Flexible Polyhedron
Flexible Polyhedron
Usage conditions apply
- Description
- The mathematician Leonard Euler once wrote,"A closed spatial figure allows no changes, as long as it is not ripped apart." Proving the "rigidity" of polyhedra was another matter. In 1813, Augustin-Louis Cauchy showed that a convex polyhedral surface is rigid if its flat polygonal faces are held rigid. In 1974, Herman Gluck proved that almost all triangulated spherical surfaces were rigid. However, in 1977 Robert Connelly of Cornell University found a counterexample, that is to say a flexible polyhedron. He built this model of such a surface some years later. It is made of cardboard and held together with duct tape. Two cutout plastic windows allow the viewer to observe changes when the polyhedron is flexed. The top section has 12 large faces and a six-faced appendage. The bottom section has 12 corresponding faces but no appendage.
- Location
- Currently not on view
- Object Name
- geometric model
- date made
- 1985
- maker
- Connelly, Robert
- Place Made
- United States: New York, Ithaca
- Physical Description
- plastic (overall material)
- paper (overall material)
- Measurements
- overall: 14 cm x 47 cm x 25.5 cm; 5 1/2 in x 18 1/2 in x 10 1/16 in
- ID Number
- 1990.0492.01
- accession number
- 1990.0492
- catalog number
- 1990.0492.01
- Credit Line
- Prof. Robert Connelly
- subject
- Mathematics
- See more items in
- Medicine and Science: Mathematics
- Science & Mathematics
- Data Source
- National Museum of American History
Nominate this object for photography.
Our collection database is a work in progress. We may update this record based on further research and review. Learn more about our approach to sharing our collection online.
If you would like to know how you can use content on this page, see the Smithsonian's Terms of Use. If you need to request an image for publication or other use, please visit Rights and Reproductions.
