Devices that their inventors claim will overcome gravity in some unspecified way outside our normal understanding of machine design. Rockets, gliders, balloons, and heavier-than-air planes are ways by which we overcome gravity to fly or, in the case of space rockets, escape from the Earth’s gravitational held (or, in general relativity theory terms, escape from the local time-warp). But this way of overcoming or escaping gravity is not what is meant in this context by an antigravity machine. It is a machine that will cancel out gravity in its locality and thus, for example, be able to escape the earth’s attraction without the huge expenditure of fuel required by a space rocket. Roger babson and his Gravity Foundation sought such a machine without success.
Babson and his collaborators in the foundation were not the only ones to seek such a machine. There have been many hopeful inventors, none successful so far. “Hopeful inventors” brush aside those who claim that their task is hopeless and point to other dreams that were once seen to be unrealizable: the transmutation of elements, voyages to the Moon and Mars, or nuclear energy. But this fails to distinguish between the impracticable and the impossible projects that pose great practical difficulties and projects that are unrealizable on fundamental grounds. Perpetual motion machines and antigravity machines fall into this second category as ideas that will tempt many but will remain dreams.