A Hoberman sphere is a kinetic structure patented by Chuck Hoberman that resembles a geodesic dome, 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 children's toys: several toy sizes exist, with the original design capable of expanding from 5.9 inches (15 cm) in diameter to 30 inches (76 cm).[ citation needed ]
A Hoberman sphere typically consists of six great circles corresponding to the edges of an icosidodecahedron. The Hoberman sphere can be unfolded by allowing certain members to spread apart. The operation of each joint is linked to all the others in a scissors mechanism like those used to mount pantograph mirrors, or how a folding chair operates. In larger models, this can be accomplished by feeding out a string or cable instead.
The largest existing Hoberman sphere is in the AHHAA Science Center in Tartu, Estonia. Fully expanded, it is 5.9 metres (19 ft) in diameter. The motorized sphere weighs 340 kilograms (750 lb), is constructed of aircraft-grade aluminum, 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. [1]
An earlier, similar but slightly smaller Hoberman sphere is in the atrium of Liberty Science Center in Jersey City, New Jersey. The 700-pound (320 kg) sphere, when fully expanded, measures 18 feet (5.5 m) in diameter. [2]
In 1993 a smaller geodesic sphere was installed at the Swiss Science Center Technorama in Winterthur, Switzerland. [3]
Richard Buckminster Fuller was an American architect, systems theorist, writer, designer, inventor, philosopher, and futurist. He styled his name as R. Buckminster Fuller in his writings, publishing more than 30 books and coining or popularizing such terms as "Spaceship Earth", "Dymaxion", "ephemeralization", "synergetics", and "tensegrity".
A planetarium is a theatre built primarily for presenting educational and entertaining shows about astronomy and the night sky, or for training in celestial navigation.
A geodesic dome is a hemispherical thin-shell structure (lattice-shell) based on a geodesic polyhedron. The rigid triangular elements of the dome distribute stress throughout the structure, making geodesic domes able to withstand very heavy loads for their size.
Rifling is the term for helical grooves machined into the internal surface of a firearms's barrel for imparting a spin to a projectile to improve its aerodynamic stability and accuracy. It is also the term for creating such grooves.
The Colt AR-15 is a lightweight, magazine-fed, gas-operated semi-automatic rifle. It is a semi-automatic version of the M16 rifle sold for the civilian and law enforcement markets in the United States. The AR in AR-15 stands for "ArmaLite Rifle", after the company that developed it in the 1950s. Colt's Manufacturing Company currently owns the AR-15 trademark for its line of semi-automatic AR-15 rifles.
A globe is a spherical model of Earth, of some other celestial body, or of the celestial sphere. Globes serve purposes similar to maps, but, unlike maps, they do not distort the surface that they portray except to scale it down. A model globe of Earth is called a terrestrial globe. A model globe of the celestial sphere is called a celestial globe.
A Bowden cable is a type of flexible cable used to transmit mechanical force or energy by the movement of an inner cable relative to a hollow outer cable housing. The housing is generally of composite construction, consisting of an inner lining, a longitudinally incompressible layer such as a helical winding or a sheath of steel wire, and a protective outer covering.
Leatherman is an American brand of multi-tool made by Leatherman Tool Group of Portland, Oregon. The company was founded in July 1983 by Timothy S. Leatherman and Steve Berliner in order to market the former's idea of a capable, easily portable hand tool with multiple functions. That same year, Leatherman Tool Group sold its first Multi-Tool, which was called the PST.
A rivet is a permanent mechanical fastener. Before being installed, a rivet consists of a smooth cylindrical shaft with a head on one end. The end opposite the head is called the tail. On installation, the deformed end is called the shop head or buck-tail.
The Tinkertoy Construction Set—commonly known as Tinkertoy, Tinker Toy, or plural forms thereof—is a construction set for children. It was designed in 1914 and was originally manufactured in Evanston, Illinois, U.S. The brand is now owned by Hasbro.
The Apollo command and service module (CSM) was one of two principal components of the United States Apollo spacecraft, used for the Apollo program, which landed astronauts on the Moon between 1969 and 1972. The CSM functioned as a mother ship, which carried a crew of three astronauts and the second Apollo spacecraft, the Apollo Lunar Module, to lunar orbit, and brought the astronauts back to Earth. It consisted of two parts: the conical command module, a cabin that housed the crew and carried equipment needed for atmospheric reentry and splashdown; and the cylindrical service module which provided propulsion, electrical power and storage for various consumables required during a mission. An umbilical connection transferred power and consumables between the two modules. Just before reentry of the command module on the return home, the umbilical connection was severed and the service module was cast off and allowed to burn up in the atmosphere.
The angular diameter, angular size, apparent diameter, or apparent size is an angular distance describing how large a sphere or circle appears from a given point of view. In the vision sciences, it is called the visual angle, and in optics, it is the angular aperture. The angular diameter can alternatively be thought of as the angular displacement through which an eye or camera must rotate to look from one side of an apparent circle to the opposite side. Humans can resolve with their naked eyes diameters down to about 1 arcminute. This corresponds to 0.3 m at a 1 km distance, or to perceiving Venus as a disk under optimal conditions.
Liberty Science Center is an interactive science museum and learning center located in Liberty State Park in Jersey City, New Jersey, United States. At its opening, it was the largest such planetarium in the Western Hemisphere and the world's fourth largest.
A pocketknife is a knife with one or more blades that fold into the handle. They are also known as jackknives (jack-knife), folding knives, EDC knife, or may be referred to as a penknife, though a penknife may also be a specific kind of pocketknife. A typical blade length is 5 to 15 centimetres.
Chuck Hoberman is an artist, engineer, architect, and inventor of folding toys and structures, most notably the Hoberman sphere.
The Sphere is a monumental cast bronze sculpture by German artist Fritz Koenig (1924–2017).
A handgun is a firearm designed to be usable with only one hand. It is distinguished from a long gun which needs to be held by both hands and braced against the shoulder. Handguns have shorter effective ranges compared to long guns, and are much harder to shoot accurately. While most early handguns are single-shot pistols, the two most common types of handguns used in modern times are revolvers and semi-automatic pistols, although other handguns such as derringers and machine pistols also see infrequent usage.
A deployable structure is a structure that can change shape so as to significantly change its size.
The American Star Bicycle was invented in 1880 by G. W. Pressey and manufactured by the H. B. Smith Machine Company in Smithville, Burlington County, New Jersey. It was characterized by a small wheel in front to avoid the problem of tipping forward inherent in other high wheelers. A Star bicycle was photographed being ridden down the steps in front of the United States Capitol in 1885 to demonstrate its longitudinal stability, and Star bicycles were used for the sport of bicycle polo in the mid-1880s. Pressey sued Smith in 1887 for royalties. The name "Star" was attributed to the double star arrangement of the spokes.
A Hoberman mechanism, or Hoberman linkage, is a deployable mechanism that turns linear motion into radial motion.