D O C U M E N T 1 0 2 A U G U S T 1 9 2 0 2 3 3
selves with this light source in other respects as well. Prof.
Bosch,[4]
who sends his
regards, is offering us a member of the physics staff from his factory. This physicist
will be officially employed by the Baden Aniline and Soda Factory and will work
with us in Potsdam. I would like to suggest Dr. Stumpf for this position and assume
that you will not have any objection to choosing him either. He is an experimental
physicist & was trained specifically in optical methods in Göttingen as a student of
Voigt.[5]
I learned enormously much here besides, while working together with Dr. Hoch-
heim;[6]
the work with gases, vacuum, etc., was something new that I first had to
learn how to do.– I hear that the construction is making good progress. Siemens &
A.E.G. have each donated 20,000 marks retroactively and, in addition to that, an-
other 20,000 marks have been obtained from Dr. Kurt Albert, director of the H. Al-
bert Chemical
Factory.[7]
I hope you are doing well. When are you going on
vacation? My address until end of August is: Dettendorf (Aibling post office), Up-
per Bavaria. With greetings also to your family, yours,
Erwin Freundlich
102. To Paul Ehrenfest
[Berlin,] 13 August 1920
Dear Ehrenfest,
The inaugural lecture is almost like the school-leaving exam nightmare; it’s an
interminable little business that lasts as long as one lives and
breathes.[1]
I cannot
be in Leyden by October 13 because I asked my boys, whom I have not seen for
one and a half years already, to Benzingen near Sigmaringen on October 4. I sug-
gest October 27. I do have a tail coat But it is just very inconvenient to drag it along
to Kiel, [Bad] Nauheim, Hechingen, Benzingen, and Leyden. Perhaps a Leydener
of about my dimensions can lend me a dress coat?—I will dare to leave mine here.
and am going to bring it along. Please arrange for the passport visa very soon, as I
am leaving Berlin on September 10 and am not going to return before Holland. I’ll
buy bow and
case.[2]
I do still owe you the 20,000 marks; calculation too compli-
cated for my poor
brain.[3]
You don’t have to pay anything more and, in my opin-
ion, still have some chance of being allowed, legitimately, to feel rotten about it.
Also don’t forget that I still owe you for the stay; this problem is almost as difficult
as the magnetic one. I did understand your account of it in the
main.[4]
If the gadol.
sulf. satisfies Langevin’s law right down to very low [temperatures], this proves
that the orientational forces are extremely weak. Even lower, it really must
degenerate, finally. The quantum treatment suffers from the problem that it is
unknown whether quantum states are possible with the angle zero and between