302
DOC.
400 MAY 1912
Finally,
mention
should be
made of
an
article in
the
Encyclopädie
der mathematischen
Wissenschaften,
in
which Ehrenfest
has
treated
statistical
mechanics
in
a
splendid
manner.[9]
To
sum
up,
Ehrenfest's
scientific
talent
and his
capability
can
be
characterized
more
or
less
as
follows.
Ehrenfest
is
a man
of
a
lucid and critical mind who has few
equals
in
his
ability
to
extract
what
is
essential
in
a
theory,
and who
is
completely
independent
vis-
a-vis
contemporary
endeavors. Both
in his
lectures
and in
conversation,
Ehrenfest
knows
how to
present
even
a
difficult
topic
in
a
clear
and
lively manner;
the members of
the
commission
had the
opportunity to
see
this for themselves
a
short
while
ago,
during
Ehrenfest's brief
stay
in
Prague.-[10]
Philipp
Frank. He
was
born
in
Vienna
in
1884
and also
studied
in
Vienna
and
Göttingen.
He
graduated
in
1906
in
Vienna,
and for
the
past
two
years
has
been
lecturing
with
great
success
as
a
Privatdozent
at
the
University
of Vienna. The
great
amount
of
able scientific work
that
this
merely
28-year-old man
has
already produced is
something
to
be
admired. He
combines
a rare
mastery
of the mathematical
tools with
a
good grasp
of the
problems
of
physics.
Frank's
most
important papers
in the field
of
physics
deal
with
the
theory
of
relativity.
In
a
paper
written
in
1908
he showed how
one
can
arrive at Minkowski's
equations
for the
electrodynamics
of
moving
bodies in
a
simple way,
starting
out from
Lorentz's electron
theory.[11]
In
two
papers
that
appeared
in
1908
and
1909,
the
space-
time
transformation of
classical
mechanics,
on
the
one
hand, and
that of the
relativity
theory,
on
the other
hand,
are
thrown
into
relief,
and it
is shown how
the former
leads
to
classical
mechanics and
to
Hertz's
electrodynamics
of
moving bodies,
and
the
latter
to
the
corresponding equations
of the
theory
of
relativity.[12]
Another
investigation
of
equally
essential
systematic significance
is
the
one
published
in
1911 together
with H.
Rothe under the
title,
"Ueber
die
Transformation der
Raum-Zeit
Koordinaten
von
ruhenden auf
bewegte Systeme" ["On
the Transformation of
Space-Time
Coordinates
from
Resting
to
Moving
Systems"].[13]
In this
paper
it
is
shown
that there
are
only
three
kinds
of
transformations,
which,
taken
together,
form
a
one-parameter, linear,
homogeneous group.
One of these transformation
groups
is
that of
classical
mechanics,
another
one
that of
the
Lorentz transformations.
Let
us
mention
only briefly
that Frank
has
written
several
original essays
of
an
epistemological
character
("Kausalgesetz
und
Erfahrung."
"Mechanismus
oder
Vitalismus?")[14]
["Law
of
Causality
and
Experience."
"Mechanism
or Vitalism?"],
which
attest
to
the author's
versatility
as
well
as
to his
endeavor
to grapple
with
general
problems
of
knowledge.
One
should also
mention several
papers
of
purely
mathematical
content,[15]
as
well
as
several
papers
in the
domain of
analytical
mechanics,[16]
which,
however,
are
of
greater
interest
from
a
mathematical than
a
physical
point
of view.
In
addition,
two
papers,
both
of which
are
in
press,
merit
special
attention because
they
are
simultaneously
interesting
as
well
as elegantly
executed.
One of the
papers is