Speed of light c

The speed of light c is, in the τ-framework, the dimensional unit-conversion factor between τ-native length and τ-native time at enrichment layer E₁. It is a Tier-I (Established) entry of the constants ledger: a unit conversion, not a free parameter, exact by 1983 SI definition and identically exact in the τ-cascade.

Categorical invariant. c = (L · H) in the dimensional cascade — the L/T conversion fixed by the τ³ → (M, L, ℏ) projection at E₁.

Primary registry anchor: IV.D33

Supporting items: IV.D255, V.D231, V.T142

1. I.K0 — Universe Postulate
2. IV.D255 — Master constant ι_τ
3. V.D231 — The ι_τ chain
4. IV.D33 — Speed of Light c — the L · H conversion at E₁
5. V.T142 — E₁ Completeness — c is one of six established unit conversions

Lean modules referenced: TauLib.BookIV.Calibration.SIReference, TauLib.BookV.Coda.ConstantsLedger

Numerical value: 299792458 ± 0 m s⁻¹

Calibration anchor: PG-P01-neutron

Calibration chain:

1. Layer 0: ι_τ = 2/(π + e)
2. Layer 2: m_n anchor sets the kg scale
3. Layer 3: c is the L · H conversion factor — exact by 1983 SI definition (the metre is *defined* by c)
4. Layer 4: c enters R_∞ = m_e c α² / (2h), a_0 = ℏ/(m_e c α), and every relativistic invariant

Manuscript reference: manuscript-sources/book-05/part07-closure/ch-closure-constants.tex

Status: Formalized

Module: TauLib.BookIV.Calibration.SIReference

Lean kind: def

Related glossary entries

• PG-C02-iota-tau Master constant ι_τ
• PG-C01-newton-g Newton's gravitational constant G
• PG-P01-neutron τ-Neutron

Referenced by

• PG-C04-planck-hbar Planck's reduced constant ℏ
• PG-C08-vacuum-permeability Vacuum permeability μ₀
• PG-C19-milgrom-acceleration Milgrom MOND acceleration a₀