" 17. This is enshrined in a second rule,fn2 which we call Rule 2: The outcome of a measurement can only be predicted probabilistically. But afterward, the measurement changes the quantum state of the system being measured, by putting it in the state corresponding to the result of the measurement. This is called collapse of the wave function. "

― Lee Smolin , Einstein's Unfinished Revolution: The Search for What Lies Beyond the Quantum