Sir George Stokes, 1st Baronet

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Sir George Stokes, Bt
Born (1819-08-13)13 August 1819
Skreen, County Sligo, Ireland
Died 1 February 1903(1903-02-01) (aged 83)
Cambridge, England
Fields Mathematics and physics
Institutions University of Cambridge
Alma mater Pembroke College, Cambridge
Academic advisors William Hopkins
Notable students Horace Lamb
Known for Stokes' law
Stokes' theorem
Stokes line
Stokes number
Stokes relations
Stokes shift
Navier–Stokes equations
Notable awards Rumford Medal (1852)
Copley Medal (1893)

Sir George Gabriel Stokes, 1st Baronet FRS (/stks/; 13 August 1819 – 1 February 1903), was a mathematician, physicist, politician and theologian. Born in Ireland, Stokes spent all of his career at University of Cambridge, where he served as the Lucasian Professor of Mathematics from 1849 until his death in 1903. Stokes made seminal contributions to fluid dynamics (including the Navier–Stokes equations), optics, and mathematical physics (including the first version of what is now known as Stokes' theorem). He was secretary, then president, of the Royal Society.




In 1849, Stokes was appointed to the Lucasian professorship of mathematics at Cambridge, a position he held until his death in 1903. On 1 June 1899, the jubilee of this appointment was celebrated there in a ceremony, which was attended by numerous delegates from European and American universities. A commemorative gold medal was presented to Stokes by the chancellor of the university, and marble busts of Stokes by Hamo Thornycroft were formally offered to Pembroke College and to the university by Lord Kelvin. Stokes, who was made a baronet in 1889, further served his university by representing it in parliament from 1887 to 1892 as one of the two members for the Cambridge University constituency. During a portion of this period (1885–1890) he also was president of the Royal Society, of which he had been one of the secretaries since 1854. Since he was also Lucasian Professor at this time, Stokes was the first person to hold all three positions simultaneously; Newton held the same three, although not at the same time.


Contributions to science[edit]

In scope his work covered a wide range of physical inquiry, but, as Marie Alfred Cornu remarked in his Rede lecture of 1899, the greater part of it was concerned with waves and the transformations imposed on them during their passage through various media.

Fluid dynamics[edit]


Creeping flow[edit]

Creeping flow past a sphere: streamlines and forces.

His work on fluid motion and viscosity led to his calculating the terminal velocity for a sphere falling in a viscous medium. This became known as Stokes' law. He derived an expression for the frictional force (also called drag force) exerted on spherical objects with very small Reynolds numbers.


The same theory explains why small water droplets (or ice crystals) can remain suspended in air (as clouds) until they grow to a critical size and start falling as rain (or snow and hail). Similar use of the equation can be made in the settlement of fine particles in water or other fluids.

The CGS unit of kinematic viscosity was named "stokes" in recognition of his work.




Stokes also investigated George Airy's mathematical description of rainbows.[2] Airy's findings involved an integral that was awkward to evaluate. Stokes expressed the integral as a divergent series, which were little understood. However, by cleverly truncating the series (i.e., ignoring all except the first few terms of the series), Stokes obtained an accurate approximation to the integral that was far easier to evaluate than the integral itself.[3] Stokes' research on asymptotic series led to fundamental insights about such series.[4]



In 1852, in his famous paper on the change of wavelength of light, he described the phenomenon of fluorescence, as exhibited by fluorspar and uranium glass, materials which he viewed as having the power to convert invisible ultra-violet radiation into radiation of longer wavelengths that are visible. The Stokes shift, which describes this conversion, is named in Stokes' honour. A mechanical model, illustrating the dynamical principle of Stokes's explanation was shown. The offshoot of this, Stokes line, is the basis of Raman scattering. In 1883, during a lecture at the Royal Institution, Lord Kelvin said he had heard an account of it from Stokes many years before, and had repeatedly but vainly begged him to publish it.


A calcite crystal laid upon a paper with some letters showing the double refraction


A paper on the long spectrum of the electric light bears the same date, and was followed by an inquiry into the absorption spectrum of blood.

Chemical analysis[edit]


Other work[edit]

Crookes Radiometer

In other departments of physics may be mentioned his paper on the conduction of heat in crystals (1851) and his inquiries in connection with Crookes radiometer; his explanation of the light border frequently noticed in photographs just outside the outline of a dark body seen against the sky (1883); and, still later, his theory of the x-rays, which he suggested might be transverse waves travelling as innumerable solitary waves, not in regular trains. Two long papers published in 1840 — one on attractions and Clairaut's theorem, and the other on the variation of gravity at the surface of the earth—also demand notice, as do his mathematical memoirs on the critical values of sums of periodic series (1847)[5] and on the numerical calculation of a class of definite integrals and infinite series (1850)[6] and his discussion of a differential equation relating to the breaking of railway bridges (1849), research related to his evidence given to the Royal Commission on the Use of Iron in Railway structures after the Dee bridge disaster of 1847.

