272 DOC.

283

DECEMBER

1916

Schwarzschild-Flamm

space?

Or

is

it rather

(since

one can

clearly speak

of

an

infinite velocity here)

that

geometry specifies

for

it the

solution to

the

motion

equations?

The

latter

seems

to

me

to be

the

case.-

In

mapping a

spherical

space

on

to

a plane space,

one can

(or must?) proceed

such

that the diminution

of

the

measuring

rod

images

in

the

mapping

is

investigated

as a

function of

the distance

from

an

intersection

point,

for which

the

“apparent”

circumference becomes

=

2n

sin

apparent

radius

-.

spherical

space

radius

Is

an

"isotropic"

representation adequate at

all,

namely,

can

it be assumed

that

the dimensions of the

measuring-rod

picture

are

independent

of its orientation with

regard

to

the

intersection

point?-

-This

mapping

possibility

ends for

an

“apparent”

radius

=

n-2

spherical

radius.

And

there

my ability

to

vizualize it also ends.

What

happens

when

the

density

of

the

spherical

mass or

the

size of

the

homogeneous sphere

is

even

greater?

Then

spaces

are

involved,

the

content

of

which

cannot

influence

the

outside

world,

can

it? The interior

of nuclear

spaces,

the

interior

of

the

celestial cosmos?

Is

the

solution for

the

gravitation

equations

of

a

spherical

shell

known?-[15]

Not

even

with Wiechert

am

I

quite

sure

about

myself.

I

lectured

unbendingly

and

firmly

that it

is

quite unforgivable

to

assume an

effect

on

gravitation

by

en-

ergy

and then

not

immediately

also

assume

that

amount

of

energy corresponding

to

the

equivalency

of

gravitational

and

inertial

mass.

And

this

is undoubtedly

right.

But what

is

not

just

as

clear

to

me is,

to

what

extent

the inertial

mass

is

given

or

suggested,

even

with

the

energy

without

the

special

theory

of relativ-

ity;

so

that

you

would have

another

proportionality

coefficient

available here just

loosely

connected

to

the electron

mass.

The

gravitational

influence

of gravitational

energy,

or

the latter

itself,

is

ulti-

mately

only

a

counter for

you,

isn’t it? On its

own,

it

has

no

tensor

properties;

it

is

negative

and therefore

(?)

has

no

place

in

your empty space.

Or read

correctly,

does

just

this last

paper

of

yours

answer

these

questions

otherwise?

Speaking

of

papers:

I

don’t have

your

gravitational

waves

paper.

Would

you

still be able to send

me a

reprint of

it? The

problem

of

whether

the

coordinate

system can,

in

principle,

be chosen

so

that the

apparent

solutions

do

not

appear

seems so

very

important

to

me!-[16]

An influenza of sorts

is

plaguing

Anna;

she

sends

warm greetings.

Still in

expectation of

it

(the influenza),

I

am

still

tolerably

well at

the

moment.-

Affectionately yours,

Michele.