D O C U M E N T 3 0 J A N U A R Y 1 9 2 1 2 5
requested me to ask you whether you might do the institute the great favor of giving
a photograph of yourself, supplied with your name, to the director. The photograph
is destined for a collection of portraits of famous men who have visited that
institute.[2]
It was at that institute that you held your lecture in Copenhagen last
summer. According to the director’s wish, it is only supposed to be exhibited as a
projected image at the New Year’s celebration at the institute, which is taking place
on February 1, and he should therefore be very grateful if it were possible for you
to send him a photograph soon so that it could be used for this purpose. In the hope
that I do not cause you undue trouble with this request, I send you and your family
best wishes for the New Year from all of us.
Yours very truly,
Niels Bohr.
30. From Paul Ehrenfest
Leyden, 22 January 1921
Dear Einstein,
My eldest brother sent me a veritable hymn of praise about you—Mr. Privy
Councillor broke into a sweat, so to speak, out of admiration for you (as a
person).[1]
—I was, naturally, enormously pleased that you treated him nicely. I
have this brother very, very much to thank for—as with all my brothers, inciden-
tally: when I was small, 5–8 years old, they always showed me and explained
everything they themselves found interesting, and I later learned not nearly as much
from anyone else as from my brothers! I received your Vienna-departure-postcard
with the Ehrenhaftianissimis in introduction.– In addition, also your letter from
Berlin.[2]
1. I’ll send the amount for Zeeman from your
account.[3]
2. I’ll inform De Haas (regarding Brussels
review).[4]
3. I’ll try to catch the drift of your comments about the Hall
effect.[5]
4. If the Stark effect of light-wave fields you mentioned were detectable, that
would be a grand thing. For now it sounds
unbelievable.[6]
5. Recently I had frequent qualms of conscience for having meddled with unso-
licited advice in the matter of the America trip. Van Aardenne, in particular, was
strictly against any
meddling.[7]
But now it’s done and I console myself with the
thought: it makes absolutely no sense that you go to America, unless it’s a way to
escape the interminable running around in the more distant future.– Now—may
God forgive me if I meddled wrongly in this affair.—Besides, he has already
punished me now: infecting me with the yearning (!!!) for an America trip, in