Wednesday 13 August 2014

James Prescott Joule

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James Prescott Joule
Joule James sitting.jpg
James Joule – physicist
Born 24 December 1818
Salford, Lancashire, England, UK
Died 11 October 1889 (aged 70)
Sale, Cheshire, England, UK
Citizenship British
Fields Physics
Known for First law of thermodynamics
Disproving Caloric Theory
Influences John Dalton
John Davies
Notable awards Royal Medal (1852)
Copley Medal (1870)
Albert Medal (1880)
James Prescott Joule FRS (/dʒuːl/;[1] (24 December 1818 – 11 October 1889) was an English physicist and brewer, built-in in Salford, Lancashire. Joule advised the attributes of heat, and apparent its accord to automated plan (see energy). This led to the law of attention of energy, and this led to the development of the aboriginal law of thermodynamics. The SI acquired assemblage of energy, the joule, is alleged for James Joule. He formed with Lord Kelvin to advance the complete calibration of temperature. Joule aswell fabricated observations of magnetostriction, and he begin the accord amid the accepted through a resistor and the calefaction dissipated, which is now alleged Joule's aboriginal law.
Contents [hide]
1 Early years
2 The automated agnate of heat
3 Reception and priority
4 Kinetic theory
5 Honours
6 Selected writings
7 Notes
8 Further reading
9 External links

Early years

The son of a affluent brewer, Joule was accomplished as a adolescent man by the acclaimed scientist John Dalton and was acerb afflicted by chemist William Henry and Manchester engineers Peter Ewart and Eaton Hodgkinson. He was absorbed by electricity, and he and his brother experimented by giving electric shocks to anniversary added and to the family's servants.
As an adult, Joule managed the brewery. Science was alone a austere hobby. Sometime about 1840, he started to investigate the achievability of replacing the brewery's beef engines with the anew invented electric motor. His aboriginal accurate affidavit on the accountable were contributed to William Sturgeon's Annals of Electricity.
Motivated in allotment by a businessman's admiration to quantify the economics of the choice, and in allotment by his accurate inquisitiveness, he set out to actuate which prime mover was the added efficient. He apparent Joule's aboriginal law in 1841, that the calefaction which is acquired by the able activity of any voltaic accepted is proportional to the aboveboard of the acuteness of that current, assorted by the attrition to advice which it experiences.[2] He went on to realise that afire a batter of atramentous in a beef engine was added economical than a cher batter of zinc captivated in an electric battery. Joule captured the achievement of the addition methods in agreement of a accepted standard, the adeptness to accession one pound, a acme of one foot, the foot-pound.
However, Joule's absorption absent from the attenuated banking catechism to that of how abundant plan could be extracted from a accustomed source, arch him to brainstorm about the convertibility of energy. In 1843 he appear after-effects of abstracts assuming that the heating aftereffect he had quantified in 1841 was due to bearing of calefaction in the aqueduct and not its alteration from addition allotment of the equipment. This was a absolute claiming to the caloric approach which captivated that calefaction could neither be created or destroyed. Caloric approach had bedeviled cerebration in the science of calefaction back alien by Antoine Lavoisier in 1783. Lavoisier's authority and the applied success of Sadi Carnot's caloric approach of the calefaction engine back 1824 ensured that the adolescent Joule, alive alfresco either academia or the engineering profession, had a difficult alley ahead. Supporters of the caloric approach readily acicular to the agreement of the Peltier-Seebeck aftereffect to affirmation that calefaction and accepted were convertible in an, at atomic approximately, capricious process.

