The Echo That Proves Itself: Quantum Echoes, Time-Reversal, and Verifiability as Physical Λ — Overview

Google's Quantum Echoes perturbs a qubit, time-reverses the evolution, and reads the returning echo - a literal round trip of the observation operator O-hat and a strange loop closed in time. In ODTOE, the celebrated property everyone cites, verifiability, is exactly the data-quality metric Λ made physical: the advantage counts as real only when repeat-and-confirm reinforcement is high enough to collapse doubt σ.