Mass Defines Reference Frame: From Mach's Principle to the Minimum Inertia Unit — A Self-Consistent Deduction within TFT

This paper is a natural extension of the core proposition of Time Field Theory (TFT) that “mass is the observer”. Starting from a long-neglected physical fact in the classical principle of relativity—reference frames are not arbitrarily selected in a finite many-body system but are uniquely determined by mass distribution—we rigorously deduce that the subsystem with the dominant mass possesses the discourse power to define the reference frame of the entire system. We further demonstrate that this conclusion provides an accurate physical mechanism for Mach’s principle: inertia is not an intrinsic property of an object, but the resistance of an object against the local time benchmark defined by the most massive source within its system. The Planck constant ħ is revealed as the minimum inertia unit, namely the minimum mass proportion eligible to participate in reference frame weight distribution, whose physical origin corresponds to the minimum existent area of biaxial phase space. The uncertainty principle is no longer treated as an independent fundamental axiom, but an inevitable consequence arising from the fact that the minimum inertia unit cannot furnish deterministic reference criteria. All derivations in this paper are strictly self-consistent with the established axiomatic system of TFT, without introducing any additional hypotheses.