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Analysis. These results should not be read as “the second law was violated.” The second law survives intact at the level of ensemble averages: $\langle$ W $\rangle$ $\geq$ $\Delta$ F always holds. What fluctuation theorems expose is a layer beneath that average — an exact statement about the full distribution, not merely its mean — and single-molecule instrumentation is precise enough to resolve that distribution. The practical payoff is a genuine inference method: biophysicists now use pulling experiments as one route to equilibrium thermodynamic quantities that are difficult or impossible to measure any other way for a molecule that only exists folded correctly for a short time.

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