In 1962, the historian of science Thomas Kuhn published a short book that changed how educated people think about intellectual progress. The Structure of Scientific Revolutions argued that knowledge does not advance through the steady accumulation of better facts. It advances through ruptures—moments when a prevailing framework, or paradigm, collapses under the weight of anomalies it cannot explain, and a new one takes its place. The Ptolemaic model of the solar system gave way to the Copernican.