3 9 2 D O C U M E N T S 3 9 6 , 3 9 7 D E C E M B E R 1 9 2 4
395. From Otto Blumenthal
[Berlin,] 15 December 1924
[Not selected for translation.]
396. To Louis A. Bauer[1]
Berlin, 16 December 1924
Highly esteemed Colleague,
I thank you cordially for sending your interesting
papers[2]
and look forward to
being able to speak with you personally in a year or two about the important prob-
lems revealed by your
observations.[3]
About two years ago, a false rumor arose to
the effect that I had found a new relation between relativity theory and the theory
of terrestrial
magnetism.[4]
Strangely enough, about half a year ago a connection
then did occur to me that does belong in this chapter, without my having succeeded
in reaching real clarity.
It seems to me as good as excluded that the magnetic field of the Earth, the Sun,
and sunspots can be explained by electric conduction or convection
currents.[5]
The
impression is much rather that rotating neutral material would be magnetically ac-
tive in a similar way to a negatively charged mass that is proportional to the mate-
rial’s
density.[6]
One thus oddly enough obtains by order of magnitude the correct
ratio between the solar field and the terrestrial field. Moreover, the following is re-
markable: ponderable mass multiplied by the root of the gravitational constant has
the same dimension as the electrically charged mass. If one accordingly makes the
assumption that the Earth’s mass acts similarly magnetically during rotation as a
gravitational
constant[7]
times (i.e., 10
times[8]
) the greater electrically charged
mass, one thus strangely obtains the right order of magnitude for the Earth’s mag-
netic
field.[9]
These connections are certainly striking. Yet I have not succeeded un-
til now in doing them justice with a reasonable theory.
With kind regards, I am yours,
397. To Otto Blumenthal
[Berlin,] 16 December
1924[1]
… Painlevé is a person who has already been working for years to cleanse the
intellectual
atmosphere.[2]
He may well have erred; yet he is of a sort that we un-