5 0 0 D O C U M E N T 2 1 4 N O V E M B E R 1 9 2 0
ist jetzt natürlich von verschieden.
Also auf Wiedersehn Dienstag!
Viele Grüsse Ihr
W. Nernst
ALS. [18 445].
[1]Paul Günther (1892–1969) took his doctor’s degree in 1917 under the guidance of Nernst; the
papers are Nernst 1919 and Günther 1920. The first one deals with what Nernst calls “Gasentartung”
(“gas degeneration”), the phenomenon that at very low temperatures, ideal gases no longer follow the
ideal gas law but are in a state where the pressure at constant volume is independent of the tempera-
ture. Nernst tries to explain this phenomenon by assuming that molecules repel each other with a force
that is inversely proportional to their mass and to the third power of their distance. A calculation of
the viscosity of hydrogen at low temperatures leads to satisfactory agreement with experimental
results. In Günther 1920 new measurements of the viscosity of hydrogen are presented that support
Nernst’s theory.
[2]Nernst 1918.
[3]Fig. 21 gives the temperature dependence of the heat of condensation of a mole of dilute gas and
the affinity (maximum work) for the same process. For the two quantities coincide; the curves
show the same general behavior as, e.g., for the melting of condensed systems.
[4]Stern 1913.
[5]See, e.g., Tamman 1918a, 1918b. Gustav Tammann (1861–1938) was Professor of Inorganic
Chemistry at the University of Göttingen and Director of its Institute of Physical Chemistry.
[6]
Nernst applies his heat theorem in the form with A the affinity (see, e.g.,
Nernst 1918, p. 68).
214. From Willem de Sitter
Waldsanatorium Arosa 29/11/20
Lieber College
Ich danke sehr für Ihren
Brief.[1]
Über die Stabilität des Milchstrassensystems, und über die Frage in wiefern es
durch seine eigene Gravitationswirkung zusammengehalten wird, hat Eddington
schöne Untersuchungen
angestellt,[2]
deren Resultat mir leider hier nicht zur Ver-
fügung steht. Aber soweit ich mich erinnern kann kommt er zu der Folgerung dass
es mit den gegebenen Sterngeschwindigkeiten sehr wohl möglich ist dass es durch
A0 AT – T
c T d E –
0
T
T2
-----------------------dT
0
T
=
c dT
0
T
E
T
T 0 =
A
E
T2
-----dT,
T
–T =