1.C: Quantum mechanics, a new set of rules for motion
While the predictions of classical mechanics are very accurate for heavy or energetic objects, like planets or baseballs, they disagree with experimental results for atoms and molecules. Instead, a different set of rules for predicting the dynamics of particles, quantum mechanics, is successful at describing atomic and molecular behavior.
The nature of motion predicted by quantum mechanics is very different from our ordinary experience. At first you will have trouble accepting that the
motion of electrons could be so much different from the motion of much heavier objects like baseballs. Moreover, quantum mechanics does not predict
precise trajectories. In fact, knowing the precise position of a particle is generally impossible in quantum mechanics. Instead, quantum mechanics only predicts the relative likelihood that a particle will be found in a variety of locations -- much different from classical mechanics! Despite these differences, the predictions of quantum mechanics coincide with those of classical mechanics for heavy particles, even though they are quite difference for electrons. In this tutorial, we will explore the relation between classical and quantum mechanics in detail.