This article is from the Conspiracy Theory Literature FAQ, by Xavier Poez firstname.lastname@example.org with numerous contributions by others.
Various authors insist that the government has captured alien
technology and have reverse engineered it for military purposes (i.e.
weaponry or flight technology, so-called antigravity devices).
According to these theories, a point in the Nevada desert called Area
51 holds this secret technology and alien spaceship fragments deep
underground. See [Cooper].