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Joseph Larmor

From Wikipedia, the free encyclopedia
Irish theoretical physicist (1857–1942)
"Larmor" redirects here. For other uses, seeLarmor (disambiguation).

Joseph Larmor
Larmor,c. 1920
Member of Parliament
forCambridge University
In office
1911–1922
Preceded bySamuel Butcher
Succeeded byJ. R. M. Butler
Personal details
Born(1857-07-11)11 July 1857
County Antrim, Ireland
Died19 May 1942(1942-05-19) (aged 84)
EducationRoyal Belfast Academical Institution
Alma mater
Known for
Political partyConservative
Awards
Scientific career
Fields
Institutions
Academic advisors
Notable students

Sir Joseph Larmor (11 July 1857 – 19 May 1942) was an Irish[3]mathematician,theoretical physicist, and British politician who made breakthroughs in the understanding ofelectricity,dynamics,thermodynamics, and theelectron theory of matter. His most influential work wasAether and Matter, a theoretical physics book published in 1900.[4]

Biography

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Joseph Larmor was born on 11 July 1857 in Magheragall,County Antrim, the son of Hugh Larmor, aBelfast shopkeeper and his wife, Anna Wright.[5] The family moved back to Belfast, where he was educated at theRoyal Belfast Academical Institution, and then studied mathematics and experimental science atQueen's College, Belfast (B.A., 1874;M.A., 1875),[6] where one of his teachers wasJohn Purser. He subsequently studied atSt John's College, Cambridge, where in 1880 he wasSenior Wrangler (J. J. Thomson was second wrangler that year) andSmith's Prizeman, getting his M.A. in 1883.[7]

After teaching physics for five years atQueen's College, Galway, Larmor accepted a lectureship in mathematics at Cambridge in 1885. In 1903, he was appointedLucasian Professor of Mathematics, a position he held until his retirement in 1932. He never married. He was knighted by KingEdward VII in 1909.[5]

Motivated by his strong opposition toHome Rule for Ireland, in February 1911 Larmor ran for and was elected a Member of Parliament forCambridge University with theConservative party. He remained in parliament until the1922 general election, at which point theIrish question had been settled. Upon his retirement from Cambridge in 1932, Larmor moved back toCounty Down in Northern Ireland.

Larmor was a plenary speaker in 1920 at theInternational Congress of Mathematicians (ICM) in Strasbourg.[8][9] He also was an invited speaker at the ICM in 1924 in Toronto and in 1928 in Bologna.

Larmor died inHolywood, County Down on 19 May 1942 at the age of 84.[10]

Research

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Larmor proposed that theaether could be represented as ahomogeneousfluid medium which was perfectlyincompressible andelastic. Larmor believed the aether was separate from matter. He unitedLord Kelvin's model of spinninggyrostats (seeVortex theory of the atom) with this theory. Larmor held that matter consisted ofparticles moving in the aether. Larmor believed the source ofelectric charge was a particle (which as early as 1894 he was referring to as theelectron). Larmor held that the flow of charged particles constitutes thecurrent ofconduction (but was not part of theatom). Larmor calculated the rate of energy (radiation) from anaccelerating electron. Larmor explained the splitting of thespectral lines in amagnetic field by theoscillation of electrons.[11]

Larmor also created the first solar system model of the atom in 1897.[12] He also postulated the proton, calling it a "positive electron". He said the destruction of this type of atom making up matter "is an occurrence of infinitely small probability".

In 1919, Larmor proposedsunspots areself-regenerativedynamo action on theSun's surface.

