John Henry Poynting

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"Poynting" redirects here. For the vector, see Poynting vector. For the theorem, see Poynting Theorem.
John Poynting
John Henry Poynting.jpg
John Henry Poynting (1852-1914)
Born (1852-09-09)9 September 1852
Monton, Lancashire, England
Died 30 March 1914(1914-03-30) (aged 61)
Birmingham, England
Residence England
Nationality English
Fields Physicist
Institutions Mason Science College, University of Birmingham
Alma mater University of Cambridge
University of Manchester
Academic advisors James Clerk Maxwell
Notable students Francis William Aston
Known for Poynting vector
Poynting effect
Poynting's theorem
Poynting–Robertson effect
Influences Edward Routh
Notable awards Adams Prize (1893)
Hopkins Prize (1893)
Royal Medal (1905)
Signature

John Henry Poynting (9 September 1852 – 30 March 1914[1][2]) was an English physicist. He was a professor of physics at Mason Science College, from 1880 to 1900, and then the successor institution, the University of Birmingham until his death.

Poynting was the youngest son of Thomas Elford Poynting, a Unitarian minister. In his boyhood he was educated at a school operated by his father. From 1867 to 1872 he attended Owen's College, now the University of Manchester, where his physics teachers included Osborne Reynolds and Balfour Stewart. From 1872 to 1876 he was a student at Cambridge University, where he attained high honours in mathematics after taking grinds with Edward Routh. In the late 1870s he worked in the Cavendish Laboratory at Cambridge under James Clerk Maxwell.[3]

He was the developer and eponym of the Poynting vector, which describes the direction and magnitude of electromagnetic energy flow and is used in the Poynting theorem, a statement about energy conservation for electric and magnetic fields. This work was first published in 1884. He performed a measurement of Newton's gravitational constant by innovative means during 1893. In 1903 he was the first to realise that the Sun's radiation can draw in small particles towards it:[4] this was later named the Poynting–Robertson effect.

He discovered the torsion-extension coupling in finite strain elasticity. This is now known as the (positive) Poynting effect in torsion.

Poynting and the Nobel prizewinner J. J. Thomson co-authored a multi-volume undergraduate physics textbook, which was in print for about 50 years and was in widespread use during the first third of the 20th century.[5] Poynting wrote most of it.[6]

He was awarded an MSc in Pure Science in 1901 by Birmingham University.[7]

Poynting lived at 11 St Augustine's Road, Edgbaston with his family and servants for some years. He previously lived at 66 Beaufort Road, Edgbaston (demolished) and died of a diabetic coma[citation needed], aged 61, at 10 Ampton Road, Edgbaston in 1914.

Works by J. H. Poynting[edit]

Craters on Mars and the Moon are named in his honour, as is the main Physics building at the University of Birmingham and the departmental society there, the Poynting Physical Society.

References[edit]

  1. ^ GRO Register of Births: DEC 1852 8c 391 BARTON - John Henry Poynting, mmn = unknown
  2. ^ GRO Register of Deaths: MAR 1914 6d 128 KING'S N. - John Henry Poynting, aged 61
  3. ^ John Henry Poynting's biography at Institute of Physics.
  4. ^ Benest, Daniel; Froeschlé, Claude (1992). Interrelations Between Physics and Dynamics for Minor Bodies in the Solar System. Atlantica Séguier Frontières. p. 437. ISBN 2-86332112-9. , Extract of page 437
  5. ^ For a lengthy though incomplete listing of the editions of Poynting and Thomson's Text-book of Physics see Worldcat.org.
  6. ^ Reported in the biography of JJ Thomson by Davis & Falconer, previewable at Google Book Search Preview.
  7. ^ http://bhamalumni.org/NetCommunity/Page.aspx?pid=1111&frcrld=1

External links[edit]