Informant38

The Nimble and the Ponderous
"But most problems associated with rapid change are due to being faster than some interacting process. For example, faster in the center of the stream than the edges leads to turbulence. The difference between an expansion and an explosion is whether other objects have time to get out of the way. Always ask, �Faster than what?� and remember that old joke about the two guys being chased by the bear. You don�t have to run faster than the bear, only faster than the other guy."
�William H. Calvin August 2003