This book provides a comprehensive discussion of quantum mechanics and illustrates the common threads associating numerous different miracles and subfields of physics. Quantum mechanics is the science of the very small. It explains the behaviour of matter and its interactions with energy on the scale of atoms and subatomic particles. Quantum mechanics (QM) developed over many decades, beginning as a set of controversial mathematical explanations of experiments that the math of classical mechanics could not explain. It began at the turn of the 20th century, around the same time that Albert Einstein published his theory of relativity, a separate mathematical revolution in physics that describes the motion of things at high speeds.