The massive leap forward of technology during the second world war was beyond what humans could achieve in such a short space of time. To cut to the chase, aliens helped, they are up there. Laugh if you want.

This world is like lost tribes in the amazon coming across the 21st century. As for anti gravity, there are too many craft or whatever defying gravity, there are loads of videos showing craft changing direction etc, showing they have pilots.

The Apollo astronauts saw craft. This is not crackpot.