Unmanned aircraft: game of drones

DEEP in the bowels of the engineering building at Oklahoma State University, Ben Loh flips a switch on a remote control. A rotor starts whirring and a white sphere the size of a large beach ball rises.

DEEP in the bowels of the engineering building at Oklahoma State University, Ben Loh flips a switch on a remote control. A rotor starts whirring and a white sphere the size of a large beach ball rises.