Please remember that this article refers to the 2010 World Cup!
Much of the pre-tournament chat, if you follow the science, was about the new ball, in part developed at Loughborough University. It is very round; more so than previously (to within less than 0.25mm). It is been made from eight thermally bonded polyurethane panels (instead of 14 stitched ones), around a latex bladder. Although the designers coated it in grooves after extensive tests in wind tunnels, many people have criticised it for being too smooth. Strangely, balls with imperfections in their surfaces, travel more predictably than smoother balls.
“If you had a golf ball without dimples, you couldn’t drive it 100 yards,” said John Eric Goff of the University of Virginia in Charlottesville. “If a baseball didn’t have stitches, you’d never hit a home run.”
The reason for this is the turbulence created when the ball is kicked. Rougher balls behave more predictably because turbulence at lower speeds prevents sudden changes of velocity. The new ball may travel further at higher speeds but then, as it decelerates from 100 kilometres per hour to about 70kph, starts to experience more drag causing it to slow unexpectedly. Goalkeepers are unhappy about this.
The tournament is also being played at very different altitudes (Johannesburg is at 1701m above sea level). This obviously has an effect upon the players’ physiology (breathlessness due to the lower oxygen concentration for example) but the ball will also travel further at lower air pressures. The reduced density of the air will change the flight of the ball meaning that not only will the players have to have acclimatised to the lower oxygen levels, they will also need to adapt to the new aerodynamics of the ball.
Fortunately, I have absolutely no interest in football although I will be as delighted as anyone when England win. My understanding of the ‘beautiful game’ can best be summed up in the following video from Adam Buxton and Joe Cornish.
Comments