Back to the Future.

This article reports on an October 7 to 9, 2004, gathering of 150 leading physicists at the University of California at Santa Barbara to speculate on the future of physics. Commemorating the 25th anniversary of the school's Kavli Institute for Theoretical Physics, they looked back at the past quarter of a century of physics and ahead to what will happen in the next. The speakers leaned heavily toward the theory side of the aisle, but an experimental device figured prominently in several talks: the Large Hadron Collider (LHC) at CERN, the European center for particle physics near Geneva. Nima Arkani-Hamed of Harvard University suggested that the LHC could reveal evidence of far stranger physics, such as that of the string theory "landscape" in which our universe is one small patch of a much larger multiverse. INSET: QUESTIONS FOR ANOTHER TIME.