Vivekanand Vellanki

This is due to Bernouli's principle.

The soccer ball is kicked on one side, making it spin as it moves in the air. Consider what happens to the air flow around the football:

When the air-flow and spin are in the same direction, the air moves faster. When the air-flow and spin are in opposite directions, the air moves slower.

This causes a pressure difference - pushing the ball towards the area where the air is moving faster.

This causes the football to curl. Depending on the wind direction, the football can curl to the left or to the right.


Good article on how to kick the football so that it starts to spin:

The same principle applies to an old cricket ball as well. It is called reverse swing in cricket and happens with an older ball - where one side of the ball is rough and other side is smooth. Air flows faster on the smoother side, and due to friction it flows slower on the rough side. This causes the pressure difference and brings Bernoulli's principle into action.

Now you know why cricketers are not allowed to take sandpaper or other sharp objects onto the field.

Manomay Shravage

When we kick the ball a side of it gets compressed and after some time the air once again fills the space up.