Ehrenfest theorem

Ehrenfest’s theorem shows how the average behavior of tiny particles like electrons follows the same rules as classical physics. It links quantum mechanics to classical physics by demonstrating that, although individual particles behave unpredictably, their average motion over time obeys familiar laws such as Newton’s equations. In essence, it bridges the gap between the strange world of quantum particles and the classical world we see daily, illustrating that the collective behavior of particles aligns with classical physics under certain conditions.