of theoretical physics, he suggested that this cycle be extended to eight
lecture courses (see “Vorschlag für die Besetzung des Extraordinariates für theoretische Physik,”
2 March 1920, SzZSa, U 110 a, Nr. 73, p. 15).
During his visit to Zurich in early December, Debye suggested that Paul Scherrer be appointed
Extraordinary Professor in Theoretical Physics (see the minutes of 15 December 1919, in SzZE
Schulratsarchiv 1919, Protokoll des Schweizerischen Schulrates, Nr. 129). Scherrer was nominated
for the position in a meeting of the Swiss School Council on 24 January (see SzZE Schulratsarchiv
1919, Protokoll des Präsidenten, 20 February 1920, Nr. 41).
Franz Tank (1890–1981) was Privatdozent at the University of Zurich. For details of his work
and career, see Meyer’s report on the position of theoretical physics in note 6.
The other members of the selection committee were the mathematicians Rudolf Fueter (1880–
1950) and Andreas Speiser (1885–1970), the chemist Paul Karrer (1889–1971), and the astronomer
Alfred Wolfer (see Bericht der Kommission für die Neubesetzung des Extraordinariates für theoret.
Physik an der phil. Fak. II., in hand of Alfred Wolfer, dean of the faculty, after 7 November 1919,
SzZU, ALF Theoretische Physik, 1918–21).
Scherrer 1916a and 1916b.
Scherrer 1915, reprinted with two additional footnotes as Scherrer 1916a, investigated the
Faraday effect (rotation of the plane of polarization of light under the influence of a magnetic field)
for molecular hydrogen, on the basis of a quantum model proposed by Debye. In his detailed report
on the candidates for the position (see note 6), Meyer complained that not only could the calculation
have been done more elegantly, following Sommerfeld 1915a, but also quotes Sommerfeld 1917, p.
500, where it is claimed that Scherrer incorrectly neglected a term in his perturbation calculation that
rendered his final results numerically wrong. Scherrer’s calculations were hence repeated by Som-
merfeld’s student Franz Pauer (1891–?), who in his doctoral thesis (Pauer 1918) found another cal-
culational error in Scherrer’s work that would affect all of his results.
Scherrer 1916b, presented to the Göttingen Academy on 8 July 1916, computed the chemical
constant of an ideal monatomic gas, as an application of Schwarzschild and Debye’s “universal
h-hypothesis” (“umfassende h-Hypothese”) to the case of ideal gases. The computation involves cal-
culation of the absolute entropy on the assumption of a quantized phase space. The entropy expression
is equivalent to the corresponding expression in Planck 1916, presented to the Berlin Academy on
8 June 1916 and issued on 22 June 1916. The equivalence can be seen by comparing eq. (12) of Scher-
rer 1916b with the equation on top of p. 663 of Planck 1916. Planck’s computation is both more