DOCS.
129,
130
OCTOBER
1915 137
facilitates
seeking
out
Q.
For
it
follows
directly
from this invariance
that
Q
must be
a
linear
homog.
function
of
the
five
expressions
on
page
1075
below
of
my
article.
That
Q/-g
had
been
set
by
me as
equal
to
the fourth
expression
given
there
can
be
justified by
the
fact
that
only
with
this
choice
does
the
theory
contain Newton’s in
approximation.
That
I
believed it
possible
to support
this
selection
on
the
SAu
equation
was
based
on error.[8]
Cordial
greetings
from
your
A.
Einstein.
130. To
Heinrich
Zangger
[Berlin,]
Friday.
[15
October
1915][1]
Dear friend
Zangger,
I
very
much
like
the
printer’s proof you
sent
me;
not
exaggeratedly
abstract
and
yet sufficiently
general.[2]
Since
coming here[3]
I
have been
working very
solidly
in
my cubbyhole.
It
has
unfortunately
become clear
to
me now
that the
“new
stars” have
nothing
to
do with
the
“lens
effect,” moreover
that,
taking
into account
the
stellar densities
existing
in
the
sky,
the
latter
must be such
an
incredibly rare
phenomenon
that
it would
probably
be futile to
expect
one
of
the
like.[4]
I
wrote
a
supplementary paper
to
my
last
year’s analysis
on
general
relativity.[5] Presently
I
am
researching
a
bit
in
heat
theory.[6]
However,
I
have
not
yet begun
the
experiment. Warburg requested
that
I wait
a
few
days.[7]
I
haven’t
seen
any
of
my
colleagues,
as
the
Academy
has
not
started
yet[8]-I still
think
back
with
bliss
on
the
Swiss
times of
free speech [Schnabelfreiheit]....
The serious accident in
the
Bieler Lake
region,
about
which
you
wrote
me,
upset
me
very
much. You
complain
about the
thoughtless
manner
in which
people
allow disasters to
happen.[9]
But
it
is
much
more
dire when
things
become
a
calamity precisely
because
they
are
in
the
focus
of
human
attention!
I
am
very glad
that
my boy
has
come
to
see you.
Do
ask him whether he
has received
my long
letter; I
almost fear he
hasn’t,
because
I
have not received
a
reply. Today
I
am
going
to
try
once
again.
But
if I
see
that the
woman
is
thwarting
all
of
my
efforts to remain in contact with
the
boy,
I
shall
use
legal
means
after
all
to
enforce
that the
boy spend
a
holiday
month with
me
every
year. Only
in
this
way
will
he
lose
the
feeling
that
he
has lost his father.
I
can’t
understand
at all
that
she doesn’t consider it her
responsibility
to leave
the
boy
with
me
occasionally.
I
noticed
distinctly
that
in front
of
others
Albert and
his