3 0 D O C U M E N T S 2 5 , 2 6 M A Y 1 9 2 3
25. From Walter Loewenheim[1]
Berlin SW 68, 128 Alte Jakob Street, 8 May 1923
Esteemed Professor,
On the occasion of a series of discussion evenings referring to your popularly
comprehensible pamphlet about relativity
theory,[2]
we stumbled upon a difficulty
that we have not managed to explain up to now. You would do me and my friends,
who are seriously endeavoring to understand your theory, a great service if you
would help us clear this cliff. The problem consists in the following:
The β-electrons of two radium preparations L and M are moving past each other
in opposite directions. The highest velocity for ν of the β-rays is, according to ver-
ified measurements , and
above.[3]
If one now relates the speed of the
electrons originating from L and M to a coordinate system rigidly linked to L and
M, then the Lorentz transformation yields the desired conversion values. One can,
however, also relate the speed of the L-electrons originating from L to the passing
M electrons and then becomes imaginary, because ν is larger than
. As only one speed is being measured, the theorem of addition does not
come into consideration.
You would be obliging us to great thankfulness, esteemed Professor, if you
would clarify this misunderstanding for us.
Yours sincerely,
Walter Loewenheim.
26. From Maja Winteler-Einstein[1]
Sestofiorentino–Colonnata, 11 May 1923
My dear little brother,
I imagine you have arrived safely home now from your trip and, as ever, are very
gratified with your stay in Holland. Hopefully you found Elsa well again. It unset-
tles me that she’s sick so
often.[2]
Was she so severely ill again? Dear Elsa, you go
through so much with your health. It would not have been at all silly of you, I think,
to have moved to
Rome.[3]
In any event, the climate and the living conditions gen-
erally are much better there than in Berlin. Nor can it be so very hard to feel at home
there either. I clearly don’t even have to say that I would have been enormously
pleased to have all of you closer by. And the Roman fascists would worry me less
2,7 1010 ⋅
1 β2 –
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