(* 26 june 1824 ; +17 december 1907) was a British mathematical physicist and engineer. At the University of Glasgow he did important work in the mathematical analysis of electricity and formation of the first and second Laws of Thermodynamics. He helped unify the emerging discipline of physics in its modern form. He also had a career as an electric telegraph engineer and inventor, which propelled him into the public eye and ensured his wealth, fame and honour. For his work on the transatlantic telegraph project he was Knighted by Queen Victoria, becoming Sir William Thomson. He had extensive maritime interests and was most rewarded for his work on the mariners compass which had until then been limited in reliability. William Thomson is also widely known for developing the basis of Absolute Zero. On his ennoblement he adopted the title Baron Kelvin of Largs in honour of his achievements in thermodynamics and is therefore often described as Lord Kelvin. He was the first UK scientist to be elevated to the House of Lords. The title refers to the River Kelvin, which flows close by his laboratory at the university of Glasgow, Scotland. Despite offers of elevated posts from several world renowned universities, Lord Kelvin refused to leave Glasgow, remaining Professor of Natural Philosophy for over 50 years. On his eventual retirement from that post The Hunterian Museum at the University of Glasgow has a permanent exhibition on the work of Lord Kelvin including many of his original papers, instruments and other artifacts. William Thomson's father, Dr. James Thomson, was a teacher of mathematics and engineering at Royal Belfast Academical Institution and the son of a farmer. He was able to make a generous provision for his favourite son's education and, installed him with extensive letters of introduction at Peterhouse, Cambridge in 1841. In 1845 Thomson graduated as Second Wrangler. In the same year he gave the first mathematical development of Faraday's idea that electric induction takes place through an intervening medium, or "dielectric", and not by some incomprehensible "action at a distance". He also devised a hypothesis of electrical images, which became a powerful agent in solving problems of electrostatics, or the science which deals with the forces of electricity at rest. It was partly in response to his encouragement that Faraday undertook the research in September 1845 that led to the discovery of the Faraday effect. Thermodynamics By 1847, Thomson had already gained a reputation as a maverick scientist when he attended the British Association for the Advancement of Science annual meeting in Oxford. He heard James Prescott Joule making ineffective attempts to discredit the caloric theory of heat and the theory of the heat engine by Sadi Carnot and Émile Clapeyron. Joule argued for the mutual convertibility of heat and mechanical work and for their mechanical equivalence. Thomson was intrigued but skeptical. Though he felt that Joule's results demanded theoretical explanation, he retreated into an even deeper commitment to the Carnot–Clapeyron school. He predicted that the melting point of ice must fall with pressure, otherwise its expansion on freezing could be exploited in a perpetuum mobile. Thomson returned to critique Carnot's original publication and read his analysis to the Royal Society of Edinburgh in January 1849, still convinced that the theory was fundamentally sound. In final publication, Thomson retreated from a radical departure and declared "the whole theory of the motive power of heat is founded on ... two ... propositions, due respectively to Joule, and to Carnot and Clausius." After reading the paper Joule wrote to Thomson with comments and questions. Thus began a fruitful, though largely epistolary, collaboration between the two men. Calculations on data rate In September 1852 Thompson married childhood sweetheart Margaret Crum but her health broke down on their honeymoon and, over the next seventeen years, Thomson was distracted by her suffering. On 16 October 1854, George Gabriel Stokes wrote to Thomson to try to re-interest him in work by asking his opinion on some experiments of Michael Faraday on the proposed transatlantic telegraph cable. Faraday had demonstrated how the construction of a cable would limit the rate at which messages could be sent — in modern terms, the bandwidth. Thomson jumped at the problem and published his response that month. He expressed his results in terms of the data rate that could be achieved and the economic consequences in terms of the potential revenue of the transatlantic undertaking. In a further analysis, he stressed the impact that the design of the cable would have on its profitability. Thomson contended that the speed of a signal through a given core was inversely proportional to the square of the length of the core. Whitehouse believed that Thomson's calculations meant that the cable had to be dropped as being practically and commercially impossible." Thomson recommended a larger conductor with a larger cross section of insulation. However, he thought Whitehouse no fool and suspected that he may have the practical skill to make the existing design work. Later expeditions Thomson took part in the laying of the French Atlantic submarine communications cable of 1869, and with Jenkin was engineer of the Western and Brazilian and Platino-Brazilian cables, assisted by vacation student James Alfred Ewing. He was present at the laying of the Pará to Pernambuco section of the Brazilian coast cables in 1873. Addicted to seafaring, in September he purchased a 126 ton schooner, the Lalla Rookh and used it as a base for entertaining friends and scientific colleagues. In 1871 he was appointed to the board of enquiry into the sinking of the HMS Captain Source: Wikipedia