, where
is the
four-vector, and
and
are its
components. The magnitude,
, of an arbitrary
four-vector, 
, can be found from
Copyright © 1999 David E. Rutherford
All Rights Reserved
We represent an arbitrary four-vector in the form
, where
is the
four-vector, and
and
are its
components. The magnitude,
, of an arbitrary
four-vector, , can be found from
In three-dimensional coordinates, the position vector is used to locate a point in space. We will use the same concept, here, to locate an event in spacetime. The spacetime vector in four-dimensional spacetime is analogous to the position vector in three-dimensional space. We now define the spacetime vector.
Two events in the unprimed frame with coordinates
and
are separated
by the spacetime vector
from
to
, where
The same two events in the primed frame have coordinates
and
, respectively.
So the spacetime vector from
to
in the
primed frame is
, where
Copyright © 1999 David E. Rutherford
All Rights Reserved
E-mail: drutherford@softcom.net