4D Mathematical Model Construction
2005 Art and Math Conference
Boulder, Colorado

George W. Hart

At the 2005 Art and Math Conference, in Boulder, Colorado, many of the participants worked together to assemble a big beautiful Zometool model. This construction is 2 meters in diameter and made from 11540 small plastic parts.

This is a 3D shadow of a uniform four-dimensional polytope, sometimes known as the runci-truncated 120-cell, consisting of 120 truncated dodecahedra, 600 cuboctahedra, 1200 triangular prisms, and 720 decagonal prisms.  But you don't have to understand what that means in order to appreciate it.

Many people worked together during a lunch break making modules.

We had to make 75 modules in five different shapes. Each module is a kind of squished truncated dodecahedron.

Most of the modules are larger than a watermelon, but some are completely flat.
(We didn't actually finish the last few of the flat ones during the conference.)

We assembled the modules together with decagonal prisms, starting at the base.

Adding modules, it grew quite quickly.

We barely stopped for lunch...

The topmost cell was tricky to attach.

A big thank you to everyone who helped!  This shot shows some of the people present at the end. The group who spent several hours completing it included Helmer Aslaksen, Doug Dunham, Tomas Garcia-Salgado, Paul Hildebrandt, Chris Kling, Francisco Lara-Dammer, Kaz Maslanka, Doug McKenna, Tony Phillips, and Scott Vorthmann.

Thank you to Carla Farsi for arranging the conference events,
and to Zometool for loaning the parts for this event.

We started in a rush, and I chose this model to make on the spur of the
moment, so I didn't realize until later that this is the same polytope that
I made a year earlier as part of a museum exhibit in Taiwan.

Photos on this page are by Chris Kling, Helmer Aslaksen, and Tomas Garcia-Salgado.