Harold Jeffreys

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Plaque to Sir Harold Jeffreys, Newcastle University

Sir Harold Jeffreys, FRS<ref name="frs">Template:Cite journal</ref><ref name="frs2">Template:Cite journal</ref> (22 April 1891 – 18 March 1989) was a British geophysicist who made significant contributions to mathematics and statistics. His book, Theory of Probability, which was first published in 1939, played an important role in the revival of the objective Bayesian view of probability.<ref name = "jaynes">Template:Cite book</ref><ref name="mactutor">Template:MacTutor Biography</ref><ref>Template:Cite journal</ref>

EducationEdit

Jeffreys was born in Fatfield, County Durham, England, the son of Robert Hal Jeffreys, headmaster of Fatfield Church School, and his wife, Elizabeth Mary Sharpe, a school teacher.<ref>Template:Cite book</ref> He was educated at his father's school and at Rutherford Technical College, then studied at Armstrong College in Newcastle upon Tyne (at that time part of the University of Durham) and with the University of London External Programme.<ref name="The Papers of Harold Jeffreys">{{#invoke:citation/CS1|citation |CitationClass=web }}</ref><ref name="DNB">Cook, Alan [rev.], "Jeffreys, Sir Harold (1891–1989)", Oxford Dictionary of National Biography, Oxford University Press, 2004; online edition, September 2004. Retrieved 1 January 2023. Template:Subscription required</ref>

Jeffreys subsequently won a scholarship to study the Mathematical Tripos at St John's College, Cambridge, where he established a reputation as an excellent student: obtaining first-class marks for his papers in Part One of the Tripos, he was a Wrangler in Part Two, and in 1915 he was awarded the prestigious Smith's Prize.<ref name="DNB"/>

CareerEdit

{{ safesubst:#invoke:Unsubst||date=__DATE__ |$B= Template:Ambox }} Jeffreys became a fellow of St John's College in 1914, retaining his fellowship until his death 75 years later. At the University of Cambridge he taught mathematics, then geophysics and finally became the Plumian Professor of Astronomy.

In 1940, he married fellow mathematician and physicist, Bertha Swirles (1903–1999), and together they wrote Methods of Mathematical Physics.

One of his major contributions was on the Bayesian approach to probability (also see Jeffreys prior), as well as the idea that the Earth's planetary core was liquid.<ref>Template:Cite journal</ref>

By 1924 Jeffreys had developed a general method of approximating solutions to linear, second-order differential equations, including the Schrödinger equation. Although the Schrödinger equation was developed two years later, Wentzel, Kramers, and Brillouin were apparently unaware of this earlier work, so Jeffreys is often neglected when credit is given for the WKB approximation.<ref name="Andrianov_2004">Template:Cite book</ref>

Jeffreys received the Gold Medal of the Royal Astronomical Society in 1937, the Royal Society's Copley Medal in 1960, and the Royal Statistical Society's Guy Medal in Gold in 1962. In 1948, he received the Charles Lagrange Prize from the Académie royale des Sciences, des Lettres et des Beaux-Arts de Belgique.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> He was knighted in 1953.

From 1939 to 1952 he was established as Director of the International Seismological Summary further known as International Seismological Centre.

The textbook Probability Theory: The Logic of Science, written by the physicist and probability theorist Edwin T. Jaynes, is dedicated to Jeffreys. The dedication reads, "Dedicated to the memory of Sir Harold Jeffreys, who saw the truth and preserved it."

It is only through an appendix to the third edition of Jeffreys' book Scientific Inference that we know about Mary Cartwright's [[Proof that pi is irrational#Cartwright.27s proof|method of proving that the number Template:Pi]] is irrational.

Opposition to continental drift and plate tectonicsEdit

Jeffreys, like many of his peers, staunchly opposed the concept of continental drift as put forth by Alfred Wegener and Arthur Holmes. This opposition persisted even into the 1960s among his colleagues at Cambridge. For him, continental drift was "out of the question" because no force even remotely strong enough to move the continents across the Earth's surface was evident.<ref name=CLewis2002>Template:Cite book</ref> As geological and geophysical evidence for continental drift and plate tectonics mounted in the 1960s and after, to the point where it became the unifying concept of modern geology, Jeffreys remained a stubborn opponent of the theory to his death.

Honours and awardsEdit

Fellow, Royal Society, 1925<ref name="frs"/>
Adams Prize, 1927 (Constitution of the Earth)
Gold Medal, Royal Astronomical Society, 1937
Buchan Prize, Royal Meteorological Society, 1929
Murchison Medal of Geological Society (Great Britain) 1939
Victoria Medal, Royal Geographical Society, 1941
Charles Lagrange Prize, Brussels Academy, 1948
Royal Medal, 1948
William Bowie Medal, American Geophysical Union, 1952
Knighted, 1953
Copley Medal, Royal Society, 1961
Vetlesen Prize, 1962

BibliographyEdit

1924: The Earth, Its Origin, History and Physical Constitution, Cambridge University Press; 5th edn. 1970; 6th edn. 1976
1927: Operational Methods in Mathematical Physics, Cambridge University Press via Internet Archive, Review:<ref>Template:Cite journal</ref>
1929: The Future of the Earth, Norton & Company
1931: Scientific Inference, Macmillan Publishers; 2nd edn. 1937;<ref>Template:Cite journal</ref> 3rd edn. 1973<ref name="Jeffreys Inference 1973 ">Template:Cite book</ref>
1931: Cartesian Tensors. Cambridge University Press;<ref>Template:Cite journal</ref> 2nd edn. 1961
1934: Ocean Waves and Kindred Geophysical Phenomena, with Vaughan Cornish, Cambridge University Press
1935: Earthquakes and Mountains, Methuen Publishing; 2nd edn. 1950
1939: Theory of Probability,<ref>Template:Cite journal</ref> Clarendon Press, Oxford; 2nd edn. 1948; 3rd edn. 1961
1946: Methods of Mathematical Physics, with Bertha S. Jeffreys. Cambridge University Press;<ref>Template:Cite journal</ref> 2nd edn. 1950; 3rd edn. 1956; corrected 3rd edn. 1966
1962: Asymptotic Approximations, Clarendon Press, Oxford
1963: Nutation and Forced Motion of the Earth's Pole from the Data of Latitude Observations, Macmillan
1971–77: Collected Papers of Sir Harold Jeffreys on Geophysics and Other Sciences, Gordon and Breach

ReferencesEdit

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External linksEdit

Template:Copley Medallists 1951–2000 Template:Guy Medal

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