thumb|James Clerk Maxwell

'''James Clerk Maxwell''' (skoskur raf og segulkraftana í safn fjögurra jöfnuhneppa sem saman kallast jöfnur Maxwells. Einnig er hann frægur fyrir að hafa komið með tölfræðilega lýsingu á kvikfræðilegri hegðun atóma í formi Maxwell dreifingarinnar.

Uppgötvanir Maxwells höfðu mikil áhrif á nútímaeðlisfræði og lögðu t.d. grundvöllinn að hinni sértæku afstæðiskenningu og skammtafræðinni. Maxwell er einnig þekktur fyrir að taka fyrstu litljósmyndina árið 1861.

Nánast allur ferill Maxwell var í háskólanum í Cambridge, þar sem rannsóknir hans byggðu oftar en ekki á miklum stærðfræðihæfileikum hans, sérstaklega á sviði rúmfræði og algebru. Með þessa hæfileika að vopni gat Maxwell sýnt fram á að raf- og segulsvið ferðast um rúmið í formi bylgna á föstum hraða ljóssins. Loks árið 1961, skrifaði Maxwell grein í fjórum hlutum í tímaritið ''Philosophical Magazine'' sem nefndist [http://www.vacuum-physics.com/Maxwell/maxwell_oplf.pdf ''On Physical Lines of Force''], þar sem hann setur fyrst fram að ljós sé í raun bylgjuhreyfing í sama miðli og er orsökin fyrir rafmagni og segulmagni.

Maxwell er álitin af mörgum - sérstaklega innan eðlisfræðinnar - vera sá vísindamaður 19. aldar sem mest áhrif hafði á 20. aldar eðlisfræði. Framlög hans til eðlisfræðinnar eru af mörgum talin mega setja til jafns við framlög Newtons og Einsteins. Árið 1931 á aldarafmæli Maxwells lýsti Albert Einstein verkum Maxwells sem "þeim mikilvægustu og þeim sem mestan ávöxt hafa borið síðan Newton var uppi."

{{Infobox Scientist
|box_width         = 300px
|name              = James Clerk Maxwell
|image             = James Clerk Maxwell.png
|image_size        = 300px
|caption           = James Clerk Maxwell (1831-1879)
|birth_date        = 
|birth_place       = Edinburgh, Scotland, United Kingdom
|death_date        = 
|death_place       = Cambridge, England, United Kingdom
|residence         = 
|citizenship       =
|nationality       = 
|ethnicity         = 
|fields            = Physics and mathematics
|workplaces        = Marischal College, Aberdeen</br>King's College London</br>University of Cambridge
|alma_mater        = University of Edinburgh</br> University of Cambridge
|doctoral_advisor  = <!--There was no PhD degree in Cambridge until 1919-->
|academic_advisors = William Hopkins
|doctoral_students = <!--There was no PhD degree in Cambridge until 1919-->
|notable_students  = George Chrystal
|known_for         = Maxwell's equations</br>Maxwell distribution</br>Maxwell's demon</br>Maxwell's discs</br>Maxwell speed distribution</br>Maxwell's theorem</br>Maxwell material</br>Generalized Maxwell Model</br>Displacement current
|author_abbrev_bot =
|author_abbrev_zoo =
|influences        =
|influenced        =
|awards            = Smith's Prize</br>Rumford Medal</br>Adams Prize
|religion          = Evangelical anti-positivist
|signature         = maxwell_sig.jpg
|footnotes         =
}}
'''James Clerk Maxwell''' (Scottish mathematician and theoretical physicist. His most significant achievement was the development of the classical Newton.

Maxwell demonstrated that electric and magnetic fields travel through space in the form of waves, and at the constant speed of light. Finally, in 1864 Maxwell wrote ''A Dynamical Theory of the Electromagnetic Field'' where he first proposed that light was in fact undulations in the same medium that is the cause of electric and magnetic phenomena. His work in producing a unified model of electromagnetism is considered to be one of the greatest advances in physics.

Maxwell also developed the Maxwell distribution, a statistical means to describe aspects of the kinetic theory of gases. These two discoveries helped usher in the era of modern physics, laying the foundation for future work in such fields as special relativity and colour photograph in 1861.

