American inventor who discovered in the 1920s that high voltage applied to asymmetric capacitors produces thrust with no fuel, no exhaust, and no propellant: the Biefeld-Brown Effect. His work specifically involved Bismuth.
Key claim
A physicist at Martin Corporation’s RIAS research institute, Louis Witten, recalled in a 2011 American Institute of Physics oral history: “There’s a guy named Townsend who claimed to have an isotope of bismuth that repelled instead of attracted.”
Modern revival
Charles Buhler at NASA Kennedy Space Center is replicating Brown’s work, getting 50 mN thrust at 400 V (vs. Brown’s 150,000 V) in hard vacuum, ruling out ion wind.
Connections
Biefeld-Brown Effect · Bismuth · Charles Buhler · Bob Lazar · Anti-Gravity · Electret