Quantum-classical correspondence

Quantum-classical correspondence describes how quantum systems, which follow the rules of quantum mechanics, transition to behave like classical systems, which follow everyday physics laws, as their size or energy scale increases. Essentially, when objects become large or observed at larger scales, their quantum weirdness diminishes, and their behavior aligns with classical physics. This connection helps us understand how the strange world of quantum particles underpins the familiar classical world we experience daily. It shows that classical physics is a natural limit or approximation of quantum mechanics for large-scale systems.