John William Strutt, 3rd Baron Rayleigh, (; 12 November 1842 – 30 June 1919) was an English mathematician and physicist who made extensive contributions to science. He spent all of his academic career at the University of Cambridge. Among many honors, he received the 1904 Nobel Prize in Physics "for his investigations of the densities of the most important gases and for his discovery of argon in connection with these studies." He served as president of the Royal Society from 1905 to 1908 and 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 known as " Rayleigh scattering", which notably explains why the sky is blue. He studied and described transverse

surface wave In physics, a surface wave is a mechanical wave that propagates along the Interface (chemistry), interface between differing media. A common example is gravity waves along the surface of liquids, such as ocean waves. Gravity waves can also occu ...

s in solids, now known as " Rayleigh waves". He contributed extensively to

fluid dynamics In physics and engineering, fluid dynamics is a subdiscipline of fluid mechanics that describes the flow of fluids— liquids and gases. It has several subdisciplines, including ''aerodynamics'' (the study of air and other gases in motion) an ...

, with concepts such as the Rayleigh number (a dimensionless number associated with natural convection),

Rayleigh flow Rayleigh flow refers to frictionless, non- adiabatic flow through a constant area duct where the effect of heat addition or rejection is considered. Compressibility effects often come into consideration, although the Rayleigh flow model certainly a ...

, the Rayleigh–Taylor instability, and Rayleigh's criterion for the stability of Taylor–Couette flow. He also formulated the circulation theory of aerodynamic lift. In optics, Rayleigh proposed a well-known criterion for

angular resolution Angular resolution describes the ability of any image-forming device such as an optical or radio telescope, a microscope, a camera, or an eye, to distinguish small details of an object, thereby making it a major determinant of image 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

Maldon, Essex Maldon (, locally ) is a town and civil parish on the Blackwater estuary in Essex, England. It is the seat of the Maldon District and starting point of the Chelmer and Blackwater Navigation. It is known for Maldon Sea Salt which is produced ...

. In his early years he suffered from frailty and poor health. He attended Eton College and

Harrow School (The Faithful Dispensation of the Gifts of God) , established = (Royal Charter) , closed = , type = Public schoolIndependent schoolBoarding school , religion = Church of E ...

(each for only a short period), before going on to the University of Cambridge in 1861 where he studied mathematics at Trinity College, Cambridge. He obtained a Bachelor of Arts degree ( Senior Wrangler and 1st

Smith's Prize The Smith's Prize was the name of each of two prizes awarded annually to two research students in mathematics and theoretical physics at the University of Cambridge from 1769. Following the reorganization in 1998, they are now awarded under the n ...

) 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.One son,

Robert Strutt, 4th Baron Rayleigh Robert John Strutt, 4th Baron Rayleigh (28 August 1875 – 13 December 1947) was a British peer and physicist. He discovered "active nitrogen" and was the first to distinguish the glow of the night sky. Early life and education Strutt was bo ...

, was also an eminent physicist and fellow of the Royal Society. In 1873, on the death of his father, John Strutt, 2nd Baron Rayleigh, he inherited the Barony of Rayleigh. He was the second

Cavendish Professor of Physics The Cavendish Professorship is one of the senior faculty positions in physics at the University of Cambridge. It was founded on 9 February 1871 alongside the famous Cavendish Laboratory, which was completed three years later. William Cavendish, 7th ...

at the University of Cambridge (following James Clerk Maxwell), from 1879 to 1884. He first described

dynamic soaring Dynamic soaring is a flying technique used to gain energy by repeatedly crossing the boundary between air masses of different velocity. Such zones of wind gradient are generally found close to obstacles and close to the surface, so the technique is ...

by seabirds in 1883, in the British journal '' Nature''. From 1887 to 1905 he was professor of Natural Philosophy at the

Royal Institution The Royal Institution of Great Britain (often the Royal Institution, Ri or RI) is an organisation for scientific education and research, based in the City of Westminster. It was founded in 1799 by the leading British scientists of the age, inc ...

