The Last Theorem was a collaboration of Arthur C. Clarke (90 years old) and Frederick Pohl (89 years old), two 
greats from the world of science fiction. Unfortunately, The Last Theorem was not great and not even that good. It is a story in the near future that follows the mathematician Ranjit Subramanian who supposedly proposed a simplistic proof of Pierre de Fermat's last theorem. Within the story of the life of Subramanian, a resident of Sri Lanka, he is captured by pirates and encounters space aliens who come to earth. In this book you will see many of Clarke's interests including a space elevator, solar sailing, omnipotent aliens, AI and computerized immortality, and the achievement of world peace. If you read this book knowing that it is not up to the level of most of Clarke's previous books, you will better enjoy this fantastic tale.