Matter-Energy Cycles in a Finite Volume: An Unvalidated Concept Note

This two-page concept note records Zhongji Ma's proposed cyclic exchange between non-rest-mass energy and the rest energy of matter in a fixed finite volume. It specifies a triangular-wave exchange function, a separate volume-partition rule, conservation of the volume-weighted mean energy density, and a density-threshold switching rule. The switching rule yields a periodic trajectory within the stipulated model. A finite numerical example illustrates how a small occupied volume can have high local density while the total mean energy density remains fixed. Status and limitations: Unvalidated and not peer reviewed. Fixed volume, phase partition and reversal thresholds are assumptions. The proposed links from maximum density to maximum hardness or gravitational effect and then to reversal remain hypotheses. No microscopic mechanism, entropy evolution, experimental data or gravitational dynamics is established. The note does not demonstrate cosmic recurrence or a new physical law.