In The Structure of Scientific Revolutions, Kuhn argues that scientific activity falls into two distinct phases:
- Normal science, which is similar to puzzle-solving; problems that science cannot solve are dismissed as peripheral.
- Revolutionary, in which the assumed peripheral problems are realized to be deep, leading to a collapse and reimagining of the science’s paradigm—basic values, methods, and commitments of the science.
Historical examples include:
- The transition from Ptolemaic cosmology (i.e., the geocentric model of the universe) to Copernican cosmology;
- The transition from Newtonian mechanics to relativity.