142
DOC.
137 NOVEMBER
1915
137. From Max Planck
Grunewald,
7 November
1915
Dear
Colleague,
I
have
now performed
the
comparison
of
my
formulas
to
those of
Tetrode and
proceeded
in
the
following
manner.[1]
If formulas
(17)
and
(16)
in Tetrode’s
paper
are
subtracted
from each
other,
the
entropy originating from
the rotations
of
the diatomic molecules
results:[2]
S(17)
-
S(16)
=
kN{ln(kT)
+
ln(2nJ)
-
2ln h
+
ln(47r)
+
1}
The
same
quantity
results from
the
theory
developed by
me
based
on
the
formula
for
the
thermodynamic
function I
recently
set down in
writing:[3]
fp 00
V
=
--
=
AbUn^(2n
+
l).
e-(»2
*+»+èV,
2
o
where
F
is
the
free
energy,
o
=
h2/8ir2JkT,
when
you
assume
T
there
very large. [4]
Then the
sum
may
be
written
as an
integral, namely:
F
=
-TNk
In
f°°
dn-2
(n+\)
e“[(n+^2+i]°
Jo 2
=
-TNk
In
=
TNk
+ In
aj
.
If
you
consider
now
that
S
=
-°L
&T'
then, through
substitution
of
the
value for
a,
we
get:
8tPJkTe
S
=
Nk
In
h2
This
is
precisely
Tetrode’s
value.[5]
I
now applied
the
theory
for
an
arbitrary
(also
“incoherent,”
or
however
else
you
want to
express
it)
degree
of freedom
as
well.[6]
It
all works
very
well
and
reliably,[7]
[Some
of
the
sidetracks
were
horrendous,
though.
But
you
probably
understand
that.]
so
that
even
the
specific
heat
of
polyatomic (rigid)
molecules
as
well
as
the
energy
of spatial
oscillators
are
easily
calculated.
I
shall tell
you
about that in
person.
With
cordial
greetings, yours,
Planck.
Previous Page Next Page

Extracted Text (may have errors)


142
DOC.
137 NOVEMBER
1915
137. From Max Planck
Grunewald,
7 November
1915
Dear
Colleague,
I
have
now performed
the
comparison
of
my
formulas
to
those of
Tetrode and
proceeded
in
the
following
manner.[1]
If formulas
(17)
and
(16)
in Tetrode’s
paper
are
subtracted
from each
other,
the
entropy originating from
the rotations
of
the diatomic molecules
results:[2]
S(17)
-
S(16)
=
kN{ln(kT)
+
ln(2nJ)
-
2ln h
+
ln(47r)
+
1}
The
same
quantity
results from
the
theory
developed by
me
based
on
the
formula
for
the
thermodynamic
function I
recently
set down in
writing:[3]
fp 00
V
=
--
=
AbUn^(2n
+
l).
e-(»2
*+»+èV,
2
o
where
F
is
the
free
energy,
o
=
h2/8ir2JkT,
when
you
assume
T
there
very large. [4]
Then the
sum
may
be
written
as an
integral, namely:
F
=
-TNk
In
f°°
dn-2
(n+\)
e“[(n+^2+i]°
Jo 2
=
-TNk
In
=
TNk
+ In
aj
.
If
you
consider
now
that
S
=
-°L
&T'
then, through
substitution
of
the
value for
a,
we
get:
8tPJkTe
S
=
Nk
In
h2
This
is
precisely
Tetrode’s
value.[5]
I
now applied
the
theory
for
an
arbitrary
(also
“incoherent,”
or
however
else
you
want to
express
it)
degree
of freedom
as
well.[6]
It
all works
very
well
and
reliably,[7]
[Some
of
the
sidetracks
were
horrendous,
though.
But
you
probably
understand
that.]
so
that
even
the
specific
heat
of
polyatomic (rigid)
molecules
as
well
as
the
energy
of spatial
oscillators
are
easily
calculated.
I
shall tell
you
about that in
person.
With
cordial
greetings, yours,
Planck.

Help

loading