CAMPUS THEORY SEMINAR
           Part of the SCIENCE AT THE EDGE Seminar Series

                      Friday, April 13, 2001
         11:30am in Room 224 Physics-Astronomy Building
                    (Refreshments at 11:15am)

      Folding and Unfolding Linkages, Paper, and Polyhedra

                          Erik Demaine
                 Department of Computer Science
                     University of Waterloo


I will present several recent results about folding and unfolding 
problems in geometry.  For example, consider a polygonal linkage made 
up of rigid bars connected in a cycle.  Can all such linkages be 
moved to become convex, while preserving all the bar lengths and 
without crossing any of the bars?  In the context of paper folding 
(origami), what shapes can be folded out of a square piece of paper?  
Both of these questions have recently been settled.  Two other bodies 
of research investigate polyhedra: unfolding polyhedra into 
nonoverlapping "nets," and gluing polygons into polyhedra.