1 3 6 D O C U M E N T S 1 4 1 , 1 4 2 N O V E M B E R 1 9 2 3
you any trouble, and I will take care of you like a daughter. Don’t laugh but con-
sider this seriously. I think you wouldn’t regret it. There’ll be enough to do for ev-
eryone and we could be together permanently. We would live in a little house out-
side of New York. My salary is large enough so that little Betty will hardly make a
difference.
from your
A. Einstein.
141. To Elsa Einstein
Leyden, Thursday. [8 November 1923]
Dear Else,
I arrived here safely today at
noon.[1]
The first familiar person I met here was—
Lise Meitner, who happens to be here right
now.[2] Ehrenfest[3]
is away until Sat-
urday. Here, all are well and sprightly and living each day without a care, complete-
ly differently from
us.[4]
Affectionate greetings to all, yours,
Albert.
All of you should write soon so that I can see how things are going over there. It is
curious not to know in the least what will happen.
142. From Wolfgang Pauli
Hamburg 36, 9 Jungius Street, 10 November 1923
Esteemed Professor,
I would like to thank you very much for kindly forwarding the correction proofs
of the paper by you and
Ehrenfest,[1]
by which you gave me great pleasure. I am
very happy about your elementary processes, in which many quanta are absorbed
or emitted at once. For, as far as I can see, they also have a corresponding analogue
in the classical theory. In the calculations by you and Hopf as well as by Fokker
based on this theory, the field strength acting on the oscillating particle from its
state of equilibrium is expanded into a Taylor
series.[2]
Upon also taking into ac-
count the quadratic and higher terms of this series in the elongation of the particle
(which are omitted in the mentioned papers), a conversion of energy per unit time
does indeed result that is proportional to the higher powers of the radiation density
and corresponds to your quantum processes of higher order.