Quotes from one of Larmor's voluminous work include:

  • "while atoms of matter are in whole or in part aggregations of electrons in stable orbital motion. In particular, this scheme provides a consistent foundation for the electrodynamic laws, and agrees with the actual relations between radiation and moving matter".
  • "A formula for optical dispersion was obtained in § 11 of the second part of this memoir, on the simple hypothesis that the electric polarization of the molecules vibrated as a whole in unison with the electric field of the radiation".
  • “…that of the transmission of radiation across a medium permeated by molecules, each consisting of a system of electrons in steady orbital motion, and each capable of free oscillations about the steady state of motion with definite free periods analogous to those of the planetary inequalities of the Solar System;”
  • “'A' will be a positive electron in the medium, and 'B' will be the complementary negative one...We shall thus have created two permanent conjugate electrons A and B; each of them can be moved about through the medium, but they will both persist until they are destroyed by an extraneous process the reverse of that by which they are formed".[13]

Discovery of Lorentz transformation

[edit]
Main article:History of Lorentz transformations § Larmor

Parallel to the development ofLorentz ether theory, Larmor published an approximation to theLorentz transformations in thePhilosophical Transactions of the Royal Society in 1897,[14]namelyx1=xϵ1/2{\displaystyle x_{1}=x\epsilon ^{1/2}} for the spatial part anddt1=dtϵ1/2{\displaystyle dt_{1}=dt'\,\epsilon ^{-1/2}} for the temporal part, whereϵ=(1v2/c2)1,{\displaystyle \epsilon =(1-v^{2}/c^{2})^{-1},} and the local timet=tvx/c2.{\displaystyle t'=t-vx/c^{2}.} He obtained the full Lorentz transformation in 1900 by insertingϵ{\displaystyle \epsilon } into his expression of local time such thatt=tϵvx/c2,{\displaystyle t''=t'-\epsilon vx'/c^{2},} and, as before,x1=ϵ1/2x{\displaystyle x_{1}=\epsilon ^{1/2}x'} anddt1=ϵ1/2dt{\displaystyle dt_{1}=\epsilon ^{-1/2}\,dt''}.[15] This was done around the same time asHendrik Lorentz (1899, 1904) and five years beforeAlbert Einstein (1905).

Larmor, however, did not possess the correct velocity transformations, which include the addition of velocities law, which were later discovered byHenri Poincaré. Larmor predicted the phenomenon oftime dilation, at least for orbiting electrons, by writing (Larmor 1897): "individual electrons describe corresponding parts of their orbits in times shorter for the [rest] system in the ratio (1 – v2/c2)1/2". He also verified thatlength contraction should occur for bodies whose atoms were held together by electromagnetic forces. In his bookAether and Matter (1900), he again presented the Lorentz transformations, time dilation, and length contraction (treating these as dynamic rather thankinematic effects). Larmor was opposed to thespacetime interpretation of the Lorentz transformation inspecial relativity because he continued to believe in an absolute aether. He was also critical of thecurvature of space ofgeneral relativity, to the extent that he claimed that an absolute time was essential to astronomy (Larmor 1924, 1927).

Recognition

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Memberships

[edit]
CountryYearInstituteTypeRef.
United Kingdom1892Royal SocietyFellow[16]
United States1903American Academy of Arts and SciencesInternational Honorary Member[17]
United States1908National Academy of SciencesInternational Member[18]
United Kingdom1910Royal Society of EdinburghHonorary Fellow[5]
United States1913American Philosophical SocietyInternational Member[19]

Honorary degrees

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TerritoryYearInstituteDegreeRef.
United Kingdom1901University of GlasgowDoctor of Laws[20]
United Kingdom1903Trinity College DublinDoctor of Science[21]

Chivalric titles

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CountryYearMonarchTitleRef.
United Kingdom1909Edward VIIKnight Bachelor[5]

Awards

[edit]
CountryYearInstituteAwardCitationRef.
United Kingdom1914London Mathematical SocietyDe Morgan Medal[22]
United Kingdom1915Royal SocietyRoyal Medal"On the ground of his numerous and important contributions to mathematical and physical science"[23]
France1918French Academy of SciencesPoncelet Prize"For the whole of his mathematical work"[24]
United Kingdom1921Royal SocietyCopley Medal"For his researches in mathematical physics"[25]

