In 1861, James Clerk Maxwell (1831–1879) demonstrated the mathematical relationship between oscillating electric and magnetic fields. In his Treatise on Electricity and Magnetism, written in 1873, Maxwell described the nature of electric and magnetic fields using four differential equations, known to physicists today as “Maxwell’s Equations.” Putting the four equations together predicted the existence of the electromagnetic wave.

Maxwell was a professor at Cambridge University in England from 1871 until his death in 1879. He published other works on thermodynamics and the motion of matter as well. He also developed the kinetic theory of gases, and performed research in the field of color vision. Although Maxwell is not widely known to the lay audience, he is revered in the scientific community, and rates in the pantheon of physics greats with Newton and Einstein.