character in many of his books: a scientist, Dr. Nera Vivaldi, frequently appeared in the role of a friend to the reader. Seemingly ageless, she appears in stories set in many different time periods, including those that take the reader into outer space. In Hyperspace, Dr. Vivaldi breaches the fourth wall by acknowledging that she is a fictional character whom the reader may recognize from having read other CYOA books. Beginning in 2012, Simon & Schuster released revised and expanded print versions of selected Packard CYOA stories: Through the Black Hole, Return to the Cave of Time and The Forbidden Castle, under the trademark “U-Ventures.” Packard conceived the idea for three more interactive series, and wrote the prototype books. The series were Space Hawks and Escape (both published by Bantam Books), and Earth Inspectors, published by McGraw Hill. He also wrote a non-fiction book about the size and scale of space and time, titled Imagining the Universe, which was published by Berkley in 1994. It was cited by Scientific American as one of the best science books for young readers of the year and by National Public Radio as one of the best science books of the year. His educational math book Big Numbers, published by Millbrook in 2000, was cited by Newsweek as one of the best children's books of the year. The six books in the Space Hawks series, which focuses on Earth's defense against space aliens, were published in mainland China in 2004 in anticipation of China's first crewed space mission. Books Tenopia Island (Escape from Tenopia, Book 1) – May 1, 1986 Choose Your Own Adventure: Vol 1 Choose Your Own Nightmare 2: Beware the Snake's Venom Deadwood City Supercomputer Book applications In 2010, Packard started a new company called U-Ventures, which began releasing Choose-Your-Own-Adventure-style applications for iPhone and iPad based on some of Packard's books. The first title, "Return to the Cave of Time" was released in August with more titles planned shortly after. References External links 1931 births Living people Princeton University alumni Columbia Law School alumni Choose Your Own Adventure writers American male writers