Abstract
The topic is whether the 4-dimensional structure constitutes a proven theory and whether it completely and effectively describes space-time phenomena. Spacetime is almost universally assumed as the basic structure for physical and cosmological thinking. Its meaning lies in the fusion of time and space into a unified entity. In the paper, the theoretical foundation and mathematical formalism are analysed. The theory is confirmed by an impressive quantity of experimental verifications. However, reasons for reflection emerge, starting from the one-way unidirectionality and irreversibility of time. The conclusion is that on space and time we know little, in the state, to be able to affirm a definitive and testable theory. Further research is necessary on what is very often considered indisputable.Finally, it doesn't seem sustainable that Special Relativity, supplemented by general Relativity, constitutes a complete and definitive theory of spatiotemporal relations.