DOC. 23
MAX
PLANCK
AS
SCIENTIST
275
point
in
accordance with the
theory
of
relativity.
Furthermore,
he showed that
the
[28]
principle
of
least action has
just
as
fundamental
a significance
in this
theory
as
in
classical mechanics.
Also,
in
an
investigation
on
the
dynamics
of
systems,
he
[29]
developed
the
important
interconnection that links the
energy
and the inertial
mass
according
to
the
theory
of
relativity. [30]
Finally,
let
us
recall Planck's
more comprehensive works,
his books
on
thermodynamics
and thermal
radiation,
which
belong among
the
masterpieces
of the
physical
literature. In these
books,
which
can
be
found
in
every physicist's
library,
[31]
Planck
brought together
most
of the
more important
results
of
his
investigations
and
made them
easily
accessible
to
his
colleagues.
Much
of
the
pleasure
with which
one
takes in
hand each
of
these books time and
again
is
attributable
to
the
straightfor-
ward,
truly
artistic
style
that characterizes all
of
the
writings
of
Planck;
studying
Planck's
writings
one
gets
the
impression
that artistic need is
one
of the
most
important
mainsprings
of his
creative
genius.
It
is not
for
nothing
that it
is
said that
after Planck
graduated
from the
Gymnasium,
he could
not
decide whether
to
study
physics or
music.
May
this man's tireless
striving
for
knowledge
be destined
to
render valuable
services
to
science in the future
as
well, and,
in
particular,
to
contribute
successfully
to
the solution of the difficulties
that
we
face
today
thanks
to
the beautiful results of
his
own
investigations.