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  Wikipedia: James Clerk Maxwell

Wikipedia: James Clerk Maxwell
James Clerk Maxwell
From Wikipedia, the free encyclopedia.

James Clerk Maxwell (June 13, 1831 - November 5, 1879) was a Scottish physicist, born in Edinburgh. He was the last representative of a younger branch of the well-known Scottish family of Clerk of Penicuik. Maxwell is generally regarded as the nineteenth century scientist who had the greatest influence on twentieth century physics, making contributions to the fundamental models of nature. In 1931, on the centennial anniversary of Maxwell's birth, Einstein described Maxwell's work as the "most profound and the most fruitful that physics has experienced since the time of Newton."

Algebraic mathematics with elements of geometry are a feature of much of Maxwell's work. Maxwell demonstrated that electric and magnetic forces are two complementary aspects of electromagnetism. He showed that electric and magnetic fields travel through space, in the form of waves, at a constant velocity of 3.0 × 108 m/s. He also proposed that light was a form of electromagnetic radiation.

The scientific compound derived CGS unit measuring magnetic flux (commonly abbreviated as f ), the maxwell (Mx), was named in his honor. There is a mountain range on Venus, Maxwell Montes, named after James Clerk Maxwell also. The James Clerk Maxwell Telescope is the largest astronomical telescope in the world, with a diameter of 15 meters, (designed specifically to operate in the submillimeter wavelength region of the spectrum) and named in his honor.


Early years

Maxwell was born in Edinburgh, Scotland, at 14 India Street. He was the only child of Edinburgh lawyer John Clerk. The house was in Edinburgh's Georgian area built after the Napoleonic Wars. The family name Maxwell was adopted by the terms of a legal requirement made upon his father to inherit an estate. The family afterwards moved to an estate at Glenlair (near Dumfries).

Maxwell's early education was given by his Christian mother and included studying the Bible. Maxwell then went to Edinburgh Academy in his youth. Maxwell's school nickname was 'Dafty', earned when he arrived for his first day of school wearing home-made shoes. At the Academy, Maxwell met Peter Tait. In 1845, at the age of 15, Maxwell wrote a paper describing mechanical means of drawing mathematical curves with a piece of string, which Professor J. D. Forbes communicated to the Royal Society of Edinburgh.

Middle years

In 1847, Maxwell attended Edinburgh University studing Natural Philosophy, Moral Philosophy, and Mental Philosophy. At Edinburgh, he studied under Sir William Hamilton. In his eighteenth year, while still a student in Edinburgh, he contributed two valuable papers to the Transactions of the same society—one of which, “On the Equilibrium of Elastic Solids,” is remarkable, not only on account of its intrinsic power and the youth of its author, but also because in it he laid the foundation of one of the most singular discoveries of his later life, the temporary double refraction produced in viscous liquids by shearing stress. In 1850, Maxwell left for Cambridge and initially attended Peterhouse but eventually left for Trinity College. In November 1851, Maxwell studied under the tutor William Hopkins (nicknamed the "wrangler maker"). A considerable part of the translation of his electromagnetism equations was accomplished during Maxwell's career as an undergraduate in Trinity.

In 1854, Maxwell graduated with a degree as second wrangler in mathematics from Trinity College, Cambridge (scoring second-highest in the mathematics exam) and was declared equal with the senior wrangler of his year in the higher ordeal of the Smith’s prize examination. For more than half of his brief life he held a prominent position in the very foremost rank of natural philosophers. Immediately after taking his degree, he read to the Cambridge Philosophical Society a novel memoir, “On the Transformation of Surfaces by Bending.” This is one of the few purely mathematical papers he published, and it exhibited at once to experts the full genius of its author. About the same time appeared his elaborate memoir, “On Faraday’s Lines of Force,” in which he gave the first indication of some of those extraordinary electrical investigations which culminated in the greatest work of his life.

From 1855 to 1872, he published at intervals a series of valuable investigations connected with the “Perception of Colour” and “Colour-Blindness,” for the earlier of which he received the Rumford medal from the Royal Society in 1860. The instruments which he devised for these investigations were simple and convenient, but could not have been thought of for the purpose except by a man whose knowledge was co-extensive with his ingenuity. In 1856, Maxwell was appointed to the chair of Natural Philosophy in Marischal College, Aberdeen, which he held until the fusion of the two colleges there in 1860.

He obtained in 1859 the Adams prize in Cambridge for an original and powerful essay, “On the Stability of Saturn’s Rings”, in which he concluded the rings could not be completely solid or fluid. Maxwell demonstrated stability could be reached only if the rings consisted of numerous small solid particles. He also mathematically disproved the nebular hypothesis (which stated that solar system formed through the progressive condensation of a purely gaseous nebula), forcing the theory to account for additional portions of small solid particles.

In 1860, he was a professor at King's College in London. In 1861, Maxwell was elected to the Royal Society. Maxwell researched elastic solids and pure geometry during this time, also.

Kinetic theory

One of Maxwell's greatest investigations bore on the “Kinetic Theory of Gases.” Originating with Bernoulli, this theory was advanced by the successive labours of Herapath, Joule, and particularly Clausius, to such an extent as to put its general accuracy beyond a doubt; but it received enormous development from Maxwell, who in this field appeared as an experimenter (on the laws of gaseous friction) as well as a mathematician.

In 1865, Maxwell moved to the estate he inherited from his father in Glenlair, Kirkcudbrightshire, Scotland. In 1868 he resigned his Chair of Physics and Astronomy at King’s College, London.

