Nowhere is steady-going more evident than in the natural world where the forces of erosion and weather create landscapes that are slowly changing over time. The French mathematician Henri Poincare first coined the term "steady-going" to describe what happens when objects in motion maintain a uniform speed in a continual straight line. In mathematical terms, this is described by a continuous function that maintains constant slope over the entire range. For instance, the speed of a car on a racetrack remains constant as it zips around the track.