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Equation 136 · The Bit Comes Back Before the Bearing

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ΔtLG\Delta t_{LG}

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ΔtLG\Delta t_{LG}

Symbol Δ t_LG

Δ tLt_LG is a part of this expression. Its role is fixed by the surrounding article and by the operations shown in the formula.

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change

change

Capital delta attached to a quantity marks a difference between two values of that quantity; the article’s sign convention determines the order.

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subscript

subscript

The lower label selects a particular version, component, or indexed member of the quantity. For example, x₀ and xₜ can be values at different positions.

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What the article says around this equation

That reversal is the honest kill criterion for the headline claim. Δ\Delta tLGt_{LG} does not vanish under fair resource matching — both thresholds are built from the same radiation, collected by the same observer, under the same scrambling dynamics — so it is not a decoder artifact in that sense. It does, however, depend on a joint choice of ϵ\epsilon and δ\delta that this article has no privileged way to fix, and for a sufficiently coarse compass paired with a sufficiently strict qubit fidelity, the ordering in the title simply does not hold. The correct statement is conditional: for comparably stringent, no-external-frame tolerances on both sides, an old black hole returns an anonymous qubit…
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That reversal is the honest kill criterion for the headline claim. Δ\Delta tLGt_{LG} does not vanish under fair resource matching — both thresholds are built from the same radiation, collected by the same observer, under the same scrambling dynamics — so it is not a decoder artifact in that sense. It does, however, depend on a joint choice of ϵ\epsilon and δ\delta that this article has no privileged way to fix, and for a sufficiently coarse compass paired with a sufficiently strict qubit fidelity, the ordering in the title simply does not hold. The correct statement is conditional: for comparably stringent, no-external-frame tolerances on both sides, an old black hole returns an anonymous qubit before it returns a compass. It is not a theorem about black holes in general, and any presentation that drops the qualifier is overclaiming what this construction actually establishes.

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