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Edward Arthur Milne

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For other people named Edward Milne, seeEdward Milne (disambiguation).
"Arthur Milne" redirects here. For the Scottish footballer, seeArthur Milne (footballer).

Arthur Milne
Born(1896-02-14)14 February 1896
Kingston upon Hull,Yorkshire, England
Died21 September 1950(1950-09-21)(aged 54)
Dublin,Ireland
Alma materTrinity College, Cambridge
Known forMilne model
Degenerate stars
Scientific career
InstitutionsVictoria University of Manchester
University of Oxford
Doctoral studentsThomas Cowling

Edward Arthur MilneFRS[1](/mɪln/;14 February 1896 – 21 September 1950) was a Britishastrophysicistand mathematician.[2][3][4][5][6]

Biography[edit]

Milne was born inHull,Yorkshire, England. He attendedHymers Collegeand from there he won an open scholarship in mathematics and natural science to study atTrinity College, Cambridgein 1914, gaining the largest number of marks which had ever been awarded in the examination.[citation needed]In 1916 he joined a group of mathematicians led byA. V. Hillfor the Ministry of munitions working on the ballistics of anti-aircraft gunnery, they became known as ′Hill's Brigands′. Later Milne became an expert on sound localisation.[7]In 1917 he became a lieutenant in the Royal Navy Volunteer Reserve. He was a fellow of Trinity College, Cambridge, 1919–1925, being assistant director of thesolarphysics observatory, 1920–1924, mathematical lecturer at Trinity, 1924–1925, and university lecturer in astrophysics, 1922–1925. He wasBeyer professor of applied mathematics,Victoria University of Manchester,1924–1928, before his appointment asRouse Ball Professor of Mathematicsand to a fellowship atWadham College, Oxford,in 1928. Milne's earlier work was in mathematical astrophysics. Much of his research in the 1930s was concerned with thetheory of relativityandcosmology.His later work, concerned with the interior structure of stars, aroused controversy. Milne wasPresident of the Royal Astronomical Society,1943–1945. During World War II he again worked on ballistics.

Milne married Margaret Scott Campbell on 26June 1928 atWithington,Manchester. Campbell, fromDornoch,Sutherland,Scotland, was the daughter of Hugh Fraser Campbell, anadvocateinAberdeen.Milne's brother, Geoffrey, then a lecturer inagricultural chemistryat theUniversity of Leeds,was best man.[8]Margaret Scott Milne died on the 5October 1938 atOxford.[9]He married secondly, Beatrice Brevoort Renwick, the third daughter of William Whetten Renwick, on 22June 1940 atSt Andrew's Church,Oxford.[10][11]William Whetten was the nephew of American architectJames Renwick Jr.,and designedSaints Peter and Paul,aRoman Catholiccathedral inIndianapolis,Indiana, United States.[12]Beatrice Brevoort Milne died at Oxford on 28August 1945, aged just 32 years.[13]Milne died of a heart attack inDublin,Ireland, while preparing to give a set of lectures. These can be found written down in one of his last published books:Modern Cosmology and the Christian Idea of God(1952).

Research into stellar atmospheres and structure[edit]

In the 1920s much of Milne's research was concerned withstars,particularly the outer layers known asstellar atmospheresthat produce the radiation observed from the Earth. He considered agrey atmosphere,a simplifying approximation in which the strength of the absorption of light by the hot ionized gas is the same at all wavelengths. This produced predictions of how temperature varies through the atmosphere, including the mathematical expression now known as the Milne Equation. He also calculated how the intensity of light from a star varies with wavelength on the basis of this model.[14][15]

Milne moved on to consider the more realistic case where the strength of the absorption of light by gas within stars (expressed by the absorption coefficient) does vary with wavelength. Using simplifying assumptions he calculated how for the Sun the strength of the absorption depends on wavelength. His results could not be explained adequately at the time, but later negatively-charged hydrogen ions(H−) were shown to be a major contributor to Milne's results.[15]

Milne, working withRalph H. Fowler,studied how the strengths of spectral lines of stars depend on their spectral type. In doing this they applied the work ofMeghnad Sahaabout the ionization of gases to stellar atmospheres.[15]

Milne worked on the structures and interiors of stars in the late 1920s and early 1930s. He often took opinions opposed to those ofArthur Eddington.[15]

Research into cosmology and relativity[edit]

From the early 1930s, Milne's interests focused increasingly onrelativity theoryandcosmology.[16]

