128

EINSTEIN ON THE

STATIC FIELD

While Einstein

1912e

(Doc. 7)

shows

the

physical reasoning

that

guided

Einstein's

attempts

to

go beyond

the

static

theory,

it

does

not

contain

any

hints of methods

more

advanced

than those used in

his

earlier

papers.

Such

hints

can

be

found

in

a

note

added

in

proof

to Einstein 1912d

(Doc. 4).

In

this note

Einstein reformulates his

static

theory

in

terms

of

a

Hamiltonian

formalism,

analogous

to

what Planck had done for

special

relativity.

He

concluded: "The Hamiltonian

equation

written above hints

at

the struc-

ture

of

the

equations

of motion of

the

mass

point in the

dynamic gravitational

field."[47]

[47]"Die

zuletzt

hingeschriebene

Hamiltonsche

Gleichung

läßt

ahnen, wie die

Bewegungs-

gleichungen

des

materiellen Punktes

im

dynamischen

Gravitationsfelde

gebaut

sind"

(Einstein

1912d

[Doc.

4],

p.

458).

For further

discussion,

see

the

editorial

note,

"Einstein's Research

Notes

on a

Generalized

Theory

of

Relativity,"

pp.

193-194.