James Prescott Joule

from Wikipedia, the free encyclopedia
James Prescott Joule

James Prescott Joule [ dʒuːl ] (born December 24, 1818 in Salford near Manchester , † October 11, 1889 in Sale ) was a British brewer who was honored as a physicist . As the offspring of a brewing family, he was the owner of a beer brewery himself and, based on technical questions of mechanical engineering and brewing, did research on scientific questions. He was "perhaps the last autodidact who made a significant contribution to the advancement of science." The SI unitThe energy was named " Joule " in his honor .

Life

Joule statue in Manchester City Hall .
Joule tombstone with a numerical value of 772.55 of the heat equivalent .

James Prescott Joule was the second son of the brewery owner Benjamin Joule (1784-1858) and his wife Alice Prescott. In addition to the older brother Benjamin (1817-1895) Joule had two younger sisters (Alice and Mary) and a younger brother John Arthur.

On August 18, 1847, James Joule married Amelie Grimes. The first son they shared was Benjamin Arthur Joule (1850–1922), their daughter was Alice Amelia (1852–1899). Amelie died in 1854, a few months after their son Henry died at the age of just three weeks.

Upon the death of his wife, James Joule moved from Acton Square to the Whalley Range in Manchester to live with his father. In 1858 James bought property in Old Trafford. Complaints from neighbors about his experiments forced him to leave. After nine years at Cliff Point, Higher Broughton, Salford, he finally moved to 12 Wardle Road in Sale.

Health problems plagued Joule from 1872 onwards. When he got into financial difficulties in later years, the British Queen Victoria granted him a pension of 200 pounds a year from 1878, at which time his mental strength waned. He died after a long illness in his house in Sale on October 11, 1889 and was buried in the Brooklands cemetery. On his tombstone the numerical value 772.55 of the heat equivalent can be seen, the energy value found by James Joule in 1878 that is necessary to heat a pound of water by one degree.

Joule as a brewer

James Joule took over and, together with his brother Benjamin, ran the brewery in Salford, which had been founded by his grandfather Wiliam a good 30 years before his birth. While some authors assume that James Joule had little to do with the brewery's business operations, others, on the contrary, assume that Joule is particularly interested in improving the technical-physical-chemical processes of his father's brewery and lead his correspondence on this with William Thomson, 1st Baron Kelvin as evidence. Accordingly, gas production in beer production was the starting point for further considerations that ultimately led to the description of the Joule-Thomson effect . When his father fell ill and his brother withdrew from the brewery, James Joule had to deal with the technical and commercial aspects of beer production. The brewery was sold in 1855 in connection with the illness and death of his father, so that Joule could devote himself entirely to his scientific experiments.

Joule as a scientist

Because he had suffered from a spinal disease from childhood that also impaired his social skills and he was considered vulnerable, the scientifically gifted Joule received private lessons with Benjamin. This began in his father's house in Broomhill, Pendlebury, through his mother's half-sister. One of their teachers was the chemist and physicist John Dalton from 1834 . Dalton taught the Joules twice a week. Joule was very keen to experiment in his youth. So Joule lost his eyebrows by experimenting with explosives. He would fly kites in a thunderstorm or shock a maid with electric batons until she passed out. In 1837 Joule set up a laboratory in the basement of the brewery.

Joule apparatus for demonstrating the equivalence of mechanical work and heat.

