Learn the principles that make this flying stick return to sender.
A boomerang is basically a single-winged aircraft propelled through the air by hand. Boomerangs have two ‘wings’ joined in a V-shape. Both wings have an airfoil-shaped cross-section just like on aircraft wing. An airfoil is flat on one side but curved on the other with one edge thinker than the other – this helps the boomerang stay in the air due to lift.
Lift is generated as the air flowing up over the curved side of the wind has further to travel than the air flowing past the flat side. The air moving over the curved surface must therefore travel quicker in order to reach the other edge of the wing.
Because the two sides of a boomerang have different air speeds flowing over them, as it spins the aerodynamic forces acting upon it are uneven. This causes the section of the boomerang moving in the same direction as the direction of forward motion to move faster through the air than the section moving in the opposite direction. These uneven forces make the boomerang start to turn in and follow a circular route, eventually heading back to the thrower.