Never mind the UFO title. The premise of this show is that flying saucer sightings are the result of sightings of secret advanced test propulsion systems. The physics is at 2:15 of the video. The interviewed engineer states that "this is nothing more than 250 turns of number 30 wire. And we took the leads and plugged it into standard house current." The video shows the coil of wire levitating. Is this bunk? If not, what is going on? It is reminiscent of the related phenomenon of "lifters" which likely is produced by ionic wind. But lifters require DC to produce a strong charge to ionize air molecules. How could AC produce the "levitation" seen in the video?