Emilie Pritchard
I am not a mathematician by training, only by inclination. I build 3D polyhedral structures by joining metal tubes with thread. These can end up as jewelry or as sculpture. My primary material is tubes of oxidized sterling silver. I also use other materials, such as gold fill, brass and anodised aluminum, usually to accent the geometry of a piece. My main building blocks are octahedra and tetrahedra, because they consist entirely of triangles. Triangles are essential because any other polyhedron won’t be rigid when made from tubes joined only with thread. By varying the lengths of the tubes, I can create structures that would be impossible with equilateral shapes.
A structure that I work with a lot is a “ribbon” of tetrahedra (tets). This piece started with a row of tets in which each is joined to the next by a single shared tube which acts as a hinge. Here that row is made of tubes of oxidized sterling silver. Then the top vertices of neighboring tets are joined with a tube made of gold fill, which creates a tet in the middle and makes the ribbon rigid. The length of that gold tube determines the upward or downward curve that the ribbon takes. This piece has 3 such ribbons that intersect at the center. Other ribbons on the edges have variations in the lengths of the base tubes that create curves in other dimensions.
My original plan was to create an icosidodecahedron. Because pentagons made of tubes joined only with thread would not be rigid, I made each of my pentagons out of 5 shallow tetrahedra surrounding a central tube as a hub. The rim of each pentagon is made from brass tubes, and the other tubes are oxidized sterling silver. When I had made half of the icosidodecahedron, I decided that I liked the hemispheric bowl form. At that point I added additional tetrahedrons to make 5 feet and a rim.