1 9 0 D O C U M E N T 3 0 5 N O V E M B E R 1 9 2 1

greetings.[9]

Tomorrow I’m visiting

Lorentz.[10]

I can’t make it to Delft anymore to

see de

Haas.[11]

Everything’s tightly scheduled for me. I had my gray suit on every-

where and all the time, now with the striped trousers, because the others are torn.

So not a trace of elegance.

Warm reg[ards] to all three of you with the

elders[12]

from your

Albert.

304. From Heinrich Zangger

Zurich, 21 November 1921

[Not selected for translation.]

305. From Theodor Kaluza

Königsberg, Pr[ussia], 34 Steinmetz St., 28 November 1921

Highly esteemed Professor,

According to your wish, I am sending you a brief summary of my idea. I first

showed how for small

[1]

everything goes smoothly and then marked the diffi-

culties in the electron’s

motion.[2]

–

It recently occurred to me that the upper limit for , still allowing for the ad-

ditional term with in the equations of motion, would be about reached if

particles of about ~ 10

6

g are charged with a few elementary

quanta.[3]

Now,

Ehrenhaft’s inconsistencies probably lie, for the most part, among the smaller par-

ticles, hence a larger specific charge, i.e., a larger

[4]

(whereas Millikan’s could

just barely pass by).[5] You will be able to see better whether it is pure idiocy to

imagine a connection here. In this case let the indicating note to (8) be omitted![6] –

Among all the possibilities that I considered for the elimination of this inconsis-

tency initially arising for the electron’s equations of motion, the one that attracts

me most is the one I sketched in the second to last section. For

( is small), the scalar T of the energy tensor [for matter not moving all that

furiously][7]

also becomes for the field equations of the 1st type:

dx0

ds

------- -

dx0

ds

------- -

dx0

ds

------- -

2

dxv

ds

------- -

gik –

ik ik

+ =

ik

T00 T44 + – ~