SCOTT RITTER, former UN weapons inspector in Iraq, to speak at Caltech on "Understanding the Roots of Terrorism: Iraq as a Case Study" at 8 p.m. in the Beckman Auditorium on the Caltech campus. The Beckman Auditorium is located near Michigan Avenue south of Del Mar Blvd. Parking is available in the lots south of Del Mar Blvd. between Wilson and Chester Ave., and in the Wilson Ave. parking structures between San Pasqual St. and Del Mar Blvd. The lecture is part of the Social Activism Speaker Series at Caltech. For info contact Greg Fletcher, Caltech Y, 626-395-6163