126

EINSTEIN

ON

THE

STATIC

FIELD

conceded that Minkowski's formalism could

only

be

used if restricted

to

infinitesimal

transformations

and

had

published a

correction

to his

earlier

theory.[30]

Einstein,

on

the other

hand,

argued

in

his

paper

that for variable

c

the

Lorentz transformations

could

not

even

hold

infinitesimally.[31]

Abraham,

who

was

notorious for

his

vehement

polemics,[32]

did not

wait

long

to

respond.

He

had

accepted

several

aspects

of Einstein's criticism

and

was

prepared

to

revise

his

equations

of

motion,[33]

but

he

now

radically questioned

Einstein's

theory

of static

gravitation

as

well

as

the

principle

of

relativity

itself. While

he

agreed

that

for variable

c

the infinitesimal

Lorentz

transformations would

not be

integrable,

he

turned this observation into

an

argument against

the

validity

of

the

theory

of

relativity.

By

abandoning

the

validity

of the

Lorentz

transformations, he claimed,

Einstein him-

self had

given

up

his theory

of

relativity. Referring to

the

weak

point

in Einstein's

theory

of

the

static

field-the

restricted

validity

of

the

equivalence principle-he

con-

cluded: "This

most recent

theory

of Einstein's thus also

rests

on shaky

ground."[34]

Einstein

responded

in

Einstein 1912h

(Doc. 8)

with

a

reflection

on

the fundamental

principles

of

the

theory

of

relativity;

he

stressed

in

particular

that the

original

relativity

theory

would

always

remain valid

in

the

case

of

a

constant

gravitational potential.

When Abraham

repeated

his criticism

in

Abraham

1912h,

Einstein

simply

broke off

the

discussion.[35]

Neither did Einstein

react

when Abraham

published

a

modified

theory

of

gravitation

later

in

1912,[36]

and he

only

briefly

commented

on

it in

late

1913

when he

gave

a

lecture

on

the

status

of the

gravitation problem

in Vienna.[37]

Abraham's

theory,

however,

continued

to

have

an

impact

on

the

contemporary

dis-

cussion of

the

problem

of

gravitation.

It

became

the

starting point

for

a

modified scalar

theory

of

gravitation

by

Gunnar

Nordström,[38]

which Einstein

in 1913

considered

to

[30]See

Abraham

1912c,

in

which Abraham refers

to

"the correction of

an

oversight,

to

which

Mr.

Einstein

kindly

drew

my

attention"

("ein

Versehen

zu

berichtigen,

auf welches ich durch

eine freundliche

Mitteilung

des Herrn Einstein aufmerksam

geworden bin").

[31]See Einstein 1912c

(Doc.

3), §4.

[32]See

Cattani and De Maria

1989.

[33]See

Abraham

1912f,

p.

1058,

and Abraham

1912g,

p.

794.

For evidence of

an

exchange

between Einstein

and

Abraham

regarding

this

problem,

see

Einstein

to

Wilhelm

Wien,

17 May

1912

(Vol. 5,

Doc.

395),

and Einstein

to

Heinrich

Zangger,

20

May

1912

(Vol. 5,

Doc.

398).

[34]"Es

beruht also auch diese

neueste

Theorie

von

Einstein auf schwankendem Grunde"

(Abraham

1912f, p.

1058).

[35]See

Einstein 1912i

(Doc. 9),

which

is

dated

August

1912

and

was

probably

written

at

a

time when Einstein

was working intently

on

the

dynamics

of

gravitation.

See the editorial

note,

"Einstein

on

Gravitation and

Relativity:

The Collaboration with Marcel

Grossmann,"

pp.

294-

301,

for further discussion.

[36]See Abraham

1912g,

which

was published on

1

September

1911.

[37]See

Einstein 1913c

(Doc.

17),

pp.

1250-1251.

[38]See

Nordström

1912.