Bernard Haisch is a German-born American astrophysicist who has done research in solar-stellar astrophysics and stochastic electrodynamics. He has developed with Alfonso Rueda a speculative theory that the non-zero lowest energy state of the vacuum, as predicted by quantum mechanics, might provide a physical explanation for the origin of inertia, and might someday be used for spacecraft propulsion. Haisch has advocated the serious scientific study of phenomena outside the traditional scope of science and is known for his interest in the UFO phenomenon as well as a variety of other unorthodox topics.