Watch Air Swirl Around a Quadcopter Drone's Rotors

If you're the type of person who throws rocks at drones, or if you've ever shot one out of the sky with a shotgun because it invaded your airspace, I have some bad news for you--other than your pending civil lawsuit. Drones will be everywhere soon. Just imagine all that infuriating bvrrr and wrrr and weeeeer. But theoretically, drones don't have to be so loud. As designers improve their understanding of drone aerodynamics, they have the potential to quiet the machines down and make them more efficient by reducing turbulence.