8 0 D O C U M E N T 9 9 M A R C H 1 9 2 1
That’s not supposed to be so, according to Herzfeld: not a process imposed by an
external field but a free one by reversal [umklapp process]. That is why I cannot see
any problem with subdividing the rods according to Beck. But Herzfeld does not
yet have anything positive to substantiate his theoretical conceptions. It seems very
reasonable to me, though. All of us at my institute are quite clumsy in carrying out
experiments. We hear the frequently noted “crackling,” too, of course. According
to Herzfeld it is supposedly composed of a wave train at Hertzian frequency of long
wavelength and indicates the irradiated angular
momentum.[9]
I have little to report about spectral lines that is new. The best is that the “mag-
neto-optical decomposition law” I published a short while ago in the
Annalen[10]
is
attracting more people and is leading to a “complete constitution formula for the
anomalous Zeeman splitting” (comp., e.g., Back in the
Naturwiss[enschaften],[11]
forthcoming). Otherwise, I launched a rebuttal against Stark, who had attacked
Bohr very foolishly in the
Jahrbuch.[12]
In addition, I recognized in Japanese obser-
vations the Stark effect of 2nd order (a supplementary effect) as proportional to the
2nd power of the field strength for
).[13]
Besides that I wrote something else
again about lubricant
friction.[14]
But now I am going to the mountains for a fort-
night with Laue, Lenz, Mie, etc., if possible, to go
skiing.[15]
So, auf Wiedersehen! Forgive the lateness of this letter. Yours,
A. Sommerfeld.
99. To Franz Oppenheim[1]
Berlin, 15 March 1921
Highly esteemed Mr. Oppenheim,
To my great joy I gathered from our telephone conversation that you are in a
position and inclined to spend substantial sums in support of scientific research in
the area of physics. I permit myself to recommend to you most enthusiastically two
grants.
1) To Professor J. Franck (Physics Institute of the University of Göttingen)
20,000 marks for the continuation of his important investigations on the energy
levels of quantum states of atoms and molecules that can be generated by electron
collision.[2]
2) To Mr. H. Boas, eng. ([Berlin] S.O.16, 40 Köpenicker
St.)[3]
10,000 marks
for the development of a novel apparatus of importance for physical astronomy (a
new kind of spectro-heliograph).
To the best of my knowledge I am certain that both these grants will lead to real
scientific advances.
I am delighted that you were so kind as to impart to me the prospect of a good-
bye
visit.[4]
Until then, cordial greetings, yours.
H