A soccer ball is an air-filled sphere with specific specifications set by FIFA (Fédération Internationale de Football Association) (International Federation of association football).
The specifications are:
· It must have a circumfrence of 68-70 cm
· The weight must be 410-450 grams (this is the dry weight, as older balls tend to get heavier when played in wet weather)
· It must be inflated to a pressure of 8-12 psi (pound per square inch)
· It must be covered with leather or “other suitable material”
The standard size of a football is the size 5. There are smaller sizes but are used for different purposes such as handball (size 3) and futsal (size 4).
Most modern footballs are stitched from 32 panels of waterproof leather or plastic, although the number of panels may vary according to the balls and their brand. Some manufacturers design balls to be played in specific weathers such as a winter ball.
Adidas has been a supplier for the World Cup since 1970. For the most recent 2006 German World Cup, Adidas provided the 14 panel thermally bonded machine pressed +Teamgeist ball, rather than a stitched one. This is a new innovation on its own, but players especially goalkeepers were complaining about the ball and how it moves in the air during flight.
Since very early times, records have shown that humans enjoy kicking a ball, or something like a ball. According to historical references and legend, early balls ranged from human heads, stitched up cloth, animal and human skulls to pig or cow bladders. Until the 1800’s, most balls were made from pig bladder so their sizes depended on the size of the bladder. In 1855, the first vulcanized rubber ball was created by Charles Goodyear. Rules for ball specifications were agreed by the English Football Association in 1872 and remains today under FIFA Laws. Since then, inflatable balls were designed and created and the development of soccer balls until now has been immense.
Balls make a very big difference in a game of soccer. It all depends on the material it is made of and how it is stitched. A physicist at Bath University, Dr. Ken Bray, has studied free-kicks from the Premiership, the World Cup and the European Championships and states that top professional players are exploiting the chaotic flight and speed of modern balls used in today’s matches.
Dr. Ken Bray states that “FIFA dictates all aspects about the ball apart from the aerodynamics”. He affirms that FIFA does not dictate how the ball will behave in the air after it is kicked. This has become a problem for goalkeepers in the 2006 German World Cup and the 2008 European Championships. The balls used in these matches were designed by Adidas and Bayer MaterialScience with just 14 panels. This gives it a change of external structure called the PSC structure (Power, Swerve and Control) and gives outfield players the advantage. Goosebump-like shapes on the surface layer give the ball more power and swerve.
All of this leads to one outcome. Goalkeepers cannot predict where the ball will go as the balls move in the air and can change direction any second. Professional keepers like Petr Cech, Stipe Pletikosa, Jens Lehman, Gianluigi Buffon, Van der Sar and many others have complained about the ball and they say that it does not give the keepers any advantage.
Players such as Manchester United’s Cristiano Ronaldo has mastered a way to kick the ball where it barely spins on its axis and this means that as air rushes over the joints of the ball, it creates turbulence that can suddenly change the ball's trajectory at any time in while still in the air.
“With Ronaldo, it is down to the physics of chaos once the ball leaves his foot. It makes it very disconcerting and unfair for goalkeepers," said Dr Bray.
Since very early days, early balls ranged from human heads, stitched up cloth, animal and human skulls to pig or cow bladders. From then on, the introduction of rubber, synthetic material and stitching has helped the ball to develop over the years. The newest ball to be created and tested is the Adidas Teamgeist II which features the goal line technology. This ball which has been tested in matches is said to be able to help referees in their decisions of goals. The intelligent technology implemented in the Teamgeist II uses a magnetic field to provide real-time feedback to a central computer, which tracks the location of the ball on the field and sends the data directly to the referee. By using a magnetic field and more stabilized and robust components within the ball, the new system is more precise rather than the previously tested which used radio transmissions. From a video created on testing the goal line technology or GLT system, it shows that every time the ‘whole’ ball crosses the goal, and indication on the referees watch appears.
This just shows the immense development of soccer balls through out history. New balls and technologies are being developed to help the game and referees on knowing the true outcome of the game. Although these technologies are implemented in balls, the thought of video technology used in the Rugby game is being opposed by football fans and players because they will erase the natural beauty of the game.
http://www.soccerball.com.pk/construct.htm
http://en.wikipedia.org/wiki/Development_of_Soccer_Ball
http://news.softpedia.com/news/The-New-World-Cup-Soccer-Ball-Troubles-Goalkeepers-27385.shtml
http://en.wikipedia.org/wiki/Soccer_ball
http://www.soccerballworld.com/History.htm