Although a vacuum is devoid of physical matter, it's not actually empty. In fact a vacuum is host to a seething "ocean" of virtual pair-production (a particle a

Although a vacuum is devoid of physical matter, it's not actually empty. In fact a vacuum is host to a seething "ocean" of virtual pair-production (a particle and it's anti-matter counterpart locked in a feynman loop) giving rise to the "Vacuum Energy" http://en.wikipedia.org/wiki/Vacuum_energy http://en.wikipedia.org/wiki/Vacuum_energy, potentially a vast untapped reservoir of essentially limitless power - if it can be harnessed :) It case you're sceptical, the "realness" of the vacuum energy is revealed by the wonderful Casimir Effect http://en.wikipedia.org/wiki/Casimir_effect http://en.wikipedia.org/wiki/Casimir_effect