Today we celebrate the 190th anniversary of the birth of Scottish mathematician and physicist James Clerk Maxwell (13 Jun 1831 – 5 Nov 1879). Between 1864 and 1873, Maxwell developed four important mathematical equations that describe the behavior of electric and magnetic fields and their interrelated nature. He showed that any oscillating electric charge produces an electromagnetic field, and that this electromagnetic field propagates outward from the oscillating charge at the speed of light. He then correctly deduced that light itself is an electromagnetic phenomenon, and proposed that since electric charges can oscillate at any frequency, there should be a whole spectrum of electromagnetic waves of which visible light is only a small part. We now know that the electromagnetic spectrum does include many other types of “light”, namely gamma rays, x-rays, ultraviolet, infrared, microwave, and radio waves. They are all exactly the same phenomenon, differing only in their properties of frequency, wavelength, and energy.