From 1932 he worked on the problem of the "expanding universe" and inRelativity, Gravitation, and World-Structure(1935), proposed analternativetoAlbert Einstein'sgeneral relativitytheory. With McCrea (1934) he also showed that the 3 models which form the foundations of modern cosmology first proposed by Friedmann (1922) using the general theory of relativity, can also be derived using only Newtonian mechanics.[17]

Milne's alternative to general relativity theory based onkinematicswas known as Kinematic Relativity. His theory was built on the special but not general theory of relativity. Because of this it has been described as a "nonrelativistic cosmology".[18]Milne’s theory met with opposition from others but inspired the steady-state theorists.[19]

Relativity, Gravitation, and World Structure[edit]

The main difference between theMilne modelof an expanding universe, and the current (Einstein's) model of an expanding universe was that Milne did not assumea priorithat the universe has a homogeneous matter distribution. He did not include the gravitation interaction into the model either.

Milne argued that under the context of Einstein's special relativity, and the relativity of simultaneity, that it is impossible for a nonstatic universe to be homogeneous. Namely, if the universe is spreading out, its density is decreasing over time, and that if two regions appeared to be at the same density at the same time to one observer, they would not appear to be the same density at the same time to another observer. However, if each observer measures its local density at the same agreed-upon proper time, the measured density should be the same. In Minkowskian coordinates, this constant proper time forms a hyperbolic surface which extends infinitely to the light-cone of the event of creation. This is true even when proper time approaches 0, the time of the creation. The universe is already infinite at the creation time!

Milne's model is, therefore, that of a sphere, with an approximately homogeneous matter distribution within several billion light years of the center which then increases to an infinite density. It can be shown that this infinite density is actually the density of the universe when at the time of the big bang. The spherical distribution is unique in that it is essentially the same after a Lorentz transformation, except that a different stationary particle is at the center. As it is the only distribution that has this property, it is the only distribution which could satisfy the cosmological principle of "no preferred reference frame." Based on this cosmological principle Milne created a model that can be described entirely within Euclidean geometry.

As of 1935, using this model, Milne published a prediction of the cosmic background radiation which appears to be of a much different character than that predicted by Eddington. In fact, many passages inRelativity, Gravitation and World Structureare devoted to attacking Eddington's preconceptions.

Religious views[edit]

Milne was a Christiantheist.[20][21]In 1950, Milne gave ten lectures on Christianity and cosmology for the Edward Cadbury lectures which he was invited to give at theUniversity of Birmingham.The lectures were published in the bookModern Cosmology and the Christian Idea of God,edited byGerald James Whitrowand published in 1952.[20]

Milne was atheistic evolutionistwho held the view that God intervenes with "deft touches" to steer mutations in the right direction.[22]

Honours[edit]

Awards[edit]

Named after him[edit]

Books by Milne[edit]

  • Thermodynamics of the Stars,Berlin: J. Springer, 1930.
  • The White Dwarf Stars,Oxford:Clarendon Press,1932.
  • Relativity, gravitation and world-structure,Oxford:Clarendon Press,1935.
  • The Inverse Square Law of Gravitation,London: Harrison and Son, 1936.
  • The Fundamental Concepts of Natural Philosophy,Edinburgh: Oliver & Boyd, 1943.
  • Kinematic relativity; a sequel to Relativity, gravitation and world structure,Oxford: Clarendon Press, 1948.
  • Vectorial Mechanics,New York: Interscience Publishers, 1948.
  • Modern Cosmology and the Christian Idea of God,Oxford:Clarendon Press,1952.
  • Sir James Jeans: A Biography,Cambridge University Press,1952.

See also[edit]

Notes[edit]

