SUMS: Schleimer -- Puzzling the 120-cell

For this week’s SUMS talk we’re lucky to have Associate Professor Saul Schleimer from
the University of Warwick, speaking about the 120-cell and the interlocking burr puzzles
it inspires.  He has asked that anyone who owns any of these puzzles to bring them along
to the talk.  

Abstract: (Joint work with Henry Segerman.)  We introduce Quintessence: a new family of
3D-printed interlocking puzzles based on the geometry and combinatorics of the
120-cell.  I’ll review spheres, polytopes and stereographic projection in dimensions two
and three before generalizing to dimension four.  We’ll briefly discuss the quaternions,
the three-sphere, isometries of three-space, polytopes, and particularly the
four-dimensional 120-cell and its combinatorial Hopf fibration on our way to building
the puzzles.