# Erratum — AP18 The Floor (FINAL, docx 4e4c7ebc…) · issued 3 September 2026

**The 420 Code · Studio G · issued beside the frozen file, which is never edited · confirmed by the author, 3 September 2026**

## 1 — The width of the empirical acceleration scale

AP18 §5 tests the floor a₀ = 1.0445 · cH₀/(2π) against an empirical acceleration scale quoted as 1.20 ± 0.02 × 10⁻¹⁰ m s⁻², citing McGaugh et al. 2016 and Lelli et al. 2017; it reports the match at H₀ = 74 as within ≈0.4 per cent and “well inside the ±1.7% uncertainty on a₀ itself”; §7 and §8 invert the relation to the prediction H₀ = 74.3 ± 1.2 km s⁻¹ Mpc⁻¹, registered as KS-45.1.

The ±0.02 is the random error alone. The sources AP18 cites give the scale as 1.20 ± 0.02 (random) ± 0.24 (systematic) × 10⁻¹⁰ m s⁻², the systematic from the stellar mass-to-light ratios and the distances. Propagated, the floor’s inversion is H₀ = 74.3 ± 14.9, not ± 1.2, and the relation cannot distinguish 67 from 74.

Corrected statements. §5: the floor is consistent with the empirical scale at any rate between about 60 and 89; at the corpus’s derived rate of 67.45 (AP48 §8) it gives 1.089 × 10⁻¹⁰, 9.2 per cent below the scale and 0.46σ on the honest error. §8, KS-45: the coefficient 0.1662 stands against the sky’s a₀/(cH₀) = 0.183 ± 0.037 at 67.45 — 0.46σ, live. §8, KS-45.1: FIRED on 3 September 2026 by AP48, on the width it registered — 5.7σ from the corpus’s own derived rate, about two sigma on the corpus’s window — as AP46 §9 pre-registered, by the desk’s ruling on the author’s delegation and the author’s own word; shown, never repaired; KS-ASM.1 is the corpus’s H₀ entry from AP48.

## 2 — One symbol

AP18 writes its geometric correction factor 2 ln(sec ½ + tan ½) ≈ 1.0445 as α, and AP21 echoes the formula as a₀ = αcH₀/(2π). The symbol collides with the fine-structure constant. The website already writes the factor as C_S² and states that it is not the fine-structure constant; the papers follow the site at their next revision.

## 3 — What does not move

AP18’s derivation of the floor’s form and of the coefficient α/(2π) ≈ 0.1662 is untouched. The floor scales with H and so predicts a higher acceleration scale at higher redshift; the 2026 measurement of the radial acceleration relation at intermediate redshift is to be read at AP18’s re-read, not here.

*Frozen files are never edited; corrections supersede, dated, in the open.*