The term gyration is given as a synonym for rotation sometimes, but I think of gyration and rotation as different things. I think gyration is just something following a circular path in at least 2 dimensions and is in fact a form of linear motion. True rotation happens when something shows a distinguishable "face" or a repeating series of faces of some sort to a fixed reference point in a cyclical manner as it goes about "rotating", and can occur in just one dimension. The true deep meaning of rotation escapes me (spin-2, etc.), because the concept is difficult and I'm not always sure what does or doesn't constitute a face. This all gets more interesting when the rotating(?) gyrating(?) things are charged and the fixed frame they are in has a magnetic field (or vice-versa). Long threads on Vort about whether the fields actually rotate with their sources, etc.
Rick M.
