bibkey: “fengcrooks2008arrow” authors: “Edward H. Feng; Gavin E. Crooks” year: 2008 title: “Length of Time’s Arrow” doi: “10.1103/PhysRevLett.101.090602” url: “https://doi.org/10.1103/PhysRevLett.101.090602” claim: “Rare highly dissipative trajectories can make average dissipation large while the trajectory Jensen-Shannon time asymmetry remains small.” strata_touched: [] license: “citation-only” triage: “anchor”

Length of Time’s Arrow

Physical Review Letters 101, 090602 (2008). Pages 090602-3–090602-4, the discussion after equation (13), equations (14)–(16), and Figure 2. The paper defines time asymmetry using trajectory Jensen-Shannon divergence and gives a rare-event mixture with large average dissipation but small overall time asymmetry. It explicitly notes that average dissipation is sensitive to unusual events and need not reliably measure whole-system time asymmetry.

This is a direct literature-attested qualitative precursor, not merely a generic entropy reference. The parity-kernel addition does not claim the large-dissipation/small-distinguishability mechanism as new. Its deductions concern the specified stationary kernel, constrained optimized asymptotic, fixed-horizon Bayes error curve, and exact rare-edge waiting law.

Primary text: https://harvest.aps.org/v2/journals/articles/10.1103/PhysRevLett.101.090602/fulltext.