D O C U M E N T 4 6 J U N E 1 9 2 0 1 8 5
with the violin. We already have the export permits for both of them. Soon you’ll
receive the first one. Then I can take the bow and case along
myself.[2]
I’ve calmed
my wife and Springer down about the inaugural
lecture.[3]
Here I have already be-
come acquainted with some interesting things of a physical nature, specifically, a
thing by Hettner who showed that the infrared gaseous spectra HCl, H2O, etc., can
be explained completely by (quasi)elastic natural oscillations along with combina-
tion tones. If, e.g.,
1
and
2
are absorption frequencies, then there are also 2 1,
2, 1+ 2, etc., as the quantum theory leads us to expect for incompletely elastic
oscillations.[4]
Furthermore, work has been done at Regener’s on the Ehrenhaft
business with droplets, which shows that the apparent lowered level of elementary
quanta are produced by too small degrees of mobility, that probably stem from gas
layers that enlarge the particle’s hydrodynamically effective radius; the existence of
such gas layers has long been established by weighing and optical
experiments.[5]
My thoughts are often still with all of you. Those were nice times that I spent
with you. I already very much miss the children with their cheerful
chattering,[6]
also our conversations and the music making. I thank your wife very particularly,
and Aunt, too, for the touchingly feminine care they bestowed on me under such
difficult domestic
circumstances.[7]
In a few days, I have to steam off for Norway;
I am taking Ilse
along.[8]
Meanwhile, the nomination might come, nice and slowly,
from The Hague. It’s good if it takes a little while longer, since it’s getting almost
too much with all this traveling in rapid succession. There’s still time in July, you
know.[9]
Dear Ehrenfest! All of you are so good and warmhearted toward me, without my
being able to explain it, spoiled and overrated heel that I am. But I am grateful to
all of you from the bottom of my heart and know how very precious this is. It’s so
remarkably good for both of us, too, that we are together more often, because it’s
as if nature made us for each other.
Warm greetings to all from your
Einstein
It was supposedly quite silly in Halle. Once again you were
right.[10]
Fokker sent
me a very elegant paper on bound electrons; he is a fine
analyst.[11]
Greet particu-
larly Van Aardenne for me, whom I did not see
again,[12]
also Lorentz and
Kamerlingh Onnes, who took such pains for me, quite
unnecessarily.[13]
Dear Ehrenfest! She [Elsa] doesn’t have time to finish writing now, because she
has to leave about the
violin.[14]
But I want you to get a sign of life from us, at last,
if only an unfinished one.