Advanced Understanding of the Gravitational Field
The common disc-shaped vehicle evidently manipulates the space-time continuum to move about in our atmosphere without the acceleration / deceleration forces we experience in man-made aircraft. (Ability to travel along the time axis would explain the reported instantaneous appearance / disappearance of disc UFOs. See also lack of time constraint during abduction.) Discs are also seen entering and leaving our oceans, lakes and rivers. (E.g., see http://www.waterufo.net.) Field manipulation serves in other ways: witnesses in several cases have described a blue light beam extending down to the ground or water surface, wherever they were abducted, serving as a conveyor belt or escalator, (the tractor beam predicted long ago in science fiction), moving them into or out of the disc, as required. (E.g., The Allagash Abductions, 1990 plastic-bound edition, p27 [Fow].) The crop circles famous in southern England and elsewhere may be an artifact of intentional field manipulation. Human physicists currently require equipment literally kilometers in diameter to study the fields associated with atomic nuclei, but Greys seem to have portable, hand-held versions of their apparatus for field manipulation: some abductees describe being "floated" along the ground when escorted back and forth to the disc.