Relativity and the Dimensionality of the World: Spacetime Is Real

In the two previous chapters we have been following the radical research team in their analysis of Galileo’s principle of relativity. Its members employed an improved version of Galileo’s method of scientific enquiry and managed not to be bothered by the counter-intuitive nature of their conclusions. Now we know that the predictions derived by the radical research team to test the reality of spacetime coincide with the predictions of special relativity. Experiment has confirmed all consequences of special relativity, but few physicists and philosophers have regarded that confirmation as a proof of the existence of spacetime.

In a perfectly determinate scheme the past and future may be regarded as lying mapped out – as much available to present exploration as the distant parts of space. Events do not happen; they are just there, and we come across them.

A. S. Eddington [28, p. 51]