The mechanical equivalent of heat

Further abstracts and abstracts with his electric motor led Joule to appraisal the automated agnate of calefaction as 838 ftВ·lbf of plan to accession the temperature of a batter of baptize by one amount Fahrenheit.[3] He appear his after-effects at a affair of the actinic area of the British Association for the Advancement of Science in Cork in August 1843 and was met by silence.[4]
Joule was audacious and started to seek a absolutely automated affirmation of the about-face of plan into heat. By banishment baptize through a perforated cylinder, he was able to admeasurement the slight adhesive heating of the fluid. He acquired a automated agnate of 770 ftВ·lbf/Btu (4.14 J/cal). The actuality that the ethics acquired both by electrical and absolutely automated agency were in acceding to at atomic one adjustment of consequence was, to Joule, acute affirmation of the absoluteness of the convertibility of plan into heat.
wherever automated force is expended, an exact agnate of calefaction is consistently obtained
— J.P. Joule, August, 1843
Joule now approved a third route. He abstinent the calefaction generated adjoin the plan done in burden a gas. He acquired a automated agnate of 798 ftВ·lbf/Btu (4.29 J/cal). In abounding ways, this agreement offered the easiest ambition for Joule's critics but Joule disposed of the advancing objections by able experimentation. Joule apprehend his cardboard to the Royal Society on 20 June 1844,[5] however, his cardboard was abandoned for publishing by the Royal Society and he had to be agreeable with publishing in the Philosophical Magazine in 1845.[6] In the cardboard he was aboveboard in his bounce of the caloric acumen of Carnot and Г‰mile Clapeyron, but his apostolic motivations aswell became evident:
I accept that this approach ... is against to the recognised attempt of aesthetics because it leads to the cessation that vis viva may be destroyed by an abnormal disposition of the apparatus: Thus Mr Clapeyron draws the inference that 'the temperature of the blaze getting 1000 В°C to 2000 В°C college than that of the boiler there is an astronomic accident of vis viva in the access of the calefaction from the boiler to the boiler.' Believing that the ability to abort belongs to the Creator abandoned I assert ... that any approach which, if agitated out, demands the abolishment of force, is necessarily erroneous.
Joule actuality adopts the accent of vis viva (energy), possibly because Hodgkinson had apprehend a analysis of Ewart's On the admeasurement of affective force to the Literary and Philosophical Society in April 1844.
Joule wrote in his 1844 paper:
... the automated ability exerted in axis a magneto-electric apparatus is adapted into the calefaction acquired by the access of the currents of consecration through its coils; and, on the added hand, that the motive ability of the electro-magnetic engine is acquired at the amount of the calefaction due to the actinic reactions of the array by which it is worked.
In June 1845, Joule apprehend his cardboard On the Automated Agnate of Calefaction to the British Association affair in Cambridge.[7] In this work, he appear his best-known experiment, involving the use of a falling weight, in which force does the automated work, to circuit a paddle-wheel in an cloistral butt of baptize which added the temperature. He now estimated a automated agnate of 819 ftВ·lbf/Btu (4.41 J/cal). He wrote a letter to the Philosophical Magazine, appear in September 1845 anecdotic his experiment.[8]


Joule's Calefaction Apparatus, 1845
In 1850, Joule appear a aesthetic altitude of 772.692 ftВ·lbf/Btu (4.159 J/cal), afterpiece to twentieth aeon estimates.[9]

Reception and priority

For the altercation over antecedence with Mayer, see Automated agnate of heat: Priority
Much of the antecedent attrition to Joule's plan stemmed from its assurance aloft acutely complete measurements. He claimed to be able to admeasurement temperatures to aural 1вЃ„200 of a amount Fahrenheit (3 mK). Such attention was absolutely aberrant in abreast beginning physics but his doubters may accept alone his acquaintance in the art of brewing and his admission to its applied technologies.[10] He was aswell ably accurate by accurate instrument-maker John Benjamin Dancer. Joule's abstracts complemented the abstract plan of Rudolf Clausius, who is advised by some to be the coinventor of the activity concept.
Joule was proposing a active approach of calefaction (he believed it to be a anatomy of rotational, rather than translational, active energy), and this appropriate a conceptual leap: if calefaction was a anatomy of atomic motion, why didn't the motion of the molecules gradually die out? Joule's annual appropriate one to accept that the collisions of molecules were altogether elastic. We should aswell bethink that the actual actuality of atoms and molecules was not broadly accustomed for addition hundred years.
Although it may be harder today to accept the attraction of the caloric theory, at the time it seemed to accept some bright advantages. Carnot's acknowledged approach of calefaction engines had aswell been based on the caloric assumption, and alone after was it accepted by Lord Kelvin that Carnot's mathematics were appropriately accurate after bold a caloric fluid.
However, in Germany, Hermann Helmholtz became acquainted both of Joule's plan and the agnate 1842 plan of Julius Robert von Mayer. Admitting both men had been alone back their corresponding publications, Helmholtz's complete 1847 acknowledgment of the attention of activity accustomed them both.
Also in 1847, addition of Joule's presentations at the British Association in Oxford was abounding by George Gabriel Stokes, Michael Faraday, and the advanced and bohemian William Thomson, after to become Lord Kelvin, who had just been appointed assistant of accustomed aesthetics at the University of Glasgow. Stokes was "inclined to be a Joulite" and Faraday was "much addled with it" admitting he harboured doubts. Thomson was absorbed but sceptical.
Unanticipated, Thomson and Joule met after that year in Chamonix. Joule affiliated Amelia Grimes on 18 August and the brace went on honeymoon. Marital activity notwithstanding, Joule and Thomson abiding to attack an agreement a few canicule after to admeasurement the temperature aberration amid the top and basal of the Cascade de Sallanches waterfall, admitting this after accepted impractical.
Though Thomson acquainted that Joule's after-effects accepted abstract explanation, he aloof into a active defence of the Carnot-Clapeyron school. In his 1848 annual of complete temperature, Thomson wrote that "the about-face of calefaction (or caloric) into automated aftereffect is apparently impossible, absolutely undiscovered"[11] – but a comment signalled his aboriginal doubts about the caloric theory, apropos to Joule's "very arresting discoveries". Surprisingly, Thomson did not forward Joule a archetype of his cardboard but if Joule eventually apprehend it he wrote to Thomson on 6 October, claiming that his studies had approved about-face of calefaction into plan but that he was planning added experiments. Thomson replied on the 27th, absolute that he was planning his own abstracts and acquisitive for a adaptation of their two views. Admitting Thomson conducted no new experiments, over the next two years he became more annoyed with Carnot's approach and assertive of Joule's. In his 1851 paper, Thomson was accommodating to go no added than A ACCOMMODATION and declared "the accomplished approach of the motive ability of calefaction is founded on ... two ... propositions, due appropriately to Joule, and to Carnot and Clausius".
As anon as Joule apprehend the cardboard he wrote to Thomson with his comments and questions. Thus began a fruitful, admitting abundantly epistolary, accord amid the two men, Joule administering experiments, Thomson analysing the after-effects and suggesting added experiments. The accord lasted from 1852 to 1856, its discoveries including the Joule-Thomson effect, and the appear after-effects did abundant to accompany about accepted accepting of Joule's plan and the active theory.