In 1838 Joule began electromagnetic experiments based on the work of William Sturgeon . His aim was to conduct a more detailed experimental investigation into what efficiency an electric motor can achieve. To do this, he experimented with different types of iron for electromagnets and their magnetic attraction. Another aspect was the quantitative investigation of the thermal effects of the current ; this heating of the current-carrying conductor is called Joule heat . In 1840 he formulated the first Joule law , according to which the heat is proportional to the product of the square of the current strength and the resistance of the circuit . Joule proved that the amount of heat generated by a battery is directly related to the amount of chemically converted metal in the battery. Joules' conclusion of his efforts to create an efficient electric motor was sobering: The best possible degree of efficiency was only 20% of the value of the optimal coal-fired steam engines of his time, with the cost of battery power being significantly higher than that of coal. The experiments on the efficiency of the loaded electric motor led Joule to questions of thermodynamics. While the amount of heat generated by the electric current exactly matched the chemical "combustion process" in the battery, this did not explain the heat generated by a magneto . According to the theory of the indestructible heat substance (" caloricum ") - since a chemical process could not be explained - the material of the detonator should cool down, which it did not. Joule's conclusion was that the heat generated must be equal to the work (he uses the term vis viva ) to operate the magneto . Because of the equivalence of mechanical work and heat he assumed, there must be a constant rate of conversion of mechanical energy and heat. He determined this heat equivalent in numerous different experiments between 1843 and 1847, for example with the compression of air or the friction between iron disks and liquids. The classic experiment named after him was carried out by him in 1843: A defined amount of mechanical energy was added to a thermally insulated amount of water and the temperature increase was then measured. His research found that a British thermal unit , the thermal energy required to heat a British pound of water by one degree Fahrenheit , is equivalent to the weight of 772.55 pounds falling from a height of one foot . In modern expression, this results in a numerical value of around 4.15 joules per calorie - in good agreement with today's value of 4.1868.

The Heilbronn doctor Robert Mayer provided proof of the heat equivalent in 1841 , although this was also initially not recognized. When Hermann von Helmholtz finally formulated the law of conservation of energy in 1847, he paid tribute to both Mayer and Joule.

In 1847 Joule spoke again in Oxford before the British Association for the Advancement of Science . This time he was able to convince his audience more than before, including George Gabriel Stokes and Michael Faraday . After initial doubts, this meeting also marked the beginning of the collaboration with William Thomson, 1st Baron Kelvin . From 1852 Joule worked with Thomson on experiments to confirm thermodynamic theories. In 1852, the two researchers showed that a gas that can expand undisturbed cools down. This Joule-Thomson effect was evidence of the assumption that weak forces exist between the gas molecules . The phrase is used in gas liquefaction and refrigeration technology. Joule also designed the ideal cycle of the hot air machine ( Joule process ).

Joule published on many other phenomena. In 1846, Joule discovered magnetostriction (which - like other effects - is called the “Joule effect”) with the change in length of magnetized ferromagnetic materials , which was used to generate ultrasonic waves . In 1847 he formulated the view that the shooting stars are bodies which immerse themselves very quickly in the earth's atmosphere, in which the converted kinetic energy leads to glowing. In 1869 he also treated the phenomenon of "green lightning" or analyzed photographs of the sun.

The fact that Joule had no academic training in science made him an outsider and clearly delayed recognition of his achievements.

“Joule is not a university physicist, Joule has no university education, but Joule is a classic gentleman who has made it his job to deal with science. But that is a role model that actually fits more in the first quarter of the 19th and especially in the 18th century. By then, science had become much more professional. "

- Peter Heering, professor for the history of physics at the University of Flensburg

It was not until around 1850 that his achievements as a physicist were recognized; despite the lack of a university degree, he was classified as a “physicist” by the Royal Society and renowned reference works such as the Encyclopædia Britannica , the Larousse , the Brockhaus or the Duden .

Honors

Joule was a member of the Manchester Literary and Philosophical Society from 1842 and its president from 1860.

From 1850 Joule was a member of the Royal Society , which awarded him the Royal Medal in 1852 ('For his paper on the mechanical equivalent of heat, printed in the Philosophical Transactions for 1850'), and in 1870 the Copley Medal ('For his experimental researches on the dynamical theory of heat ').

Honorary doctorates were awarded to him in 1857 ( Trinity College Dublin ), 1860 ( University of Oxford ), 1871 ( University of Edinburgh ).

In 1867 he became an honorary member of the Royal Society of Edinburgh . In 1870 he was elected to the Académie des Sciences in Paris, in 1874 to the American Academy of Arts and Sciences and in 1887 to the National Academy of Sciences .

He was President of the British Association for the Advancement of Science and from 1857 an honorary member of the Institution of Engineers and Shipbuilders in Scotland

In 1880 he received the Albert Medal of the Royal Society of Arts ('For having established, after most laborious research, the true relation between heat, electricity and mechanical work, thus affording to the engineer a sure guide in the application of science to industrial pursuits' ).

A memorial for Joule is in the north choir of Westminster Abbey and a statue is in Manchester Town Hall (across from that for Dalton).

In his honor, the SI unit of energy , work and amount of heat is called “ Joule ” ( unit symbol J). This award, which only a few scientists received, was decided a few weeks before his death at the second International Electricity Congress in Paris.

