Robert Silverberg is a prolific American author and editor, best known for writing science fiction. He is a multiple winner of both Hugo and Nebula Awards, a member of the Science Fiction and Fantasy Hall of Fame, and a Grand Master of the Science Fiction Writers of America. Alvaro Zinos-Amaro is the co-author, with Silverberg, of a new science-fiction work, When the Blue Shift Comes, told in two novella-sized parts.