Maxwell, James Clerk

SUBJECT AREA: Chemical technology, Electricity

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b. 13 June 1831 Edinburgh, Scotland

d. 5 November 1879 Cambridge, England

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Scottish physicist who formulated the unified theory of electromagnetism, the kinetic theory of gases and a theory of colour.

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Maxwell attended school at the Edinburgh Academy and at the age of 16 went on to study at Edinburgh University. In 1850 he entered Trinity College, Cambridge, where he graduated four years later as Second Wrangler with the award of the Smith's Prize. Two years later he was appointed Professor at Marischal College, Aberdeen, where he married the Principal's daughter. In 1860 he moved to King's College London, but on the death of his father five years later, Maxwell returned to the family home in Scotland, where he continued his researches as far as the life of a gentleman farmer allowed. This rural existence was interrupted in 1874 when he was persuaded to accept the chair of Cavendish Professor of Experimental Physics at Cambridge. Unfortunately, in 1879 he contracted the cancer that brought his brilliant career to an untimely end. While at Cambridge, Maxwell founded the Cavendish Laboratory for research in physics. A succession of distinguished physicists headed the laboratory, making it one of the world's great centres for notable discoveries in physics.

During the mid-1850s, Maxwell worked towards a theory to explain electrical and magnetic phenomena in mathematical terms, culminating in 1864 with the formulation of the fundamental equations of electromagnetism (Maxwell's equations). These equations also described the propagation of light, for he had shown that light consists of transverse electromagnetic waves in a hypothetical medium, the "ether". This great synthesis of theories uniting a wide range of phenomena is worthy to set beside those of Sir Isaac Newton and Einstein. Like all such syntheses, it led on to further discoveries. Maxwell himself had suggested that light represented only a small part of the spectrum of electromagnetic waves, and in 1888 Hertz confirmed the discovery of another small part of the spectrum, radio waves, with momentous implications for the development of telecommunication technology. Maxwell contributed to the kinetic theory of gases, which by then were viewed as consisting of a mass of randomly moving molecules colliding with each other and with the walls of the containing vessel. From 1869 Maxwell applied statistical methods to describe the molecular motion in mathematical terms. This led to a greater understanding of the behaviour of gases, with important consequences for the chemical industry.

Of more direct technological application was Maxwell's work on colour vision, begun in 1849, showing that all colours could be derived from the three primary colours, red, yellow and blue. This enabled him in 1861 to produce the first colour photograph, of a tartan. Maxwell's discoveries about colour vision were quickly taken up and led to the development of colour printing and photography.

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Bibliography

Most of his technical papers are reprinted in The Scientific Papers of J.Clerk Maxwell, 1890, ed. W.D.Niven, Cambridge, 2 vols; reprinted 1952, New York.

Maxwell published several books, including Theory of Heat, 1870, London (1894, 11th edn, with notes by Lord Rayleigh) and Theory of Electricity and Magnetism, 1873, Oxford (1891, ed. J.J.Thomson, 3rd edn).

Further Reading

L.Campbell and W.Garnett, 1882, The Life of James Clerk Maxwell, London (the standard biography).

J.J.Thomson (ed.), 1931, James Clerk Maxwell 1831–1931, Cambridge. J.G.Crowther, 1932, British Scientists of the Nineteenth Century, London.

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