The paper referred to is here: The aerodynamics of the beautiful game by J.W.M. Bush<p><a href="http://math.mit.edu/~bush/wordpress/wp-content/uploads/2013/11/Beautiful-Game-2013.pdf" rel="nofollow">http://math.mit.edu/~bush/wordpress/wp-content/uploads/2013/...</a><p><pre><code> one can only be puzzled to note that striking a smooth
beach ball or an old, worn volleyball with spin has just
the opposite effect
</code></pre>
I'm having great difficulty believing this. I've spun many beach balls and struck man old, worn volleyballs and have never seen a ball curve the wrong way. I've also dealt with many smooth ping-pong balls, and have even sanded off the dimples on golf balls to see the aerodynamic effect.<p>I'm not saying it's mathematically impossible, just that I didn't think it would be possible to find this effect in the real world. Maybe I've just never tried something smooth enough. Is there some reasonable home demonstration of this that I can try to prove it to myself? They say they did it with a latex band around a soccer ball?