374
THE
RADIATION
PROBLEM
to prevent
the
electron's
electrical
masses
from flying apart
under
the
influ-
ence
of
their electric interaction.
The
relation
h
=
e2/c
seems
to
me
to
indicate
that
the
same
modification
of
the
theory
that
will
contain the ele-
mentary quantum
e as a
consequence
will also contain the
quantum
structure
of radiation
as
a
consequence.
The
fundamental
equation
of
optics
1
O2~
___
__
- =0
will
have to
be
replaced
by an
equation
in which
the universal
constant
e
(probably its square)
also
appears
in
a
coefficient.
The equation
sought
(or
the
system
of
equations sought) must
be
homogeneous
in its dimensions. It
must
remain
unchanged upon
application
of
the Lorentz transformation. It
[70]
cannot be
linear
and
homogeneous.
It
must-at
least if Jeans'
law
is really
valid in the limit
of
small
v/T
-lead
to
the
form
D(q)
=
0
for
large
amplitudes
in
the limit.
I have not
yet
succeeded
in
finding
a
system
of
equations
fulfilling
these conditions
which would have looked
to
me
suitable for the construction
[71]
of the
elementary
electrical
quantum
and the light
quanta.
The
variety of
possibilities
does not
seem so
great,
however,
for
one
to have to
shrink
from
this task.
Addendum
From
what
has
been
said
above
under 4.
in
this
paper,
the
reader could
easily
get
an
incorrect
impression
about the
standpoint
taken
by
Mr.
Planck
with
regard
to
his
own
theory of
thermal radiation.
I
therefore
deem
it
appropriate
to
note
the
following.
In
his
book,
Mr.
Planck
emphasized
in several places that his
theory
should
not
yet be viewed
as
something complete and
final.
At
the
end
of
his
introduction, for
example,
he
says
verbatim: "I find it
important,
however,