The Observable Now on the Spiral

A mid-series synthesis separating what has been metrically pinned about "the present" from what remains to measure. Two presents: the point-present (Δθ=0, an unreachable boundary at every scale) and the observable now (Δθ=π/2, the Margolus–Levitin quarter-turn), derived from antipodal orthogonality e^{iπ}=−1 with the mean-energy clock at the midpoint, so the orthogonality point is e^{iπ/2}=i. The quarter-turn and the k_B ln2 registration cost are scale-invariant; the duration of the now scales (~100 as at the atomic floor, the Planck time at the limit). The ladder's ends mirror across 123 orders of magnitude in entropy: atomic floor (S~k_B, T~10^5 K, ns, inward) vs de Sitter ceiling (S≈3.3×10^122 k_B, T≈2×10^-30 K, never reached). Simultaneity has measure zero — a shared present needs zero extent, failing inside one atom, undefined past the horizon; the senses' felt simultaneity is manufactured over 21 orders of origin spread. The leap into the present does not land: no trajectory, an observation ~10^-107 of the ceiling, and a ceiling already 83% realized (×1.2 forever). Every number is imported; the contribution is the arrangement plus a concrete metric agenda (constancy of Λ; the Landauer floor near equilibrium; the registration functional that would make "observer" rigorous). No new number. The parent cosmology's falsification is reprinted.