  To clarify some aspects of the application of Special Relativity, spacetime
is sliced into null geodesic hypersurfaces as an alternative to the
hypersurfaces of simultaneity normally adopted. Events at particle locations on
the hypersurface are identified as the causal event set. It is demonstrated
that a Lorentz boost applied to the causal event set maintains the property of
connectedness and with this formalism it is simple to derive the redshift
equation. The twin paradox is naturally explained as an instantaneous
reconfiguration of particle position 4-vectors in the frame of the accelerated
object. The metaphysical implications are examined with the tentative
conclusion that a relationist view of spacetime is more consistent with this
treatment than the substantivalist viewpoint.
