A wing is not a "suction machine." The low pressure on top is caused by the air following a curved path. For a fluid parcel to move in a curve, there must be a net inward force (centripetal force). That force comes from a pressure difference: lower pressure toward the center of curvature. The top of the wing is the center of curvature, so pressure drops. Section 4: The Circulation Explanation (The Mathematically Honest Version) In advanced physics, we use circulation (Γ). This is not a fiction; it is a measurable quantity: the line integral of velocity around a closed loop enclosing the wing.

Understanding Aerodynamics: Arguing from the Real Physics

Moving beyond "equal transit time" and other convenient fictions.