DOCS.

8,

9

MAY 1914

15

With

cordial

greetings

to

you, your wife,

and

your

dear

little

ones,

yours,

Einstein.

My

little

boy

is

better

but

not

yet

well.

They

have been here for

a

long

while.[3]

The

zero

point

energy

for ideal

gases peers mockingly

out of Sackur’s

exper-

iments.[4]

Stern’s

analysis

on

gas dissociation,

which

you

had

encouraged

him

into

doing,

speaks

against

Nernst's theorem.[5] Planck believes he

can

refute

my

reservations

regarding

osm[otic]

pressure.

Note

on

the

envelope: "Forgive

the

unmanly

paper

and

do not

hope

for

greetings

from

the hand

of

the

gentle

sex.

The

content is

as

coarse

as

its writer!"

9.

From

Paul

Ehrenfest

Leyden, 20 May 1914

Dear

Einstein,

Cordial

thanks for

your

letter!-[1]

I

am

triumphant!

This time

I

am

the

brighter

one.

You

protest

that

in

the

weighting

function

G(q,

p,

a1, a2), a1, a2

offend

Boltzmann's spirit-I

do not want

to

dispute

the

latter-but

you

yourself

have

been

working

with such

a

G(p, q, a)

for

almost

10

years!!!![2]

Namely

with

Planck's

assumption of

the

quantization of energy [Energiestu-

fenannahme]-this is

a

G(p,

q,

a).-[3]

Proof:

Let

the

energy

of

a

resonator

be

E(q,

p,

a,

B)=1/2(a2q2+B2p2);

thus the

frequency:

v=aB/2n.

Then,

according

to

Planck,

G(q,p,a,B)=r(E(q,p,a,B)/(aB/2n))

where

T(i)

is

a

discontinuous function

especially

with Planck

(= 0

for all values

except

for

i

=

0, h,

2h.....for

these

value[s] =

1).

If

I

change

a

(the

resonator

intensity)

and

ß

(the reciprocal

factor

of inertia),

then the

"Planck"

ellipses

deform

on

the

q,

p

plane.[4]