---
id: scene.phase-shift-chain
act: 2
status: proof-object
demonstrates:
  - reachability-is-historical
  - carriers-are-substitutable
  - exact-replay-is-not-the-object
human_anchor: moon of the eleventh planet
claims: [C2, C4, C5]
---

# Scene: the phase-shift chain

Money sentence. After a historical transformation of a transition boundary, a later state-class becomes reachable by many routes; before that transformation, the class is unreachable in every admissible reconstruction that lacks an equivalent change.

## Sequence as observed

1. Before impact: a catalytic film occupies pores on a moon of the eleventh planet. Distribution treated statistically in the first archive.
2. Ordinary impact. Near the margin the film survives beneath fractured conductive mineral.
3. For 38 local days, ejecta differ from neighbours below canonical confidence. Difference is charge persistence, not mass or elemental composition.
4. Almost all grains neutralize. A fraction too small to move the ejecta cloud remains coupled longer.
5. One population crosses a current sheet during companion high-transfer. The sheet would have torn without them. Where it tears changes. Energy contribution is negligible. Geometry is not.
6. A displaced stream intersects the seventh planet's outer magnetic environment. Narrow-band emission shifts phase.
7. The phase shift slightly extends one high-atmosphere reaction path. A trace compound rides a rising structure it would otherwise miss. The compound does not survive transfer. Surface states on carrier particles do.
8. 411 local years with no required downstream observation.
9. Carriers meet porous bodies between seventh and fourth regions. One film variant persists through a radiation cycle that previously eliminated it. The variant is not locally superior. It persists because post-damage establishment conditions changed.
10. Controls: omit incoming particles → variant disappears. Substitute random surface states of equal complexity → many variants, not this one.
11. Farther inward, near the fourth planet, altered grains enter a plasma structure that contains no original compound and no original ejecta. All material carriers have been replaced. A radiative mode appears with no admissible route from the pre-impact reconstructed state.

## Ablations

| Restoration | Later mode |
|---|---|
| Full chain removed | absent |
| Impact only, charges normalized | absent |
| Charge persistence, grains cross sheet at different orbital phase | absent |
| Observed tear forced without earlier grains | phase shift can appear; later mode can appear |
| Alternate routes to the same tear | same topological change; not the original material history |

## Ensemble result

Gross environment held fixed. Random impacts, fields, damage, noise within observed ranges. No specific conductivity alteration. No after-the-fact equivalent.

Some models are more complex than the observed system. Some imitate the fourth-planet pattern in frequency and energy.

None enters the observed causal class. In that class the radiative structure couples to particles that passed through the altered film network, enabling a later exchange. Imitations lack the coupling surface. Available consequences differ.

## Extractable result

The preserved object is not the impact, the grains, or the phase shift.
It is the change in which later states can be produced.

No field in `[req.root]` exists for reachability as distinct from present distinction.
Expanding the representation to specify future transformations that can alter reachability recreates the first archive explosion.