7 ms·

The Magnus Effect and the World Cup Match Ball

40 points by adamcarson 12y ago

abfan1127 12y ago
why don't they mention golf balls? Golf balls used to be smooth, but caddies found that used dented balls flew straighter and golfers had more control.
- Gmo 12y ago
  Mostly because this article is made because of the football/soccer world cup which is currently taking place in Brazil, and they don't mention any other sports ?
ScottBurson 12y ago
I'd wager that no sport makes more use of the Magnus effect than table tennis. The ball is extremely light, and top players routinely spin it at 6000 to as much as 9000 rpm. And not just on occasional shots, either -- almost every ball is spinning heavily in some direction. I'd have to check to be sure, but I think the Magnus acceleration can be greater than that due to gravity. It certainly can be of the same order.
- Al__Dante 12y ago
  It can definitely be greater, because a table tennis ball with backspin follows an upward trajectory.
dmourati 12y ago
For details on how Roberto Carlos sets up a free kick, watch this video: http://www.uefa.com/trainingground/skills/video/videoid=761187.html http://www.uefa.com/trainingground/skills/video/videoid=7611...
- aagha 12y ago
  Thanks so much for posting that link. Carlos is so Zen when it comes to soccer: "The ball is for playing".
tegeek 12y ago
In cricket, the Magnus Effect produce "reverse swing". https://www.youtube.com/watch?v=No2Nz4R4HUs https://www.youtube.com/watch?v=No2Nz4R4HUs
nhebb 12y ago
Related: Sixty Symbols did a video about the Jabulani football used in 2010: http://www.sixtysymbols.com/videos/football.htm http://www.sixtysymbols.com/videos/football.htm Sixty Symbols (from the University of Nottingham) does a nice job making videos about physics that are approachable for non-physicists.
irremediable 12y ago
Lovely stuff. Back in my undergrad degree, the professor who taught basic fluid mechanics loved to use the Magnus effect as an example. I think his explanation would have been much improved by some FEA like we see here. COMSOL's a cool package, incidentally. It makes FEA much easier for people who don't have much experience of it, but do know a fair bit about the physical phenomena they're trying to model. I had a few gripes with the system back when I used it for modelling thermal degradation in motors, but overall it was very impressive.

40 points by adamcarson 12y ago

why don't they mention golf balls? Golf balls used to be smooth, but caddies found that used dented balls flew straighter and golfers had more control.

Gmo 12y ago
Mostly because this article is made because of the football/soccer world cup which is currently taking place in Brazil, and they don't mention any other sports ?

ScottBurson 12y ago

I'd wager that no sport makes more use of the Magnus effect than table tennis. The ball is extremely light, and top players routinely spin it at 6000 to as much as 9000 rpm. And not just on occasional shots, either -- almost every ball is spinning heavily in some direction. I'd have to check to be sure, but I think the Magnus acceleration can be greater than that due to gravity. It certainly can be of the same order.

Al__Dante 12y ago
It can definitely be greater, because a table tennis ball with backspin follows an upward trajectory.

dmourati 12y ago

For details on how Roberto Carlos sets up a free kick, watch this video: http://www.uefa.com/trainingground/skills/video/videoid=761187.html http://www.uefa.com/trainingground/skills/video/videoid=7611...

aagha 12y ago
Thanks so much for posting that link. Carlos is so Zen when it comes to soccer: "The ball is for playing".

tegeek 12y ago

In cricket, the Magnus Effect produce "reverse swing". https://www.youtube.com/watch?v=No2Nz4R4HUs https://www.youtube.com/watch?v=No2Nz4R4HUs

nhebb 12y ago

Related: Sixty Symbols did a video about the Jabulani football used in 2010: http://www.sixtysymbols.com/videos/football.htm http://www.sixtysymbols.com/videos/football.htm Sixty Symbols (from the University of Nottingham) does a nice job making videos about physics that are approachable for non-physicists.

irremediable 12y ago

Lovely stuff. Back in my undergrad degree, the professor who taught basic fluid mechanics loved to use the Magnus effect as an example. I think his explanation would have been much improved by some FEA like we see here. COMSOL's a cool package, incidentally. It makes FEA much easier for people who don't have much experience of it, but do know a fair bit about the physical phenomena they're trying to model. I had a few gripes with the system back when I used it for modelling thermal degradation in motors, but overall it was very impressive.