DOC.

35

201

velocity of

light.

K

will

maintain this

velocity

until

the radiation

com-

plex,

whose

spatial extension is

very

small in

comparison

with the

cavity

of

K,

gets

absorbed

by

B.

The

duration of the

hollow

cylinder's

motion

is

(apart

from

terms

of

higher order) equal to

a/V,

if

a

denotes the distance

from

A

to B.

After

absorption

of

the

radiation

complex

by

B,

the

body K

is

again

at rest.

During

the radiation

process

under consideration,

K

has

shifted

a

distance

of

c

_

1

S

a

7

1'

7

to

the left.

In the cavity

of

K,

let

us

have

a

body k (imagined

as

massless for

the

sake

of

simplicity) next to

a

(likewise

massless) mechanism

that

can move

the

body

k, which

shall first

be

located in

B,

back and

forth

between

B

and

A.

After the

amount

of radiation

S

has been

absorbed

by

B,

this

amount

of

energy

shall

be

transferred

to

k,

and

then

k moved

to

A.

Finally,

the

amount

of

energy S

shall

again

be taken

up

in

A

by

the

hollow

cylinder

K,

and k

shall

be

moved

back to

B

again. The

whole

system

has

now

undergone

a

complete

cyclic

process,

which

one

can imagine

to be

repeated

arbitrarily

often.

If

one

assumes

that the carrier

body

k

remains massless

even

after it

has

absorbed the

amount

of

energy

S,

then

one

also

has to

assume

that the

return

transport

of

the

amount

of

energy S

is

not

associated with

a change

in position of the

hollow cylinder

K.

Thus

the

only

outcome

of the

entire

cyclic

process

is

a

shift

ö

of the

whole

system

to

the left;

by

repeating

the

cyclic

process, one

can

make

this

shift

as

large

as

desired.

We

thus

arrive

at

the result that

an

initially

stationary

system can change

the

position of its

center

of

gravity

arbitrarily

greatly

without

having

external

forces

acting

upon

it,

and

without

undergoing

any permanent change.

It is clear that the result

does

not

contain

any

inner contradictions;

however,

it

does

contradict the

laws

of

mechanics,

according to

which

a body