284
DOC.
42
SPECIAL AND GENERAL RELATIVITY
The
Lorentz
Transformation
39
from
which, by
division,
the
expression
x'
=
ct'
immediately
follows.
If
referred
to
the
system
K',
the
propa-
gation
of
light
takes
place according to
this
equation.
We thus
see
that
the
velocity
of transmission relative
to
the reference-
body
K'
is also
equal to
c.
The
same
result
is
obtained
for
rays
of
light
advancing
in
any
other direction whatsoever.
Of
course
this
is not surprising,
since the
equations
of the Lorentz
trans-
formation
were
derived
conformably to
this
point
of
view.