68
DOC.
56 FEBRUARY
1915
56. To
Michele Besso
[Berlin,]
(13
Wittelsbacher
St.)
12
February
[1915][1]
Dear
Michele,
Your
postcard is
stirring up
my guilty
conscience
again;
I
am
writing
now
before it has subsided again.
I
was
worn out
by
influenza;
but
now
it's
over.[2]
Miza’s address
is:
30
Volta
St.,
Zurich.
I
am
very
satisfied
with the
separation,
despite
hearing
about
my boys only extremely rarely.
The
peace
and
tranquillity
does
me
tremendous
good,
and
no
less
so
the
extremely agreeable, really
fine
relationship
with
my
cousin,[3]
the
permanent
nature of which
is guaranteed
by
a
renunciation
of
marriage. Presently
Natanson
from
Lvov,
theor.
physicist[4]
and
fellow
kinsman,
of whom
I
have become
very fond,
is
here.
I
corresponded
with
your
friend of former times Straneo
(now
in
Rome)
about
gravitation.[5]
This
theory is
being
received
with
very great
interest
by
our
Italian
colleagues.[6]
I
am
also
corresponding avidly
with Lorentz
about
it.[7]
As
regards science,
I
have two
fine
matters
to report
to
you:
1)
Gravitation.
Redshift
of spectral
lines.
(Spectroscopic)
binary
stars have
the
same mean velocity
within
the
radius of vision. The
mass
of the
stars
results
from
the
Doppler periodic
line fluctuation. The
component
of
larger mass
against
the
component
of smaller
mass
ought
to
exhibit
a mean
redshift in
the
spectr.
lines.[8]
This is
confirmed,
since
the
stars’ radii
can
also be
estimated
(apparently
from
the
(light
intensity and)
spectral
type);
thus
there
is
even an
approximate
quantitative
test of
the
theory,
with
satisfactory
results.
2)
Experimental
confirmation
of
Ampère’s
molecular current
hypothesis.
If
para-
magnetic
molecules
are
spinning-top
electrons
[Elektronenkreisel],
then
each
mag-
netic moment
I
corresponds
to
mechanical
angular
momentum
M
in the
same
orientation
of
the
magnitude[9]
M =
1.13
.
10-7I.
As
I
changes, a
rotation
moment
appears (-dm/dt).
When
the
magnetization
of
a
small
hanging
rod
is
inverted,
it
experiences
an
axial
rotation
moment,
the
existence
of which
I,
together
with
Mr.
de Haas
(Lorentz’s son-in-law),
have
proven
with
experiments performed
at
the
Reich
Institute.
The
experiment
will
be
coming
to
an
end
soon.[10]
With
it
the
existence of
zero
point
energy
has also
been
proven
in
a
single
instance.[11] A
wonderful
experiment;
what
a
pity
that