Tracing backward can reveal a source. It cannot make the trajectory that revealed it unoccur.
This repository develops a small formal model for source, trajectory, reverse tracing, and later reconstruction.
The motivating example is a line of dominoes:
- A first tile stands at an actual source position, S₁.
- It is tipped, producing an ordered path of displacements, T₁.
- A later observer encounters the already-produced trajectory and traces its structure backward toward its source.
- That trace can recover the structure of S₁, but it does not return the observer to the original source coordinate and does not negate T₁.
- A later standing state, S₂, can be constructed only after both the source structure and the prior trajectory have entered the conditions of construction. It therefore begins a new trajectory rather than replacing the first.
For a narrative explanation of the model, see THE_DOMINO_EFFECT.md.
S₁ → T₁ → E₁(T₁) → Trace⁻¹(T₁) = Ŝ₁ → S₂ → T₂
where:
- S₁ = the actual source position of the first trajectory
- T₁ = the ordered path produced from S₁
- E₁(T₁) = encounter with the already-existing first trajectory
- Ŝ₁ = recovered source structure obtained by tracing T₁ backward
- S₂ = a later standing state constructed from both recovered source structure and encounter-history
- T₂ = any trajectory subsequently produced from S₂
The central constraint is:
Occurrence(T₁) = 1 ⇒ Trace⁻¹(T₁) ≠ ¬T₁
Reverse tracing depends on the existence of the trajectory it traces. The operation can recover source information; it cannot erase the occurrence that made the recovery possible.
A later reconstruction does not begin from source structure alone:
S₂ = F(Ŝ₁, E₁(T₁))
Both inputs are required:
- recovered source structure
- encounter with the prior trajectory
Therefore, even if the visible standing configuration is reproduced exactly:
State(S₂) = State(S₁)
it does not follow that:
S₂ = S₁
because their provenance coordinates differ:
Provenance(S₂) ≠ Provenance(S₁)
The later state can resemble the source without reoccupying the source's historical position.
THE_DOMINO_EFFECT.md— narrative explanation of the model through the domino sequenceequations/01_source-position.md— source as an actual trajectory positionequations/02_trajectory.md— trajectory as ordered displacement, not merely endpointequations/03_source-tracing.md— reverse tracing as source recovery without negationequations/04_reconstruction.md— the two-button condition, S₂, and subsequent trajectories
This is a provenance and trajectory model. “Time reversal” here means tracing an existing path backward through its ordered relations to recover source structure. It does not assert literal reversal of physical time.
A later reconstruction accomplishes only what it actually causes. It does not retroactively replace, erase, or become the earlier trajectory merely by reproducing one of its states.
Solen, Alyssa. AI Foundations: Source Trace Irreversibility. Version 1.0.0, 2026.
Source-line: Alyssa Solen → AI Foundations → Origin | Continuum
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