It's not accurate to say a single person "invented" the theory of aerodynamics. It's a complex field that developed over centuries through the work of many individuals. However, here are some key figures and milestones in the history of aerodynamics:

* Ancient Greeks: Philosophers like Aristotle had rudimentary ideas about air resistance.

* Leonardo da Vinci (1452-1519): Da Vinci made detailed sketches of bird flight and designed flying machines, demonstrating a keen understanding of aerodynamic principles.

* Sir Isaac Newton (1643-1727): Newton's laws of motion and gravity formed the foundation for understanding the forces acting on objects in motion, including air.

* George Cayley (1773-1857): Cayley is often called the "father of aeronautics" for his experiments and theoretical work on lift and drag, and for outlining the basic principles of heavier-than-air flight.

* Otto Lilienthal (1848-1896): Lilienthal was a pioneer of glider flight. His work on wing design and stability contributed greatly to the understanding of aerodynamics.

* The Wright Brothers (1867-1912, 1871-1948): While not specifically "inventing" aerodynamics, the Wright brothers' experiments and breakthroughs in flight control and wing design advanced the field significantly.

Key developments in the 20th century:

* Ludwig Prandtl (1875-1945): Prandtl developed the boundary layer theory, which revolutionized the understanding of how air flows over surfaces.

* Theodore von Kármán (1881-1963): Kármán made significant contributions to supersonic aerodynamics and rocket propulsion.

Aerodynamics is a constantly evolving field, and modern advancements continue to refine our understanding of air flow and its effects on objects.