William Thomson a.k.a. Lord Kelvin
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William Thomson was a figure of great importance in history of science and as an engineer. He formulated the second law of thermodynamics and co-operated with James Prescott Joule which discovered Joule-Thomson effect as a physicist. As an engineer, he helped in solving many of the difficulty in laying the first transatlantic cable, improving on mariner's compass and quality of signal in telegraph, and invented both mirror galvanometer and the siphon recorder which earn him fame and fortune. In recognition of his work on the cable, William Thomson was knighted by Queen Victoria and later raised to the status of Baron Kelvin of Largs. He die on 17 Dec. 1907 and is buried in Westminster abbey beside Sir Isaac Newton.
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Early life and work
Family and the young Thomson
William Thomson was born on 26 June, 1824 in Belfast, Ireland. His father, Dr. James Thomson was the head of the mathematical department of the royal academical institution. William and his older brother James were home schooled by their father while the other children were tutored by their elder sisters. William began study at Glasgow University in 1834 at the age of 10, which was not unusual at that period.
Their father took them on a tour in Germany in 1840, intended for the boys to learn the language at first hand, but William have just discovered a book on Fourier's work on mathematical physics which completely absorbed him and influence him greatly later in his career. He have no time for speaking German. Jean Baptiste Joseph Fourier's work have been attacked by many British mathematicians which still working in the shadow of Isaac Newton, so naturally the young William wrote his first published scientific paper under the pseudonym P.Q.R.in 1841, defending Fourier, and submitted to the Cambridge Mathematical Journal by his father. Two more paper was publish under the name P.Q.R.. His third paper On the uniform motion of heat in homogeneous solid bodies, and its connection with the mathematical theory of electricity made remarkable connection between mathematical theories of heat conduction and electrostatics, that it was call one of the most valuable science-forming ideas by James Clerk Maxwell.
Education
In 1841, with his father paving the way, Thomson was admitted into Peterhouse, Cambridge. Before graduated with a Smith's Prize at 1845, he was very active in sports and the culture such as music. He even won the Silver Sculls and rowed in the winning boat of the Oxford and Cambridge Boat Race. In 1845, he made the first mathematical development of faraday's idea that electric induction takes place through an intervening medium, or dielectric, and not by some "action at a distance" like Newton suggested.
Soon after gaining a fellowship at Peterhouse, Cambridge, Thomson spent time to study under the great physicist Henri Victor Regnault at Paris who was working on Thermodynamics. In 1846, Thomson was appointed to teach at his old university in Glasgow, which he remained for 53 years, at the age of 22.
It was said he often forgetting he was talking to students and not himself in class. Something in the subject matter would suggest an idea to him and he would cover the blackboards with figures that meant nothing to his audience. Professor Thomson was popular amount student who loved physics. They were interested in his discussion of physical meaning instead of stereotyped textbook phases. Fortunately for him, university sessions only lasted 6 months of the year, and he was left with great deal of free time to pursue his own research.
Thermodynamics
In 1847, while Thomson was attending the annual meeting of the British
Association for the Advancement of Science in Oxford, he heard
James Prescott
Joule discrediting the caloric theory of heat and the theory of
the heat
engine built upon it by Sadi Carnot and Émile Clapeyron and
favor for Mutual convertibility of heat and mechanical work and for their
mechanical equivalence. This spark his interest in thermodynamics again. Later,
he found that "to a given amount of mechanical work there is a corresponding
definite amount of heat, and from this, he proposed an absolute temperature
scale in which a unit of heat descending from a body A at the temperature T°
of this scale, to a body B at the temperature (T-1)°, would give out the
same mechanical effect [work], whatever be the number T. Such
a scale would be quite independent of the physical properties of any specific
substance." quote from Wikipedia.org. This work supported Joule's work with combination of
works from Sadi Carnot and Émile Clapeyron, gain these discoveries the attention
they deserved.
As soon as Joule read the paper he wrote to Thomson with his comments and questions. Thus began a fruitful, though largely epistolary, collaboration between the two men, Joule conducting experiments, Thomson analyzing the results and suggesting further experiments. The collaboration lasted from 1852 to 1856, its discoveries including the Joule-Thomson effect, and the published results did much to bring about general acceptance of Joule's work and the kinetic theory.
From his second law of thermodynamics, he led to the speculation of the end of the university as heat death. When a close system such as the university have converted all its mechanical work into heat and this heat is uniformly distributed in all space, there can not be any more work done to sustain motion or life. In physical terms, it has reached maximum entropy.
