Relativity and the Dimensionality of the World: Spacetime Is Real

Summary

By addressing the question of dimensionality of objects involved in relativity of simultaneity, length contraction, and time dilation, it has been shown that the presentist view can avoid a direct contradiction with relativity if the existence of those objects is regarded as ontologically relativized. However, even this relativized version of presentism contradicts relativity, as shown by the analysis of the twin paradox in Sect 5.5. Therefore the only view that is consistent with relativity is four-dimensionalism.

It has also been shown that a number of fundamental issues such as conventionality of simultaneity, change, passage, temporal becoming, flow of time, consciousness, and free will look completely different in three-dimensional and four-dimensional worlds. This means that the question of the nature of spacetime precedes those issues and for this reason should be resolved first.