506 DOC. 25 SOLVAY DISCUSSION REMARKS
matisch
drückt
sich dies
dadurch
aus,
dass in
v
eine additive Konstante
unbestimmt bleibt. Aus diesem Grunde
löst
die
Betrachtung
nach meiner
Meinung
das Problem nicht.
IV. Planck
In
his lecture,
Planck examined various
ways
of
accounting
for the
spectral
distribu-
tion of
black-body
radiation. In
one
approach,
which
corresponds
to his
earlier deri-
vation
of
his
formula for
black-body
radiation
by
methods
of
statistical
physics,
he
determined the
probability
of
a
given
macroscopic
state
by counting
the combina-
torial
possibilities
for
realizing
this
state
in
terms
of
microscopic configurations
(Boltzmann's
"complexions");
see
Planck
1914,
pp.
86-87. In
his first comment
on
Planck's
lecture,
Einstein summarized the
critique
of this
approach,
which
he
had
earlier
presented
in
Einstein
1909b
(Vol.
2,
Doc.
56), pp.
187-188. In
line
with
his
earlier
analysis
and
in contrast
to
Einstein,
Planck
applied
the
quantum hypothesis
as
well
as
statistical methods
only
to matter
that
interacts with radiation and
not di-
rectly
to
radiation
itself.
In the discussion this controversial
point
was
first
taken
up
by
Jeans and
subsequently
commented
upon by
Einstein
in
his second
remark, refer-
ring
to
Lorentz's
analysis
of radiation
(Lorentz
1912).
In his
lecture,
Planck also
presented
his
second
attempt
at
a
theory explaining
the
black-body
radiation formula
(for a
historical
discussion,
see
Kuhn
1978,
pp.
235ff). According
to Planck's "second
theory,"
the
quantum hypothesis plays
a
role
only
for
the
emission of
radiation, while
Maxwell's
equations
are
supposed
to be
valid for
absorption
as
well
as
for radiation
in
matter-free
space.
In
his
last remark
during
the
discussion,
Einstein
argues
that
it
is
not
possible
to
introduce
any
form of the
quantum hypothesis
for the emission
by
an
oscillator,
but
he upholds
classical
electrodynamics
in
the
space surrounding
it.
His reference
to
Planck's
original theory is probably
a
reference
to
Planck's
attempts
at
an
analysis
of
black-body
radiation
prior
to
the introduction of the
quantum
hypothesis
(see
Planck
1900a).
No.
51
(Planck et
al.
1914a, p. 95;
Planck
et
al.
1912,
p. 115)
1)
An
der Art und
Weise,
wie
Herr
Planck Boltzmanns
Gleichung
anwen-
det,
ist für mich
befremdend,
dass
eine
Zustandswahrscheinlichkeit
W
einge-
führt
wird,
ohne dass
diese
Grösse
physikalisch
definiert wird. Geht
man so
vor,
so
hat Boltzmanns
Gleichung
zunächst
gar
keinen
physikalischen
Inhalt.
Auch der
Umstand,
dass W
der Anzahl der
zu
einem Zustand
gehörigen
Komplexionen
gleich
gesetzt
wird
ändert
hieran
nichts;
denn
es
wird nicht
angegeben,
was
die
Aussage,
dass
irgend
zwei
Komplexionen gleich
wahr-
scheinlich
seien,
bedeuten soll. Wenn
es
auch
gelingt,
die
Komplexionen
so
zu
definieren,
dass
S
aus
Boltzmanns
Gleichung
der
Erfahrung gemäss
heraus–