Epistemology in Cyclic Time
  Consider the scenario, in which human civilization undergoes periodic eras of progression and regression, and consequently, changes in cosmological knowledge are cyclic. There exist solutions of general theory of relativity, such as the G\"{o}del universe, in which the cosmos is rotating. If the real universe is indeed rotating, than this would be a reversion to rotating universe models, used in ancient cosmological models. We argue that such reversions in physical models would be inevitable in a space-time in which time is having $S^1$ (circular) topology. 
Moninder Singh Modgil