This is one of my all-time favorites! Anti-gravity simplified: If you drop a buttered piece of bread it will fall on the floor butter-side down. If a cat is dropped from a window or other high place it will land on its feet. With this in mind if you attach a buttered piece of bread, butter-side up to a cat's back and toss them both out the window. Will the cat land on its feet? Or will the bread land butter-side down? In theory, even if you are too lazy to do this experiment yourself you should be able to deduce the obvious result. The laws of butterology demand that the butter must hit the ground The equally strict laws of feline aerodynamics demand that the cat land on its feet. If the combined construct were to land, nature would have no way to resolve this paradox. Therefore they simply do not fall. That's right you clever mortal (well, as clever as a mortal can get) you have discovered the secret of antigravity! To expand on this theory a buttered cat when released will quickly move to a height where the forces of cat-twisting and butter repulsion are in equilibrium. This point can be modified by scraping off some of the butter providing lift or removing some of the cat's limbs to allow descent. Most of the civilized species of the universe already use this principle to drive their space ships within a planetary atmosphere. The loud humming heard at most UFO sightings are in fact, the purring of several hundred tabbies. The one obvious danger of course is if the cats manage to eat the bread off their backs. They will instantly plummet to earth. This rare instance actually happened in Roswell 50 or so years ago. The cats of course will land on their feet. This doesn't do them much good however since right after they make their graceful landing several thousand tons of red-hot starship and pissed-off aliens crash down on top of them.