To be fair John wasn't saying it would be anti gravity though, apparently this "non fictional" machine makes a magnetic field that it can use to counteract earths magnetic field. That would be some pretty cool technology but I think it'll be a bit more complicated then some mercury plasma spinning around. Maybe a better question would be, "Is it possible to and what would it take to counteract the earths magnetic field to levitate an object against the pull of gravity?" instead of the rather more creationist style approach saying "well here's a thing I'm not really sure if it exists but I've heard from a source that it's said to work this way, prove it to me." that many smart people who mean well tend to slip into.
