Hanne Kekkonen

Assistant Professor of Mathematics
Delft University of Technology
Delft, Netherlands
I'm a mathematician interested in visualising topological shapes and using them to introduce otherwise difficult to grasp mathematical concepts to the general public. I create shapes from several different medium and I'm especially interested in (negative) curvature.
Hyperbolic Phizz net
30 x 30 x 30 cm
This 'hyperbolic football' was created using Phizz origami units, surrounding a heptagon by seven hexagons resulting in tiling {6;6;7}.

The hyperbolic plane has constant negative curvature and is too large to lie flat. You can approximate a hyperbolic surface by surrounding a heptagon (internal angles 128.57°) by seven hexagons (internal angles 120°). A vertex where two hexagons and one heptagon meet then sums up to 368.57°, creating a 8.57° excess compared to 360°, which would create a flat surface.