David Kirkpatrick

July 1, 2010

Soccer — here comes the science

Filed under: Science, Sports — Tags: , , , , , , — David Kirkpatrick @ 11:55 pm

I’ve already done a blog post on scientific research behind this year’s World Cup ball, the Jabulani — now here’s news on a Physics Today article on the science behind soccer. (Hint: hit the link in the release for the article.)

The release:

Study explains science of soccer

College Park, MD (July 1, 2010) — With the attention of sports fans worldwide focused on South Africa and the 2010 FIFA World Cup, U.S. scientist John Eric Goff has made the aerodynamics of the soccer ball a focus of his research.

In an article appearing in the magazine Physics Today this month, Goff examines the science of soccer and explains how the world’s greatest players are able to make a soccer ball do things that would seem to defy the forces of nature.

Goff’s article looks at the ball’s changing design and how its surface roughness and asymmetric air forces contribute to its path once it leaves a player’s foot. His analysis leads to an understanding of how reduced air density in games played at higher altitudes — like those in South Africa — can contribute to some of the jaw-dropping ball trajectories already seen in some of this year’s matches.

“The ball is moving a little faster than what some of the players are used to,” says Goff, who is a professor of physics at Lynchburg College in Virginia and an expert in sports science.

For Goff, soccer is a sport that offers more than non-stop action — it is a living laboratory where physics equations are continuously expressed. On the fields of worldwide competition, the balls maneuver according to complicated formulae, he says, but these can be explained in terms the average viewer can easily understand. And the outcomes of miraculous plays can be explained simply in terms of the underlying physics.

Goff also is the author of the recently published book, “Gold Medal Physics: The Science of Sports,” which uncovers the mechanisms behind some of the greatest moments in sports history, including:

  • How did Cal beat Stanford in the last seconds with five lateral passes as the Stanford marching band was coming on to the field?
  • How did Doug Flutie complete his “Hail Mary” touchdown pass that enabled Boston College to beat Miami?
  • How did Lance Armstrong cycle to a world-beating seven Tour de France victories?
  • How did Olympic greats Bob Beamon (long jump), Greg Louganis (diving) and Katarina Witt (figure skating) achieve their record-setting Olympic gold?

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The article “Power and spin in the beautiful game” appears in the July, 2010 issue of Physics Today and is available at http://www.physicstoday.org/beautiful_game.html

ABOUT PHYSICS TODAY

Published by the American Institute of Physics, Physics Today is the most influential and closely followed physics magazine in the world, informing readers about science and its place in the world with authoritative features, news coverage and analysis, and fresh perspectives on technological advances and ground-breaking research. Physics Today Online (www.physicstoday.org) serves as the magazine’s home on the Internet, with all of its content available to subscribers and continually building a valuable online archive.

ABOUT AIP

The American Institute of Physics is a federation of 10 physical science societies representing more than 135,000 scientists, engineers, and educators and is one of the world’s largest publishers of scientific information in the physical sciences. Offering partnership solutions for scientific societies and for similar organizations in science and engineering, AIP is a leader in the field of electronic publishing of scholarly journals. AIP publishes 12 journals (some of which are the most highly cited in their respective fields), two magazines, including its flagship publication Physics Today; and the AIP Conference Proceedings series. Its online publishing platform Scitation hosts nearly two million articles from more than 185 scholarly journals and other publications of 28 learned society publishers.

June 9, 2010

The 2010 World Cup ball — here comes the science

Filed under: et.al., Science, Sports — Tags: , , , , , , , — David Kirkpatrick @ 2:03 am

I’m getting pretty excited about this year’s World Cup. It’s a fun tournament and a truly international sporting event. There’s already been some controversy over this year’s ball, so how did it perform in the lab? Here’s research from the University of Adelaide.

The release:

Will the new World Cup soccer ball bend?

Physics plays a role in on-ground action

Physics experts at the University of Adelaide believe the new ball created for the 2010 World Cup, called the Jabulani, will play “harder and faster”, bending more unpredictably than its predecessor.

But why? And what will it mean for the game?

“The Jabulani is textured with small ridges and ‘aero grooves’ and represents a radical departure from the ultra-smooth Teamgeist ball, which was used in the last World Cup,” says Professor Derek Leinweber, Head of the School of Chemistry & Physics at the University of Adelaide, who has previously written about and lectured on the aerodynamics of cricket balls, golf balls and the 2006 World Cup soccer ball, the Teamgeist.

Along with student Adrian Kiratidis, who is studying for his Master of Philosophy (MPhil) in Physics, Professor Leinweber has been reviewing the physics behind soccer balls and what that means for the Jabulani. Adrian is also a soccer enthusiast.

“While the governing body FIFA has strict regulations on the size and weight of the balls, they have no regulations about the outside surface of the balls,” Professor Leinweber says.

“The Teamgeist was a big departure at the last World Cup. Because it was very smooth – much smoother than a regular soccer ball – it had a tendency to bend more than the conventional ball and drop more suddenly at the end of its trajectory.

“By comparison, the aerodynamic ridges on the Jabulani are likely to create enough turbulence around the ball to sustain its flight longer, and be a faster, harder ball in play.

“The Jabulani is expected to ‘bend’ more for the players than any ball previously encountered. Players are also discovering new opportunities to move the ball in erratic ways, alarming the world’s best goalkeepers. By the time the ball reaches the goalkeeper, the Jabulani will have swerved and dipped, arriving with more power and energy than the Teamgeist.”

University of Adelaide students have also put the new World Cup soccer ball to the test on the soccer field. Based on Professor Leinweber’s theories, they’ve attempted to “bend” the Jabulani and have also kicked the Teamgeist and a regular soccer ball for comparison.

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