. 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 external pinnae). The theory posits that we use two primary cues for sound lateralisation, using the difference in the phases of

sinusoid A sine wave, sinusoidal wave, or just sinusoid is a mathematical curve defined in terms of the ''sine'' trigonometric function, of which it is the graph. It is a type of continuous wave and also a smooth periodic function. It occurs often in ma ...

al components of the sound and the difference in amplitude (level) between the two ears. Lord Rayleigh Vanity Fair 21 December 1899

In 1904 he was awarded the Nobel Prize for Physics "for his investigations of the densities of the most 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 The Advisory Committee for Aeronautics (ACA) was a UK agency founded on 30 April 1909, to undertake, promote, and institutionalize aeronautical research. In 1919 it was renamed the Aeronautical Research Committee, later becoming the Aeronautical ...

, 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 part 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 spoke up only if politics attempted to become involved in science. Many of the papers that he wrote on

lubrication Lubrication is the process or technique of using a lubricant to reduce friction and wear and tear in a contact between two surfaces. The study of lubrication is a discipline in the field of tribology. Lubrication mechanisms such as fluid-lubric ...

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 home in Witham, Essex. He was succeeded, as the 4th Lord Rayleigh, by his son

Robert John Strutt Robert John Strutt, 4th Baron Rayleigh (28 August 1875 – 13 December 1947) was a British peer and physicist. He discovered "active nitrogen" and was the first to distinguish the glow of the night sky. Early life and education Strutt was bo ...

, 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 Francis Derwent Wood (15 October 1871– 19 February 1926) was a British sculptor. Biography Early life Wood was born at Keswick, Cumbria, Keswick in Cumbria and studied in Germany and returned to London in 1887 to work under Édouard Lantér ...

in St Andrew's Chapel at Westminster Abbey.

Religious views

Rayleigh was an

Anglican Anglicanism is a Western Christian tradition that has developed from the practices, liturgy, and identity of the Church of England following the English Reformation, in the context of the Protestant Reformation in Europe. It is one of th ...

. Though he did not write about the relationship of science and religion, he retained a personal interest in spiritual matters. When his scientific papers were to be published in a collection by the Cambridge University Press, Strutt wanted to include a religious quotation from the Bible, but he was discouraged from doing so, as he later reported: Still, he had his wish and the quotation was printed in the five-volume collection of scientific papers. In a letter to a family member, he wrote about his rejection of

materialism Materialism is a form of philosophical monism which holds matter to be the fundamental substance in nature, and all things, including mental states and consciousness, are results of material interactions. According to philosophical materiali ...

and spoke of Jesus Christ as a moral teacher: He held an interest in parapsychology and was an early member of the Society for Psychical Research (SPR). He was not convinced of spiritualism but remained open to the possibility of

supernatural Supernatural refers to phenomena or entities that are beyond the laws of nature. The term is derived from Medieval Latin , from Latin (above, beyond, or outside of) + (nature) Though the corollary term "nature", has had multiple meanings si ...

phenomena. Rayleigh was the president of the SPR in 1919. He gave a presidential address in the year of his death but did not come to any definite conclusions.

Honours and awards

The lunar crater '' Rayleigh'' as well as the Martian crater '' Rayleigh'' were named in his honour. The asteroid

22740 Rayleigh 22740 Rayleigh, provisional designation , is a Zhongguo asteroid from the outermost region of the asteroid belt, approximately in diameter. It was discovered on 20 September 1998, by Belgian astronomer Eric Elst at the La Silla Observatory in Ch ...

was named after him on 1 June 2007. A type of surface waves are known as Rayleigh waves. The

rayl A Rayl, rayl or Rayleigh is one of two units of specific acoustic impedance or, equivalently, characteristic acoustic impedance; one an MKS unit, and the other a CGS unit. These have the same dimensions as momentum per volume. The units are nam ...

, a unit of

specific acoustic impedance Acoustic impedance and specific acoustic impedance are measures of the opposition that a system presents to the acoustic flow resulting from an acoustic pressure applied to the system. The SI unit of acoustic impedance is the pascal-second per cub ...

, is also named for him. Rayleigh was also awarded with (in chronological order): *

(1864) *

Royal Medal The Royal Medal, also known as The Queen's Medal and The King's Medal (depending on the gender of the monarch at the time of the award), is a silver-gilt medal, of which three are awarded each year by the Royal Society, two for "the most important ...