Maxwell is considered by many physicists to be the most influential nineteenth century scientist on twentieth century physics. His contributions to the science are considered by many to be of the same magnitude as those of Einstein himself described Maxwell's work as the "''most profound and the most fruitful that physics has experienced since the time of Newton.''"<ref>McFall, Patrick
[http://www.maxwellyear2006.org/html/press_coverage.html "Brainy young James wasn't so daft after all"] ''The Sunday Post'', 23 April 2006</ref> Einstein kept a photograph of Maxwell on his study wall, alongside pictures of Michael Faraday and Isaac Newton.<ref>"Einstein's Heroes: Imagining the World through the Language of Mathematics", by Robyn Arianrhod
UQP, reviewed by Jane Gleeson-White, 10 November 2003, The Sydney Morning Herald.</ref>
== Biography ==
===Early life, 1831&ndash;1839===
James Clerk Maxwell was born on Clerk of Penicuik; his brother being the 6th Baronet.<ref>
{{citation
|title = John Clerk-Maxwell of Middlebie
|publisher = thePeerage.com
|url = http://www.thepeerage.com/p22717.htm#i227165
|accessdate = 2008-02-16}}</ref> He had been born John Clerk,<ref>
{{citation
|title = James Clerk
|publisher = thePeerage.com
|url = http://www.thepeerage.com/p22717.htm#i227169
|accessdate = 2008-02-16}}</ref> adding the surname Maxwell to his own after he inherited a country estate in Middlebie, Kirkcudbrightshire from connections to the Maxwell family, themselves members of the peerage.<ref name="oxford_506"/> Maxwell's parents did not meet and marry until they were well into their thirties,<ref>Tolstoy, p11</ref> unusual for the times, and Frances Maxwell was nearly 40 when James was born. They had had one earlier child, a daughter, Elizabeth, who had died in infancy.<ref>Campbell, p1.</ref> They named their only surviving child James, a name that had sufficed not only for his grandfather, but by many of his ancestors.

The family moved when Maxwell was young to "estate.<ref>Mahon, pp186-187</ref> All indications suggest that Maxwell had maintained an unquenchable curiosity from an early age.<ref>Tolstoy, p13</ref> By the age of three, everything that moved, shone, or made a noise drew the question: "what's the go o' that?".<ref>Mahon, p3</ref> In a letter to his sister-in-law Jane Cay in 1834, his father described this innate sense of inquisitiveness:
<blockquote> He is a very happy man, and has improved much since the weather got moderate; he has great work with doors, locks, keys, etc., and "show me how it doos" is never out of his mouth. He also investigates the hidden course of streams and bell-wires, the way the water gets from the pond through the wall ...<ref name="Campbell_p12">Campbell, p12</ref></blockquote>

===Education, 1839&ndash;1847===
Recognizing the potential of the young boy, his mother Frances took responsibility for James' early education, which in Victorian era was largely the job of the woman of the house.<ref name="Tolstoy_p15-16">Tolstoy, pp15-16</ref> She was however taken ill with abdominal Jemima, herself a talented artist.<ref name="mahon_p12-14">Mahon, pp12-14</ref>

right|thumb|325px|Edinburgh Academy, where Maxwell was schooled
The ten-year old Maxwell, raised in isolation on his father's countryside estate, did not fit in well at school.<ref name="mahon_p10">Mahon, p10</ref> The first year had been full, obliging him to join the second year with classmates a year his senior.<ref name="mahon_p10"/> His mannerisms and Daftie".<ref>Mahon, p4</ref> Maxwell, however, never seemed to have resented the epithet, bearing it without complaint for many years.<ref>Campbell, pp23-24</ref> Any social isolation at the Academy however ended when he met Lewis Campbell and Peter Guthrie Tait, two boys of a similar age, and themselves to become notable scholars. They would remain lifetime friends.<ref name="oxford_506"/>

Maxwell was fascinated by geometry at an early age, rediscovering the regular polyhedra before any formal instruction.<ref name="mahon_p12-14"/> Much of his talent went unnoticed however, and, despite winning the school's scripture biography prize in his second year, his academic work remained unremarkable,<ref name="mahon_p12-14"/> until, at the age of 13, he won the school's mathematical medal, and first prizes for English and poetry.<ref>Campbell, p43</ref>

For his first scientific work, at the age of only 14, Maxwell wrote a paper describing a mechanical means of drawing foci. His work, ''Oval Curves'', was presented to the James Forbes, professor of natural philosophy at Descartes having examined the properties of such multifocal curves in the seventeenth century, though Maxwell had simplified their construction.<ref>Mahon, p16</ref>

===Edinburgh University, 1847&ndash;1850===
right|thumb|Edinburgh University
Maxwell left the Academy in 1847 at the age of 16 and began attending classes at the Sir William Hamilton, who lectured him on James Forbes on natural philosophy.<ref name="oxford_506"/>
Maxwell did not however find his classes at Edinburgh very demanding,<ref>Tolstoy, p46</ref> and was able to immerse himself in private study during free time at the university, and particularly when back home at Glenlair.<ref>Campbell, p64</ref> There he would experiment with improvised chemical and electromagnetic apparatus, but his chief preoccupation was the properties of stresses, and with a pair of polarising prisms gifted him by the famous scientist William Nichol, would view the coloured fringes developed within the jelly.<ref>Timoshenko, p58</ref> Maxwell had discovered photoelasticity, a means of determining the stress distribution within physical structures.<ref>
{{cite book
| last = Russo
| first = Remigio
| title = Mathematical Problems in Elasticity
| publisher = World Scientific
| date = 1996
| pages = p73 | isbn = 9810225768 }}
</ref>

