The success of soccer player Christiano Ronaldo’s powerful “knuckleball” strike is due to fluctuating aerodynamic lift forces.

Kicking a soccer ball in the knuckleball style means it travels with a very low spin with sideways movement on its way towards goal.

It was previously thought that this lateral movement was caused by the way the player’s foot connects with the ball or the structure of the ball itself.

But new research reveals this lateral movement can be observed under other conditions, such as by dropping steal beads into tanks of water.