Graeco Latin Squares (and spheres)

The pictures below represent a Graeco-Latin square of size ten and its image mapped onto a rotating sphere. A large-scale square (about three meters on a side) was located on the first floor of Bradley Hall.

To define a Graeco-Latin square, start with a simpler object, a Latin square. A Latin square can be thought of as an n-by-n array colored with n colors in such a way that each row and each column have no duplicate colors. A Graeco-Latin square is the superimposition of two ``orthogonal'' Latin squares. Notice that the lower left-hand corner of the Graeco-latin square contains a three-by-three Graeco-Latin square using the ``colors'' white, black and gray.

We actually have an mng version (open file format) of the spinning sphere, but for now very few browsers can render it, so we have chosen to be politically incorrect and render an animated gif version.

Last modified on 16 Nov 2006 by Sarunas.