Armored with safety glasses, hearing protection, and a fire-retardant lab coat, fire researcher Emma Veley carefully cradled a frying pan of raw bacon into a laboratory surrounded by wires and sensors. Mounted on the ceiling above, 12 smoke detectors waited patiently in a neat row. Veley closed the door behind her, placed the pan on a hot plate, and turned up the heat. Watching her through a large window in the next room, Amy Mensch started a timer and monitored the computer readouts that would show exactly when each alarm would “smell the bacon.”