This article presents a logical critique of the concept of spacetime in Special Relativity (SR). Through a thought experiment involving a physical object observed from two inertial frames, we highlight the contradiction between a single objective reality and the observer-dependent spacetime intervals that follow from the Lorentz transformation. Physically, spacetime is defined as a four-dimensional structure in which space and time are unified, yet mathematically the spacetime interval depends on the choice of coordinate system. Logically, this implies that a single object is ascribed multiple simultaneous extensions in spacetime, which conflicts with the requirement of a single objective physical reality. The analysis suggests that spacetime, as defined in SR, cannot be interpreted as an objective property of physical reality but functions as a relational construct dependent on the observer.
Jan Slowak (Wed,) studied this question.