XX
INTRODUCTION TO VOLUME
3
of
progress just
as
preconceptions
about
simultaneity
had
once
done. Einstein
took
this
parallel seriously enough
to
express
it
in
a
letter
to Arnold
Sommerfeld
early
in
1910.[21] Despite
his
hopes
that
he
could "hatch this
favorite
egg,"
nothing
came
of
it.[22]
Einstein
did, however, complete
a
paper
in
August
1910
that
decisively
eliminated what had
appeared
to
be
a
possible
way
of
preserving
classical
electromagnetic
theory.[23]
It
was
clear
by
this time
that
the combination of
electromagnetic theory
and the
equipartition
theorem of classical
statistical
mechanics
led to
disastrous
consequences-a
distribution law for
black-body
radiation
that
produced
what Paul Ehrenfest
was
to
name
"the
Rayleigh-
Jeans
catastrophe
in
the ultraviolet." Could this
catastrophe
be blamed
en-
tirely
on an
inappropriate
application
of the
equipartition
theorem?
Perhaps
if
one
avoided
applying
it
to
the
electromagnetic
oscillations
themselves,
or
to
the
high-frequency
vibrations
of material
oscillators,
one
could
still
salvage
electromagnetic theory.
Einstein's
paper,
written
in collaboration with
Ludwig
Hopf,
closed this
possible escape
route.
They
studied the
momentum
fluctua-
tions of
a
material oscillator
interacting
with the
black-body
radiation. In-
stead of
calculating
these fluctuations from
a
given
radiation distribution
law,
as
Einstein had done in
1909,
they
calculated the fluctuations
directly
from
electromagnetic theory,
and then determined the
distribution
law.
The
equi-
partition
theorem
was
applied only
to
the translational motion of
gas
mole-
cules, a
long-established
and
thoroughly justified
use
of this theorem. The
result
was, once
again,
the
unacceptable Rayleigh-Jeans
law.
Electromagnetic
theory
could
not account
for the
properties
of radiation without
undergoing
some
fundamental
changes.
The riddle of radiation
must
have demanded
more
of Einstein's
thought
and
energy
than
anything
else in
this
period, though only
traces
of
his
think-
ing appear
in
his
published
work.
By
November
1910 he
was enthusiastically
reporting
another
possible
route to
the
answer,
this time in
a
letter
to
his
former
collaborator,
Jakob
Laub.[24]
"At
present
I
have
great hopes
for
solving
the
radiation
problem,
and
without
light
quanta.
I
am
immensely
curi-
ous as
to
how the
thing
will
come
out.
The
energy principle
in its
current
form
would have
to be
given up."
A week
later he informed Laub
that
this
[21]See
Einstein
to
Arnold
Sommerfeld,
19 January
1910.
[22]"Ich
will sehen,
ob ich dieses
Lieblingsei
nicht doch noch ausbrüten kann." Einstein to
Jakob
Laub,
31
December
1909.
[23]Einstein
and
Hopf
1910b
(Doc.
8).
[24]"Gegenwärtig habe ich
grosse Hoffnung,
das
Strahlungsproblem
zu
lösen, &.
zwar
ohne
Lichtquanten.
Ich bin
riesig
neugierig, wie sich
die Sache macht. Auf das
Energieprinzip
in
seiner
heutigen
Form müsste
man
verzichten." Einstein
to
Jakob
Laub, 4
November
1910.