ASuper Ball orSuperball is atoybouncy ball based on a type ofsynthetic rubber invented in 1964 by chemistNorman Stingley. It is an extremelyelasticball made of Zectron,[1] which contains thesynthetic polymerpolybutadiene as well ashydrated silica,zinc oxide,stearic acid, and other ingredients.[2] This compound isvulcanized withsulfur at a temperature of 165 °C (329 °F) and formed at a pressure of 3,500 psi (24 MPa). The resulting Super Ball has a very highcoefficient of restitution,[3][4][5] and if dropped from shoulder level on a hard surface, a Super Ball bounces nearly all the way back; thrown down onto a hard surface by an average adult, it can fly over a three-story building.
Stingley sought uses for hispolybutadiene synthetic rubber, as well as someone to manufacture it. He first offered his invention to the Bettis Rubber Company, for whom he worked at the time,[6] but they turned it down because the material was not very durable.[7] So Stingley took it to toy companyWham-O; they worked on developing a more durable version which they still manufacture today.[8][9]
"It took us nearly two years to iron the kinks out of Super Ball before we produced it," saidRichard Knerr, President of Wham-O in 1966.[10] "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."[10]
Super Ball became afad when it was introduced.[11] Peak production reached over 170,000 Super Balls per day.[12] By December 1965, over six million had been sold, and U.S. presidential adviserMcGeorge Bundy had five dozen shipped to theWhite House for the amusement of the staff.[1][12][13][14] Wham-O executive vice-president Richard P. Knerr knew that fads are short-lived. "Each Super Ball bounce is 92% as high as the last," he once said. "If our sales don't come down any faster than that, we've got it made."[14] Initially, the full-sized 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.[15]
In the late 1960s, Wham-O made a giant Super Ball roughly the size of a bowling ball as a promotional stunt.[8][9] 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.[8][9]
ComposerAlcides Lanza purchased several Super Balls in 1965 as toys for his son, but soon he started experimenting with the sounds that they made when rubbed along the strings of a piano.[16] This resulted in his compositionPlectros III (1971), in which he specifies that the performer should use a pair of Super Balls on sticks as mallets with which tostrike and rub the strings and case of a piano.[16]
Lamar Hunt, founder of theAmerican Football League (AFL) and owner of theKansas City Chiefs, watched his children play with a Super Ball and then coined the termSuper Bowl. He wrote a letter toNational Football League (NFL) commissionerPete Rozelle dated July 25, 1966: "I have kiddingly called it the 'Super Bowl,' which obviously can be improved upon." The league's franchise owners had decided on the nameAFL–NFL World Championship Game, but the media immediately picked up on Hunt'sSuper Bowl name, which became official beginning with thethird annual game in 1969.[17][8][18][19]
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."[20] 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.[21]
High school physics teachers use Super Balls to educate students on usual and unusual models of impacts.[22]
The "rough" nature of a Super Ball makes its impact characteristics different from those of otherwise similar smooth balls.[23][24] The resulting behavior is quite complex.[24] The Super Ball has been used as an illustration of the principle oftime reversal invariance.[25]
A Super Ball is observed to reverse the direction of spin on each bounce.[26][27][28] 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.[28] Tangential compliance is the degree to which one body clings to rather than slips over another at the point of impact.[29]
For bounces on a wooden bench top, the coefficient of restitution,....is typically about e = 0.8.
...on a hard surface...0.85 for a superball
Lamar Hunt, who died in December, coined the term Super Bowl in the late 1960s after watching his kids play with a Super Ball, the bouncy creation of iconic toy manufacturer Wham-O.
Superball.
A Rough ball which conserves kinetic energy exhibits unexpected behavior after a single bounce and bizarre behavior after three bounces against parallel surfaces. The Wham-O Super-Ball...appears to approximate this behavior...quite different from that of a...smooth ball
Super balls are simple toys that exhibit surprisingly complex behavior. Part of the fun of a super ball is a result of the high friction between the rubber of the ball and the surface it bounces against. This friction places moments on the ball that cause it to spin after bouncing. The exchange of energy between rotational and translational forms that occurs at each collision makes the super ball's behavior difficult to predict.
Strobe photographs of a spinning, bouncing `superball' are analysed to determine whether observed reversals of spin during bouncing fit a model analogous to Newton's experimental law of restitution. Rough, but imperfect agreement is found.
When a superball is thrown forwards but with backspin, it is observed to reverse both direction and spin for a few bounces before settling to bouncing motion in one direction.