A moon crater was named after Joule.

Works

literature

  • L. Rosenfeld: Joule, James Prescott . In: Charles Coulston Gillispie (Ed.): Dictionary of Scientific Biography . tape 7 : Iamblichus - Karl Landsteiner . Charles Scribner's Sons, New York 1973, p. 180-182 .
  • P. Volkmann: Technology pioneers: namesake of units of physical units. VDE Verlag, Berlin / Offenbach 1990, ISBN 3-8007-1563-5 , pp. 63-67.
  • Isaac Asimov: Biographical Encyclopedia of Science and Technology. Herder, Freiburg / Basel / Vienna 1974, ISBN 3-451-16718-2 , pp. 285-287.

Individual evidence

  1. ↑ Quote Oxford English Dictionary (OED) : Although some people of this name call themselves dʒaʊl , and others dʒəʊl , it is almost certain that JP Joule (and at least some of his relatives) used dʒuːl .
  2. ^ Hermann von Helmholtz: speeches and lectures . SEVERUS Verlag, June 1, 2010, ISBN 978-3-942382-14-4 , p. 346.
  3. ↑ Károly Simonyi: cultural history of physics . Harri Deutsch, Thun, Frankfurt a. M. 1995, ISBN 3-8171-1379-X , pp. 368 .
  4. ↑ a b c d e f BIOGRAPHICAL INDEX OF FORMER FELLOWS OF THE ROYAL SOCIETY OF EDINBURGH 1783 - 2002 . The Royal Society of Edinburgh, July 2006, ISBN 0902198 84 X .
  5. ^ A b c Donald SL Cardwell: James Joule: A Biography . Manchester University Press, 1991, ISBN 978-0-7190-3479-4 , p. 285. (= Appendix 4)
  6. ↑ Entry on Find a Grave
  7. ↑ Entry on Find a Grave
  8. ↑ a b c d e f g h i j k l Alan Gall: James Joule - Brewer and Man of Science , Brew. Hist., 115, pp. 2-6 ( online )
  9. ↑ Entry on Find a Grave
  10. ↑ Joule's Story
  11. ↑ a b c d Anke Wilde: James Prescott Joule - Beer Brewers and Tinkerers ( Online )
  12. ↑ a b c d Katarzyna Przegietka / Vanessa Schmid: Biography of James Prescott Joule ( Online  ( page no longer available , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. )@1@ 2Template: Toter Link / www.uni-flensburg.de  
  13. ↑ Description of the experiment: Robert L. Weber; Eric Mendoza: Cabinet of physical rarities: An anthology to think along with, to reflect on and to think further . Springer-Verlag, March 9, 2013, ISBN 978-3-322-89411-3 , p. 65 , whereby the “patient” remains nameless. The experiment is dated May 31, 1841.
  14. ↑ a b c d e Donald Cardwell: Viewegs history of technology . Springer-Verlag, March 8, 2013, ISBN 978-3-322-83123-1 , p. 197.
  15. ↑ Gustav Schmidt: Equation of state of the atmospheric air compilation = Annalen der Physik . tape 247 , no. 9 , 1880, p. 171-176 , doi : 10.1002 / andp.18802470911 .
  16. ^ On Sunset seen by Southport
  17. ↑ quoted from Anke Wilde: James Prescott Joule - Beer Brewers and Tinkerers ( Online )
  18. ↑ James Prescott Joulei in the Encyclopædia Britannica
  19. ↑ James Prescott Joule in Larousse
  20. ↑ 1911
  21. ^ Joule in Duden-Online
  22. ^ List of members since 1666: letter J. Académie des sciences, accessed on December 1, 2019 (French).
  23. ↑ Honorary Members
  24. ↑ Entry at the International Astronomical Union (IAU) Working Group for Planetary System Nomenclature (WGPSN)

Web links

Commons : James Prescott Joule  - Collection of Images, Videos and Audio Files
Wikisource: James Prescott Joule  - Sources and full texts
personal data
SURNAME Joule, James Prescott
BRIEF DESCRIPTION British physicist
DATE OF BIRTH December 24, 1818
PLACE OF BIRTH Salford
DATE OF DEATH October 11, 1889
Place of death Sale (Greater Manchester)