Harold Jeffreys

This article is not about William H. Jefferys, also both an astronomer and a Bayesian.

Harold Jeffreys
Born	22 April 1891 Fatfield
Died	18 March 1989 Cambridge
Fields	mathematics
Notable awards	Gold Medal of the Royal Astronomical Society in 1937

Plaque to Sir Harold Jeffreys, Newcastle University

Sir Harold Jeffreys, FRS (22 April 1891 – 18 March 1989) was a mathematician, statistician, geophysicist, and astronomer. His seminal book Theory of Probability, which first appeared in 1939, played an important role in the revival of the Bayesian view of probability.

Biography

Jeffreys was born in Fatfield, Washington, County Durham, England. He studied at Armstrong College in Newcastle upon Tyne, then part of the University of Durham, and with the University of London External Programme. He then went to St John's College, Cambridge and became a fellow in 1914. At Cambridge University he taught mathematics, then geophysics and finally became the Plumian Professor of Astronomy.

He married another mathematician and physicist, Bertha Swirles (1903–1999), in 1940 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. He was knighted in 1953.

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 credit for the WKB approximation.

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, Jeffreys received the Prix Charles Lagrange from the Académie royale des Sciences, des Lettres et des Beaux-Arts de Belgique.

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

Opposition to continental drift

Jeffreys was a strong opponent of continental drift. 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.

Honours and awards

• Fellow, Royal Society, 1925
• 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
• 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

Bibliography

• The Earth, Its Origin, History and Physical Constitution, Cambridge University Press, 1924
• Operational Methods in Mathematical Physics, Cambridge University Press, 1927
• The Future of the Earth, Norton & Company, c. 1929
• Scientific Inference, Macmillan, 1931
• Ocean Waves and Kindred Geophysical Phenomena, with Vaughan Cornish, Cambridge University Press, 1934
• Earthquakes and Mountains, Methuen, 1950
• Asymptotic Expansions, Clarendon Press, Oxford, 1962
• Theory of Probability, 3rd edition, Clarendon Press, Oxford, 1961
• Nutation and Forced Motion of the Earth's Pole from the Data of Latitude Observations, Macmillan, 1963
• Cartesian Tensors, Cambridge University Press, 1969
• Collected Papers of Sir Harold Jeffreys on Geophysics and Other Sciences, Gordon and Breach Science Publishers, 1971–77

See also

• List of geophysicists
• List of physicists

Further reading

• David Howie, "Interpreting Probability: Controversies and Developments in the Early Twentieth Century" (Cambridge University Press, 2002)
• Maria Carla Galavotti. "Harold Jeffreys' Probabilistic Epistemology: Between Logicism And Subjectivism". British Journal for the Philosophy of Science, 54(1):43–57 (March 2003). (A review of Jeffreys' approach to probability; includes remarks on R.A. Fisher, Frank P. Ramsey, and Bruno de Finetti. Also online: [1])
• Bertha Swirles, Reminiscences and Discoveries: Harold Jeffreys from 1891 to 1940, Notes and Records of the Royal Society of London, Vol. 46, No. 2, pp. 301–308 (1992). [2]

External links

• Photographs of Harold Jeffreys at Emilio Segrè Visual Archives, American Institute of Physics.
• O'Connor, John J.; Robertson, Edmund F., "Harold Jeffreys", MacTutor History of Mathematics archive, University of St Andrews, http://www-history.mcs.st-andrews.ac.uk/Biographies/Jeffreys.html .
• Biography of Vetlesen Prize Winner – Sir Harold Jeffreys
• Harold Jeffreys as a Statistician
• Harold Jeffreys at the Mathematics Genealogy Project.