DOC.
38 QUANTUM
THEORY OF RADIATION
231
A2
=
lA2.
(22a)
According
to
our
hypotheses,
each
elementary process,
induced
or
spontaneous,
transfers
to
the
molecule
the
momentum
A
=
-
O,
where
O
is
the
angle
between the
X-axis
and
a
direction
subject
to
the laws
of
chance. One therefore
gets
A2
=
l(hv)
3
c.
(23)
[p.
60]
We
can use (22a)
because
we assume
all
elementary processes
that
occur
to
be
mutually independent
events. l
is
then the total number
of
elementary
events
occurring during
time
r.
This is twice
as
large
as
the number of induced
processes
Zn
-
Zm
during r. Consequently,
l=
ljPnBnme~
kT
PT. (24)
From
(23),
(24),
and
(22)
follows
A2
=
_2_'ÄV
r
35
2
_
in
™
kT
PnB"e " p.
(25)
§7.
Result
In order to
show
that,
according
to
our
basic
hypotheses,
the momenta exerted
by
the
radiation
upon
the molecules do
not
disturb the
thermodynamic equilibrium,
we
only
have
to
insert the values of
Aa/r
and
R,
which
we
calculated in
(25)
and
(21),
after
we
replace
the value
P
~
3V
dv^1
~
e
kT
in
(21)
by
phv/3kt
according
to
(4).
It shows
immediately
that
our
fundamental
equation
(12)
is
satisfied.-
With
this,
our
deliberations
come
to
a
close.
They provide strong support
for the