#world since [[Humans tend to think in linearities and causations]], the world often surprises our linear-thinking minds --> [[Nonlinearities contribute to complex system behaviors]] Examples: - As the flow of traffic on a highway increases, car speed is affected only slightly over a large range of car density. Eventually, however, small further increases in density produce a rapid drop-off in speed. And when the number of cars on the highway builds up to a certain point, it can result in a traffic jam, and car speed drops to zero. - Soil erosion can proceed for a long time without much affect on crop yield-until the topsoil is worn down to the depth of the root zone of the crop. Beyond that point, a little further erosion can cause yields to plummet. - A little tasteful advertising can awaken interest in a product. A lot of blatant advertising can cause disgust for the product.