From Process to Duration: Periodic Process Realism and the Physical Grounding of Metric Time

Abstract

This paper defends Periodic Process Realism (PPR): the view that metric time is physically grounded in stable recurring processes rather than in an independent temporal container or in spacetime geometry alone. The thesis is realist—periodicities exist independently of observers—but anti-substantival: no further temporal medium is required beyond the processes that furnish temporal metric. PPR is orthogonal to the A-theory/B-theory debate about temporal ontology; it instead challenges the standard Eternalist assumption that metric temporal structure is given by geometry without reference to the physical processes through which it becomes determinate. The argument distinguishes temporal order, temporal metric, temporal direction, and lived temporality, and locates periodicity specifically at the metric layer. Four lines of support are developed. First, modern chronometry and metrology define and stabilize temporal units through recurrent phenomena, and the corrective apparatus of metrology reveals an asymmetry between convention and physical periodicity. Second, a conceptual argument bridges measurement and ontology: stable recurrence is not merely how we measure metric time but a physical grounding condition for metric comparability. Third, a universal-acceleration thought experiment shows that background temporal frameworks do no explanatory work unless physically realized in processes. Fourth, the view is compatible with relativity and with relational approaches to time in quantum theory. Objections concerning non-periodic duration, thermodynamic directionality, Shoemaker-style time without change, Bergsonian durée, and the first-completed-cycle problem are addressed. The result is a layered account of temporality: physical process supplies temporal order, stable periodicity supplies the temporal metric, thermodynamic entropy supplies the arrow of time, and consciousness supplies lived temporal experience.

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