What is a human? What is a machine? From artificial retinas to artificial intelligence, science and technology are beginning to blur the distinction between the two. In this program, ABC News anchor Ted Koppel and correspondent Robert Krulwich talk with Michael Schrage, of the MIT Media Lab; engineer and inventor Danny Hillis; inventor Ray Kurzweil, author of The Age of Spiritual Machines; professor of cybernetics Kevin Warwick, reputedly the world’s first true cyborg; and others about the present state of human/machine hybrids—and future advances that may lie just over the horizon. (45 minutes)