Edward Bullard

For the American politician and educator, seeEdward B. Bullard.For the American engineer, seeEdward P. Bullard Jr.

Sir Edward Bullard
Born	(1907-09-21)21 September 1907 Norwich,Norfolk,England
Died	3 April 1980(1980-04-03)(aged 72) La Jolla,California. United States
Alma mater	University of Cambridge
Known for	Dynamo theory
Awards	Hughes Medal(1953) The Chree Medal and Prize(1957) Gold Medal of the Royal Astronomical Society Fellow of the Royal Society Wollaston Medal(1967) Vetlesen Prize(1968) Royal Medal(1975) William Bowie Medal(1975) Maurice Ewing Medal(1978)
Scientific career
Fields	Geophysics
Institutions	British Admiralty,National Physical Laboratory,University of Cambridge
Thesis	1. Electron scattering. 2. Pendulum Observations.(1932)
Doctoral advisor	Patrick Blackett
Doctoral students	Thomas Gaskell Harvey Gellman Robert Ladislav Parker Nigel Weiss
5thDirector of NPL
In office 1948–1955
Preceded by	Edward Victor Appleton(Acting)
Succeeded by	Reginald Leslie Smith-Rose(Acting)

Sir Edward Crisp BullardFRS(21 September 1907 – 3 April 1980) was a Britishgeophysicistwho is considered, along withMaurice Ewing,to have founded the discipline of marine geophysics. He developed the theory of thegeodynamo,pioneered the use ofseismologyto study the sea floor, measuredgeothermalheat flow through the ocean crust, and found new evidence for the theory ofcontinental drift.

Early life

Bullard was born into a wealthy brewing family inNorwich,England. He was educated atNorwich Schooland later studied Natural Sciences atClare College, Cambridge.He studied underErnest Rutherfordat theCavendish LaboratoryofUniversity of Cambridgeand in the 1930s he received his PhD degree as a nuclear physicist.

Bullard found poor career prospects for nuclear physicists during theGreat Slump,so in 1931 he switched fields to take a job asdemonstratorin the department of geodesy and geophysics at Cambridge. The department had been founded in 1921 when it consisted of only one person,Sir Gerald Lenox-Conyngham.By 1931 Lenox-Conyngham had persuaded the university that he needed additional staff, so had been given funds for a junior post. Bullard was appointed to this position on the recommendation of Rutherford. At the same timeHarold Jeffreyswas appointedreaderin geophysics.Over the next eight years, these three researchers made numerous advances in geophysics.

DuringWorld War II,he was an experimental officer atHMS Vernonof theAdmiralty Mining EstablishmentwithFrancis Crick,Thomas GaskellandRobert Boyd,working on the development ofdegaussingtechniques to protect shipping frommagnetic mines.

Career

Bullard held a chair at theUniversity of Torontofrom 1948 to 1950 and was head of theNational Physical Laboratorybetween 1950 and 1955. He wasknightedin the1953 Coronation Honours List.He returned to Cambridge in 1955, first as an assistant in research, then as a Reader and finally to a chair created for him in 1964. He was a founding fellow ofChurchill College, Cambridge.

Bullard became one of the most important geophysicists of his day. He also did studies of the ocean floor, even though he suffered from seasickness and could rarely take scientific trips on the ocean. He was important todynamo theory,hence his most important work concerned the source of the Earth's magnetic field. He was often frustrated by efforts to increase geophysical interest at the University of Cambridge. In his career he won theHughes Medal,theVetlesen Prizeand theGold Medal of the Royal Astronomical Society.He was elected to theAmerican Academy of Arts and Sciencesin 1954.In 1965, he was awarded theAlexander Agassiz Medalfrom theNational Academy of Sciences,of which he was a member,for his significant investigations of the earth from its surface to its core. He was elected to theAmerican Philosophical Societyin 1969.

Then during the early 1960s Bullard and his associates used a computer to try to fit all of the continents together. Instead of using the shorelines, as other geophysicists had done, he used a depth of 914 meters (3000 ft) below sea level. This depth corresponds to about halfway between the shoreline and the ocean basins and represents the true edge of the continents. By doing this he discovered a near perfect fit among the continents put together. With this discovery he helped further the idea of a supercontinent that an earlier geophysicist,Alfred Wegener,had suggested callingPangaea.It turned out a posteriori that a very similar result had been published thirty years earlier by the French geologistBoris Choubert,but this work published in French in a francophone journal of low international influence had remained virtually unknown.

After retiring from Cambridge in 1974 he settled to a position at theUniversity of California, San Diego.Bullard died in La Jolla, California, in 1980. His papers are held by theChurchill Archives Centre.

See also

• List of geophysicists

Further reading

• Shor, Elizabeth N.(28 February 1984). "E.C. Bullard's first heat-probe".Eos.Vol. 65, no. 9. pp. 73–74.Bibcode:1984EOSTr..65Q..73S.doi:10.1029/EO065i009p00073-01.

• Wilson, J. Tuzo,Memorial to Edward Crisp Bullard(PDF)

External links

• University of California San Diego obitat theWayback Machine(archived 13 July 2007)
• Bullard photo
• Cambridge article
• Edward Bullardat theMathematics Genealogy Project