For newcomers
We live inside a packing of tiny cells. They pass movement to their neighbours. That handoff is what we call the speed of light. Matter is a lasting dent in the packing. Dents block the inflow. Blocking is force. Nothing pulls. The universe pushes.
The sky’s quiet glow is microwave. That glow is the packing’s working pressure, still arriving. It is not leftover light from a first day. There was no first day.
Light past the Sun is late because it ran slower, not because empty space got longer. Hotter means more pressure. More pressure means far-away light crawls. Climb from the microwave: infrared is this cycle’s jam. Colour sits behind that jam. Hard gamma is where through-going light stops.
The other way is radio, then a wave as big as the whole stack — not a wave at all, just still. If the bath goes all the way cold, the push that we call gravity shuts off. What was seated spreads. That dump reloads the packing until far-away light cannot move. Then the jam opens. We meet infrared coming down. We sit in the microwave again.
When the door opens is not yet a derived date. The order of the climb is.
For scientists and physicists
SoT: Engine/include/sdt/laws.hpp. Cycle arithmetic: Theory/07_Cyclic_Reiteration.md. Chain status: COMPUTED. Fire-time amplitude: PENDING. Do not relabel the chain as ontology.
Δt = ∫ dl/cfar − ∫ dl/c∞ · cfar = c∞(1 − z)² · z = ϟ/r
c(1−z) alone is falsified (exactly half Shapiro). Factor 2 is DERIVED (hop and tick both close). Same z is solar C1, z = ϟ/R = 2.123×10⁻⁶, 0.03%.
1+z = T/TCMB = (P/Pnow)1/4 = 1/(1 − zdepth)
N = T/TCMB = λnow/λ · P = N⁴ Pnow · cfar = c/N²
FIRAS: T_CMB = 2.7255 K OBSERVED; z_release = 1089 OBSERVED; T_release = 2970.8 K COMPUTED. Wien b DERIVED (B07). Do not insert FIRAS z = 1089 into (1−z)²; z_depth at Clearing is 1089/1090 ≈ 0.999.
Reverse-map: photosphere as through-going speed 0, Earth orbit as match to local c. Weak-field SI: c_far(R_☉) = c − 1273 m/s, c_far(1 AU) = c − 6 m/s because ϟ_☉ ≪ R_☉. Cosmological N is the same identities at depth.
FIRAS N = 1090 → λ = 975 nm (near-IR), c_far = 252 m/s. CR17b R=1 → 1571 nm. Visible 750–380 nm is behind the wall. Pair threshold: λ = 1.21 pm, N = 8.76×10⁸. Bath P = Peff: λ = 4.30 fm, N = 2.48×10¹¹, c_far ≈ 4.9×10⁻¹⁵ m/s.
Heat death: N → 0 ⇒ P → 0 ⇒ Law III gravity off ⇒ gravitational seats empty (not metric expansion). Recharge climbs until c_far → 0. c/√3 (FD05) is the fluid ceiling on the way down, not the recharge target. Locally measured c is never zero. c_∞ ≈ c + 105 m/s (galactic floor). R_CMB class X. FIRAS distortion < 50 ppm is the CMB gate.