15 Great Circles

Last weeks Math Monday article showed the intersection of 4,5 and 6 great circles made using CDs and left the reader with a challenge to assemble a model of 15 intersecting great spheres, well challenge accepted.

I used a 3D modelling program to subdivide a dodecahedron, which gave me points in the middle of each face and the middle of each edge. From there I reconstructed the basic triangular 'unit' and once I had the required angles I used inkscape to add the great circle outline to the model. Perhaps a complicated route but it works. (svg here)

Oh yeah, and maths is beautiful

Each 'unit' of the sphere was made from 2 pieces of card so each edge of the final model is exactly 2 pieces of card thick and no more this makes the whole construction quite sturdy.