Transatlantic cable
Thomson and the Bandwidth Problem
The most important contribution from William Thomson was probably his
involvement in laying the transatlantic cable and improvement on the quality of
signal received. In 1854, Stokes wrote to Thomson asking his opinion on the
Bandwidth problems in a transatlantic telegraph cable. Old telegraph cable was
made with copper core and insulator covering it, this works fine in shorter
distance but once they are put underground or submerge in water, the quality
decrease dramatically. Faraday explain this in term of water/earth and copper
core act as a long capacitor and inductor to retard the rate electricity moving
through it. Also the long distance of wire will increase in the overall
resistance of the cable made many thought it is not feasible to lay down a
transatlantic cable. Thomson jumped at the problem and published his response.
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 1855 analysis,
Thomson stressed the impact that the design of the cable would have on its profitability.
This is known in history as the
Bandwidth problems.
Soon after his publication, he was named chief director in the Atlantic Telegraph Company, a consultant on laying the first cable. Thomson contended that the speed of a signal through a given core was inversely proportional to the square of the length of the core and recommended using a purer copper to lower resistance and improve on the conductivity, and increase the thickness of cross-section on the cable. Thomson's results were disputed at a meeting of the British Association in 1856 by Wildman Whitehouse, the electrician of the Atlantic Telegraph Company. Whitehouse had possibly misinterpreted the results of his own experiments but was doubtless feeling financial pressure as plans for the cable were already well underway. He believed that Thomson's calculations implied that the cable must be "abandoned as being practically and commercially impossible."
Scientist turn engineer
The failure of Whitehouse to acknowledge the design flaw of the cable would
come back later to haunt him as the first two cable fail to deliver what it
promise and
break very soon after. Thomson argued they must build a new and
better cable. Using one of his invention, the mirror galvanometer
which enhance the signal greatly, the new cable was a success. As electrical
engineer of the expedition and the man most responsible for its success, William
Thomson was knighted by Queen Victoria. He later would further improve on the
sensitivity of receiving signal by inventing the
siphon recorder.
During the expedition of laying transoceanic cables, he noticed the sailors repeat the inaccurate and time consuming process of deep-sea sounding which was important in laying cable. Thomson thought of a was batter than a sinker at the end of a long rope, he use the pressure of the deep sea to calculate how deep the ocean is. Today Thomson's sounding device, which evolved into a seven-strand steel cable 300 fathoms in length, is still in use.
When he was ask to write an article on the mariner's compass for a technical journal, he found that he knew very little about it. He studied the compasses then in use, and was surprised at how faulty they are, the needles were heavy, often 15 inches long. They were mounted on larch card that suppose to make them steady, but in fine weather they often stalled and in stormy weather they were practically useless. After reading some studies of compass deviation, Thomson decided that a shorter needle mounted on a lighter card would be an improvement. A slow horizontal swing will avoid unsteadiness besides lessening the amount of friction to prevent sticking of the needle. He also realized that it was essential to shield a compass from the magnetism of the ship's ironwork. His improved mariner's compass was used almost universally until the advent often gyrocompass.
Honor, awards and death
Beside his knighting in 1866, He was a Fellow of the
Royal Society since 1851 and President from 1890 to 1895. William Thomson
was raised to the peerage of Baron Kelvin of Largs on 1892, to perpetuate the
name of the Kelvin River near Glasgow University. He is a Knight Grand Cross
of the Victorian Order and one of the first members of the Order of Merit
according to Wikipedia. At 1896, Glasgow honored him for having completed a
half-century as a Professor at the university. He retired 3 years later but on
the very same day of his resignation he enrolled as a special student in
scientific research. For 8 more years he worked until his death on 23,Dec 1907.
He was buried beside Sir
Isaac Newton in Westminster
Abbey in London.
In May 1921, Scientists gathered at the Institute of Civil Engineers to award the newly created Kelvin Medal in honor of Lord Kelvin.
Notes/Reference
This website was create with material from Wikipedia.org, a chapter on Lord Kelvin from Famous Men of Science by Sarah K. Bolton and scienceworld.wolfram.com. Pictures are from http://www.faradic.net/~gsraven/fons_images/Page_13/09_ThomsonGalvanom1.JPG, www.atlantic-cable.com/ CablePioneers, www.maths.gla.ac.uk/ research/groups/fluids-mhd/.
