Quantum Bayes' rule finds application in quantum physics

Researchers have discovered a quantum version of Bayes' rule, a 250-year-old probability theory, applying it to quantum physics. This new quantum Bayes' rule, derived from a fundamental principle of minimum change, allows for updating beliefs in quantum systems based on new information, similar to how it's used in classical probability. The discovery has potential applications in quantum computing, including error correction and machine learning, and validates previous theoretical proposals for a quantum Bayes' rule.