  Newton's Second Law defines inertial mass as the ratio of the applied force
on an object to the responding acceleration of the object (viz., F=ma). Objects
that exhibit finite accelerations under finite forces are described as being
"massive'' and this mass has usually been considered to be an innate property
of the particles composing the object. However mass itself is never directly
measured. It is inertia, the reaction of the object to impressed forces, that
is measured. We show that the effects of inertia are equally well explained as
a consequence of the vacuum fields acting on massless particles travelling in
geodesic motion. In this approach, the vacuum fields in the particle's history
define the curvature of the particle's spacetime. The metric describing this
curvature implies a transformation to Minkowski spacetime, which we call the
Connective transformation. Application of the Connective transformation
produces the usual effects of inertia when observed in Minkowski spacetime,
including hyperbolic motion in a static electric field (above the vacuum) and
uniform motion following an impulse. In the case of the electromagnetic vacuum
fields, the motion of the massless charge is a helical motion that can be
equated to the particle spin of quantum theory. This spin has the properties
expected from quantum theory, being undetermined until "measured'' by applying
a field, and then being found in either a spin up or spin down state.
Furthermore, the zitterbewegung of the charge is at the speed of light, again
in agreement with quantum theory. Connectivity also allows for pair creation as
the Connective transformation can transform positive time intervals in the
particle spacetime to negative time intervals in Minkowski spacetime.
