Symmetry Flow

Watercolor paper, watercolor pencil, stainless steel wire, electrical tape
2020

Bridges Art Exhibition, virtual, August 2020
Joint Mathematics Meetings Exhibition of Mathematical Art, virtual, January 2021
Fundamental Regions: The Math/Art of Susan Goldstine, Boyden Gallery, St. Mary's College of Maryland, January - March 2022

Catalog Page

click for video

A kinetic flowchart for identifying the 17 wallpaper groups. The mobile follows Brian Sanderson's classification system for symmetries that fill the plane, which first sorts by the largest order of rotational symmetry. The initial split in the mobile is between patterns with and without an order 3 rotation; the branches then subdivide into maximum rotation orders 6, 3, 4, 2, and 1. Further branchings filter by reflections, glide reflections, and the relationships between different symmetries. Roughly speaking, within each cluster the more reflection symmetry a pattern has, the lighter the color.

My thanks go to Louise Gould for her advice on desktop cutting machines, and to Alison Frane for teaching me how to make wire mobiles.

Click on the still images to see video of Symmetry Flow.