Roberto Carlos's free kick goal against France in 1997 is the stuff of legend. Some bored physicists, probably tired of looking for the Higgs boson, have figured out exactly how and why it happened.
There's a new paper out in the New Journal of Physics, that has a lot to do with fluid mechanics and rotational physics and shit like that. I won't make you read it all, because despite what your teachers tell you, you really don't need to use science after high school.
But the gist is this: for a spinning object, such as Carlos's ball, there comes a point in its trajectory when the drag of the surrounding air slows it down to a sufficient speed. At that speed, the spiral of the ball increases exponentially, meaning the soccer ball will start curving more and more the farther it goes. In Carlos's case, it appeared to curve sharply at the last moment.
That's no accident, or a strong gust of wind as many have surmised. Any ball, kicked from a long enough distance with sufficient rotation, will act this way.
For this kick and a number of others, Carlos is remembered as a master of set pieces. But really, he just tried for spectacular goals like this all the time, and we only recall the successful ones. I'm willing to wager he sent more balls wide than any of his contemporaries.
Best free kick ever by Roberto Carlos was no fluke, claim scientists [Daily Telegraph]