Kinetic theory

Kinetics is the science of motion. Joule was a adherent of Dalton and it is no abruptness that he had abstruse a close acceptance in the diminutive theory, even admitting there were abounding scientists of his time who were still skeptical. He had aswell been one of the few humans acceptant to the alone plan of John Herapath on the active access of gases. He was added greatly afflicted by Peter Ewart's 1813 cardboard On the admeasurement of affective force.
Joule perceived the accord amid his discoveries and the active access of heat. His class notebooks acknowledge that he believed calefaction to be a anatomy of rotational, rather than translational motion.
Joule could not abide award antecedents of his angle in Francis Bacon, Sir Isaac Newton, John Locke, Benjamin Thompson (Count Rumford) and Sir Humphry Davy. Admitting such angle are justified, Joule went on to appraisal a amount for the automated agnate of calefaction of 1034 foot-pound from Rumford's publications. Some avant-garde writers accept criticised this access on the area that Rumford's abstracts in no way represented analytical quantitative measurements. In one of his claimed notes, Joule contends that Mayer's altitude was no added authentic than Rumford's, conceivably in the achievement that Mayer had not advancing his own work.
Joule has been attributed with answer the Blooming Flash abnormality in a letter to the Manchester Literary and Philosophical Society in 1869: actually, he just acclaimed (with a sketch) the endure glimpse as bluish green.[12]

Honours

oule died at home in Sale[13] and is active in Brooklands cemetery there. The cairn is inscribed with the bulk "772.55", his acute 1878 altitude of the automated agnate of heat, in which he begin that this bulk of foot-pounds of plan have to be expended at sea akin to accession the temperature of one batter of baptize from 60 to 61 F. There is aswell a citation from the Gospel of John, "I have to plan the works of him that beatific me, while it is day: the night cometh, if no man can work" (9:4). The Wetherspoon's accessible abode in Sale, the boondocks of his death, is called afterwards him "The J. P. Joule". The ancestors brewery still lives on but now amid in MARKET Drayton (see joulesbrewery.co.uk for added advice on origins).


Fellow of the Royal Society, (1850);
Royal Medal, (1852) вЂ˜For his cardboard on the automated agnate of heat, printed in the Philosophical Transactions for 1850’;
Copley Medal, (1870) вЂ˜For his beginning researches on the dynamical approach of heat’;
President of Manchester Literary and Philosophical Society, (1860);
President of the British Association for the Advancement of Science, (1872, 1887);
Honorary Membership of the Institution of Engineers and Shipbuilders in Scotland[1], (1857);
Honorary degrees:
LL.D., Trinity College Dublin, (1857);
DCL, University of Oxford, (1860);
LL.D., University of Edinburgh, (1871).
He accustomed a civilian account alimony of ВЈ200 per annum in 1878 for casework to science;
Albert Medal of the Royal Society of Arts, (1880) вЂ˜for accepting established, afterwards a lot of arduous research, the accurate affiliation amid heat, electricity and automated work, appropriately affording to the architect a abiding adviser in the appliance of science to automated pursuits’.
There is a canonizing to Joule in the arctic choir alley of Westminster Abbey, admitting he is not active there, adverse to what some biographies state.
A bronze by Alfred Gilbert, stands in Manchester Boondocks Hall, adverse that of Dalton.