SupertallWe are living in a new urban age, and its most tangible expression is the supertall: megastructures that are dramatically bigger, higher, and more ambitious than any in history. Cities around the world are racing to build the first mile high building, stretching the limits of engineering and design as never before. In this fascinating work of urban history and design, TED resident Stefan Alhimself an experienced architectexplores the factors that have