How does a UFO Fly?

Today we received an interesting video that made us think about the possibilities of UFO levitation.
Check out this video and let us know how you think UFOs levitate so clean and swift as they do. Do they use some kind of propellor system? Or do they use magnetic propulsion? There must be a few theorists out there. We of World UFO Day aren’t really rocket scientists, so if anyone has any ideas feel free to contact us at info@worldufoday.com. How does a UFO Fly?