If you’ve been following the World Cup at all you’ve probably heard about the controversy surrounding the new Jabulani soccer ball from Adidas. What you may not know is that the MLS has been using the ball for the entire 2010 season. And MLS players aren’t any happier about it than the international stars are.
But what is it about the ball that makes it so unpredictable? Well, it turns out you might need to be a rocket scientist to understand. But NASA, with the help of San Jose Earthquakes rookie midfielder Steven Beitsahour, studied the flight characteristics of the Jabulani and the results should send shivers down the spines of goalkeepers worldwide who have yet to encounter the new ball:
A little dust and a high speed camera and the unpredictable movements of the Jabulani are easy to see. Tim Lincecum would kill for movement like that!
"It's quite obvious. You're seeing a knuckle-ball effect," said Rabi Mehta, an aerospace engineer at NASA Ames. Mehta explained that when a relatively smooth ball with seams flies through the air without much spin, the air close to the surface is affected by the seams, producing an asymmetric flow. This asymmetry creates side forces that can suddenly push the ball in one direction and cause volatile swerves and swoops.
Now those calling to a return to previous balls have a little scientific evidence to back up their arguments, though perhaps it would be more persuasive if the NASA video's production values entered the 20th century!
H/T: Dirty Tackle