While working on the seemingly related phenomena of electricity and magnetism, James Clerk Maxwell derived a set of equations to describe how the two interrelated. His equations showed that since an electric field that changed over time generated a magnetic field, and conversely a varying magnetic field induced an electric field, then the two ought to self-support and produce an electromagnetic wave that rippled through empty space. As Wilczek so poetically describes, the situation “takes on a life of its own, with the fields dancing as a pair, each inspiring the other”. Maxwell could also use his equations to calculate how fast such an electromagnetic undulation would travel, and he found that it matched what had already been measured for the speed of light. For Maxwell, it was obvious that this correspondence was no coincidence; that, in fact, the underlying agent of light, a mystery that had foxed Newton, was no more than a mutually supporting disturbance in magnetic and electric fields. To use the parlance of modern physics, this was a monumental feat of reductionism, as Maxwell had achieved in one go the unification of the theories of electricity, magnetism and light.