D O C U M E N T 8 5 J U L Y 1 9 2 0 2 1 7
M (mass) = D (density) ·
l3 (length3)
Take Newton’s law
= accel. · mass = .
Hence equation of dimensions:
.
Newton’s law is therefore not invariant to measuring-rod changes if one also con-
siders the law of the propagation of light. Then one must transform T like l (if in
every system is supposed to hold). So one cannot carry out any simi-
larity transformation without altering the unit of density or the gravitational con-
stant. The law of gravitation in connection with a constant velocity of light thus
does not allow any measuring-rod transformations if the density of a substance can
be regarded as something rigid (independent of its prehistory).
Now to Dällenbach’s
example.[12]
The conductor rotating upon itself is naturally
chargeless. In the case of the double conductor,
the total charge is obviously also nil, as the enclosed sketch shows. Nowhere do I
see anything particularly paradoxical here, since no Galilean system rotating along
with the rotating conductor exists. The latter case can only be dealt with by a trans-
formation according to general relativity. That a rotating conductor generates no
charge is connected to the incompatibility between the systemÊs conditions and the
Lorentz contraction of the electron body relative to the matter. The existence of an
acceleration, in and of itself, has nothing to do with it, in my opinion.
Acceleration is, in a certain sense, absolute, because at every location there is an
acceleration-free and rotation-free state (local system without a gravitational field),
and relative to said local system one can define accelerations in this case. There is
no question that charges must form on a rotating magnetic rod, completely disre-
garding every relativistic theory. These charges must lead to a field outside of the
magnet, which must, in principle, be detectable. But there is nothing problematic
about that.
k-----------
MM
r2
-
Ml
T2
------ -
k M 1– l3T 2– D 1– T 2– = =
c
l
T
-- - 1 = =
i
i
v
v