Thomas Townsend Brown

Thomas Townsend Brown (March 18, 1905 – October 27, 1985) was an American inventor whose experiments and research on electricity based anti-gravitational observable momentum by ionizing different materials led him to believe he discovered a type of anti-gravity. He believed this was caused by strong electric fields. Instead of anti-gravity, what Brown observed has generally been attributed to electrohydrodynamics, the movement of charged particles that transfer their momentum to surrounding neutral particles in the air, also called "ionic drift" or "ionic wind". For most of Brown's life, he developed devices based on his ideas, promoting them for use by industry and the military. The phenomena came to be called the "Biefeld–Brown effect" and "electrogravitics". He was granted multiple patents.

Brown's research influenced some amateur experimenters who build "ionic propulsion lifters" powered by high voltage. There are still claims that Brown discovered anti-gravity, an idea popular with the unidentified flying object (UFO) community and spawning numerous conspiracy theories.