What could be more different than magnetism, electricity, and light? Yet, in the 19th century, James Clerk Maxwell showed that these phenomena were simply different manifestations of the same fundamental laws. He described all these, as well as radio waves, radar, and radiant heat, by a unique and elegant system of equations.1
James Clerk Maxwell was born in Edinburgh, Scotland, on 13 June 1831. He was the only child of John Clerk, an Edinburgh lawyer. Shortly after James’ birth, John Clerk and his family moved to a country estate at Glenlair, near Edinburgh, which he inherited from his Maxwell ancestors. At that time, John Clerk adopted the additional surname Maxwell. The family lived a comfortable, middle-class life.
James’ early education was given by his mother, a dedicated Christian, and included studying the Bible. James’ exceptional memory became apparent at this time when he memorized all of Psalm 119. By the age of 8, James found his toys uninteresting. He preferred to apply his great curiosity to simple scientific investigations. For example, he used a tin plate to reflect sunlight, and made observations of the life-cycle of the frog.
His mother taught him to see God’s scientific genius and compassionate hand in the beauties of nature. This conviction that there was complete harmony between scientific investigation and God’s teachings in the Bible had a great influence on James’ life and work. Sadly, his mother died when he was still only 8. His father then engaged a tutor for his son.
In 1841, James began formal schooling at the Edinburgh Academy. Poor health frequently kept him absent, but his academic progress was excellent. His first scientific paper—a mathematical analysis involving the ellipse—was published when he was only 15.
In 1847, James entered the University of Edinburgh and soon published two more scientific papers. In 1850, he enrolled at Cambridge University, graduating four years later with first-class honours in mathematics. He was also awarded a prestigious prize for original research in mathematically analyzing the stability of the rings around Saturn. Maxwell concluded that Saturn’s rings could not be completely solid or fluid. Instead they must consist of small but separate solid particles—“a conclusion that was corroborated more than 100 years later by the first Voyager space probe to reach Saturn”.2
After graduating, Maxwell joined the staff at Cambridge University, lecturing on optics and hydrostatics as well as doing research in these areas.
In 1856, he left Cambridge to return to Scotland to be near his father whose health was failing. His father died before James began his new appointment as Professor of Physics at Marischal College in Aberdeen. Two years later, Maxwell married Katherine Mary Dewar, whose father was the principal of Marischal College. James and Katherine Maxwell’s marriage was happy, but childless.
When Marischal College merged with King’s College, Aberdeen, to become the University of Aberdeen, Maxwell unsuccessfully applied for a vacancy at the University of Edinburgh. The successful applicant for that position was Percy Guthrie Tait, a former school-friend of Maxwell’s. Tait, another committed Christian, also achieved considerable success in mathematics and physics.
In 1860, Maxwell became Professor of Physics and Astronomy at King’s College in London. Here he supervised the measurement and standardization of electrical units for the British Association for the Advancement of Science in 1863.
In 1865, he left London and moved to the estate in Scotland which he had inherited from his father. Here he devoted himself to his research and writing on electricity and magnetism. In the year of Maxwell’s birth (1831), famous English physicist Michael Faraday had invented the electric generator, which used a moving magnet to produce electricity. He also demonstrated that an electric current produced magnetism. Faraday was convinced that these electromagnetic forces extended into the space around the conductor, but he was not able to complete his work in this area. However, Faraday’s idea of a force field in the surrounding space gave rise to the wider generalization known as field theory.
Maxwell’s major aim in his research on electricity and magnetism was to produce the mathematical framework underlying Faraday’s experimental results and his ideas on field theory. The four mathematical equations Maxwell produced are ranked with Sir Isaac Newton’s laws of motion and Albert Einstein’s theory of relativity as the most fundamental contributions to physics.
When Maxwell calculated the speed of electromagnetic waves, he found that their speed was virtually the same as the speed of light. He concluded that light was another type of electromagnetic wave. Maxwell proposed that electromagnetic waves with other wavelengths should exist as well. When German physicist Heinrich Hertz produced the first man-made radio waves in 1887 (eight years after Maxwell’s death), Maxwell’s electromagnetic theory was fully confirmed. (Radio waves have longer wavelengths than visible light.)
The later discovery of X-rays was further confirmation of Maxwell’s predictions. (X-rays are a form of electromagnetic radiation with ultra-short wavelengths.) Twentieth century communication technology stems largely from Maxwell’s work. Radio, television, radar and satellite communication all have their origins in his electromagnetic theory.
