DescriptionBrad Call judges an electric marble sorter (17182097775).jpg
Brad Call, a design chief with the U.S. Army Corps of Engineers Sacramento District, listens to Marissa Mavy explain her marble sorter project at Folsom High School's Eighth Annual Engineering Challenge April 17, 2015, in Folsom, California. Student projects included: hovercrafts, catapults, Tesla coils, electromagnetic propulsion devices, pneumatic wind turbines, hydrogen fuel cells, solar electric boats and cars, gene transformation, and orthopedic implants. (U.S. Army photo by Todd Plain/Released)