DOCS.
192,
193
FEBRUARY
1916
195
c)
the
mixed
crystal
existing
at
T
=
0,
unordered
by definition,
can
be
produced
(sufficiently exactly)
by
the
reverse
process
and has
entropy
0,
you
have not
provided
the
least
argum.
in
support.[4]
Right
from
your
detailed
correspondence
I
gather
that
you
do not separate
the
cases (a) (b)
and
(c)
distinctly,
whence in
my
view
your
error originates.
You
hold
the
following impossible position:
“Thermodynamically,
only
ordered
crystals
exist at absolute
zero.
Conse-
quently,
the
entropy
of mixed
crystals,
even
when
real,
i.e.,
unordered,
must be
calculated
as
if they
were
ordered.”
Write
me
your
answer
briefly
and
to
the
point (such
as a
postcard).
It
is
easier
then
to
answer
concisely.
With best
regards, yours,
Einstein.
193. To
David
Hilbert
[Berlin,
18 February
1916][1]
Highly
esteemed
Colleague,
Many
thanks
for
taking
my
wishes into consideration.[2]
I will
not inform
you
of
the
exact
time
of
my
arrival
so
that
you
do
not
inconvenience
yourself.
At all
events,
it will
only
be
on
Thursday.
I
gladly accept your
and
your
wife’s
kind
invitation
to
stay with
you.
That the
affair with H.
promises
to
turn
out
favorably
pleases
me
greatly, especially
since
I
am
not
going
to
receive
the
call to Vienna
because Smoluchowski
will
receive the
appointment there.[3] Important
matters
can
be carried
out at
the
observatory even
with
relatively
modest
means,
in
particular,
beside
the
Jupiter
matter,[4]
the
question
of
redshift for fixed
stars.[5]
It
will
be
a
joy
when
everything
has
straightened
itself out!
Best
regards, yours,
A.
Einstein.