270 DOC.
42
SPECIAL AND
GENERAL RELATIVITY
EIGHT
On
the
Idea
of
Time in
Physics
Lightningthe
has
struck the
rails
on our
railway
embank-
ment at two places A
and B far
distant
from
each other.
I
make additional assertion
that these
two light-
ning
flashes
occurred
simultaneously.
If
I
ask
you
whether
there
is
sense
in
this
statement,
you
will
answer
my question
with
a
decided “Yes.” But if
I
now
approach
you
with the
request
to
explain
to
me
the
sense
of the
statement
more
precisely,
you
find
after
some
consideration
that the
answer to
this
question
is
not
so
easy
as
it
appears
at
first
sight.
After
some
time
perhaps
the
following
answer
would
occur
to
you:
“The
significance
of the
statement is
clear
in
itself
and
needs
no
further
explanation;
of
course
it would
require
some
consideration if
I
were
to
be commissioned
to
determine
by
observations whether
in
the actual
case
the
two events
took
place simultaneously
or
not.”
I cannot
be
satisfied
with this
answer
for
the
following
reason.
Supposing
that
as a
result of
ingenious
consideration
an
able
meteorologist
were
to
dis-
cover
that the
lightning must always
strike the
places
A
and
B
simultaneously,
then
we
should be faced with the task of
25
Previous Page Next Page