Like any complex topic, electromagnetic theory has its own vocabulary. When speaking about dielectrics we may refer to their permittivity, and discussions on magnetic circuits might find terms like reluctance and inductance bandied about. At a more practical level, a ham radio operator might discuss the impedance of the coaxial cable used to send signals to an antenna that will then be bounced off the ionosphere for long-range communications.
It’s everyday stuff to most of us, but none of this vocabulary would exist if it hadn’t been for Oliver Heaviside, the brilliant but challenging self-taught British electrical engineer and researcher. He coined all these terms and many more in his life-long quest to understand the mysteries of the electromagnetic world, and gave us much of the theoretical basis for telecommunications.
The Family Business
To say that Oliver Heaviside’s early life stacked the deck against him is more than a mild understatement. He was born in 1850 in the same gritty London neighborhood that Charles Dickens grew up in, surrounded by the same sorts of characters bred from poverty and the societal changes forced by industrialization. Oliver’s own father, a wood engraver for the publishing industry, saw his trade become irrelevant due to technological advances. The four Heaviside sons suffered from the resultant poverty, as well as the physical abuse doled out by their embittered and frustrated father.
Oliver attended school for only a few years, during which time he showed promise. Family circumstances prevented him from continuing his formal education, and by 16 his academic career was over. But what the family lacked financially they made up for in connections. His mother’s sister had married the great physicist Charles Wheatstone, who took Oliver and his brother Arthur under his wing, putting them to work in Wheatstone’s Electric Telegraph Company.
Like his formal education, his foray into gainful employment would be successful but short-lived. He did manage to publish several scholarly papers on electrical measurements during his time in the telegraph industry, including improvements to his uncle’s famous Wheatstone bridge circuit. His work was good enough to earn praise from famed scientist William Thomson, Lord Kelvin. But Heaviside had a difficult personality that grated on his managers and peers, and he suffered from vague and unspecified ailments that he was sure would worsen if he continued to work. So at the age of 24, he gave up his position and went to live with his parents.
Loading the Lines
Heaviside would never be employed again in the traditional sense, but he was by no means idle. He began a long, productive period of independent research, working largely in isolation in a spare room in his parents’ house. He explored the problems of transmission lines, like the long-noted “skin effect” where the high-frequency alternating currents tended to flow toward the outer surface of a conductor. Heaviside was able to mathematically explain the skin effect for the first time. During this same period, he patented the first coaxial cable, described as “two insulated conductors … one of them inside the other,” for the purpose of reducing mutual inductance between circuits.
One of his major accomplishments was a simplification of the by-then famous but fiendishly complex set of equations James Clerk Maxwell expounded in his Treatise on Electricity and Magnetism. Heaviside’s recasting of the equations in vector terminology resulted in the four equations now taught today as Maxwell’s equations, and gave Heaviside the tools he needed to continue his explorations of electromagnetism.
As the action in the communications industry shifted from telegraph to telephone in the latter part of the 19th-century, new models that described the circuits between transmitter and receiver were needed. Oliver’s brother Arthur was by then an engineer working on telephone lines and trying to conquer the problem of distortion in long-distance connections. Arthur had noticed that as the number of telephones added to a transmission line in parallel increased, the perceived distortion on the line decreased. He turned to his brother Oliver for an explanation.
Oliver delved into circuit theory to explore the problem and came to the conclusion that the only practical way to decrease distortion would be to increase the inductance of the transmission line. By adding inductors of exactly the right value in series spaced at precise intervals along a line, the frequency response of the line in the voice frequencies would be flattened and noise reduced. Arthur Heaviside presented his brother’s findings to his superiors in the British Post Office, but the “loading coils” that Oliver prescribed were not adopted, due perhaps to his abrasive manner.
Up, Up, Up to the Heaviside Layer
Despite being bitter about the rejection, Heaviside continued his research. He turned to the exploration of electromagnetic radiation and in 1902 predicted the existence of a layer of charged particles in the upper atmosphere that would be capable of reflecting radio waves. Predicted independently by American electrical engineer Arthur Kennelly, it became known as the Kennelly-Heaviside layer. Physicists were skeptical of its existence until it was proven in 1924; we now know this as the E-layer of the ionosphere that makes long-distance radio communication possible.
By the turn of the century, Heaviside received widespread recognition for his achievements, earning a Fellowship in the Royal Society in 1891. He would continue his research, living on a stipend from the Royal Society, and eventually become the first recipient of the Faraday Medal. But his later years were difficult; his declining health and increasing eccentricity caused him to withdraw into deeper isolation. He replaced the furnishings in his house with blocks of granite and wandered around in a disheveled state with his fingernails painted bright pink. In February of 1925, at the age of 74, he fell from a ladder and died.
Oliver Heaviside’s life was anything but ordinary. He shunned the companionship that most people seek, replacing it instead with a drive to understand the nature of the electromagnetic world. He was able to turn the liability of a lack of formal mathematical training into an asset, simplifying the formulations of Maxwell for everyone, and giving himself a framework to understand a complex and wondrous world. That he laid much of the theoretical groundwork for the communication networks that we enjoy today and yet received little in the way of recognition and nothing in compensation is sad, but perhaps the only way his story was likely to end.