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).