Why are so many giraffes gay? Has human evolution stopped? Where did our alphabet come from? Can robots become self-aware? Can lobsters recognize other lobsters by sight? What goes on inside a black hole? Are cell phones bad for us? Why can't we remember anything from our earliest years? Full of the mysteries of life, the universe, and everything, this is a fascinating and unputdownable exploration of the limits of human knowledge of our planet, its history and culture, and the universe beyond.