Leo Seren, aged 83, died January 3, 2002, in Evanston, Illinois. The son of Russian-Jewish immigrant parents, Mr. Seren entered the University of Chicago on a scholarship. The day after he received his Ph.D. in physics in 1942, he began work on the Manhattan Project. Although he worked at Los Alamos, New Mexico, and the Argonne National Laboratory, Mr. Seren turned against any military use of nuclear power. He then focused on renewable energy sources such as solar, wind and water power. He enjoyed classical music, especially Bach, and nature. He marveled at the beauty of autumn leaves and the structure of sunflowers. He had many adventures flying his plane throughout the world. A member of the Club since 1958, he presented seven papers.