Nearly every empire worthy of the name—from ancient Rome to the United States—has sought an Egyptian obelisk to place in the center of a ceremonial space. Obelisks—giant standing stones, invented in Ancient Egypt as sacred objects—serve no practical purpose. For much of their history their inscriptions, in Egyptian hieroglyphics, were completely inscrutable. Yet over the centuries dozens of obelisks have made the voyage from Egypt to Rome, Constantinople, and Florence; to Paris, London, and New York.
Janos Bolyai (1802-1860) was a mathematician who changed our fundamental ideas about space. As a teenager he started to explore a set of nettlesome geometrical problems, including Euclid's parallel postulate, and in 1832 he published a brilliant twenty-four-page paper that eventually shook the foundations of the 2000-year-old tradition of Euclidean geometry.