This paper constructs a pure inertial frame thought experiment with uniform linear motion throughout, free of acceleration, turnaround, and gravitational interference. Strictly following the core principles of special relativity and eliminating all interfering physical variables, it analyzes the interpretive contradictions of time dilation layer by layer in a minimalist spacetime observation scenario. Based on the equivalence of inertial frames and the deduction of time dilation, the experiment yields the result that between equivalent inertial frames, mutual observation shows each other’s time flow is slowed down. To resolve this contradiction, special relativity uses the relativity of simultaneity to attribute bilateral time dilation to a reference frame measurement artifact, yet recognizes time dilation as an objective physical reality in comparable experimental scenarios. The core stance of this paper is: special relativity does not provide a consistent and unified physical picture of spacetime; mere conceptual distinctions cannot resolve the intuitive contradictions at the observational level. Moreover, experiments such as particle lifetime extension manifest real physical effects that cannot be fully explained by the theoretical division between proper time and coordinate time. Further, from the perspective of scientific falsifiability, bilateral time dilation in a never-meeting pure inertial scenario can be neither experimentally verified nor falsified. Relativity achieves self-consistency by artificially defining clock-comparable = real and non-clock-comparable = apparent, rather than relying on objective physical evidence. This paper fully presents this two-level progressive core conflict, reveals the inherent tension and double standard in the interpretation of spacetime reality in special relativity, and provides a powerful critical framework for reflecting on the theoretical foundation of relativity based on principles of scientific philosophy.
jingkai cheng (Fri,) studied this question.