Savas Dimopoulos is a theoretical physicist widely known for proposing (with Howard Georgi) the supersymmetric extension of the standard model of particle physics, the self-contained picture of fundamental particles and their interactions. His theories about the supersymmetric unification of the strong and electroweak forces, first published in 1981, were subsequently confirmed by experiments at the Stanford Linear Accelerator Center and CERN. Dr. Dimopoulos’s and Dr. Georgi’s prediction of the presence of “superpartners” of each of the fundamental particles will be tested at CERN’s Large Hadron Collider beginning in 2007. More recently Dr. Dimopoulos (with Nima Arkani-Hamed and Gia Dvali) made the startling suggestion that the extreme weakness of gravity can be attributed to the existence of large extra dimensions of space, perhaps as big as a millimeter, where the scale at which gravity becomes comparable to other forces is lowered to the electroweak scale. Among the implications of his thinking is the notion that our universe is a three-dimensional island floating inside a fourth dimension—a membrane called a D-brane—and but one of innumerable parallel universes. Motivated by his consideration of the anthropic principle, he has recently proposed (together with Nima Arkani-Hamed) the theory of split supersymmetry, which also will be tested at the Large Hadron Collider in two years. A native of Athens, Dr. Dimopoulos was graduated from the University of Houston and received his Ph.D. in physics from the University of Chicago in 1978. He did post-doctoral work at Columbia University and joined the Stanford faculty in 1979. He also has taught at Harvard and served as a visiting professor at the University of California, Santa Barbara, and Boston University. From 1994 to 1997, he was a staff member at CERN. The recipient of an Alfred P. Sloan Foundation Fellowship and a Distinguished Alumnus Award of the University of Houston, Dr. Dimopoulos is a fellow of the Japanese Society for the Promotion of Science. He is the author of 147 scientific papers.