3 4 D O C U M E N T S 2 9 , 3 0 M A Y 1 9 2 3
29. To Mileva Einstein-Maric
Berlin, 18 May 1923
Dear Mileva,
I agree about buying the
house.[1]
But be well advised regarding the price and
conditions, most preferably by Albert Karr. I’ll have the money sent out as soon as
I have heard from you. But it’s still unclear to me in whose name the remainder is
to be deposited. Do inform yourselves at last about the capital
tax.[2]
If all of you
are persuaded on the basis of careful consideration, then close immediately and, if
need be, have Karr pay the money out to you in advance. He, in turn, will get it im-
mediately back from Stockholm. In a hurry, yours,
Albert.
I’ll be writing the boys in tranquility as soon as I have time.
30. From Hermann Weyl[1]
Zurich, 52 Bolley St., 18 May 1923
Dear Colleague,
In the correction proof I had forwarded a short note to you which, among other
things, contains a somewhat precipitous criticism of your new approach and which
I will suppress, provided it is still
possible.[2]
By way of an apology I would like to
indicate that I had earlier made a similar attempt following
Eddington[3]
and then
did not notice enough the difference between your approach and my earlier one. In
the interim I calculated a little further and obviously cannot help it that, according
to your new theory, the dynamic effect of the electromagnetic field always only re-
sults from a small cosmological magnitude.
In order to perform approximation calculations, I assume is small compared
to and write, in order to express this, instead of .[4]
The reciprocal matter
(riαrαk
is, developed from powers of ε,
. Through substitution in the definition equation in paren-
theses and comparison there then result the relations
, , .
If the juggling with the indices is determined by , then the designation is
correct, and one has
ϕik
giκ gik εϕik + rik = gik ϕik +
rik δik)
=
gik εϕik – ε2γik… + =
giαgαk
δik =
giαϕαk ϕiαgαk
=
giαγαk ϕiαϕαk
=
gik
ϕik