Diameter of the Circumscribed Hypersphere of a Unit Four-Dimensional Hyperrectangle — Spacetime Dimensionality, the Origin of Time, and the Beginning of the Universe as Derived from a Discrete Packing Model

English: A purely mathematical thought experiment. Starting from two assumptions — discreteness and the existence of stable minimal units — and the principle of volume conservation, we deductively derive: (1) n = 4 as the minimal non-trivial dimension where √n is an integer; (2) a 1-versus-3 asymmetry from single-axis reversal of signed volume, structurally analogous to the Minkowski signature (−,+,+,+); (3) the possibility of expansion from a zero-volume initial state without violating conservation; (4) time as an emergent order from statistical alignment of reversal axes. All cosmological language (Big Bang, matter, antimatter, etc.) is metaphorical. This paper makes no physical claims, no empirical predictions, and no assertions about the actual universe. 日本語: 純粋に数学的な思考実験。離散性と安定な最小単位の存在という2つの仮定、および体積保存則から、(1) √nが整数となる最小の非自明次元としてn=4、(2) 符号付き体積の1軸反転によるミンコフスキー計量の符号構造(−,+,+,+)との構造的類似、(3) 体積ゼロからの保存則を破らない展開の可能性、(4) 反転軸の統計的整列としての時間の創発を演繹的に導出する。宇宙論的用語(ビッグバン、物質、反物質等)はすべて比喩である。物理的主張・実証的予言・現実の宇宙に関する断言は一切含まない。