James Clerk Maxwell: Theoretical Physicist and Mathematician

James Clerk Maxwell was a Scottish theoretical physicist and mathematician who did pioneering work in electromagnetism and the kinetic theory of gases. He was born on 13 November 1831 in Edinburgh, to John and Frances Maxwell. As a child, James proved to have an insatiable curiosity in the world around him, showing a particular fascination with geometry. Recognising his intellectual potential, his father sent him to the prestigious Edinburgh Academy in 1841.

Here Maxwell made life-long friends with Lewis Campbell and Peter Guthrie Tait, who would themselves go on to become notable scholars. While at the Academy, aged only 14, Maxwell wrote his first academic paper, entitled ‘Oval Curves’, which was presented to the Royal Society of Edinburgh. In 1847, Maxwell went on to study at the University of Edinburgh, where two more of his papers were presented to the Royal Society by his tutor, as he was considered too young to present them himself.

In 1850, he entered Trinity College, Cambridge to study mathematics, where he graduated in 1854. He was made a Fellow of Trinity College in 1855, but just a year later the Chair of Natural Philosophy at Marischal College, Aberdeen, was vacated and he successfully applied for the position. Whilst there, Maxwell focused on a study of the planet Saturn’s rings, the nature of which was much debated. In 1859 he submitted a paper which argued that stability of the rings could be achieved only if they consisted of numerous small solid particles. For this Maxwell won the Adams Prize, awarded by Cambridge University.

In 1860, Maxwell became the Chair of Natural Philosophy at King’s College London, where he displayed the world’s first colour photograph, for which he was awarded the Rumford Medal by the Royal Society of London the same year. He also became involved with investigating the kinetic theory of gases. While this subject had already been extensively researched by the likes of James Joule and Rudolf Clausius, Maxwell’s experiments made great advances in the laws of gaseous friction.

In particular, in 1866 he developed a formula called the Maxwell distribution, which gives the fraction of gas molecules moving at a specified velocity at any given temperature. In the kinetic theory, temperatures and heat involve only molecular movement. This approach generalised the previously established laws of thermodynamics and explained existing observations and experiments in a better way than had been achieved previously.

However, arguably Maxwell’s most important achievement was his extension and mathematical formulation of Michael Faraday’s theories of electricity and magnetic lines of force. In his research, Maxwell showed that a few relatively simple mathematical equations could express the behaviour of electric and magnetic fields and their interrelated nature; that is, an oscillating electric charge produces an electromagnetic field. These four partial differential equations first appeared in fully developed form in his work Electricity and Magnetism published in 1873.

A committed Christian all his life, James Maxwell became an elder in the Church of Scotland in his later years, in addition to his work at the Laboratory. Sadly, he died in Cambridge of abdominal cancer on 5 November 1879 at the relatively young age of 48 and was buried at Parton Kirk, near Castle Douglas in Galloway, close to where he grew up. His name has been honoured in a number of ways, such as the Maxwell unit, a compound derived centimetre-gram-second unit measuring magnetic flux, the Maxwell Gap in the Rings of Saturn and the James Clerk Maxwell Telescope, the largest sub-millimetre-wavelength astronomical telescope in the world, with a diameter of 15 metres.

His discoveries helped usher in the era of modern physics, laying the foundation for such fields as special relativity and quantum mechanics. Many physicists regard Maxwell as having the greatest influence on 20th-century physics and his contributions to science are considered by many to be of the same magnitude as those of Isaac Newton and Albert Einstein. On the centenary of Maxwell's birthday, Einstein himself described Maxwell's work as the "most profound and the most fruitful that physics has experienced since the time of Newton". Upon visiting the University of Cambridge, he was told by his host that he had done great things because he stood on Newton's shoulders. Einstein is reported to have replied: "No, I don't. I stand on the shoulders of Maxwell".

Some content sourced from Wikimedia Commons (CC BY-SA 4.0).