Lord Rayleigh
John William Strutt, 3rd Baron Rayleigh
Born	12 November 1842(1842-11-12) Langford Grove, Maldon, Essex, England
Died	30 June 1919 (aged 76) Terling Place, Witham, Essex, England
Nationality	United Kingdom
Fields	Physics
Institutions	University of Cambridge
Alma mater	University of Cambridge
Doctoral advisor	Edward John Routh
Doctoral students	J. J. Thomson George Paget Thomson Jagdish Chandra Bose
Known for	Discovery of argon Rayleigh waves Rayleigh scattering Rayleigh criterion Duplex Theory Theory of Sound Rayleigh flow
Notable awards	Nobel Prize for Physics (1904)
Signature

John William Strutt, 3rd Baron Rayleigh OM (12 November 1842 – 30 June 1919) was an English physicist who, with William Ramsay, discovered the element argon, an achievement for which he earned the Nobel Prize for Physics in 1904. He also discovered the phenomenon now called Rayleigh scattering, explaining why the sky is blue, and predicted the existence of the surface waves now known as Rayleigh waves.

[edit] Biography

Strutt was born in Langford Grove, Essex and in his early years suffered frailty and poor health. He attended Harrow School and began studying mathematics at Trinity College, University of Cambridge, in 1861. In 1865, he obtained his BA (Senior Wrangler and 1st Smith's prize) and MA in 1868.^[1] He was subsequently elected to a Fellowship of Trinity. He held the post until his marriage to Evelyn Balfour, daughter of James Maitland Balfour in 1871. He had three sons with her.^[2]

In 1873 his father, John Strutt, 2nd Baron Rayleigh, died and he inherited the Barony of Rayleigh.

He was the second Cavendish Professor of Physics at the University of Cambridge, following James Clerk Maxwell in this position from 1879 to 1884. He first described dynamic soaring by seabirds in 1883, in the British journal Nature.

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Around the year 1900 Lord Rayleigh developed the Duplex (combination of two) Theory of Human sound localization using two binaural cues, and interaural time delay (ITD) and interaural level difference (ILD) (assuming a spherical head with no external pinnae). Humans perceive sound objects spatially, using the difference in the phase (time delay) of the sound and the difference in amplitude (level) between the two ears, in a similar way that stereoscopic sight provides depth perception. The theory posits that we use two primary cues for azimuth (horizontal location) as well as for a 3-dimensional bearing, although pinnae reflections are considered a main cue for vertical localisation. For example, when you hear a seagull call, you can determine roughly the location of the sound on mental x, y, and z axes.

Lord Rayleigh was elected Fellow of the Royal Society on 12 June, 1873, and served as president of the Royal Society from 1905 to 1908. From time to time Lord Rayleigh participated in the House of Lords; however, he only spoke up if politics attempted to become involve in science. He died on 30 June, 1919, in Witham, Essex.^[3]

[edit] Honours and Awards

Craters on Mars and the Moon are named in his honor as well as a type of surface wave known as a Rayleigh wave. The asteroid 22740 Rayleigh was named in his honour on 1 June 2007.^[4]

• Smith's Prize (1864)
• Royal Medal (1882)
• Matteucci Medal (1894)
• Member of the Royal Swedish Academy of Sciences (1897)
• Copley Medal (1899)
• Order of Merit (1902)
• Nobel Prize for Physics (1904)
• Rumford Medal (1920)

[edit] Publications

• The Theory of Sound vol. I (London : Macmillan, 1877, 1894) (alternative link: Bibliothèque Nationale de France
• The Theory of Sound vol.II (London : Macmillan, 1878, 1896) (alternative link: Bibliothèque Nationale de France)
• The Becquerel rays and the properties of radium (London, E. Arnold, 1904)
• Scientific papers (Vol. 1: 1869–1881) (Cambridge : University Press, 1899–1920)
• Scientific papers (Vol. 2: 1881–1887) (Cambridge : University Press, 1899–1920)
• Scientific papers (Vol. 3: 1887–1892) (Cambridge : University Press, 1899–1920)
• Scientific papers (Vol. 4: 1892–1901) (Cambridge : University Press, 1899–1920)
• Scientific papers (Vol. 5: 1902–1910) (Cambridge : University Press, 1899–1920)
• Scientific papers (Vol. 6: 1911–1919) (Cambridge : University Press, 1899–1920)

[edit] See also

• Rayleigh criterion
• Rayleigh fading
• Rayleigh number
• Rayleigh quotient
• Rayleigh (unit) (named after his son)
• Rayleigh–Jeans law
• Rayleigh law
• Rayleigh distribution
• Rayleigh–Taylor instability
• Plateau–Rayleigh instability
• Rayleigh Medal
• Rayleigh–Bénard convection
• Rayleigh's method of dimensional analysis

[edit] References

[edit] External links

• About John William Strutt
• O'Connor, John J.; Robertson, Edmund F., "John Strutt, 3rd Baron Rayleigh", MacTutor History of Mathematics archive, http://www-history.mcs.st-andrews.ac.uk/Biographies/Rayleigh.html .