  A possible connection between the electromagnetic quantum vacuum and inertia
was first published by Haisch, Rueda and Puthoff (1994). If correct, this would
imply that mass may be an electromagnetic phenomenon and thus in principle
subject to modification, with possible technological implications for
propulsion. A multiyear NASA-funded study at the Lockheed Martin Advanced
Technology Center further developed this concept, resulting in an independent
theoretical validation of the fundamental approach (Rueda and Haisch, 1998ab).
Distortion of the quantum vacuum in accelerated reference frames results in a
force that appears to account for inertia. We have now shown that the same
effect occurs in a region of curved spacetime, thus elucidating the origin of
the principle of equivalence (Rueda, Haisch and Tung, 2001). A further
connection with general relativity has been drawn by Nickisch and Mollere
(2002): zero-point fluctuations give rise to spacetime micro-curvature effects
yielding a complementary perspective on the origin of inertia. Numerical
simulations of this effect demonstrate the manner in which a massless
fundamental particle, e.g. an electron, acquires inertial properties; this also
shows the apparent origin of particle spin along lines originally proposed by
Schroedinger. Finally, we suggest that the heavier leptons (muon and tau) may
be explainable as spatial-harmonic resonances of the (fundamental) electron.
They would carry the same overall charge, but with the charge now having
spatially lobed structure, each lobe of which would respond to higher frequency
components of the electromagnetic quantum vacuum, thereby increasing the
inertia and thus manifesting a heavier mass.
