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Equation 20 · Part 2 · The Arrow of Time and the Engine of Evolution

Symbol T

kBTln⁡2k_{\mathrm B}T \ln 2
TT

What this part means

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

Its job in the formula

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

The passage around this formula

None of this derives Darwin from physics, and it does not need to. Natural selection is a logically separate claim — that heritable variation plus differential reproduction produces adaptation — that would remain true in a hypothetical universe with a different thermodynamic arrow, or none at all, provided that universe still somehow supported heredity. What the physics in this article supplies is the reason no such universe was ever going to get the chance: without a low-entropy past there is no preferred direction for anything to accumulate in; without decoherence and Landauer’s bound there is no such thing as a record that stays written; without fluctuation theorems there is no exact…

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A variable is a named place for a value. Its letter is a local label: x can mean position in one formula and a data point in another.

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Sources cited in the article section

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