John Worrell Keely
He was either one of the greatest scientists who ever lived or one of the greatest con artists. In the late 1800's reporters and scientists who witnessed Keely's experiments suggested fraud and that somehow he used compressed air to display his gravity control devices.
One witnessed experiment was the levitation of a two ton steel sphere. Then, to prove he had control, he reversed the effect that caused levitation adding an undetermined amount of weight to the two-ton ball which caused it to not defy gravity but bury itself in the ground.
Gravity Control is a matter of time.
Anti-gravity technology research in electromagnetic propulsion and other technologies is under development, and we would like to document its discovery.