9 comments

[ 3.4 ms ] story [ 31.1 ms ] thread
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.
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 ?
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.
It can definitely be greater, because a table tennis ball with backspin follows an upward trajectory.
Related: Sixty Symbols did a video about the Jabulani football used in 2010:

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.

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.