Theodore von Karman, a Hungarian physicist, spent much of the first decade of the 1900s trying to figure out why certain things — airplane wings, bridge supports, buildings, and submarines — would suddenly and Karman Vortex spontaneously begin to vibrate. The vibration, once started, would often amp up and up until the entire structure would spin out of control or fall apart. This, understandably, was a major problem. This was subsequently dubbed the Karman Vortex
Karman’s first insight was that the closer to cylindrical the object’s shape was, the more it tended to vibrate. His second insight led him to turn away from the actual object and toward its medium. And after looking at the medium that moved over these objects, he noticed something.
Aerodynamics are at their best when the air (or any gas, or liquid) flows neatly around the object, conforming exactly to the object’s shape. This is why wings open with a curve and taper off behind, parting the air quickly but letting it flow over the curves and break away from the wing going pretty much directly back. By sending air streaming directly back, the object gets a push directly forward. Of course wings divert the air slightly down, giving the plane a slight lift, as well, but they still give the air an orderly path to follow.