Portland State University drop tower defies gravity
Mark Weislogel, a mechanical engineering professor, describes Portland State University's new drop tower to physics students from Tualatin High School. The tower, one of three in the nation, is used to create nearly weightless conditions for objects in a 400-pound metal canister that is dropped five stories. High speed video cameras record experiments as they are subjected to zero gravity for about two seconds while the canister falls. Read more