DOC. 16

FUNDAMENTAL DIFFICULTY

IN

PHYSICS

423

Eine

eigentliche

Theorie ist noch nicht zustande

gekommen,

doch kann

man

wohl mit Sicherheit

sagen:

die

Punktmechanik

gilt

nicht für rasch

periodische

Prozesse,

und auch

die

gewohnte Auffassung

von

der

Verteilung

der Strah-

lungsenergie

im

Raume ist nicht aufrecht

zu

erhalten.[7]

A.

Einstein.

ADS

(GyB,

Handschriften-Abteilung,

Slg.

Darmst.,

D

722.11).

[2

138].

This document

was

en-

closed in

a

letter

by

Einstein

to

Ludwig

Darmstaedter of the

same

date. It

was

written

in

response

to

a

request by Darmstaedter,

who wished

to

make

original manuscripts

by

promi-

nent

scientists available to

historically

interested scholars.

[1]Einstein

similarly singled

out

periodic processes as requiring a change

in

the foundations

of

classical

physics

in

a

letter

to Sommerfeld;

see

Einstein

to

Arnold

Sommerfeld,

July

1910.

[2]For

an

overview of Einstein's contributions

to

the derivation of

thermodynamic principles

from

mechanics,

see

Vol.

2,

the editorial

note,

"Einstein

on

the Foundations of Statistical

Physics," pp.

41-55;

for

a

discussion of

his

analysis

of the limits of classical

thermodynamics

and

his

contribution

to

the determination of molecular

dimensions,

see

Vol.

2,

the editorial

note,

"Einstein

on

Brownian

Motion,"

pp.

206-222. For

comments

on

his

derivation of the

Rayleigh-Jeans

formula for

black-body

radiation

on

the basis

of

classical physics,

see

Vol.

2,

the

editorial

note,

"Einstein's

Early

Work

on

the

Quantum Hypothesis," pp. 134-148, and, in

particular, pp.

137-138.

[3]In

Einstein

1905i

(Vol. 2,

Doc.

14).

Einstein

had

proposed

the

light quantum hypothesis

as

a

heuristic

interpretation

of Wien's formula for the

high frequency/low temperature part

of the

black-body

spectrum,

but his

argument

was

highly

controversial

at

the

time; see, e.g.,

Vol.

2,

the editorial

note,

"Einstein's

Early

Work

on

the

Quantum Hypothesis," pp.

134-148.

[4]A

similar

list

of

phenomena

that

cannot be explained

on

the basis

of

classical physics

is

found

in

Einstein

1909c

(Vol. 2,

Doc.

60),

pp.

490-491.

For

the

relationship

between deviations

from the

law of

Dulong-Petit

and the need

to

change

the foundations of classical

physics,

see

Einstein

1907a

(Vol.

2,

Doc.

38).

[5]See

Planck

1900b.

[6]Einstein's

theory

of

specific

heats,

based

on

the

quantum hypothesis, was

at

that time

receiving experimental

confirmation from the research of Nernst and

collaborators;

see

Nernst

1910a.

[7]According

to

Einstein

1909c

(Vol.

2,

Doc.

60), p.

499,

in

a new theory

of radiation the

energy

of the

electromagnetic

field

might possibly

be

localized

in

singularities.

See

also

"Re-

sponse

to

Manuscript

of Planck

1910a" (Doc.

3),

pp.

177-178,

where

he

expressed

himself

firmly

on

this

point:

"At the

same

time I

am

of

the

decided

opinion

that the

development

of

the

electrodynamics

of

relativity

will

lead

to

a

localization of

energy

other

than that which

we are

at

present

accustomed

to

accept

without

good

reason.

Without

ether,

the

continuous distribu-

tion of

energy

in

space

seems an

absurdity

to me"

("Hierbei

bin

ich

entschieden

der

Meinung,

dass die

Entwickelung

der

Relativitätselektrodynamik

zu

einer anderen Lokalisation der

Energie

führen

wird,

als

wir

sie

gegenwärtig

ohne Grund anzunehmen

gewohnt

sind.

Ohne

Aether erscheint mir continuierlich

im

Raume verteilte

Energie ein

Unding").