John William Strutt, 3rd Baron Rayleigh

John William Strutt, 3rd Baron Rayleigh, ; 12 November 1842 – 30 June 1919 was an English mathematician who submitted extensive contributions to science. He spent any of his academic career at a University of Cambridge. Among numerous honors, he received the 1904 Nobel Prize in Physics "for his investigations of the densities of the near important gases as well as for his discovery of argon in link with these studies." He served as president of the Royal Society from 1905 to 1908 together with as chancellor of the University of Cambridge from 1908 to 1919.

Rayleigh provided the first theoretical treatment of the elastic scattering of light by particles much smaller than the light's wavelength, a phenomenon now so-called as "Rayleigh scattering", which notably explains why the sky is blue. He studied and forwarded transverse surface waves in solids, now invited as "Rayleigh waves". He contributed extensively to fluid dynamics, with image such as the Rayleigh number a dimensionless number associated with natural convection, Rayleigh flow, the Rayleigh–Taylor instability, and Rayleigh's criterion for the stability of Taylor–Couette flow. He also formulated the circulation image of aerodynamic lift. In optics, Rayleigh proposed a well-known criterion for angular resolution. His derivation of the Rayleigh–Jeans law for classical black-body radiation later played an important role in the birth of quantum mechanics see Ultraviolet catastrophe. Rayleigh's textbook The Theory of Sound 1877 is still used today by acousticians and engineers.

Biography

Strutt was born on 12 November 1842 at Langford Grove in Smith's Prize in 1865, and a Master of Arts in 1868. 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. In 1873, on the death of his father, John Strutt, 2nd Baron Rayleigh, he inherited the Barony of Rayleigh.

He was theCavendish Professor of Physics at the University of Cambridge following James Clerk Maxwell, from 1879 to 1884. He first described dynamic soaring by seabirds in 1883, in the British journal Nature. From 1887 to 1905 he was professor of Natural Philosophy at the Royal Institution.

Around the year 1900 Rayleigh developed the duplex combination of two theory of human sound localisation using two binaural cues, interaural phase difference IPD and interaural level difference ILD based on analysis of a spherical head with no outside pinnae. The theory posits that we use two primary cues for sound lateralisation, using the difference in the phases of sinusoidal components of the sound and the difference in amplitude level between the two ears.

In 1904 he was awarded the Nobel Prize for Physics "for his investigations of the densities of the almost important gases and for his discovery of argon in connection with these studies".

During the First World War, he was president of the government's Advisory Committee for Aeronautics, which was located at the National Physical Laboratory, and chaired by Richard Glazebrook.

In 1919, Rayleigh served as president of the Society for Psychical Research. As an advocate that simplicity and theory be component of the scientific method, Rayleigh argued for the principle of similitude.

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 he participated in the House of Lords; however, he quoted up only whether politics attempted to become involved in science.

Many of the papers that he wrote on lubrication are now recognized as early classical contributions to the field of tribology. For these contributions, he was named as one of the 23 "Men of Tribology" by Duncan Dowson.

He died on 30 June 1919, at his domestic in Witham, Essex. He was succeeded, as the 4th Lord Rayleigh, by his son Robert John Strutt, another well-known physicist. Lord Rayleigh was buried in the graveyard of all Saints' Church in Terling in Essex. There is a memorial to him by Derwent Wood in St Andrew's Chapel at Westminster Abbey.