artnet interviews Rafael Lozano-Hemmer, artist of OPEN AIR, an interactive public art installation for Philadelphia. Commissioned by the Association for Public Art, OPEN AIR will be running nightly from September 20 to October 14. Using a free mobile app developed by Lozano-Hemmer’s studio, participants’ voices and GPS positions will control 24 powerful robotic searchlights placed along a half-mile section of the Parkway – creating giant three-dimensional “light sculptures.”