(1882) *Member of the American Philosophical Society (1886) * Matteucci Medal (1894) * Member of the

Royal Swedish Academy of Sciences The Royal Swedish Academy of Sciences ( sv, Kungliga Vetenskapsakademien) is one of the Swedish Royal Academies, royal academies of Sweden. Founded on 2 June 1739, it is an independent, non-governmental scientific organization that takes special ...

(1897) *

Copley Medal The Copley Medal is an award given by the Royal Society, for "outstanding achievements in research in any branch of science". It alternates between the physical sciences or mathematics and the biological sciences. Given every year, the medal is t ...

(1899) * Nobel Prize in Physics (1904) *

Elliott Cresson Medal The Elliott Cresson Medal, also known as the Elliott Cresson Gold Medal, was the highest award given by the Franklin Institute. The award was established by Elliott Cresson, life member of the Franklin Institute, with $1,000 granted in 1848. The ...

(1913) *

Rumford Medal The Rumford Medal is an award bestowed by Britain's Royal Society every alternating year for "an outstandingly important recent discovery in the field of thermal or optical properties of matter made by a scientist working in Europe". First awar ...

(1914) Lord Rayleigh was among the original recipients of the

Order of Merit The Order of Merit (french: link=no, Ordre du Mérite) is an order of merit for the Commonwealth realms, recognising distinguished service in the armed forces, science, art, literature, or for the promotion of culture. Established in 1902 by K ...

(OM) in the

1902 Coronation Honours The 1902 Coronation Honours were announced on 26 June 1902, the date originally set for the coronation of King Edward VII. The coronation was postponed because the King had been taken ill two days before, but he ordered that the honours list shou ...

list published on 26 June 1902, and received the order from King Edward VII at

Buckingham Palace Buckingham Palace () is a London royal residence and the administrative headquarters of the monarch of the United Kingdom. Located in the City of Westminster, the palace is often at the centre of state occasions and royal hospitality. It ...

on 8 August 1902. He received the degree of ''Doctor mathematicae (

honoris causa An honorary degree is an academic degree for which a university (or other degree-awarding institution) has waived all of the usual requirements. It is also known by the Latin phrases ''honoris causa'' ("for the sake of the honour") or ''ad hono ...

)'' from the Royal Frederick University on 6 September 1902, when they celebrated the centennial of the birth of mathematician Niels Henrik Abel. ''(in Norwegian)'' Sir William Ramsay, his co-worker in the investigation to discover argon described Rayleigh as "the greatest man alive" while speaking to Lady Ramsay during his last illness.

H. M. Hyndman Henry Mayers Hyndman (; 7 March 1842 – 20 November 1921) was an English writer, politician and socialist. Originally a conservative, he was converted to socialism by Karl Marx's '' Communist Manifesto'' and launched Britain's first left-wing ...

said of Rayleigh that "no man ever showed less consciousness of great genius".

Bibliography

Rayleigh, John William Strutt – Theory of sound, 1894 – BEIC 6738003

*
The Theory of Sound vol. I
' (London : Macmillan, 1877, 1894) (alternative link
Bibliothèque Nationale de France
OR (Cambridge: University Press, reissued 2011, ) *
The Theory of Sound vol.II
' (London : Macmillan, 1878, 1896) (alternative link
Bibliothèque Nationale de France
OR (Cambridge: University Press, reissued 2011, ) *
Scientific papers (Vol. 1: 1869–1881)
' (Cambridge : University Press, 1899–1920, reissued by the publisher 2011, ) *
Scientific papers (Vol. 2: 1881–1887)
' (Cambridge : University Press, 1899–1920, reissued by the publisher 2011, ) *
Scientific papers (Vol. 3: 1887–1892)
' (Cambridge : University Press, 1899–1920, reissued by the publisher 2011, ) *
Scientific papers (Vol. 4: 1892–1901)
' (Cambridge : University Press, 1899–1920, reissued by the publisher 2011, ) *
Scientific papers (Vol. 5: 1902–1910)
' (Cambridge : University Press, 1899–1920, reissued by the publisher 2011, ) *
Scientific papers (Vol. 6: 1911–1919)
' (Cambridge : University Press, 1899–1920, reissued by the publisher 2011, )

References

External links