blacksundae

Geoffrey West, courtesy of Cosmic Variance:

[T]o what extent are cities or corporations an extension of biology? Are they “just” very large organisms? Analogous scaling laws reflecting underlying social network structure point to general principles of organization common to all cities, but, counter to biological systems, the pace of social life systematically increases with size. This has dramatic implications for growth, development and particularly for sustainability: innovation and wealth creation that fuel social systems, if left unchecked, potentially sow the seeds for their inevitable collapse.

Read on.

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.

Look at pictures and videos here. [via NOTCOT.org]