482 DOCS.
467,
468
FEBRUARY
1918
(u
=
1,2,3)
then,
metrically,
the
infinite realm
does not have
the
nature of
a
point
and
cannot be transformed into
finitude,
without the
appearance
of
an
inadmissible
singularity.
But
if
such
a
transformation
is
possible,
then
I
simply
name
the world
finite
(i.e.,
finite
as
measured in
standard
measure).
Then
it
can
be
represented
as a
continuum closed in
upon
itself,
and
special
boundary
conditions
are
eliminated.
I
claim that, from
a consistently
relativistic
point of
view,
this
is
the
only possibility.
Your
remark
on
the
continuation of the
guv's
from
one
position
seems
to
me
to
be
supported
by
a
physically illegitimate
postulate.
The
legitimate requirement
reads
as
follows:
It
must be
possible
to continue
the
universe
beyond
a
spatially
complete
cross-section
by
means
of
the
differential
equations.
This continuation
must be
uniquely determined,
apart
from
the
ambiguity
attached
to
the
free choice
of coordinates.[6]
It
is
very improbable
to
me
that
the
pv's
can
be
subjected
to
additional
conditions in
the
manner
you
believe. The
relation
dAa
9ßa
+
9v
dAa
I
i
-ría'
^9¡iv,
=
0
dxv
dxu dXn
changes
into
an
evidently
invalid condition for
the
electrical
field at
an
infinites-
imal
gravitational
field
(dguv/dxa=0).
Best
regards, yours,
A.
Einstein.
468. From Hermann Coenen[1]
Breslau
XVI,
21
February
1918
Esteemed Mr.
Einstein,
I
was delighted
with
your book,
which
appeared
with
Vieweg,[2]
and thank
you very
much.
I
already
had
this
book of
my own
accord and have
thus
passed
on
the
first
copy
to
the
Library
of
the
Roy.
Surg.
Clinic. Your
gift copy
to
me, however,
I
shall
keep
with
especial pleasure
but
request
the
kindness of also
writing
a
little
dedication
in it.
I
hope
that,
with
your
loaded
schedule,
this
does
not inconvenience
you
too
much.
Your
handwritten
message pleased
me even more
than
the
book, though,
and
in
the
next
few
days
I
shall have
the
occasion of
going over
your
figures
with
Prof.
Wilkens,
the
astronomer
at
the
local
observatory,[3]
since
I
would
get
stuck alone.
Should
you
be
acquainted
in Berlin with
my
friend Prof.
e[xtra]o[rdinarius]
and
Health
Councillor Moritz
Borchardt,
6
Dörnberg
Street,
Director of
the
Surgery
Previous Page Next Page