# Oliver Heaviside

## Oliver Heaviside: Biography

Born: 18 May 1850

Died: 03 February 1925

Leaving school, however, did not mean abandoning learning. With the guidance of his uncle, Sir Charles Wheatstone, an inventor of an early telegraph and a well-known musical instrument maker, Heaviside studied languages (German and Danish), music, and learned telegraphy.

With his knowledge of telegraphy and Danish, and probably with some help from his famous uncle, Heaviside got a job as a telegraph operator in Denmark. While working there, Heaviside noticed that signals from England to Denmark could be sent faster than those sent from Denmark to England. Those in the telegraph industry thought this was due to some strange and unknown property of the 347-nautical mile undersea cable carrying the messages. Heaviside wasn’t so sure and was able to show mathematically that if everything is identical on both ends of the cable, the maximum rate must be the same in both directions. He then showed, again mathematically, that any difference must be due to different resistance at each end. Simply put, the equipment in England had lower electrical resistance and could push more current faster into the capacitance of the cable, and thus could send at a higher rate.

During this time, Heaviside began an independent study of advanced topics such as calculus and James Clerk Maxwell’s new theory of electromagnetics. Heaviside found the latter especially compelling:

“I browsed through it and I was astonished! I read the preface and the last chapter, and several bits here and there; I saw that it was great, greater and greatest...I was determined to master the book and set to work.”

Maxwell’s theory provided Heaviside with his life’s work.

Maxwell’s theory predicts “electromagnetic waves” that travel with the speed of light. Heaviside reasoned that electromagnetic waves could travel on a telegraph cable too. At the time, it was believed that the electric telegraphic pulses diffused, or “soaked” in the telegraph cable. Although the mathematical cables that arose from diffusion theory worked for short cables, they failed for longer cables. Heaviside’s equations, based on Maxwell’s electromagnetic waves, worked for cables of all lengths.

This finding had practical applications for telegraph communications. For example, Heaviside actually solved one of the biggest problems affecting long distance telegraph and telephone communication—distortion. It was known that different frequencies travel with different speeds on a long cable. For example, the low bass frequencies in a voice signal travel faster than the high treble frequencies. When the cable is long enough, the frequencies smear, and both voice and telegraph signals become garbled noise. Heaviside used his equations to show that if inductances (i.e., a small coil of wire) were added along the length of the cable, the distortion could be reduced.

Heaviside and his theory ran into problems. His papers were difficult to read and most people did not understand him. Heaviside was not one to suffer fools. His sharp remarks and lack of diplomacy created enemies in the scientific community who suppressed and ridiculed his work. As a result it took 20 years and a rediscovery of the inductance idea by Silvanus Thompson before long distance telephone calls could become a reality.

Heaviside’s most important work involving Maxwell’s theories was what he did with Maxwell’s equations. Maxwell’s equations are the laws that electric and magnetic fields must follow. However, Maxwell never wrote the four simple-looking equations we use today. Rather, in 1873 Maxwell published a set of 20 equations in 20 different variables. These were difficult to understand, which made Maxwell’s theory slow to be accepted. By 1884, however, Heaviside was not only able to understand them, but to simplify them as well. For example, using “vector notation,” he combined sets of three equations into one. Heaviside also recognized that Maxwell’s equations did not require the use of “potentials.” These potentials that Maxwell used extensively could just be treated as mathematical quantities derived from the electric and magnetic fields. Today, we call them “Maxwell’s equations,” but Maxwell himself never saw them in this form.

Heaviside continued working with Maxwell’s equations for the remainder of his life. Among other things, he developed the concept of “operators,” which reduced complicated differential equations to simple algebraic equations, a technique every electrical engineer today knows as “Laplace Transform Theory.” He also introduced the concept of reactance, i.e., the “resistance” of an inductor or capacitor. In spite of all of Heaviside’s discoveries, his name lives on today only as one of the first (along with Arthur E. Kennelly) to propose the existence of the ionosphere. The E layer of the ionosphere is sometimes known as the Heaviside-Kennelly Layer.

As on old man, Heaviside spent his final years comfortably, although his mental powers diminished. “I have become as stupid as an owl,” he once bluntly stated. Heaviside died at the age of 74.