DOCS.
195,
196
DECEMBER
1909
145
I
haven't
discovered much.
The
most interesting
discovery
is
that
one can
specify
an
infinite manifold of
energy
distributions that
are
compatible
with Maxwell's
equations.
Perhaps
the solution of the
quantum question
lies
therein after
all. For,
if
u,
v,
w
=
current
density
p
is
el.
density
Tx,
Ty, Tz,
p
are
potentials,
then
one can assume
the
energy
density[3]
pp
+ (Txu +
·
+
. )
+
P
a2(p
__
dp2
\
\
P
dt
+
/
a
_
*n x
\
\
dt x
_
2 dt
+
·
+
/
This
expression
can
be
generalized
by
replacing
(p
with
P
d\|j
dt
with
P
+
at
'
dx
etc.,
where
\|/
is
an
arbitrary
solution of
the
diff.
eq.[4]
A\|j
Maxwell's
eq.
I hope
this
is not
a
mock-window.
Cordial
greetings
from
your
dt
=
0.
This
is
compatible
with
Albert
[...][5]
196.
To Jakob
Laub
Zurich, 31
December
1909
Dear
Mr.
Laub,
I
was
delighted
with
your postcard,
even
if it
aroused terrible
pangs
of
conscience in
me
because
I have
not
written
to
you
for such
a
long
time. But
I
have not
done
so
for
the
simple reason
that
I
am
very
busy.
I
take
my
lectures
very
seriously,[1]
so
that
I must
spend
much
time
on
their
preparation.
6
hours
a
week and
an
evening
seminar does
not
seem
like
much,
but
it
is.[2]
The
only reason why
I
did not send
you
the
Salzburg
talk[3]
was
that
it
does
not
contain
anything new.
But
I
am sending
it
to
you now.
Have
you
seen
Coehn's
paper
on
current
flows and electro-osmosis[4] This
is
most
interesting