D O C U M E N T 2 3 1 D E C E M B E R 1 9 2 0 3 3 1
First, as far as the publication of papers by me on the relativity problem is con-
cerned, a collection of the more important ones already exists that appeared with
Teubner in German, which I am having forwarded to you at the same
course I have no objection to a translation by you and Dr.
Might it not
seem appropriate to you to translate the papers by Lorentz and Minkowski as well?
As regards the finances, I would be satisfied if I received one shilling per copy.
Your offer to lend journals to me and send them to me regularly demonstrates a
sense of good will rarely encountered in this
I warmly shake your hand
for it. However, I am not in a position to make use of your great kindness because
I am anyway not in a position to study so many papers myself; I learn about most
of them from oral reports at our
during which the papers by English
physicists are frequently and thoroughly discussed. Recently, the papers by Aston,
especially, found enthusiastic reception among
In thanking you heartily again for your kind letter, I am with amicable regards,
231. From Erwin Freundlich
[Potsdam,] 14 December 1920
Below are the requested densities: the formula for the spatial density in star
clusters is set in the following
the corresponding apparent density projected
onto a plane is:
& a are constants; = number of stars per unit area in the center of the cluster.
The total number of stars
; a thus means the radius of the corresponding homogeneous
cluster with the same total number of stars and a mean density equal to the central
density in the real star cluster.
According to this formula the drop in density in the Messier 3 cluster (N[ew]
G[eneral] C[atalogue] 5272) for a count of all the stars up to a limiting size class,
without taking types into
f r N 1