In his eighteenth year, Maxwell contributed two papers for the ''Transactions of the Royal Society of Edinburgh''&mdash;one of which, ''On the Equilibrium of Elastic Solids'', laid the foundation for an important discovery of his later life: the temporary viscous liquids by shear stress.<ref>Timoshenko, pp268-278</ref> The other was titled ''Rolling Curves''. As with his schoolboy paper ''Oval Curves'', Maxwell was considered too young to stand at the rostrum and present it himself, and it was delivered to the Royal Society by his tutor Kelland.<ref>Glazebrook, p23</ref>

===Cambridge University, 1850&ndash;1856===
thumb|right|A young Maxwell at [[Trinity College, Cambridge|Trinity College, Cambridge. He is holding one of his colour wheels.]]
In October 1850, already an accomplished mathematician, Maxwell left Scotland for Cambridge University.<ref name="oxford_506"/> He initially attended Peterhouse, but before the end of his first term transferred to Trinity College, where he believed it would be easier to obtain a fellowship.<ref>Glazebrook, p28</ref> At Trinity, he was elected to the elite secret society known as the wrangler-maker".<ref></ref> A considerable part of Maxwell's translation of his electromagnetism equations was accomplished during his time in Trinity.

In 1854, Maxwell graduated from Trinity with a degree in mathematics. He scored second highest in the final examination, coming behind fellowship, a process that he could expect to take a couple of years.<ref name="Mahon_p47-48">Mahon, pp47-48</ref> Buoyed by his success as a research student, he would be free, aside from some tutoring and examining duties, to pursue scientific interests at his own leisure.<ref name="Mahon_p47-48"/>

The nature and perception of spinning tops invented by Forbes, and was able to demonstrate that white light would result from a mixture of red, green and blue light.<ref name="Mahon_p51"/> His paper, ''Experiments on Colour'', laid out the principles of colour combination, and was presented to the Royal Society of Edinburgh in March 1855.<ref name="Tolstoy_p64-65">Tolstoy, pp64-65. The full title of Maxwell's paper is ''Experiments on Colour, as perceived by the Eye, with remarks on Colour-blindness''.</ref> This time, it would be Maxwell himself who delivered his lecture.<ref name="Tolstoy_p64-65"/>

Maxwell was made a fellow of Trinity on Chair of Natural Philosophy at Marischal College, Aberdeen, had become vacant, and urged to apply.<ref name="Campbell p126">Campbell, p126</ref> His father assisted him in the task of preparing the necessary references, but died on 2 April at Glenlair before either knew the result of Maxwell's candidacy.<ref name="Campbell p126"/> Maxwell nevertheless accepted the professorship at Aberdeen, leaving Cambridge in November 1856.<ref name="Glazebrook_p43-46"/>

=== Aberdeen University, 1856&ndash;1860 ===
The twenty-five year old Maxwell was a decade and a half younger than any other professor at Marischal, but engaged himself with his new responsibilities as head of department, devising the syllabus and preparing the lectures.<ref name="Mahon_p69-71">Mahon, pp69-71</ref> He committed himself to lecturing 15&nbsp;hours a week, including a weekly ''pro bono'' lecture to the local working men's college.<ref name="Mahon_p69-71"/> He lived in Aberdeen during the six months of the academic year, and would spend the summers at Glenlair, which he had inherited from his father.

thumb|James and Katherine Maxwell, 1869.
His mind was focussed on a conundrum which had eluded scientists for two hundred years: the nature of Saturn's rings. It was unknown how they could remain stable without breaking up, drifting away or crashing into Saturn. The problem took on a particular resonance at this time as ''Voyager'' flybys of the 1980s.
<!--Replace later: He also mathematically disproved the nebular hypothesis (which stated that the solar system formed through the progressive condensation of a purely gaseous nebula), forcing the theory to account for additional portions of small solid particles.-->

Maxwell had in 1857 befriended the Principal of Marischal, the Reverend Daniel Dewar, and through him he was to meet Dewar's daughter, Katherine Mary Dewar. They were engaged in February 1858, marrying in Aberdeen on 2 June that year. Comparatively little is known of Katherine, seven years Maxwell's senior: Maxwell's biographer and friend Campbell adopted an uncharacteristic reticence on the subject, though describing their married life as "one of unexampled devotion".<ref>Tolstoy, pp88-91</ref>

