University of Virginia associate professor Kamin Whitehouse thinks people want to know where everyone is in their house: Who’s taking the long shower? Who left the air conditioner on when they left the house? “Today’s smart home sensors are about appliances, lights, and devices in the home, but not really about the people,” said Whitehouse. “By demonstrating the exciting things that become possible when a home better understands the people who live there, we hope to inspire a new generation of products and technologies.” To make his point, Whitehouse outfitted four Charlottesvile, Virginia, homes with sensors to track who enters what room, and what appliances and utilities that person uses. The data is then beamed up to the cloud and back down to a smartphone app named the “Marauder’s Map.” Harry Potter fans will recognize the reference to “The Prisoner of Azkaban,” in which Harry uses a magic map to track the footsteps of characters and unlock the mysteries of his school.