Michio Kaku, professor of theoretical physics and co-founder of string field theory, is the author of nine books, including the best-selling "Hyperspace: A Scientific Odyssey Through Parallel Universes, Time Warps, and the 10th Dimension," and most recently, "Visions: How Science Will Revolutionize the 21st Century." His doctorate-level textbooks are required reading at top physics labs worldwide.