Chapter Five

Putting His Theories to Practice

“The popularization of scientific doctrines is producing as great an alteration in the mental state of society as the material applications of science are effecting in its outward life. Such indeed is the respect paid to science, that the most absurd opinions may become current, provided they are expressed in language, the sound of which recalls some well-known scientific phrase.”

—James Clerk Maxwell

In his early thirties, Maxwell embarked upon what would become an obsession. He was searching to bring to fruition a theory on electromagnetism that would fill in all the blanks left behind by others and answer all of the age-old questions once and for all. In doing so, he had to account for the four known effects of electricity and magnetism:

1. Opposite electrical charges attract and like charges repel with a force inversely proportional to the square of the distance between the two.
2. Opposite magnetic poles attract; like poles repel with a force inversely proportional to the distance between them, and poles always occur in north/south pairs.
3. The electrical current of a wire creates a circular magnetic field, with its orientation dependent upon that of the current.
4. Fluctuating magnetic fields through a loop of wire induces an electrical current in the wire, with its orientation dependent upon whether the fluctuation increases or decreases.

In his efforts, Maxwell tackled the second principle first. Taking this principle into account, he envisioned a series of rotating spherical cells that were closely packed together. He pictured the cells spinning with their centers expanding out due to the effect of centrifugal force. Since the cells were closely packed together, as soon as one would expand, the others would react and resist the expansion. Maxwell furthermore postulated that if the cells all turned in the same direction, they would soon exert a collective pressure at right angles to their axes of spin. Along the axes of spin, the opposite would happen, creating tension. Without going into a whole lecture course in this book, the end result of Maxwell’s observations was that the spin of the cells was the determining factor for the direction of a magnetic field at any given time.

From this, Maxwell then further deduced that his rotating cells must have smaller particles he referred to as “idle wheels” in between, helping the flow of energy along. At this point, Maxwell had successfully taken into account both the second and third principles of electromagnetism. He then went on to try his luck with the fourth regarding the fluctuation of magnetic fields.

In recognizing this known principle, James determined that like a flywheel his rotating cells behaved as active stores of energy in order to be able to react with a counterforce should any outside force attempt to alter their spin. Maxwell declared that it was this store of energy if properly conducted that could be used as a power source, thereby explaining the basis of how all electronic devices functioned.

When some serious help with the preeminent electrical device of Maxwell’s day—the telegraph—was needed, it was James Clerk Maxwell who was called upon for assistance. For some time, engineers had been attempting to lay a viable telegraph cable underneath the Atlantic Ocean that could effectively carry signals sent from England to North America. Maxwell was well aware of these difficulties as his associate and frequent source of intellectual banter, William Thomson, had worked extensively on the project. The first major effort was made in 1858 but proved to be a complete failure. Most famously, it managed to carry a slow and much-delayed message between Queen Victoria of England and President James Buchanan of the United States before conking out completely.

Maxwell, never one to miss a good punchline, took the opportunity to playfully mock his friend’s efforts. He was on a train ride to Glasgow when he penned his humorous lyrics for “The Song of the Atlantic Telegraph Company.” Joking about the failed attempt to lay telegraph cables under the Atlantic Ocean, the song rather cheekily declared:

“Under the sea, under the sea,

No little signals are coming to me.

Under the sea, under the sea,

Something has surely gone wrong,

And it’s broke, broke, broke;

What is the cause of it does not transpire

But something has broken the telegraph wire.”

All humor aside, in light of this inability to lay transatlantic cables, it was determined that a physical standard of electrical resistance was needed in order to make sure the equipment used had the necessary specifications to carry electrical current. Since Maxwell had already standardized the whole process in his treatises, he was a natural choice for the task. Maxwell proposed spinning a wire made of copper to generate a magnetic field. He then recommended having a magnetic needle placed in the middle of the coil so that it would settle at the fixed angle of Earth’s magnetic field.

With the right formulas in place, Maxwell could use this to determine the absolute measure of the coil’s electrical resistance. As a result of his findings, a standard of electrical resistance had been established, and the first transatlantic telegraph cables were laid, thereby putting Maxwell’s theory to practice in a very demonstrative and powerful way.