EINSTEIN
ON
GRAVITATION
AND RELATIVITY:
THE
STATIC
FIELD
I
In
1911,
after
having pondered
on
the
problem
of
gravitation
for several
years,
Einstein
began
to
formulate
a
theory
of the static
gravitational
field. His
early
ideas
on
the
static
field
were
published
in
Einstein
1911h
(Vol. 3,
Doc.
23),
Einstein 1912c
(Doc.
3),
and
Einstein 1912d
(Doc.
4)
and
are
characterized
by
two
important
features: the
first
one
is
the
principle
of
equivalence,
which
provides
the
heuristics for
the
theory;
the second
is
the role
played by
the
speed
of
light,
which
is
assumed
to be
variable
and
serves as a
scalar
potential
for the
gravitational
field.
Einstein's work led
to
a
harsh
controversy
with Max
Abraham,
who
published
a
rival
theory
at
about the
same
time. Einstein
1912h
(Doc.
8)
and
Einstein 1912i
(Doc.
9) represent
Einstein's
side
of
this
polemic.
A note
added
in
proof
to
Einstein 1912d
(Doc.
4)
and the short
paper
Einstein 1912e
(Doc.
7)
document Einstein's
first
steps beyond
the static
case.
Traces
of Einstein's
early attempts
to
deal with the
problem
of
gravitation
are
also found
in
his
"Scratch Notebook"
(Vol. 3, Appendix A),
as
well
as
in
his
correspondence
of
these
years.[1]
II
The
ground
for Einstein's
1912
theory
of
the
static
gravitational
field
had been broken
five
years
earlier when
he
analyzed
the
problem
of
gravitation
in
his review of the
theory
of
relativity.[2]
In
this review Einstein for the
first
time formulated the
hypoth-
esis of the
equivalence
of
uniformly
accelerated reference frames
and
static homo-
geneous gravitational fields,
a
hypothesis
later
to
become known
as
the
"principle
of
equivalence."[3]
At
the time he did
not
publish any
further
thoughts
on
how
to
con-
struct
a
relativistic
theory
of
gravitation[4]
but limited himself
to drawing
a
number of
specific
conclusions from
this
hypothesis,
most
notably
the
gravitational
red shift and
the
bending
of
light rays
in
a
gravitational field.[5]
[1]For
historical discussions of Einstein's
theory
of the
static
gravitational field,
see
Pais
1982,
sec.
11,
Norton
1984,
Maiocchi
1985,
and Cattani and De Maria
1989.
[2]See
Einstein
1907j
(Vol.
2,
Doc.
47), §§17-20,
and the corrections
to this
paper,
Einstein
1908b
(Vol.
2,
Doc.
49).
For historical discussions
of
this
review,
see
Vol.
2,
the editorial
note,
"Einstein
on
the
Theory
of
Relativity,"
pp.
273-274, and
Miller
1992.
[3]For
a
discussion of
the
relevance of Einstein's
principle
of
equivalence
to
the
development
of
general relativity,
as
well
as
for
a
survey
of Einstein's
subsequent
reformulations of
this
principle, see
Norton
1985.
[4]For
evidence that Einstein did have such
thoughts,
see
his
recollections
in
Einstein
1933
and Einstein
1979,
pp.
62-66.
[5]Various calculations related
to
the
bending
of
light rays
are
also found
in
his "Scratch
Notebook"
(Vol. 3, Appendix A).