Miscellaneous

OTSOG: James Clerk Maxwell

Note: This article is hosted here for archival purposes only. It does not necessarily represent the values of the Iron Warrior or Waterloo Engineering Society in the present day.

James Clerk Maxwell (1831-1879) was born in rural Scotland and, after his mother’s early death, was raised by a single father. His childhood is almost stereotypical for a “genius”—growing up, he was rather socially awkward and endured bullying in school, but his dad saw that he had an unusual curiosity and encouraged him to keep going. By the time he was done high school, his peers had started giving him grudging respect—somehow this weirdo was winning academic awards and writing scientific papers.

Maxwell started university at Edinburgh, but soon he transferred to Cambridge. It was a time of great change in physics—Michael Faraday had recently proved that electricity and magnetism were related, and Joule and Mayer (see OTSOG April 1st) had just discovered the law of conservation of energy. In 1854, Maxwell completed the Tripos, the infamously tough exams for graduating math students. Within a few years of his graduation, he had a made a name for himself in four different fields.

First, he published an optics paper. In an experiment with multicoloured tops, he noticed that if you spun it fast enough, the colours would combine and you would see yet another colour. He concluded that white light was a combination of the three primary colours red, blue, and green.

Next, he published a paper on astronomy. He showed, using Newton’s laws, that Saturn’s rings couldn’t actually be a single solid structure, but instead were an illusion caused by a large number of small objects orbiting around Saturn. This was confirmed a century later by NASA’s Voyager space probes.

By extension, if Saturn’s rings were actually made of many small objects, Maxwell thought, perhaps gases also consisted of many atoms, with heat being merely the kinetic energy of these atoms. The kinetic theory of gases was not a new theory—Daniel Bernoulli had proposed it a century earlier. But Maxwell set to work to create a formula determining the probability that a gas molecule would have a certain velocity. This, after further refinement by Ludwig Boltzmann, resulted in the Maxwell-Boltzmann distribution and gave birth to the bane of many a Nano student, statistical mechanics.

Finally, he published a paper discussing electromagnetism. At the time, most scientists thought magnetism was just a force acting at a distance. But Faraday observed magnetic fields with lines of force—this suggested to Maxwell that magnetism didn’t just act at a distance, but something, somehow, had to be moving along these lines. Now scientists had also been wondering for a long time how we could even see the Sun and the stars—if it was just empty space, how could light travel through it? Maxwell’s stroke of genius was to realize that these two problems were related: electromagnetic radiation travelled as waves, and visible light was just one form of it. Based on the work of scientists before him, he published a number of equations to describe how electromagnetism worked. Today, these have been simplified to four formulas, known as Maxwell’s equations.

Additionally, Maxwell hypothesized that solid materials failed when the distortion energy passed a maximum level; several decades later, Richard von Mises would derive a formula for this, which is still used today to determine the force required to break a material. Maxwell also published a paper on speed regulation in steam engines, which would prove to be the beginning of control system theory.

In 1874, the University of Cambridge set up an experimental physics lab, and Maxwell was chosen to run it. His fame was such that many other professors came to hear his first lecture. Maxwell, who was prepared to teach a regular course, ended up lecturing about temperature unit conversions to some of the world’s most brilliant scientists! Unfortunately, soon after his return to Cambridge, his health began to fail, and he was unable to actually implement a lab course for physics students. In 1879, just 48 years old, his life was claimed by abdominal cancer. It was left to Baron Rayleigh (covered in OTSOG last Nov. 26), his successor, to actually implement a physics lab course.

As engineers, we love inventors—people who build appliances, cars, electronic gadgets, and so on for all of us to use. We like to think that science is a means to an end, begging to be applied in real life, to make our lives easier. But often, the genius scientists we rely on were happy simply to learn about the universe, perhaps to see beauty in how it all worked. Maxwell was no exception; a deeply spiritual man who loved writing poetry, many of his private writings explored the philosophical and religious implications of his findings.

It was left to others to turn Maxwell’s work into technologies. Notably, inventors would soon use non-visible types of electromagnetic radiation to deliver radio and television broadcasts. Colour photography got its start from his optics theories. Later scientists also found his work fruitful. Einstein acknowledged a debt to Maxwell, as it was through the latter’s electromagnetic equations that he discovered the significance of the speed of light, which would lead to his ground-breaking work on relativity.

No matter which engineering program you’re in, you’ve almost certainly learned—or rather, crammed last minute and have now forgotten—something which traces its roots back to Maxwell. His shadow is inescapable. And though he was just 5’4” in his life, his legacy is giant.

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