This is a picture of a stream of oil entering a pool of the same substance, bouncing off the bottom, and arcing back out.
Normally a liquid stream colliding with a pool of liquid merges immediately upon contact, perhaps also bringing air into the pool with it. However when the pool is moving as the stream hits, it can slide along the surface being separated from the pool by a thin layer of air. The air layer supports the jet and lubricates the motion between it and the bath. The same process happens when sliding a piece of paper across a desk or when a car hydroplanes on a wet road. But instead of a hard surface like the desk or the road, the jet is on top of a liquid surface, which is flexible like a trampoline. Because of the weight of the jet and the force required to change directions, the surface is pressed downward and a dent is formed in the shape of a bowl. The sliding jet then ramps out of this bowl and into the air.
Now I have no idea whatsoever what that means, but damn does it look neat. And I'm not much of one for reading long scientific explanations, but I'm fairly certain this proves many theories, including, but not limited to: the theory that wormholes exist. That time travel is possible. That science is cool, and that motor oil makes a great sexual lubricant in a pinch.
Two more pictures and a worthwhile VIDEO after the jump.
We can follow a fluid parcel sequentially through (1) the jet's initial stages of falling, (2) its separation from the bulk fluid by a thin layer of air, (3) its bending upwards, and (4) its bounce and subsequent flight. Keep in mind that the bath is moving to the right in this picture.