Advances in experimental techniques allowed nineteenth-century physicists to develop increasingly refined concepts of electromagnetism. The mathematical formulations of electromagnetism culminated in Scottish physicist James Clerk Maxwell's development of a set of equations that accurately described electromagnetic phenomena. By the dawn of the twentieth century, Maxwell's equations allowed an increasing exploitation of the electromagnetic spectrum. Radio waves were to spark a twentieth-century communications revolution and x rays quickly became the forerunner of many important medical diagnostic tools based on electromagnetic properties. Moreover, Maxwell's formulations profoundly shaped the development of modern relativity and quantum theories by providing a precise set of formulas with enormous predictive power. Twentieth-century physicists such as German physicist Max Planck, German American physicist Albert Einstein, and Danish physicist Niels Bohr all credited Maxwell with laying the essential foundations for modern physics.

Maxwell collected and first published electromagnetic field equations in 1864. In particular, Maxwell built...