Hoberman Sphere

Chuck Hoberman studied sculpture at Cooper Union, graduating in 1979, and then mechanical engineering at Columbia, a combination that explains the sphere. His "radial expansion/retraction truss structures," filed in April 1990 and granted US patent 5,024,031 in June 1991, arranged scissor linkages, the same principle as a pantograph mirror or a folding chair, into six great circles matching the edges of an icosidodecahedron, so the whole shell could grow and shrink while keeping its shape. He formed Hoberman Associates in 1990, and the Museum of Modern Art added a Hoberman Sphere to its collection in 1994, before there was a toy.

The toy came in 1995, when Hoberman and his wife Carolyn founded Hoberman Designs to sell it. The classic version expands from about 5.9 inches (15 centimeters) to 30 inches (76 centimeters), the plastic struts snapping open in a satisfying rush, and it became a fixture of museum shops and classrooms as much as toy stores. Hoberman won the Chrysler Design Award in 1997 and was a finalist for the Smithsonian's National Design Award in 2000.

The giants are the same mechanism scaled up and pulled by cable or motor. The Liberty Science Center in Jersey City hangs one that opens to 18 feet across and weighs 700 pounds; the AHHAA Science Center in Tartu, Estonia has the largest, 5.9 meters (19 feet) and 340 kilograms of aircraft-grade aluminum, motorized and choreographed to music and lights; Switzerland's Technorama installed a smaller one as early as 1993. Hoberman's Arch was the centerpiece of the medals plaza at the 2002 Salt Lake City Winter Olympics, and his expanding video screen toured with U2's 360° shows through 2011. The toy, meanwhile, never left the shelves.