44
FOUNDATIONS
OF STATISTICAL PHYSICS
have read
a
book
by
Planck,
possibly
the
Vorlesungen
über
Thermodynamik,
sometime
before the fall
of
1901.[25]
Many years
later,
Einstein recalled
that,
when he
began
work
on
the
foundations of
statistical
physics,
he
was
not familiar with the work
of
Gibbs and Boltzmann,
which
he
characterized
as "totally
exhaustive
of
the
subject"
("den
Gegenstand
tatsächlich
erschöpfenden").[26]
It
is, indeed,
improbable
that Einstein knew
Gibbs's
Elementary
Principles
in
Statistical
Mechanics[27] when he wrote his three
papers on
statistical
phys-
ics.[28]
And in
1911
he went
so
far
as
to
write:
"Had
I
known
Gibbs's
book at
that
time, I
would
not
have
published
those
papers
at
all,
but would have confined
myself
instead to
the treatment
of
just a
few
points"
("Wenn mir das Gibbssche Buch damals
bekannt
ge-
wesen
wäre,
hätte ich
jene
Arbeiten
überhaupt
nicht
publiziert,
sondern mich
auf
die
Behandlung einiger weniger
Punkte
beschränkt").[29]
But the extent
of
his
knowledge
of
Boltzmann's
work
is
harder
to
determine. As noted
above,
he
certainly
had studied Boltz-
mann's
Gastheorie, which
is
cited
in
two
of
the
papers.
Thus, the
question
is
whether
he
knew
any
of Boltzmann's
earlier
papers on
the
subject,
the contents
of
which
are
not
always
covered in the Gastheorie.[30] A letter
of
Einstein's from
September 1901, in
which
he
refers
to his recent
study
of Boltzmann's
"works,"[31] suggests
that he
may
have
read
some
of
these, as
do certain features
of
his
papers.[32]
His first
published
mention
of
Gibbs,
as
well
as
of
a
pre-Gastheorie
work
by Boltzmann,
is
in
1909.[33]
He
was clearly
well
acquainted
with
Gibbs's
research
by
the time he lectured at the
University
of
Zurich in the
summer
semester
of
1910.[34]
[25]
See Mileva Maric
to Einstein,
early
No-
vember
1901
(Vol. 1,
Doc.
123).
Only
two
books
by
Planck had been
published by
this
date,
Planck
1887 and
Planck
1897. In Einstein
1913,
Einstein
praised
Planck
1897
very highly
and indicated that
a copy was
in
every physi-
cist's
library.
[26]
Einstein 1979,
p.
44.
[27]
See Gibbs 1902.
[28]
It
is unlikely
that Einstein read the
English
edition,
Gibbs 1902,
and the German translation
did
not appear
until 1905. A
copy
of
Gibbs 1905
is
in
Einstein's
personal
library.
It
is
possible
that Einstein learned
something
about
Gibbs's
approach
from
Planck's
review of Gibbs 1902 in
the
Beiblätter
zu
den Annalen
der
Physik
(Planck
1903a),
which
was
not published,
how-
ever,
until after Einstein 1903
(Doc. 4).
He
may
also have read
Planck's
paper
(Planck 1904)
in
the Boltzmann Festschrift
(Meyer,
S.
1904)
comparing
Boltzmann's
and
Gibbs's
concep-
tions
of
entropy.
Einstein reviewed several
pa-
pers
from this
Festschrift
for the
Beiblätter
(see
the editorial
note,
"Einstein's
Reviews
for
the
Beiblätter
zu
den Annalen
der
Physik"),
which
also
published a
review of
Planck's
paper
(see
Valentiner
1905).
[29]
Einstein
1911c,
p.
176. This
paper was a
reply
to
Hertz,
P. 1910a, which criticizes certain
features
of Einstein's
papers on
statistical
phys-
ics
(see
Einstein 1902b
[Doc. 3], note 20,
and
Einstein 1903
[Doc.
4],
note 17).
Hertz
was one
of
the few
physicists
at
the time who took Ein-
stein's
approach
to
the foundations
of
statistical
physics seriously as an
alternative
to
Gibbs's
work. Einstein and Hertz
were corresponding by
the
summer
of
1910
(see
Einstein
to
Paul
Hertz,
14
August
1910),
and
Rudolf
Hertz,
Paul's
son,
reports
that
they
had met
while
Einstein
was
still
working
in Bern
(private communication).
[30]
For
a
survey
of
the
development
of
Boltz-
mann's
views, see
Klein
1973.
[31]
Einstein
to
Marcel Grossmann, 6
Septem-
ber
1901 (Vol.
1,
Doc.
122).
[32]
These features
are
indicated in the notes
to
Docs.
3, 4,
and 5.
[33]
See Einstein 1909b
(Doc. 56),
p.
186,
fn.
3,
for
a
mention
of Gibbs's
investigations;
and
p.
187
for
a
reference to Boltzmann 1877.
[34]
Einstein's
lecture notes
on
kinetic
theory
incorporate
both the
vocabulary
and notation
of
Gibbs 1902.