Physical principles of football

In 1997, Brazilian soccer player roberto carlos kicked a free kick 35 meters away, and there was no direct route to the goal. His shot flew the ball over the player's head, and when the ball was about to go out of bounds, it turned sharply to the left and hit the goal. How did he do it?

There is a little knowledge of physics behind one of the greatest goals in history-Magnus effect means that when there is relative motion between fluid and rotating solid, it will produce a lateral wise force on the rotating body.

The athlete sends the ball to the right with one foot in the air, and at the same time makes the ball spin by itself. The flying direction of the ball relative to the ball is opposite to the airflow direction, and the airflow on both sides of the football slows it down.

On the right side of the ball, the airflow is opposite to the rotation direction of the ball, and the airflow speed becomes smaller, which increases the pressure; On the left side of the ball, the airflow rotates in the same direction as the ball, and the airflow speed increases and the pressure decreases. This pressure difference makes the ball spin to the left. If the ball doesn't spin, it will fly in a straight line in the direction that the athlete tries hard.