Lol, as for the anti-grav machine, i dont believe it, i believe we will one day create artifitial gravity in space (without the aid of centrifugal force) but as for anit-grav, impossible.

Something you may find intresting tho, you can create a perpetual motion device quite easily by spining an object in a zero gravity vacume at a temp of -283 degrese C with no light touching it , (an enviroment such as space).