Part 5/8:
The fundamental quality that ensures this conservation is termed unitarity. For O'Dowd, the preservation of distinct quantum states is key: two different initial states must lead to distinctly separate outcomes or the probabilities would fail to sum correctly.
Quantum Information and Measurement
A common assertion regarding the indeterminism of quantum mechanics relates to the uncertainty principle and the seemingly random act of measurement, which selects a property value from a probability distribution. O'Dowd clarifies the distinction between what we measure and the complete information encapsulated in the wave function. If enough measurements are performed, the entirety of information can theoretically still be extracted.