World Cup soccer ball travels faster and farther at high altitudes
World Cup soccer balls will travel faster and straighter through Johannesburg's thin air, a NASA scientists has warned.
World Cup players might notice some strange things happening to their kicks because of the peculiar aerodynamics of playing soccer at the high altitude of the Johannesburg, South Africa, stadium, a NASA scientist warned today.Skip to next paragraph
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At altitude, the air pressure is lower, and so are aerodynamic effects such as drag and lift, ultimately causing balls to travel faster and straighter than they would at lower altitude. Johannesburg is 5,500 feet (1,680 meters) above sea level, even higher than Denver.
"When they play there, the ball will behave differently because of air density compared to other stadiums," said Rabi Mehta, an aerospace engineer at NASA Ames Research Center in Moffett Field, Calif. "When watching the games recently, you often see long passes that overshoot, and I think that's because of this effect."
Physics on the field
Drag is the force of air resistance pushing against a ball's motion and slowing it down, while lift is a force causing a ball to swerve off a straight path. Both forces are caused by the presence of air, so with less air molecules around, these forces are reduced. Thus, the same kick in Johannesburg compared with one at sea level would cause a soccer ball to travel faster and on a less curved path.
Players who are aware of altitude's effect on aerodynamics could have an advantage over those who don't, Mehta said.
"If they understand what happens in certain situations, that improves their performance," Mehta told LiveScience. "When the person is producing a pass he has to realize, 'I need to kick it not as hard as I would at sea level, otherwise it's going to go out of bounds.'"
In addition, the altitude can be tough physiologically for players not used to it. Less atmosphere means less oxygen to breathe, which causes a strain on athletes as they must breathe harder to get enough oxygen to their straining muscles. People can adjust to altitude, and their bodies will begin producing more red blood cells to take advantage of the oxygen that is available. But this takes time, so players who live at high altitude or arrive early enough to acclimatize have a definite advantage.