578 DOC.

556

JUNE

1918

This world

can

be

obtained

from

the

gravitational effect

of

a

fluid which

is

con-

centrated

at

the

“equator” (on

a

two-dimensional

surface).

Two-dimensionally

it

is

easy

to draw

a

straightforward

comparison

with

my

conception (where

time

is

omitted

because of

the

field’s

static

character):[15]

In

my

solution,

the

matter

is

distributed

evenly

over

the entire

surface of

the

sphere;

for de

Sitter,

it

is

concentrated

at

the

equator

(r/R

=

s/2).

Einstein

de

Sitter

evenly

distributed

matter

void

matter at

the equator

void

De

Sitter

incorrectly

believes

that

his solution does not

presuppose

the

exis-

tence of matter.

Weyl

has shown in his

book[16]

which

will

appear shortly,

that

de Sitter’s

case

really

is

obtained

as a limiting case

of

the

more general

Void

Matter

of finite

density

distributed

over

equatorial

zone.

Void

as

I asserted

without

proof

in

my

notice.[17]

If

the

world

really

were so,

the

fixed

stars would have

to

have

enormous

ve-

locities

so

that

they

could

maintain

their statistical

distribution,

owing

to

the

tremendous

differences in

gravitational

potential

that

would have

to

exist be-

tween

the

various

points

of

such

a

world.

The

nonexistence

of great

stellar

veloc-

ities

compels

us

to believe

that

on a

large

scale matter is

not all

that

unevenly

distributed

throughout

the

universe.

With

amicable

greetings, yours very

truly,

A.

Einstein.