The hedge in Radley churchyard is a wave that isn't going anywhere. If you didn't know, Radley is a village near Oxford, The wave is a type called a saw-tooth wave. The mathematician Fourier showed that all complicated wave shapes like this could be made by adding together rounded sine waves of different frequencies. This wave has a particularly vicious equation
http://mathworld.wolfram.com/FourierSeriesSawtoothWave.html but this page does have a picture showing how the rounded waves make up the saw-tooth.
