Sand Drawings and Mirror Curves

To accompany the telling of a story or recounting of a fable, men of the Chokwe people in south-central Africa traditionally made sand drawings, called sona, to illustrate the tale. These highly stylized geometric illustrations also served as memory aids.

Sand drawing. Paulus Gerdes

Plaited mat designs. Mark Schlatter

Lion’s stomach design. Mark Schlatter

Example of a sona design in which both horizontal and vertical mirrors are required to trace out the corresponding single-loop light path.