A ball moving through air experiences two major forces: lift and drag. Drag slows the forward motion, whereas lift acts in a direction perpendicular to it. The magnitude of these forces depends on the behavior of the boundary layerThe boundary layer is the layer of fluid in the immediate vicinity of a bounding surface. In the atmosphere the boundary layer is the air layer near the ground affected by diurnal heat, moisture or momentum transfer to or from the surface. On an aircraft of air moving with the ball surface.

Every modern golf ball has dimples; their purpose is to increase and shape the lift and drag forces by modifying the behavior of the boundary layer. It should be noted that drag and lift forces exist also on smooth balls: they are only modified, not created, by dimples.

One effect of dimples is a reduction of drag, contributing to the increased length of flight of dimpled balls compared with smooth ones.

A spinning ball deforms the flow of air around it, thus acting similar to an airplane wing. Backspin is imparted in almost every shot due to the golf club’s loft (i.e. angle between the clubface and a vertical plane). A backspinning ball experiences an upward lift force which makes it fly higher and longer than a ball without spin would. Sidespin occurs when the clubface is not aligned perpendicularly to the direction of swing, leading to a lift force that makes the ball curve to a side. These lift forces are further increased through the presence of dimples.

QI Supposedly to testify or give testimony is to actually swear by ones bollocks, as in “may my bollocks be removed if I give false witness.”

Wether any gonads were actually ever removed is a matter of debate.

(Women obviously were not allowed to give evidence and the evidence of slaves was only admissable if obtained or confirmed after torture)