SEMINAR      Thursday, 30 September 2004 - h. 15:00  Aulditorium B. Touschek     G. Rajalakshmi (Bangalore) Torsion Balance Experiment to Study Casimir force Abstract The presence of finite energy in quantum vacuum has profound implications to physics at the microscopic and macroscopic levels. In particular, a pair of infinite planar conductive plates placedin vacuum separated by a distance d, imposes boundary conditions on the fluctuating vacuum fields. This leads to a force between the plates, first proposed by H B G Casimir in 1948. Experiments to measure Casimir force have been carried out since the 1950s. These experiments explore the submicron to submillimeter distance scales in order to study quantum vacuum and also provide constraints for unification theories that predict new macroscopic forces at these distance scales. In this talk I present an overview of our experimental efforts to study Casimir force using a torsion balance in the 1 - 10micron range.