James Bradley

James Bradley

: "This article describes the English astronomer; for other people sharing the name, see James Bradley (disambiguation)"Infobox Scientist
name = James Bradley



birth_date = March 1693
birth_place = Sherborne, nr Cheltenham, Gloucestershire, England
death_date = death date and age|1762|07|13|1693|03|01
death_place = Skiveralls House, Chalford, Gloucestershire, England
nationality = United Kingdom
field = Astronomy
work_institutions = University of Oxford
Ashmolean Museum
alma_mater = Balliol College, Oxford
doctoral_advisor =
doctoral_students =
known_for = Astronomer Royal
influences =
influenced =
prizes = Copley Medal, 1748
footnotes =

James Bradley (March 1693 – July 13, 1762) was an English astronomer, Astronomer Royal from 1742. He is best known for discovering the aberration of light while attempting to detect stellar parallax.cite book |last=Hirshfeld |first=Alan |authorlink= |title=Parallax:The Race to Measure the Cosmos |year=2001 |publisher=Henry Holt |location=New York, New York |isbn=0-8050-7133-4 ]

Biography

Bradley was born at Sherborne, near Cheltenham in Gloucestershire, in March 1693. He entered Balliol College, Oxford, on March 15 1711, and took degrees of B.A. and M.A. in 1714 and 1717 respectively. His early observations were made at the rectory of Wanstead in Essex, under the tutelage of his uncle, the Rev. James Pound, himself a skilled astronomer, and was elected a fellow of the Royal Society on November 6 1718.

He took orders on becoming vicar of Bridstow in the following year, and a small sinecure living in Wales was also procured for him by his friend Samuel Molyneux. He resigned his ecclesiastical preferments in 1721, when appointed to the Savilian chair of astronomy at Oxford, while as reader on experimental philosophy from 1729 to 1760, he delivered 79 courses of lectures at the Ashmolean Museum.

Bradley worked with Samuel Molyneux until Molyneux's death in 1728 trying to measure the parallax of Gamma Draconis. However, while not finding the expected parallax, they instead found an unexplained motion which shortly after Molyneux's death Bradley realized was caused by the aberration of light. The discovery of the aberration of light which was conclusive evidence for the movement of earth and hence the correctness of Aristarchus and Kepler's theories was announced to the Royal Society in January 1729 ("Phil. Trans." xxxv. 637). This aberration also allowed Bradley to accurately estimate the speed of light which had previously been shown to be finite by the work Ole Rømer and others. The observations upon which it was founded were made at Molyneux’s house on Kew Green. Bradley did not announce the supplementary detection of nutation until February 14 1748 ("Phil. Trans." xlv. I), when he had tested its reality by minute observations during an entire revolution (18.6 years) of the moon’s nodes. In 1742, he had been appointed to succeed Edmund Halley as Astronomer Royal; his enhanced reputation enabled him to apply successfully for a set of instruments costing GB£1,000; and with an 8-foot quadrant completed for him in 1750 by John Bird, he accumulated at Greenwich in ten years materials of inestimable value for the reform of astronomy. A crown pension of GB£250 a year was conferred upon him in 1752.

He retired in broken health, nine years later, to the Cotswold village of Chalford in Gloucestershire, where he died at Skiveralls House on 13 July 1762. The publication of his observations was delayed by disputes about their ownership; but they were finally issued by the Clarendon Press, Oxford, in two folio volumes (1798, 1805). The insight and industry of Friedrich Wilhelm Bessel were, however, needed for the development of their fundamental importance.

References

Further reading

Rigaud’s Memoir, prefixed to "Miscellaneous Works and Correspondence of James Bradley, D.D." (Oxford, 1832), is practically exhaustive. Other sources of information are: "New and General Biographical Dictionary", xii. 54 (1767); "Biog. Brit." (Kippis); Fouchy’s "Eloge", "Paris Memoirs" (1762), p. 231 (Histoire); Delambre’s "Hist. de l’astronomie au 18e siècle", p. 413.

###@@@KEY@@@###


Wikimedia Foundation. 2010.

Игры ⚽ Нужно решить контрольную?

Look at other dictionaries:

  • James Bradley — (* 3. März 1693 in Sherborne[1]; † 13. Juli 1762 in Chalford) war ein englischer Geistlicher und Astronom …   Deutsch Wikipedia

  • James Bradley — James Bradley. James Bradley (marzo de 1693 13 de julio de 1762) fue un astrónomo inglés, nombrado Astrónomo Real de la corona inglesa en 1742. Es famoso por su descubrimiento de la aberración de la luz. Vida y obra …   Wikipedia Español

  • James Bradley — Pour les articles homonymes, voir Bradley. James Bradley Naissance Mars 1693 Sherborne (Gloucestersh …   Wikipédia en Français

  • James Bradley (disambiguation) — James Bradley may refer to:*James Bradley (1693 ndash;1762), English astronomer * Lt.James Howard Bradley (1844 ndash;1877), American soldier (7th Infantry) *James Bradley, Australian author *Jim Bradley (born 1945), Canadian politician *Jim… …   Wikipedia

  • James Bradley (author) — James Bradley (c. February, 1954 ) is an American author, specializing in historical nonfiction chronicling the Pacific theatre of World War II.His father, John Bradley, was one of six men who became famous for being photographed raising the… …   Wikipedia

  • James Bradley (Australian writer) — James Bradley (born May 15, 1967) is an Australian novelist and critic. Born in Adelaide, South Australia, he trained as a lawyer before becoming a writer.His books include three novels and a book of poetry. His novels have been published… …   Wikipedia

  • James Bradley Orman — James Orman James Bradley Orman (* 4. November 1849 in Muscatine, Muscatine County, Iowa; † 21. Juli 1919) war ein US amerikanischer Politiker (Demokratische Partei) und von 1901 bis 1903 der 12. Gouverneur des …   Deutsch Wikipedia

  • James Bradley Orman — (November 4, 1849, to July 21, 1919) was an American politician and railroad builder. He served as governor of Colorado from 1901 to 1903. He was a Democrat.Orman was born in Muscatine, Iowa and grew up on his family s farm there. In 1869, he… …   Wikipedia

  • James Bradley Thayer — (January 15, 1831 – February 14, 1902) American legal writer and educationist.Born at Haverhill, Massachusetts, he graduated at Harvard College in 1852, and at the Harvard Law School in 1856, in which year he was admitted to the bar of Suffolk… …   Wikipedia

  • James Bradley (footballer) — Infobox Football biography playername = James Bradley fullname = James Edwin Bradley dateofbirth = May 5, 1881 cityofbirth = Stoke on Trent countryofbirth = England dateofdeath = death date and age|1954|3|12|1881|5|5 cityofdeath = Blackpool… …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”