Even though the subject has been dead for a while, there are still people who peek here so I thought I'd give a hand to those still looking. In so called telegraphical shortcut:
Bernoulli's Principle
What do jet airplanes and a baseball pitcher's curveball have in common? They both depend on Bernoulli's principle for their operation. Bernoulli's principle states that the faster a fluid (such as air or water) flows over a surface, the less pressure the fluid exerts on that surface.
In the case of the jet airplane, air travels faster over the top of the wing than across the bottom of the wing. Since the pressure on top of the wing is reduced, the airplane is pushed upward. A pitcher can cause a baseball to curve by making it spin. On one side of the ball, air carried along by the spinning ball rushes past in the same direction the ball is traveling. On the other side of the ball, air is pushed in the opposite direction. On the side of the ball where air is traveling faster, pressure is reduced. Higher air pressure on the opposite side of the ball pushes it out of a straight path, causing it to curve.
Read more:
http://www.scienceclarified.com/A-Al/Ae ... z3AkL1oMiz