Principles of Flight	(2/7)
Objects fly because of pressure difference.

Have you ever noticed how a golf ball arcs upwards? When hit with a big club like a 1 wood, it starts off relatively low, and as it gathers distance and slows down, it starts to arc upward into the sky. Then its spin slows, and it descends. Why?

A golf ball arcs up into the sky, because it spins backwards. Yes but how exactly does it accomplish this paradoxical feat? Observe the cogs in a classical mechanism. To make the system move to the right, the big purple cog must spin in which direction? Clockwise or counterclockwise? Clearly to get the black wheel cogs moving clockwise, the larger suspended cog must spin in the opposite direction. This is what the golf ball does too.

What happens is that the dimples on the golf ball play the same role as the teeth in the cogs. If the golf ball had no dimples and the cog had no teeth, they would lose traction. The dimples cause tiny pockets of spinning air to form; the spinning of these vortices, forces the air outwards away from the center of each vortex, lowering the pressure inside. The vortices of air assume the shape that the flying object forms them into. By spinning backwards, the golf ball spins the low pressure vortices forwards, giving lift and forward momentum at the same time. The golf ball rolls over these pockets, like a person walking on a barrel or slipping on marbles, or a clown walking on a ball. Just like the cog. As the ball starts its flight some of its forward momentum is lost, converted into the vortices of low pressure air. As it loses this forward momentum, it increases its upward momentum, actually soaring at a higher vertical velocity than when it started its journey. This is because that forward moving energy has now become upward moving energy. Without dimples, the ball would not do this quite so effectively. It would meander like a smooth bubble does. This flying process is much more stable in the golf ball because of the diimples, giving extra lift, and even counteracting wind. If you wanted to make heavy weather golf balls, make the dimples slightly bigger. Less distance, but more accuracy.