Eve Torrence

Professor Emeritus of Mathematics
Randolph-Macon College
Ashland, Virginia, USA

I enjoy using paper to create models to enhance my understanding of geometric objects. Through the process of creating a 3-dimensional form I am able to truly understand its structure. The mental challenge of designing a model and the physical challenge of building it are particularly satisfying when combined.

This piece was inspired by eight-color double tori created by Susan Goldstine in ceramics, crochet and bead crochet and a different crochet version by Moira Chas.

Crazy Eight
16 x 50 x 23 cm

In 1890 Percy Heawood proved that any map drawn on a double torus can be colored with eight colors so that regions that share a boundary are different colors. This modular origami model is constructed from 100 Sonobe units and shows that a map requiring eight colors exists. There are eight regions and every region shares a boundary with the other seven. The design was determined through experimentation and graph coloring. The creases give the sculpture a frenzied look and the slight twist lends an off-balance feel to the structure. Directions for building this model, as well as two distinct seven-color torus maps, can be found in my 2022 Bridges workshop paper.