  1. ^McCrea, W. H.(1951)."Edward Arthur Milne. 1896–1950".Obituary Notices of Fellows of the Royal Society.7(20): 420–426.doi:10.1098/rsbm.1951.0010.JSTOR769028.S2CID192057220.
  2. ^O'Connor, John J.;Robertson, Edmund F.,"Edward Arthur Milne",MacTutor History of Mathematics Archive,University of St Andrews
  3. ^McCrea, W. H.(1951)."Edward Arthur Milne".Monthly Notices of the Royal Astronomical Society.111(2): 160–170.Bibcode:1951MNRAS.111R.160..doi:10.1093/mnras/111.2.160a.
  4. ^Plaskett, H. H.(1951)."Edward Arthur Milne".Monthly Notices of the Royal Astronomical Society.111(2): 170–172.Bibcode:1951MNRAS.111R.160..doi:10.1093/mnras/111.2.160a.
  5. ^McCrea, W. H.(1950)."Edward Arthur Milne".The Observatory.70(859): 225–232.Bibcode:1950Obs....70..225M.Retrieved10 June2016.
  6. ^"Obituary: Edward Arthur Milne".Journal of the British Astronomical Association.61(3): 75–77. 1951.Bibcode:1951JBAA...61R..75.Retrieved10 June2016.
  7. ^Van der Kloot, W.(2011). ″Mirrors and smoke: A. V. Hill, his brigands, and the science of anti-aircraft gunnery in world war I.″ Notes Rec. R. Soc. Lond.65:393–410.
  8. ^"University Professor Weds".Leeds Mercury.Leeds. 27 June 1928. p. 5.OCLC1016307518.Retrieved13 August2021– via British Newspaper Archive.
  9. ^"Deaths".Aberdeen Press and Journal.10 October 1938. p. 1.ISSN2632-1165.OCLC271459455.Retrieved13 August2021– via British Newspaper Archive.
  10. ^"Forthcoming Marriages".The Times.No. 48643. 15 June 1940. p. 9.ISSN0140-0460.GaleCS151729871.
  11. ^"Marriages".The Times.No. 48651. 25 June 1940. p. 1.ISSN0140-0460.GaleCS17118937.
  12. ^Divita, James J. (1994)."General Entries".In Bodenhamer, David J.; et al. (eds.).The Encyclopedia of Indianapolis.Indianapolis:Indiana University Press.p. 1216.ISBN978-0-253-31222-8.OCLC940538156.Archivedfrom the original on 13 August 2021.Retrieved13 August2021– via The Encyclopedia of Indianapolis.
  13. ^"Deaths".The Times.No. 50234. 30 August 1945. p. 1.ISSN0140-0460.GaleCS17252638.
  14. ^Chandrasekhar, S.(1980)."The 1979 Milne Lecture – Edward Arthur Milne: His Part in the Development of Modern Astrophysics".Quarterly Journal of the Royal Astronomical Society.21(2): 93–107.Bibcode:1980QJRAS..21...93C.Retrieved12 June2016.
  15. ^abcdTayler, R. J.(1996)."E. A. Milne (1896–1950) and the Structure of Stellar Atmospheres and Stellar Interiors".Quarterly Journal of the Royal Astronomical Society.37(3): 355–363.Bibcode:1996QJRAS..37..355T.Retrieved12 June2016.
  16. ^Whitrow, G. J.(1996)."E. A. Milne and Cosmology".Quarterly Journal of the Royal Astronomical Society.37(3): 365–367.Bibcode:1996QJRAS..37..365W.Retrieved12 June2016.
  17. ^McCrea, W. H.;Milne, E. A. (1934). "Newtonian universes and the curvature of space".Quarterly Journal of Mathematics.5:73–80.Bibcode:1934QJMat...5...73M.CiteSeerX10.1.1.630.3318.doi:10.1093/qmath/os-5.1.73.This Newtonian derivation is sometimes incorrectly also ascribed to Friedmann.
  18. ^Nye, Mary Jo. (2003).The Cambridge History of Science: Volume 5, The Modern Physical and Mathematical Sciences.Cambridge University Press. p. 529.ISBN0-521-57243-6
  19. ^Levy, Michael I. (2010).The Universe: A Historical Survey of Beliefs, Theories, and Laws.Britannica Educational Publishing. p. 185.ISBN978-1-61530-055-6
  20. ^abMcCrea, W. H. (1953). "Reviewed Work: Modern Cosmology and the Christian Idea of God by E. A. Milne".The Mathematical Gazette.37(370): 137–139.doi:10.2307/3608962.JSTOR3608962.
  21. ^Painter, Alfred W. (1953). "Reviewed Work: Modern Cosmology and the Christian Idea of God by E. A. Milne".The Journal of Religion.33(2): 156.doi:10.1086/484426.
  22. ^Bowler, Peter J. (2001).Reconciling Science and Religion: The Debate in Early-Twentieth-Century Britain.University of Chicago Press. p. 413.ISBN0-226-06858-7
  23. ^"E.A. Milne Centre for Astrophysics, University of Hull – University of Hull".

References[edit]

Preceded by Beyer Chair of Applied MathematicsatUniversity of Manchester
1925–1928 		Succeeded by
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