The evolution of the skyscraper and a look at how high buildings can become. The role that steel is described, and how steel frames have played a part, the elevator's role in the ""face for the sky"", the challenge that wind presents, making a building flexible, and what stops us from building skyscrapers that exceed today's tallest ones. The physical properties of earth materials are shown. Mass, energy, and momentum, elastic and inelastic collisions, force and motion, and technological design.