Publications

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  • 1884, "Least action as the fundamental formulation in dynamics and physics",Proceedings of the London Mathematical Society.
  • 1887, "On the direct applications of first principles in the theory of partial differential equations",Proceedings of the Royal Society.
  • 1891, "On the theory of electrodynamics",Proceedings of the Royal Society.
  • 1892, "On the theory of electrodynamics, as affected by the nature of the mechanical stresses in excited dielectrics",Proceedings of the Royal Society.
  • 1893–97, "Dynamical Theory of the Electric and Luminiferous Medium",Proceedings of the Royal Society; Philosophical Transactions of the Royal Society. Series of 3 papers containing Larmor's physical theory of the universe.
  • 1896, "The influence of a magnetic field on radiation frequency",Proceedings of the Royal Society.
  • 1896, "On the absolute minimum of optical deviation by a prism",Proceedings of the Cambridge Philosophical Society.
  • Larmor, J. (1897)."A Dynamical Theory of the Electric and Luminiferous Medium. Part III. Relations with Material Media".Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences.190:205–493.Bibcode:1897RSPTA.190..205L.doi:10.1098/rsta.1897.0020.
  • 1898, "Note on the complete scheme of electrodynamic equations of a moving material medium, and electrostriction",Proceedings of the Royal Society.
  • 1898, "On the origin of magneto-optic rotation",Proceedings of the Cambridge Philosophical Society.
  • Larmor, J. (1900),Aether and Matter , Cambridge University Press; Containing theLorentz transformations on p. 174.
  • 1903, "On the electrodynamic and thermal relations of energy of magnetisation",Proceedings of the Royal Society.
  • 1904, "On the mathematical expression of the principle of Huygens" (read 8 Jan. 1903),Proceedings of the London Mathematical Society, Ser. 2, vol. 1 (1904), pp. 1–13.
  • 1907, "Aether" inEncyclopædia Britannica, 11th ed. London.
  • 1908, "William Thomson, Baron Kelvin of Largs. 1824–1907" (Obituary).Proceedings of the Royal Society.
  • 1921, "On the mathematical expression of the principle of Huygens –II" (read 13 Nov. 1919),Proceedings of the London Mathematical Society, Ser. 2, vol. 19 (1921), pp. 169–80.
  • 1924, "On Editing Newton",Nature.
  • 1927, "Newtonian time essential to astronomy",Nature.
  • 1929,Mathematical and Physical Papers. Cambridge Univ. Press.[26]
  • 1937, (as editor),Origins of Clerk Maxwell's Electric Ideas as Described in Familiar Letters to William Thomson. Cambridge University Press.[27]

Larmor edited the collected works ofGeorge Stokes,James Thomson, andWilliam Thomson.

  • 1900 copy of Aether and Matter
    1900 copy ofAether and Matter
  • Title page to a 1900 copy of Aether and Matter
    Title page to a 1900 copy ofAether and Matter
  • First page of the preface to Aether and Matter
    First page of the preface toAether and Matter
  • First page of Aether and Matter
    First page ofAether and Matter

See also

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EnglishWikisource has original works by or about:

