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A Super Ball (a.k.a. SuperBall) is a toy bouncing ball based on a type of synthetic rubber invented in 1964 by chemist Norman Stingley. It is an extremely elastic ball made of Zectron which contains the synthetic polymer polybutadiene as well as hydrated silica, zinc oxide, stearic acid, and other ingredients. This compound is vulcanized with sulfur at a temperature of 165 °C and formed at a pressure of 3500 psi. The resulting Super Ball has a very high coefficient of restitution, and dropped from shoulder level, a Super Ball bounces nearly all the way back; thrown down by an average adult, it can leap over a three-story building.
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Toys similar to Super Balls are more generally known as bouncy balls, a term that covers other balls by different manufacturers with different formulations.
History
After Stingley invented Polybutadiene synthetic rubber, he sought uses for it, as well as someone to manufacture it. He first offered his invention to the Bettis Rubber Company, for whom he worked at the time. Because the material was not very durable, they turned it down, so he took it to toy company Wham-O that worked on developing a more durable version. This version is still manufactured by Wham-O.
"It took us nearly two years to iron the kinks out of Super Ball before we produced it," said Richard Knerr, President of Wham-O, in 1966. "It always had that marvelous springiness ... But it had a tendency to fly apart. We've licked that with a very high-pressure technique for forming it. Now we're selling millions."
When Super Ball was introduced, it became a fad. Peak production reached over 170,000 Super Balls per day. By December 1965 over six million had been sold, and U.S. Presidential adviser McGeorge Bundy had five dozen Super Balls shipped to the White House for the amusement of the staff. Knowing that fads are often short-lived, Wham-O Executive Vice-president Richard P. Knerr said, "Each Super Ball bounce is 92% as high as the last. If our sales don't come down any faster than that, we've got it made." Initially, the full-size Super Ball sold for 98¢ at retail; by the end of 1966 its colorful miniature versions sold for as little as 10¢ in vending machines.
In the late 1960s Wham-O made a "giant" Super Ball, roughly the size of a bowling ball, as a promotional stunt. It fell from the 23rd story window (some reports say the roof) of an Australian hotel and destroyed a parked convertible car on the second bounce.
The composer Alcides Lanza, in his composition Plectros III (1971), specified that the performer should use a pair of Super Balls on sticks as mallets with which to strike and rub the strings and case of a piano. Lanza purchased several Super Balls in 1965 as toys for his son, but soon he started experimenting with the sounds they made when rubbed along the frame or strings of a piano. Several years later, Plectros III resulted.
After watching his children play with a Super Ball, Lamar Hunt, founder of the American Football League, coined the term Super Bowl. In a July 25, 1966, letter to NFL commissioner Pete Rozelle, Hunt wrote, "I have kiddingly called it the 'Super Bowl,' which obviously can be improved upon." Although the leagues' owners decided on the name "AFL-NFL Championship Game," the media immediately picked up on Hunt's "Super Bowl" name, which would become official beginning with the third annual game.
Physical properties
According to one study "If a pen is stuck in a hard rubber ball and dropped from a certain height, the pen may bounce to several times that height." If a Super Ball is dropped without spin onto a hard surface, with a small ball bearing on top of the Super Ball, the bearing rebounds to a great height.
High school physics teachers use Super Balls to educate students on usual and unusual models of impacts.
The "rough" nature of a Super Ball makes its impact characteristics different from otherwise similar smooth balls. The resulting behavior is quite complex. The Super Ball has been used as an illustration of the principle of Time Reversal Invariance.
A Super Ball is observed to reverse the direction of spin on each bounce. This effect depends on the tangential compliance and frictional effect in the collision. It cannot be explained by rigid body impact theory, and would not occur were the ball perfectly rigid. Tangential compliance is the degree to which one body clings to rather than slips over another at the point of impact.