To fully understand what makes a boomerang work, it is necessary to understand the basic principles of lift and flight as well as two other laws of physics.
Lift is important because a boomerang is simply two airplane wings joined in the middle.
The other two principles involve the spinning of the boomerang and how that spinning creates the return. Aborigines are credited with the invention of the returning boomerang and the oldest one found in Australia is around 14,000 years old. The best theories surrounding the subject are that returning boomerangs accidentally evolved from the non-retuming hunting throw sticks. Boomerangs are a wonderful fusion of Stone Age man and Space Age Technology. For every action there is an equal and opposite reaction.