Objects that cannot be taken apart with two hands

Have you ever felt, when you were trying to put something together, that you needed an extra hand?

This sculpture represents research results on the number of hands that a robot would need to assemble collections of simple geometric objects. It is made from 30 identical aluminum tubes, grouped and colored as five twisted tetrahedra. The construction is based on the symmetries of a dodecahedron -- from different views you can see two-fold, three-fold, and five-fold symmetries.

-- Jack Snoeyink (snoeyink@cs.ubc.ca)