Hoberman sphere
Encyclopedia
Chuck Hoberman
Chuck Hoberman is an inventor of folding toys and structures, most notably the Hoberman sphere. He won the Chrysler Design Award for Innovation and Design in 1997 and was a finalist for the 2000 Smithsonian National Design Award.-Creations:In addition to toys such as the Hoberman sphere,the...
that resembles a geodesic dome
Geodesic dome
A geodesic dome is a spherical or partial-spherical shell structure or lattice shell based on a network of great circles on the surface of a sphere. The geodesics intersect to form triangular elements that have local triangular rigidity and also distribute the stress across the structure. When...
, but is capable of folding down to a fraction of its normal size by the scissor-like action of its joints. Colorful plastic versions have become popular as a child's toy: several toy sizes exist, with the original design capable of expanding from 15 cm (6 inches) in diameter to 76 cm (30 inches).
A Hoberman sphere is not a true sphere, but a polyhedron
Polyhedron
In elementary geometry a polyhedron is a geometric solid in three dimensions with flat faces and straight edges...
known as an icosidodecahedron
Icosidodecahedron
In geometry, an icosidodecahedron is a polyhedron with twenty triangular faces and twelve pentagonal faces. An icosidodecahedron has 30 identical vertices, with two triangles and two pentagons meeting at each, and 60 identical edges, each separating a triangle from a pentagon...
. The Hoberman sphere can be unfolded by allowing certain members to spread apart. This can be accomplished by feeding out a string or cable in the larger models. The operation of each joint is linked to all the others in a manner conceptually similar to the extension arm on a wall-mounted shaving mirror.
The largest existing Hoberman sphere is in the atrium of Liberty Science Center
Liberty Science Center
Liberty Science Center is an interactive science museum and learning center located in Liberty State Park in Jersey City, New Jersey.The center, which first opened in 1993 as New Jersey's first major state science museum, has science exhibits, the largest IMAX Dome theater in the United States,...
in Jersey City, New Jersey
Jersey City, New Jersey
Jersey City is the seat of Hudson County, New Jersey, United States.Part of the New York metropolitan area, Jersey City lies between the Hudson River and Upper New York Bay across from Lower Manhattan and the Hackensack River and Newark Bay...
. Fully expanded, it is 18 feet (5.5 m) in diameter. The motorized sphere weighs 700 pounds (320 kg), is constructed of stainless steel
Stainless steel
In metallurgy, stainless steel, also known as inox steel or inox from French "inoxydable", is defined as a steel alloy with a minimum of 10.5 or 11% chromium content by mass....
and aluminium
Aluminium
Aluminium or aluminum is a silvery white member of the boron group of chemical elements. It has the symbol Al, and its atomic number is 13. It is not soluble in water under normal circumstances....
, and continually oscillates between its compact and expanded states.
The sphere is suspended above the Center's Science Court and is actuated with a computer-based motion control system. This system opens and closes the sphere in a programmed series of lyrical motions choreographed to music, lighting and special effects. - source: http://www.philipvaughan.net/public.html"
Its inventor, Chuck Hoberman
Chuck Hoberman
Chuck Hoberman is an inventor of folding toys and structures, most notably the Hoberman sphere. He won the Chrysler Design Award for Innovation and Design in 1997 and was a finalist for the 2000 Smithsonian National Design Award.-Creations:In addition to toys such as the Hoberman sphere,the...
, holds several patents on folding
Folding
Fold or folding may refer to:* Paper folding, the art of folding paper* Book folding, in book production* Skin fold, an area of skin that folds* Fold , in the game of poker, to discard one's hand and forfeit interest in the current pot...
techniques.