Quantum mechanics (QM) is the study of matter and energy at the microscopic level. QM makes bizarre predictions about how matter works. For example, quantum entanglement occurs when two or more particles become correlated such that measuring the state of one instantaneously affects the state of the other, even if they are separated by vast distances. This phenomenon has been experimentally confirmed.
A second example comes from the famous double-slit experiment. A quantum particle such as an electron or a photon is fired at a barrier with two slits. If the particle is not observed, it passes through both slits simultaneously to form an interference pattern (a series of alternating dark and bright bands produced on a screen behind the barrier). But if the particle is observed, the interference pattern disappears.
The double-slit experiment, first carried out with multiple photons or electrons and afterwards with single particles, showing a clear wave interference pattern on the screen or, alternatively, a clumped particle pattern.
Predictions from QM are borne out to a remarkably accurate degree. For example, the theoretical prediction for a quantity known as Dirac’s…