1 7 0 D O C U M E N T S 2 7 , 2 8 M A Y 1 9 2 0
27. From Max von Laue
Zehlendorf, 17 Albertinen St., 22 May 1920
Dear Einstein,
As I am not going to be seeing you here before my Stockholm trip, and because
after my return the matter is easily forgotten, I would now like to write you about it.
A short while ago you said the way in which I presented the consistency of the defi-
nition of time synchronization, in my book (p. 51 of the third ed.), was not
elegant.[1]
Under the condition that light followed each path there and back in the
same time interval, it would be trivial. But this condition was supposedly not obvious.
I now had another look at the matter, particularly since I have to prepare the 4th
edition soon. My response is: On p. 51 I am speaking exclusively of frames of ref-
erence in which the propagation of light occurs at the same velocity in all direc-
tions, consequently also in the direction opposite to the same path. This appears
explicitly directly before the consideration in question, namely, on l. 3 from the top
on page 51. Therefore the consideration is acceptable. Now, you call it
trivial.[2]
That is a matter of intellectual ability; and you must excuse me if I do not consider
you as quite the norm in that. So I am thinking of leaving the relevant section as it
is.[3]
I hope to see you on 9 June at the
colloquium.[4]
I have a couple of very minor
and perhaps very stupid questions about general relativity.
With warm regards, yours,
M. Laue.
28. From Carl H. Unthan[1]
Charlottenburg 9, 3 Linden Avenue, on Whitsunday, 23 May 1920
Esteemed Professor,
You will kindly pardon me if I must again take up your valuable time, with some
delay, owing to pressing and unpostponable obligations. For me one letter is no
cause for great effort; considering that in the last period I have been spending many
a day sitting at the typewriter for 12 to 14 hours and working through up to 36 folios
of translations in 5 languages.
I too have been a pacifist for a long while
now.[2]
No platonic relationship toward
pacifism satisfied me; I involved myself energetically in the polemics between Po-
pert, Otto Ernst, Siemering, etc., versus Fried, von Gerlach, von Ossietzki and the
rest of the scum, who cannot outdo themselves in fawning submissiveness and dis-