Quantum Measurements Reveal a Fundamental Limit to Knowledge Gain

Scientists at Hiroshima University, Natsuki Ogo and Holger F. Hofmann, have identified a precise relationship between the information acquired during a quantum measurement and the consequential physical changes inflicted upon the measured system. Ogo and colleagues demonstrate how this connection is fundamentally expressed through the Hilbert space superpositions of corresponding eigenstates, revealing that the probability of an observable physical change can be determined through the Bayesian update of probabilities associated with the information obtained in the measurement process. This analysis firmly establishes the superposition principle as the defining limit governing the unavoidable trade-off between information acquisition and disturbance, a…