DOC. 42 SPECIAL AND GENERAL RELATIVITY
419
problem
of
space
in
general
and
on
the
step-by-step
modifications
of
our
ideas about
space
under relativistic
aspects.
I wanted
to show
that
space-time
is not
something
to which
we can
attribute
independent
existence,
disconnected from the
objects proper
of
physical reality. Physical objects
are
not within
space,
but
objects are
rather
spatially
extended.
The
concept
of
'empty space'
thus loses its
meaning."
[15]...
was
appended:
"A
simple
derivation of
the
Lorentz transformation
is
given
in the
appendix."
[26]...
was appended:
"The
general theory
of
relativity suggests
the idea
that
the
electric
mass
of
an
electron is held
together by gravitational
forces."
...
[31]...
was appended:
"See the somewhat
more
elaborate
exposition
in the
appendix."
[37]... final
quotation
marks: "It is the
gravitational
field also that
gives
the
jerk
to the observer."
...
[44]...
was appended:
"The existence
of
the
theoretically
demanded deflection
of
light
has
been
photographically
documented at the solar
eclipse on May 30,
1919,
by
the
English
astronomer
Eddington."
...
[47]...
was appended:
"For the whole
consideration
one
has to
use
the Galilean
(nonrotating)
system
K
as a
reference
body,
because
we
may assume
the
validity
of
the results
of
the
special theory
of
relativity only
with
respect
to K
(relative to
K'
there is
a gravitational
field)."
[49]... in the hand
of
Ilse Einstein: "Note: This
interpretation
has often been
opposed
as
unconvincing
because not
only
the
measuring
rods
but
also the circular
disk would suffer
tangential
contraction. This
argument
is
not
cogent
because the
rotating
disk cannot be viewed
as a
Euclidean
rigid body;
such
body
would shatter
when
brought
to rotation,
according
to
the
postulated
reasons.
In
reality
the disk
plays
no
role in the whole
consideration,
but
only
the system-of rods at
rest
relative
to
each
other-which
rotates
as
a
totality
of
radially
and
tangentially positioned
rodlets."
[55]...
was appended:
"See in
the
appendix.
The
relations
(11a)
and
(12),
which
are
derived there for
coordinates,
apply
also
to
differences
of
coordinates
and,
therefore,
to coordinate differentials
(as
infinitely
small
differences)."
[56]...
by
the
following one:
"This
assignment
need not
even
be such that would