The Non-Substantiality of Time: An Argument Based on the Criterion of Physical Reality

This paper proposes a core criterion for physical entities: an existence is a physical entity if and only if it can participate in energy transfer, information exchange, or causal interactions "in the present moment" and possesses a non-zero physical carrier. Based on this criterion, combined with the spacetime description of relativity and experimental conclusions from quantum mechanics and thermodynamics, this paper analyzes the ontological status of the "past," "present," and "future." The study finds that the "past" is information encoded in current entities (neural structures, rock molecules, detection devices, etc.), while the "future" is a probabilistic trend based on the current physical state; neither can independently participate in present interactions. Only the material motion and entity interactions of the "present" have fundamental physical reality. "Time" is not an independently existing physical container, but a derived concept describing the order and rhythm of changes in material motion states. Its mathematical expression (such as the relativistic spacetime metric) is essentially a simplified model of material motion correlations. This view provides a new perspective for resolving time ontological paradoxes and reconstructing the foundational framework of physics.