← All parts of this equation

Equation 9 · Part 1 · The Statistical Mechanics of Irreversibility at Molecular Scale

Symbol Δ s_tot

⟨Δstot⟩≥0,\left\langle \Delta s_{\mathrm{tot}} \right\rangle \ge 0,
Δstot\Delta s_{\mathrm{tot}}

What this part means

Δ sts_tot 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

Δ sts_tot 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

Jensen’s inequality then gives ⟨Δstot⟩≥0\left\langle \Delta s_{\mathrm{tot}} \right\rangle \ge 0. which is the ensemble second law. The derivation is compact, but the assumptions are not optional. One must define the reverse experiment correctly, include relevant reservoirs and boundary terms, and avoid silently replacing the full state with an observed projection. Apparent violations often diagnose missing variables or an incorrectly specified conjugate process rather than new thermodynamics.

Read this part in the article →

Learn the underlying idea

A subscript is a label attached below a symbol. It often selects a time step, component, category, or member of a sequence.

Open the illustrated subscripts: which member of a family? guide →

See this notation across published equations →

The article lists its research sources here.