The performance of ufos seems to indicate some form of gravity control, and the experiments of Townsend Brown and others seem to show that gravity control and inexhaustible "free" energy are possible, and may be different sides of the same coin. In either case, gravity control is a challenge to modern physics, since its twin pillars, relativity and quantum mechanics, do not allow for it. Modern physics has other problems as well. Relativity, in particular, rests on two discoveries of nineteenth century physics:Maxwell's euations and the Michelson-Morley experiment that supposedly disproved the existence of the hypothetical luminiferous aether, a mysterious substance that supposedly carried light waves, and, possibly, gravity, and perhaps was the basic substance of which all other matter was composed.
Michelson and Morley split a light beam into two beams, one pointed in the direction of Earth's supposed motion through space and one at right angles to it, then reflected and recombined them, looking for the interference patterns that would show that Earth's movement through the aether had affected the propagation of the baems. Finding none, they announced that the aether did not exist, and relativity is based on this assumption. Challenges were immediate, including suggestions that Earth dragged the aether along with it, or that the motion through the aether shortened the measuring devices (suggested by physicist Conrad Lorentz). Nevertheless, the establishment pronounced the aether dead.
Not so fast. How did Michelson and Morley know the direction of Earth's movement? Our planet both rotates on its axis and circles the Sun; you are facing forward for both movements only if you face due east right after midninght. But our Sun also rotates around the center of our galaxy and drifts relative to other stars, and our galaxy moves relative to other galaxies in the local group, and the entire universe is supposedly expanding. At the time of the experiment, astronomers did not even know galaxies existed! So how did Michelson and Morley know in what direction to point their light beams? The answer is that they did not know, and the nonexistence of the aether has not been proven, and the whole of modern physics rests on very shaky ground.