DOCS.
401-403 DECEMBER
1917 411
be able to
solve
these
paradoxes
for
me
in
a
satisfactory
manner.
With
best
regards, yours truly,
Hans
Thirring.
402. From
Erwin Freundlich
Babelsberg,
Berlin,
4 December 1917
Dear Mr.
Einstein,
My
research
agenda
for the immediate time to
come
will
be
the
following:[1]
1)
For
verification of
light deflection
in
the
gravitational field: Development
of
a
method
of
photographic
imaging
of stars
in
the
proximity of
the
Sun; furthermore,
preparatory
researches for
a
solar
eclipse
in
1919
and
development
of
Kapteyn’s
parallax
method
for stellar occultations
by
Jupiter.
First
of
all,
I
am
going
to
acquire
at
Potsdam the
requisite practical
skills in
astrophotography.
2)
For verification
of
a
red
shift of spectral
lines for
fixed stars:
Development
of
the
new
measurement
technique
with
the
photoelectric measuring
instrument
presently
under
construction[2] and
development
of
both the statistical method
and
the direct
one
with
spectroscopical binary stars,
both
components
of which
are
visible.
I
shall in
part try
to
use
existing
data,
and in
part
have to
obtain
new
data
myself.
Here
also,
first
of
all,
accumulation
of practical
knowledge
in
the
production
of
spectral
images
from
fixed stars.
With best
regards,
E.
F. Freundlich.
403.
To Heinrich
Zangger
[Berlin,]
6
December
1917
Dear friend
Zangger,
It
is
shameful how
long
it
has been since
I wrote
you;
I
seem
to have
inherited
my
sloth in
writing
from
my
Albert,
for
he is
even
lazier.[1]
I
had trouble
reading
your
postcard.
Were
you
in Lausanne with
Perrin?
I
know him
very
well
from
the
Brussels conferences and from
my stay
in
Paris[2]
and do
like
him. Do
you
know
what
my
wife’s
illness
is
exactly?
Is
it
an
ulcer
on
the
spinal cord,
or
multiple
sclerosis
perhaps? Is
there,
in
your
opinion, any prospect
of
recovery?[3]
Please