The Theory of Relativity and the Reality of Time

Abstract: The introduction of the special and general theory of relativity had significant implications for the notion of time, especially the relativity of clock time. Many physicists and philosophers concluded that the theory also showed that time was unreal and that the universe was a four-dimensional block universe. The argument focussed on particular aspects of the theory – relative simultaneity and general covariance, respectively– to arrive at this conclusion. But while it is true that views about time can be inferred from the theory of relativity, the unreality of time is not a deductive consequence of the theory. It is therefore possible to ask whether the theory is compatible with the reality of time. If invariant features of the theory are taken into account, - the space-time interval ds and entropic relations - as will be argued in this paper, a dynamic notion of time emerges as a philosophical consequence of the theory of relativity. This paper defends a Heraclitean, dynamic view, against the predominant Parmenidean, static view of time.