Polytopes in Italy

March 2006

George W. Hart

I was invited by Michele Emmer to give two lectures and two workshops in Italy in March 2006. The lectures were at the Matematica e Cultura Conference in Venice and then the University of Rome, "La Sapienza". Above you can see the result of a public polytope construction I led at an outdoors workshop in the Campo Sant' Angelo, one of the city squares in Venice. We built a plastic model of the "expanded 120-cell"---a three-dimensional shadow of an interesting four-dimensional object. (hi-res image)

At the start of the construction, the 4860 Zometool parts are in these bags on this table.

We got to work assembling various modules.

Above is the center module, a regular dodecahedron.

Here you can see an assortment of modules arranged on the pavement.

The modules are then assembled in a specific arrangement.

Many people can work on it from all sides. It gets more intricate as we add additional layers.

The final result is rather attractive.

At one point, the local police investigated. Apparently polizia find public polyopes funny.

The Venetian assembly, above, was on sunday morning, March 26. That afternoon, we disassembled it, and in the evening I brought the parts by train down to Rome.  The next morning, I led another assembly of the same structure, this time with math and architecture students of the University of Rome.  We worked in the court yard of the mathematics building, "Guido Castelnuovo":

Again, the process begins with various modules.

These are assembled around a central core.

It grows more interesting with additional layers.

Some students found a new way to attach the top components.

Here is the final result.  Later we brought it inside for display.

Thank you Michele Emmer and Piero Negrini for making my trip and the construction possible.
And thank you
Zometool for providing the parts.