Unpublished research[edit]

But large as is the tale of Stokes's published work, it by no means represents the whole of his services in the advancement of science. Many of his discoveries were not published, or at least were only touched upon in the course of his oral lectures. An excellent example is his work in the theory of spectroscopy.

Lord Kelvin




In another way, too, Stokes did much for the progress of mathematical physics. Soon after he was elected to the Lucasian chair he announced that he regarded it as part of his professional duties to help any member of the university in difficulties he might encounter in his mathematical studies, and the assistance rendered was so real that pupils were glad to consult him, even after they had become colleagues, on mathematical and physical problems in which they found themselves at a loss. Then during the thirty years he acted as secretary of the Royal Society he exercised an enormous if inconspicuous influence on the advancement of mathematical and physical science, not only directly by his own investigations, but indirectly by suggesting problems for inquiry and inciting men to attack them, and by his readiness to give encouragement and help.

Contributions to engineering[edit]

The Dee bridge after its collapse


Fallen Tay Bridge from the north


As a result of his evidence, he was appointed a member of the subsequent Royal Commission into the effect of wind pressure on structures. The effects of high winds on large structures had been neglected at that time, and the commission conducted a series of measurements across Britain to gain an appreciation of wind speeds during storms, and the pressures they exerted on exposed surfaces.

Work on religion[edit]

Stokes held conservative religious values and beliefs. In 1886 he became president of the Victoria Institute, which had been founded to defend evangelical Christian principles against challenges from the new sciences, especially the Darwinian theory of biological evolution. He gave the 1891 Gifford lecture on natural theology.[8] He was also the vice president of the British and Foreign Bible Society and was actively involved in doctrinal debates concerning missionary work.[9]

Legacy and honours[edit]

Stokes George G.jpg
  • From the Royal Society, of which he became a fellow in 1851, he received the Rumford Medal in 1852 in recognition of his inquiries into the wavelength of light, and later, in 1893, the Copley Medal.
  • In 1869 he presided over the Exeter meeting of the British Association.
  • From 1883 to 1885 he was Burnett lecturer at Aberdeen, his lectures on light, which were published in 1884–1887, dealing with its nature, its use as a means of investigation, and its beneficial effects.
  • On 6 July 1889 Queen Victoria created him the Baronet Stokes of Lensfield Cottage in the Baronetage of the United Kingdom; the title became extinct in 1916.[10]
  • In 1891, as Gifford lecturer, he published a volume on Natural Theology.
  • His academic distinctions included honorary degrees from many universities, together with membership of the Prussian Order Pour le Mérite.




  1. ^ "Stokes, George Gabriel". A Cambridge Alumni Database. University of Cambridge. 
  2. ^ See:
  3. ^ See:
  4. ^ See, for example, Wikipedia's articles "Stokes line" and "asymptotic expansions" as well as the obituary of mathematician Robert Balson Dingle (1926-2010), who investigated asymptotic series.
  5. ^ G. G. Stokes (presented: 1847 ; published: 1849) "On the critical values of the sums of periodic series," Transactions of the Cambridge Philosophical Society, 8 : 533-583.
  6. ^ G. G. Stokes (presented: 1850 ; published: 1856) "On the numerical calculation of a class of definite integrals and infinite series," Transactions of the Cambridge Philosophical Society, 9 (part 1) : 166-188.
  7. ^ Rothery, Henry (1880). "Report of the Court of Inquiry and Report of Mr Rothery Upon the Circumstances attending the Fall of a Portion of the Tay Bridge on the 28th December 1879". Her Majesty's Stationery Office. p. 44. 
  8. ^ "Lucasian". Retrieved 8 April 2008. 
  9. ^ Schlossberg, Herbert. (2009). Conflict and crisis in the religious life of late victorian Englan. New Brunswick, NJ: Transaction Publishers. p. 46. ISBN 978-1-4128-1027-2. 
  10. ^

Further reading[edit]

External links[edit]

Parliament of the United Kingdom
Preceded by
Henry Cecil Raikes
Alexander Beresford Hope
Member of Parliament for Cambridge University
With: Henry Cecil Raikes to 1891
Sir Richard Claverhouse Jebb from 1891
Succeeded by
Sir Richard Claverhouse Jebb
Sir John Eldon Gorst
Academic offices
Preceded by
Charles Edward Searle
Master of Pembroke College, Cambridge
Succeeded by
Arthur James Mason