Why does a wing generate wing tip vortices when generating lift?

The correct answer is: **Because of the pressure difference between the upper and the lower surface, together with the fact that the wing is finite.**

When a wing generates lift, there is a pressure difference created between the higher pressure air below the wing and the lower pressure air above the wing. For a finite wing (as opposed to an infinite wing), this pressure difference causes the high-pressure air to flow around the wingtips toward the lower pressure areas above the wing. This flow creates swirling motions in the air at the wingtips, known as wingtip vortices. These vortices are a byproduct of lift generation and are indicative of the energy lost to frictions and turbulence around the wing's edges.