California Institute of Technology

the highest point on campus. According to tradition, a claim was once made that the shattering of a pumpkin frozen in liquid nitrogen and dropped from a sufficient height would produce a triboluminescent spark. This yearly event involves a crowd of observers, who try to spot the elusive spark. The title of the event is an oblique reference to the famous Millikan oil-drop experiment which measured e, the elemental unit of electrical charge.
On Ditch Day, the seniors ditch school, leaving behind elaborately designed tasks and traps at the doors of their rooms to prevent underclassmen from entering. Over the years this has evolved to the point where many seniors spend months designing mechanical, electrical, and software obstacles to confound the underclassmen. Each group of seniors designs a "stack" to be solved by a handful of underclassmen. The faculty have been drawn into the event as well, and cancel all classes on Ditch Day so the underclassmen can participate in what has become a highlight of the academic …