THE EINSTEIN-BESSO MANUSCRIPT
ON THE
MOTION
OF
THE PERIHELION
OF
MERCURY
I
The
manuscript,
written
jointly
by
Einstein
and his
lifelong
friend Michele
Besso,
deals
with the
perihelion
motion of
Mercury[1] on
the
basis of
the
"Entwurf"
theory.[2]
Internal and external evidence
suggest
that
the two
men closely
collaborated
on
this
problem during
a
visit
by
Besso with Einstein
in
Zurich
in June
1913.
The
bulk of
the
manuscript
was
presumably
written
during
this
visit. Einstein
may
have added
some
material later
in
1913;
some
of
the
Besso material
is
certainly
from
later,
most
likely
from
early
1914.
From
early
on
in his
search for
a new
relativistic
theory
of
gravitation,
Einstein
was
interested
in the
problem
of
Mercury's perihelion.
In
a
letter
to
a
friend
in
1907,[3]
Ein-
stein had
already expressed
his
hope
that
such
a
theory
would
explain
the
anomalous
advance of
Mercury's perihelion.
After
this
letter,
however,
the
Mercury
anomaly
is
not
mentioned
again,
neither
in
Einstein's
published papers
nor
in
surviving correspon-
dence,
until
late
1915.[4]
On
18
November
1915
Einstein
presented
a paper[5]
to the
Prussian
Academy
of Sciences
showing
that
his
new,
still
developing general theory
of
relativity yields
a
perihelion
advance for
Mercury
of 43"
per century,
in
striking
agreement
with observation. The
success
carried
over
unproblematically
to the final
version of
the
theory published shortly
thereafter.[6]
When Einstein
subsequently reported
on
his
new
theory to
Sommerfeld[7] and
Lorentz,[8]
he
mentioned that
one
of
the
reasons
for
abandoning
the 1913
"Entwurf"
theory
was
that
it
failed
to
explain
the
Mercury
anomaly.[9]
In the
letter
to
Sommer-
feld, he
explicitly
mentioned that
the
"Entwurf"
theory predicts
a
perihelion
advance
for
Mercury
of 18"
per century.
This
is also the
number
given
by
Droste
in
a
paper
published
in
December
1914.[10]
The
manuscript
under discussion reveals that Einstein
actually
did
the
calculation
himself,
shortly
after
he and
Grossmann
had
finished
the
"Entwurf"
paper[11]
in
early
1913.
The
expression
Einstein
and
Besso arrived
at
for
[1]For
a
discussion of the
history
of
the
problem
of the anomalous advance of the
perihelion
of
Mercury,
see
Roseveare
1982.
[2]See
the
editorial
note,
"Einstein
on
Gravitation
and
Relativity:
The Collaboration with
Marcel
Grossmann,"
pp.
xx,
for
more on
this
theory.
[3]Einstein to
Conrad
Habicht,
24
December
1907
(Vol.
5,
Doc.
69).
[4]There
is
a
reference
to
calculations
on
perihelion
motion
in
a
letter
to
Erwin
Freundlich,
dated
30
September
1915.
[5]Einstein
1915d.
[6]Einstein
1915e.
[7]Einstein
to
Arnold
Sommerfeld,
28
November
1915.
[8]Einstein
to H.A. Lorentz,
1
January
1916.
[9]See
Norton
1984,
sec.
7.
[10]Droste
1914, p.
1010.
[11]Einstein
and Grossmann
1913 (Doc. 13).