D O C U M E N T 4 3 J U N E 1 9 2 0 1 8 1
(2)
it follows from (1) and (2):
Thus the pressure tensor is calculated.
It is clear, incidentally, that terms of the pressure tensor that contain second de-
rivatives of the temperature, according to location, cannot result out of
this consideration.– *
As I am writing all this down, I suddenly have second thoughts about the whole
theory. The length of path does not enter into the expression, rather, e.g.,
must be expressed by a formula of the form , where can now only
depend on molecular mass m, temperature T, and molecular density n. has the
dimensions , which in the available quantities is only in the form
Nonsense! Heat flow still has to be incorporated, of course! This thing is
correct.[9]
Please put a little pressure on Edith to finish off the matter. Specifically, she
ought to calculate an example to a quantitative and, if possible, an experimentally
verifiable level. I do indeed believe that she was held back and think it very nice of
you to defend
her.[10]
Give her my regards.
With best regards to you and the rest of my Zurich physicist friends, I am, yours,
A. Einstein.
*The paragraph in brackets is struck out.
43. To Klaus Hansen[1]
Berlin, W. 30, 5 Haberland St., 4 June 1920
Dear Sir,
I found your letter of May 15 upon my return from
Holland.[2]
I am now ready
for the trip and only await more detailed information from you. Because I am some-
what overstrained, it would be a great relief for me if I could take my stepdaughter,
who is at the same time my secretary—Ilse Einstein—along with me on the
trip.[3]
So as not to incur any additional expense for you, I request that you please procure
T A B
x
T
x
T
C
grad2T
+ + =
A =
B C + =
C .=
x x
2
T
Txx Tyy
grad2T
1
energy length
-----------------------------------
Previous Page Next Page