bouncing silicone

Figure 1. A falling liquid stream rebounds off a deep bath of the same silicone oil.

"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.

The bouncing jet is a new example of steady noncoalescence and a new example of a fluid flow with multiple stable states at the same conditions."