In 1866, he statistically formulated, independent of Ludwig Boltzmann, the Maxwell-Boltzmann kinetic theory of gases. In the kinetic theory, temperatures and heat involve only molecular movement. This approach generalized the previous laws of thermodynamics, explaining the observations and experiments in a better way. Maxwell's work on thermodynamics led him to develop the thought experiment, Maxwell's demon.


The great work of Maxwell's life was devoted to electricity. Maxwell's most important contribution was the extension and mathematical formulation of earlier work on electricity and magnetism by Michael Faraday, André-Marie Ampère, and others into a linked set of twenty differential equations in quaternions. Between 1864 and 1873, Maxwell conducted research and demonstrated that the equations could express the behavior of electromagnetic fields and their interrelated nature.

Maxwell began by reading, with the most profound admiration and attention, the whole of Faraday’s extraordinary self-revelations, and proceeded to translate the ideas of that master into the succinct and expressive notation of the mathematician. The equations allow for the existence of a self-propagating electromagnetic wave which has the same velocity as that of light, suggesting that light is in fact that electromagnetic wave. The theory demonstrated that the oscillating electric charge produces a magnetic field. Maxwell's great object, as it was also the great object of Faraday, was to overturn the idea of action at a distance.

This was the first hint that there are at least two perfectly distinct methods of arriving at the known formulae of static electricity. The step to magnetic phenomena was comparatively simple; but it was otherwise as regards electromagnetic phenomena, where current electricity is essentially involved. The first paper of Maxwell’s in which an attempt at an admissible physical theory of electromagnetism was made was communicated to the Royal Society in 1867. But the theory, in a fully developed form, first appeared in 1873 in his great treatise on Electricity and Magnetism.

Availing himself of the admirable generalized co-ordinate system of Lagrange, Maxwell showed how to reduce all electric and magnetic phenomena to stresses and motions of a material medium, and, as one preliminary, but excessively severe, test of the truth of his theory, he pointed out that (if the electromagnetic medium be that which is required for the explanation of the phenomena of light) the velocity of light in vacuo should be numerically the same as the ratio of the electromagnetic and electrostatic units. In fact, the means of the best determinations of each of these quantities separately agree with one another more closely than do the various values of either. Maxwell used the concept of the aether to explain electromagnetic radiation. The validity of the self-propagating electromagnetic wave suggestion was later demonstrated in experiments by Heinrich Rudolf Hertz, and was fundamental to the invention of radio. Ludwig Boltzmann helped present the Maxwell equation to the general population in his lectures on Maxwell's theory.

A similar mathematical system was used later by Einstein for the theory of relativity. Relativity and Maxwell's theory have many similarities, and it can be said that Maxwell's formulation of electromagnetism was a precursor of the theory of relativity. Heaviside reduced the complexity of the theory down to four differential equations, known now collectively as Maxwell's Laws or Maxwell's equations. Maxwell's Laws describe the nature of static and moving electric and magnetic charges, and the relationship between the two, namely electromagnetic induction.

Later years and afterwards

Maxwell also made contributions to the area of optics and colour vision, being credited with the discovery that colour photographs could be formed using red, green, and blue filters. He had the photographer Thomas Sutton photograph a tartan ribbon three times, each time with a different colour filter over the lens. The three images were developed and then projected onto a screen with three different projectors, each equipped with the same colour filter used to take its image. When brought into register, the three images formed a full colour image. Maxwell's work on colour blindness allowed him to win the Rumford Medal by the Royal Society of London. He wrote an admirable textbook of the "Theory of Heat" (1871), and an excellent elementary treatise on "Matter and Motion" (1876). The three photographic plates now reside in a small museum at 14 India Street, Edinburgh, the house where he was born.

In 1871, he was the first Cavendish Professor of Physics at Cambridge. Maxwell supervised the development of the Cavendish laboratory. He superintended every step of the progress of the building and of the purchase of the very valuable collection of apparatus with which it was equipped at the expense of its munificent founder, the seventh duke of Devonshire (chancellor of the university, and one of its most distinguished alumni). One of Maxwell’s last great contributions to science was the editing (with copious original notes) of the Electrical Researches of Henry Cavendish, from which it appeared that Cavendish researched such questions as the mean density of the earth and the composition of water, among other things.

On November 5, 1879, Maxwell died of abdominal cancer.

The extended biography "The Life of James Clerk Maxwell", by his former schoolfellow and lifelong friend Professor Lewis Campbell, was published in 1882 and his collected works, including the series of articles on the properties of matter, such as “Atom,” “Attraction,” “Capillary Action,” “Diffusion,” “Ether,” etc., were issued in two volumes by the Cambridge University Press in 1890.


"Aye, I suppose I could stay up that late." — Maxwell, on being told on his arrival at Cambridge University that there would be a compulsory 6 a.m. church service

"[Electromagnetism] velocity is nearly that of light ... have strong reason to conclude that light in such a way itself (including radiant heat, and other radiation if any) is an electromagnetic disturbance propagated through the electromagnetic field according to waves into the form of electromagnetic laws." — James Maxwell

"The special theory of relativity owes its origins to Maxwell's equations of the electromagnetic field" — Albert Einstein

"He achieved greatness unequalled." — Max Planck

"From a long view of the history of mankind - seen from, say, ten thousand years from now - there can be little doubt that the most significant event of the 19th century will be judged as Maxwell's discovery of the laws of electrodynamics" — Richard Feynman

"Maxwell's importance in the history of scientific thought is comparable to Einstein's (whom he inspired) and to Newton's (whose influence he curtailed)" — Ivan Tolstoy (Biographer)


See also

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From Wikipedia, the free encyclopedia. 
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