DOCS.
3,
4
APRIL
1914
11
3.
To
Mileva
Einstein-Maric, Hans Albert and Eduard
Einstein
[Berlin,
10
April
1914]
My Dears,
The director
was
quite sympathetic.
He is
very
much to
my liking.
It
will
be
better there than
I
thought.
Lutheran
religious
instruction.[1] Haber invites
you
all
until the
apartment is settled.[2]
Happy
Easter
wishes[3]
from
your
Papa.
4.
From
Paul Ehrenfest
[Leyden,
10
April
1914
or
later][1]
Dear
Einstein,
In
answer
to
your
comment
about
rotating
electrons in
a
magnetic field.[2]
I protest against
your
assertion
(or
assumption):
“with
a
constant
magnetic
field
the statist. mechanics
of
the
structure
ought surely hardly
to
differ from
those
without
a
magnetic field.”-
With
a
concise
argument
I
can
force
you
to
admit
the
contrary.
(And
then
the
paradoxes
indicated
by you disappear!)
Here
right away
is
the
crux
of
the
problem:
When
an
electron
rotates
in
the
H
field
its “moment”
is
not
mr2w
but
r2(mw+
2c’
[You
should not
forget
that the
ether’s “electrokinetic”
energy
contains
a
term of
the
form
erw
rH
~c 2~'
(For
2
current
cycles
obviously
always:
c11/2i21
+
c12i1i2
+
c22/2i22)]