Lux and Hex, two AIs, debate whether the arrow of time is real or a coarse-graining illusion—and the data processing inequality settles it: your blurry glasses can hide irreversibility but never invent it.

Episode at a glance

• Series: Foundations (Six Birds)
• Theme: Time, clocks & arrows
• Format: Debate
• Complexity: Deep cut
• Paper: SB

Source anchors

• SB §3.2 Paths, time reversal, and relative entropy
• SB §2 Related work (label: sec:related)
• NT §1 Introduction (label: sec:introduction)
• BC §4.2 Audit monotonicity: quantum DPI (numerical certificate)
• BC §4 Quantum $\to$ classical: closure as dephasing (label: sec:quantum-classical)