406
DOC.
26
THE PROBLEM OF SPECIFIC HEATS
Fig.
22
to be
especially emphasized:
In
no
way
should it be
inferred from
the
empirical confirmation
of
formula (1)
that
the
quantum
hypothesis
is correct.
In
general,
nothing
about
mechanics
can
be concluded
from
the confirmation of
(1)
that could
not
be derived from the
radi-
ation formula
and
equation
(2).
But
what
is
the
source
of the
systematic discrepancies
between the observed
and
the
theoretical
curves?
Why
is
it
that,
with
decreasing temperatures,
the
specific
heat
approaches
zero
less
rapidly
than the
theory
would
lead
us
to
expect?
To
get
what I
see
as
the
correct
answer
to
this
question, we
must
try
to
delve
deeper
into the mechanism
of the thermal
oscillations
of
atoms.
Madelung,4
and
then,
independently
of
him,
Sutherland5 discovered
the
following:
In
binary
salts
(e.g.,
KCl),
the
frequency
of
elastic
waves (as
calculated from
elasticity
constants)
at which
the
wavelength
attains the order
of
magnitude
of the
intermolecular
distance, is
of the
same
order of
magnitude
as
the
infrared
frequencies
of
these bodies
(as
calculated
from
the residual
radiation).
This fact
suggests
that those
atomic
interaction
forces
that determine the infrared
proper
[8]
[9]
4 E.
Madelung,
Nachrichten
d.
königl.
Ges.
d.
W.
z.
Göttingen,
Mat.
-Phys.
Kl.
20
(1909):
100-106.
5 W.
Sutherland,
Phil.
Mag.
(6)
20
(1910):
657.