On December 7, instructors shot off the traditional confetti cannons to mark the end of this year’s 2.009 Product Engineering Processes class. There was certainly plenty to celebrate. Student teams had just finished giving their final presentations, which featured demos of the eight prototypes they’d thought up, designed, built, tested, and polished over the course of the semester. In keeping with the 2015 “magic” theme, the new products they created included a hands-free door opener for toilet stalls, a safety device for climbers and cavers (demonstrated by a pair of climbers rappelling down from the ceiling in Kresge), a device that helps blind people learn Braille, an automated theater spotlight, and a kite-shooting game involving sensors and lasers. This year marked the 20th that David Wallace has led the storied class in mechanical engineering. Known for his willingness to don crazy costumes in the classroom (he’s been everything from Richard Simmons in a sparkly tank top and silky shorts to a princess in a blond wig), he sported a top hat and tails for the occasion.