Round and Round

A Look at Rotations in the Animal World

I spent countless hours watching one of my sons swimming his rounds in a pool and preparing for backstroke competitions (and winning quite a few of them). At that time I began to wonder about the mechanics of the “wheeling” motions of the arms of the back-stroking swimmers. Seeing how they thrashed the water reminded me of propeller propulsion. Yet, surprisingly, true rotation, in other words turning in circles relative to some other part of the body of a machine, is virtually absent from the living world. —>