During the 1850s, outstanding mathematical physicist William Thomson had been demonstrating a common mathematical framework underlying the experimental results in various areas of physics such as heat, mechanical motion, fluid (gas or liquid) motion, electricity and magnetism. This constituted a significant theoretical extension of the work done by previous scientists. Maxwell’s electromagnetic theory linking electromagnetism with light and later with radio waves was a great contribution to this process of unifying the theoretical framework in physics.
Maxwell gratefully acknowledged his indebtedness to Thomson who had been his mentor. (Thomson was later known as Lord Kelvin.)
Maxwell is widely acknowledged as the nineteenth century scientist whose work had the greatest influence on twentieth century physics. His electromagnetic theory and its associated field equations “paved the way for Einstein’s special theory of relativity, which established the equivalence of mass and energy. Maxwell’s ideas also ushered in the other major innovation of 20th century physics, the quantum theory”.3
In 1840, English physicist James Joule had established a relationship between heat and mechanical motion. This principle gave rise to the scientific discipline called thermodynamics, which includes the study of the motion of gas molecules.
In 1848, Joule became the first scientist to estimate the velocity (speed) of gas molecules. However, Joule treated all molecules as if they travelled at the same speed. In reality, the velocities of the molecules are not equal. They vary markedly as a result of collisions with other molecules. By applying the methods of probability and statistics, Maxwell worked out the most probable distribution of speeds of the molecules. This distribution is known today as the ‘Maxwell distribution of speeds’.
As a result of his application of statistics, thermodynamics was extended into the new field of statistical thermodynamics. Maxwell’s introduction of the idea of probability into physics was probably his most important contribution to physics apart from his work on electromagnetism.
Maxwell also made significant advances in the area of optics and colour vision. His research on colour blindness was recognized when he was awarded the Rumford Medal by the Royal Society of London. Maxwell was one of the first scientists to demonstrate colour photography. He also undertook research relating to elastic solids and pure geometry.
Maxwell was elected to the Royal Society in 1861, a prestigious association of scientists, as a result of his early work on electromagnetism. In 1871, he became professor of experimental physics at Cambridge University. Here, he supervised the planning and construction of the Cavendish laboratory, which became a centre renowned for significant advances in physics.
Maxwell strongly opposed Darwin’s theory of evolution, which was becoming popular at that time. He believed that the speculations involved in evolutionary thinking contradicted scientific evidence. In a paper he presented to the British Association for the Advancement of Science in 1873, he said:
Maxwell was able to refute evolutionary thinking in another important way. He mathematically disproved the nebular hypothesis proposed in 1796 by French atheist, Laplace. Laplace suggested that the solar system began as a cloud of gas which contracted over millions of years to produce planets and so on. Laplace claimed there was thus no need for a Creator. This philosophy was eagerly embraced by the opponents of Christianity.
However, Maxwell demonstrated two major flaws in Laplace’s theory, and proved mathematically that such a process could not occur. Laplace’s theory was subsequently discarded.
Maxwell was convinced that scientific investigation and the teachings of the Bible were not only compatible but should be linked together. This was reflected in a prayer found among his notes: “Almighty God, Who hast created man in Thine own image, and made him a living soul that he might seek after Thee, and have dominion over Thy creatures, teach us to study the works of Thy hands, that we may subdue the earth to our use, and strengthen the reason for Thy service; so to receive Thy blessed Word, that we may believe on Him Whom Thou hast sent, to give us the knowledge of salvation and the remission of our sins. All of which we ask in the name of the same Jesus Christ, our Lord.”5
In this prayer, Maxwell affirmed his belief in the teachings found in the Book of Genesis—God is the Creator, who made man in His own image, and gave man control over and responsibility for the animals. The second part of the prayer contains the Gospel message—that Jesus Christ was sent by God to save us from our sins.
Maxwell had an extensive knowledge of the Bible, and was an elder of the church which he helped establish near his home at Glenlair. His Christian commitment was also very practical. He gave generously of both his time and money. He frequently visited the sick and those confined to their homes, and he read to them and prayed with them. He was also modest and displayed absolute integrity.
His compassion and self-sacrificing attitude were clearly evident, as J.G. Crowther writes in a biography of Maxwell:
Maxwell died of abdominal cancer at Cambridge on 5 November 1879, aged 48. He was greatly respected by those he had known and with whom he had worked. One of his close colleagues wrote: