1 9 4 D O C U M E N T 5 6 J U N E 1 9 2 0
I do not know how far your nomination to Leyden has
come;[4]
I hope we shall
see you again soon.
Best regards to you, also in the name of my wife and
children.[5]
Yours truly,
W. H. Julius.
55. From David Reichinstein[1]
Leipzig, Flossplatz
29II,
14 June 1920
[Not selected for translation.]
56. To Hendrik A. Lorentz
[Christiania, Grand
Hotel,][1]
15 June 1920
Highly esteemed Colleague,
Already in Haarlem I told you that it will be a great pleasure for me to accept the
invitation to the Solvay congress. I shall likewise be glad to take on the
report.[2]
It
is a heartfelt need of mine to see our French friends in particular after such long and
difficult times and to shake their hands. It also pleases me that it is still possible,
even today, to be treated as an internationally minded person, without being com-
partmentalized into one of the two big
drawers.[3]
The time spent in Holland is still vivid in my mind’s eye. I only regret the great
effort that I caused you and Mr. Kamerlingh-Onnes. I should have thought of such
an option as having my trip to Holland postponed by a couple of months, which I
would have had no difficulty
doing.[4]
In Berlin, Mr.
Hettner[5]
recently showed that the observed infrared eigenfre-
quencies (absorption) of vapors (excluding Bjerrum’s rotational
influence)[6]
can
be described in the form
,
where are the actual eigenfrequencies; are low, positive whole num-
bers (or zero). This fits nicely with Bohr’s theory if one assumes that in the poten-
tial energy the quadratic terms in the deviations from the state of rest are the
primary, but not quite the only, critical
factor.[7]
The basic frequencies , etc.,
furnish interesting touchstones for molecular models.
With cordial greetings to you and your esteemed wife, I am, your devoted ser-
vant,
A. Einstein.
v m1
1
m2
2
+=
1 2
, m1, m2
1 2
,