For author Thomas Kunh, the normal view of science as a linear and cumulative set of scientific knowledge is a mistake. He argues that there are paradigm breaks throughout history. For the author, a scientific paradigm is a set of theories, knowledge, methods, and values about what science, knowledge, and scientific research are, accepted by the scientific community. Thus, the paradigm has explanatory power to account for phenomena, but the moment a certain number of anomalies occur (that is, phenomena that the paradigm cannot explain), it has exhausted its explanatory power and a crisis occurs. Thus, the period of normal science with a current paradigm is followed by a period of crisis and the advent of a new paradigm that does explain more phenomena. A clear example of this is the transition from egocentrism to heliocentrism.