References

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  1. ^abcd"Joseph Larmor".Mathematics Genealogy Project. North Dakota State University. Retrieved14 July 2025.
  2. ^ab"Joseph Larmor - Physics Tree".academictree.org. Retrieved14 July 2025.
  3. ^"Sir Joseph Larmor | Irish physicist | Britannica".
  4. ^Eddington, A. S. (1942)."Joseph Larmor. 1857–1942".Obituary Notices of Fellows of the Royal Society.4 (11):197–207.doi:10.1098/rsbm.1942.0016.
  5. ^abcdBiographical Index of Former Fellows of the Royal Society of Edinburgh 1783 – 2002(PDF).Royal Society of Edinburgh. July 2006. p. 40.ISBN 0-902-198-84-X. Archived fromthe original(PDF) on 4 March 2016. Retrieved12 March 2017.
  6. ^From Ballycarrickmaddy to the moon Lisburn.com, 6 May 2011
  7. ^"Larmor, Joseph (LRMR876J)".A Cambridge Alumni Database. University of Cambridge.
  8. ^"Questions in physical indetermination by Joseph Larmor"(PDF).Compte rendu du Congrès international des mathématiciens tenu à Strasbourg du 22 au 30 Septembre 1920. 1921. pp. 3–40. Archived fromthe original(PDF) on 27 December 2013.
  9. ^H, H. B. (7 October 1920)."The International Congress of Mathematicians".Nature.106 (2658):196–197.Bibcode:1920Natur.106..196H.doi:10.1038/106196a0. In his plenary address, Larmor advocated the aether theory as opposed to Einstein's general theory of relativity.
  10. ^"Joseph Larmor".MacTutor History of Mathematics Archive. University of St Andrews. Retrieved5 April 2024.
  11. ^Histories of the Electron: The Birth of Microphysicsedited by Jed Z. Buchwald, Andrew Warwick
  12. ^The Zeeman Effect and the Discovery of the Electron, Theodore Arabatzis, 2001.
  13. ^”A Dynamical Theory of the Electric and Luminiferous Medium.— Part III". Joseph Larmor, Phil. Trans., A, vol. 190, 1897, pp. 205–300.
  14. ^Larmor, Joseph (1897),"On a Dynamical Theory of the Electric and Luminiferous Medium, Part 3, Relations with material media" ,Philosophical Transactions of the Royal Society,190:205–300,Bibcode:1897RSPTA.190..205L,doi:10.1098/rsta.1897.0020
  15. ^Larmor, Joseph (1900),Aether and Matter , Cambridge University Press
  16. ^"Search past Fellows".Royal Society. Retrieved22 November 2025.
  17. ^"Joseph Larmor".American Academy of Arts and Sciences. Retrieved15 November 2023.
  18. ^"Joseph Larmor".National Academy of Sciences. Archived fromthe original on 1 February 2024. Retrieved15 November 2023.
  19. ^"Member History".American Philosophical Society.Archived from the original on 15 November 2023. Retrieved15 November 2023.
  20. ^"Glasgow University Jubilee".The Times. No. 36481. London. 14 June 1901. p. 10. Retrieved5 January 2024 – via Newspapers.com.
  21. ^Dublin University Calendar, A Special Supplemental Volume for the year 1906-7. Vol. III. Dublin: Hodges, Figgis, and Co. Ltd. 1907.
  22. ^"Winners of the De Morgan Medal of the LMS".MacTutor History of Mathematics Archive. University of St Andrews. Retrieved29 January 2024.
  23. ^"Royal Medal".Royal Society.Archived from the original on 25 September 2015.
  24. ^"Prize Awards of the Paris Academy of Sciences for 1918".Nature.102 (2565):334–335. 26 December 1918.Bibcode:1918Natur.102R.334..doi:10.1038/102334b0.
  25. ^"Copley Medal".Royal Society.Archived from the original on 6 September 2015. Retrieved19 October 2016.
  26. ^Gronwall, T. H. (1930)."Review:Mathematical and Physical Papers, by Sir Joseph Larmor"(PDF).Bull. Amer. Math. Soc.36 (7):470–471.doi:10.1090/s0002-9904-1930-04975-7.
  27. ^Page, Leigh (1938)."Review:Origins of Clerk Maxwell's Electric Ideas as Described in Familiar Letters to William Thomson, by Sir Joseph Larmor"(PDF).Bull. Amer. Math. Soc.44 (5): 320.doi:10.1090/s0002-9904-1938-06738-9.

Further reading

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External links

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Parliament of the United Kingdom
Preceded by Member of Parliament forCambridge University
19111922
With:John Rawlinson
Succeeded by
Copley Medallists (1901–1950)
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