George Constable is a freelance writer and editor with a longstanding interest in science and technology. For Time-Life Books and Discovery Books, he has contributed to volumes about spaceflight, computers, health, and the environment. He is the author of 11 books on subjects ranging from prehistoric humans to the modern Olympic Games.
Bob Somerville worked for 20 years at Time-Life Books, writing and editing books on a wide variety of subjects, including archaeology, astronomy, computers, human physiology and psychology, and history. He now works as a freelance writer and editor based in Forest Heights, Maryland.