In 1860, Marischal College merged with the neighbouring King's College to form the University of Aberdeen. There was no room for two professors of Natural Philosophy, and Maxwell found himself in the extraordinary position for someone of his scientific stature of being laid off. He was unsuccessful applying for Forbes' recently vacated chair at Edinburgh, the post going to Tait, but was granted instead the Chair of Natural Philosophy at King's College London.<ref name="Glazebrook_p54>Glazebrook, p54</ref> After recovering from a near-fatal bout of smallpox in the summer of 1860, Maxwell headed south to London with his wife Katherine.<ref>Tolstoy, p98</ref>

=== King's College London, 1860&ndash;1865 ===
Maxwell's time at King's was probably the most productive of his career. He was awarded the Royal Society's Rumford Medal in 1860 for his work on colour, and elected to the Society itself in 1861.<ref name="Tolstoy_p103-104">Tolstoy, p103</ref> This period of his life would see him display the world's first colour photograph, develop further his ideas on the viscosity of gases, and proposed a system of defining physical quantities, now known as dimensional analysis. Maxwell would often attend lectures at the Royal Institution, where he came into regular contact with Michael Faraday. The relationship between the two men could not be described as close&mdash;Faraday was 40&nbsp;years Maxwell's senior and showing signs of senility&mdash;but they maintained a strong respect for each other's talents.<ref>Tolstoy, pp100-101</ref>

The time is especially known for the advances Maxwell made in electromagnetism. He had examined the nature of electromagnetic fields in his two-part 1861 paper ''On Physical Lines of Force'', in which he had provided a conceptual model for electromagnetic induction, consisting of tiny spinning cells of magnetic flux. A further two parts to the paper were published early in 1862, in the first of which he discussed the nature of electrostatics and displacement current. The final part dealt with the rotation of the plane of polarisation of light in a magnetic field, a phenomenon discovered by Faraday and now known as the Faraday effect.<ref>Mahon, p109</ref>

===Later years===
In 1865, Maxwell resigned the chair at King's College London and returned to Glenlair with Katherine.

He wrote a textbook of the ''Theory of Heat'' (1871), and an elementary treatise on ''Matter and Motion'' (1876). Maxwell was also the first to make explicit use of dimensional analysis, also in 1871.

In 1871, he became the first Cambridge. Maxwell was put in charge of the development of the 7th 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.

He died in Cambridge of Parton Kirk, near Castle Douglas in Galloway, Scotland.
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.

===Christianity===
All information available suggests that neither in his adolescence, nor in his later years, did Maxwell reject the fundamental principles of his Christian faith.<ref name="Rel0"> McNatt, Jerrold L. [http://www.asa3.org/ASA/PSCF/2004/PSCF9-04McNatt.pdf "James Clerk Maxwell’s Refusal to Join the Victoria Institute"] ''Perspectives on Science and Christian Faith'', September 2004</ref><ref name="Rel00"> </ref> Ivan Tolstoy, author of one of Maxwell's biographies, remarked at the frequency with which scientists writing short biographies on Maxwell often omit the subject of his religion. Maxwell's spiritual beliefs and related activities have been the focus of several peer-reviewed and well-referenced papers.<ref name="Rel0"/><ref name="Rel00"/><ref name="Rel1"> Theerman, Paul "James Clerk Maxwell and religion", ''American Journal of Physics'', 54 (4), April 1986, p.312–317 </ref><ref>  </ref> Attending both Presbyterian and Episcopalian services as a child, Maxwell later underwent an Evangelical conversion (April 1853).<ref name="Rel1"/> This committed him to an anti-positivist position.<ref name="Rel1"/>

===Personality===
As a great lover of British poetry, Maxwell memorized poems and wrote his own. The best known is ''Rigid Body Sings'' closely based on ''Comin' Through the Rye'' by Robert Burns, which he apparently used to sing while accompanying himself on a guitar. It has the immortal opening lines<ref>
{{cite web
|title=Rigid Body Sings
|work=PhysicsSongs.org
|url=http://www.haverford.edu/physics-astro/songs/rigid.htm
|accessdate=2008-04-15}}</ref>

:''Gin a body meet a body''
:''Flyin' through the air.''
:''Gin a body hit a body,''
:''Will it fly? And where?''

A collection of his poems was published by his friend Lewis Campbell in 1882.

==Contributions==
=== Electromagnetism===

thumb|A postcard from Maxwell to [[Peter Guthrie Tait|Peter Tait.]]
Maxwell had studied and commented on the field of electricity and magnetism as early as 1855/6 when ''On Faraday's lines of force'' was read to the Cambridge Philosophical Society. The paper presented a simplified model of Faraday's work, and how the two phenomena were related. He reduced all of the current knowledge into a linked set of differential equations with 20 equations in 20 variables. This work was later published as ''On Physical Lines of Force'' in March 1861.<ref> James Clerk Maxwell, ''[http://upload.wikimedia.org/wikipedia/commons/b/b8/On_Physical_Lines_of_Force.pdf On Physical Lines of Force]'',  Philosophical Magazine, 1861</ref>