**Wilhelm Oseen** was a Swedish mathematician who worked in fluid dynamics.

- Wilhelm Oseen attended school in Halmstad, where he showed he had many talents.
- He loved both mathematics and history but found it very hard to decide which of these subjects he wanted to pursue at university.
- While attending school he wanted to learn more than his teachers were giving him, so he studied both history and mathematics on his own, going well beyond the school syllabus.
- Not wanting to make a choice between these topics, after graduating from the secondary school in Halmstad on 5 June 1896, he enrolled as a student at Lund University still keeping his options open.
- At Lund University, where he enrolled on 8 September 1896, Oseen was taught mathematics by, among others, Victor Bäcklund.
- During the time that the author (Oseen) heard him (in the late 1890s) Bäcklund carried a double burden.
- Outside of the regular four lectures a week he gave a beginner's course in mechanics with exercises, also four hours a week.
- His interest in his audience was manifested by, among other things, invitations to a yearly party where lobster was a standing ingredient.
- Oseen graduated from Lund University with the degree Filosofie kandidat (equivalent to B.Sc.) on 14 December 1897.
- He continued his studies at Lund and was awarded the degree of Filosofie licentiat (perhaps between an M.Sc. and a Ph.D.) on 12 April 1900.
- His first publication appeared in 1900, namely On the general mapping of geodesic circles of a surface through contact transformations (Swedish).
- He spent the winter semester of 1900-01 at the University of Göttingen in Germany where he attended David Hilbert's lectures on partial differential equations.
- Both Hilbert and Felix Klein were strong influences on Oseen who published two further papers in 1901 and also a dissertation.
- is a continuation of the investigations by H Hugoniot ...
- The paper only deals with the theories for perfect gases and makes repeated references to Helmholtz's lectures on the mathematical principles of acoustics, edited by A König and C Runge.
- The additions to Hugoniot's work refer to the expression for the propagation velocity of a wave when an adiabatic wave movement spreads over a slow current, and also to the propagation of a discontinuous wave in space.
- We also want to emphasise that an analytical derivation of the Doppler principle is given in the course of the investigation.
- H Hugoniot is Pierre-Henri Hugoniot (1851-1887) who is remembered today in the Rankine-Hugoniot conditions, the Rankine-Hugoniot relations, the Rankine-Hugoniot equation and several other concepts.
- In contrast, the number of different types in 3-space is considerably larger.
- Of these groups in space, three were first discovered by Lie and are analogous to the groups on the plane ...
- Finally Kowalewski has shown that the two primitive groups mentioned are the only primitive groups of contact transformations in space.
- This paper contains the determination of some other classes of finite, continuous, irreducible groups of contact transformations in space.
- The classes examined include the two imprimitive groups set up by Lie and also four, it appears, new groups.
- Oseen's 1901 dissertation is On the finite, continuous, irreducible contact transformation groups in space (Swedish).
- He continued to publish with two papers appearing in 1902.
- He was appointed as a substitute professor of mathematics at the University of Lund on 1 December 1904 and held this position until 1 October 1906.
- During this period, Oseen's publications were all in pure mathematics with the exception of three papers, Contribution to the theory of wave motion in currents (Swedish) (1901), Contributions to the theory of wave motion in flows (Swedish) (1902) and On a case of vortex motion in a fluid (Swedish) (1902).
- Tragically, Gärd died at the age of nine on 14 October 1918.
- The new advance in Lorentz's research was that he took into account the viscosity of the liquid.
- This had usually been neglected in previous work, mainly because it considerably complicated the mathematical model.
- Oseen further developed Lorentz's study by considering, among other things, time-dependent fluid movements.
- He published On the theory of the movement of a viscous fluid (Swedish) (1907) but also works on other applied topics such as On Dirichlet"s problem in the heat equation (Swedish) (1907) and On the theory of the discontinuous movements of an electron (Swedish) (1907).
- He began applying for a professorship in mechanics and mathematical physics at the University of Uppsala, using his most recent work on applications of mathematics to support his case.
- In the meantime, on 13 July 1907, he was appointed to a post as a substitute professor of physics at the University of Lund.
- On 11 September 1909 he took up the appointment as professor of mechanics and mathematical physics at the University of Uppsala.
- It was a position he held for the rest of his career.
- His inaugural lecture in Uppsala was entitled 'The question of the will of freedom, viewed from a scientific point of view', showing his lifelong interest in philosophy.
- In 1911 he published Über die Stokes'sche formel, und über eine verwandte Aufgabe in der Hydrodynamik Ⓣ(On Stokes' formula and a related problem in hydrodynamics).
- Stokes had produced a formula for the resistance experienced by a sphere moving at a constant, infinitely low speed in a viscous, incompressible fluid.
- This formula worked in three dimensions but produced contradictions when applied to 2-dimensional flows.
- Oseen became one of the first Swedish scientists to accept Niels Bohr's atomic model.
- You will understand what an inspiring it had on one who has not met a scientific colleague for over a year.
- By your theory, how is it possible to explain hydrogen's exceptional status in this question?
- Weaker binding of the electrons?
- Once again, thank you.
- Your friend, C W Oseen.
- We note Oseen's comments about not having scientific colleagues at Uppsala.
- In 1921 he was elected to the Royal Swedish Academy of Sciences and, in the same year, he proposed Albert Einstein for a Nobel prize.
- Oseen became a member of the Royal Swedish Academy of Sciences' Nobel Committee for Physics in 1922 and he was able to argue strongly for the Nobel prize for physics being awarded to Einstein.
- Given Einstein's standing today it is difficult to understand the problem of convincing the committee that Einstein was worthy of the award.
- The theory of relativity, for which Einstein is best known today, was not considered well enough supported by experimental evidence by many scientists, both members of the committee and other scientists.
- Oseen presented the committee with a carefully, strongly, well-written document arguing that Einstein be awarded the 1921 reserve prize for his 1905 work on the photoelectric effect.
- Finally the committee was persuaded to make the award to Einstein in December 1922 (although in fact Einstein did not attend the presentation ceremony since he was on a voyage to Japan).
- Another of Oseen's very influential papers was published around the time that he was making the case for Einstein's Nobel prize.
- On 9 March 1921 he submitted his paper Eine Methode, die Zustandsgleichung der beliebigen Flüssigkeiten oder Gasen exakt zu berechnen Ⓣ(A method to calculate the equation of state for diverse liquids and gases).
- Their actual task has been to infer the equation of state for a gas or a liquid, whose atoms interact with each other through known, but largely arbitrary forces.
- Although the 1920 International Congress of Mathematicians was called 'International', it was a limited definition of International.
- Mathematicians from Germany, Austro-Hungary, Bulgaria and Turkey were excluded.
- Oseen played a role in restoring truly international relations at this difficult time by initiating the International Congresses for Applied Mechanics.
- An informal gathering organised by Theodore von Kármán and Tullio Levi-Civita in Innsbruck in 1922 was followed by the First International Congress of Applied Mechanics held in Delft in 1924.
- Although this was a fully international meeting, the International Congress of Mathematicians in Toronto in 1924 did not allow mathematicians from Germany, Austro-Hungary, Bulgaria and Turkey to attend.
- Nevertheless, Oseen attended the International Congress of Mathematicians in Toronto in 1924 but did not lecture at the congress.
- He published in German the important book Neuere Methoden Und Ergebnisse In Der Hydrodynamik Ⓣ(Newer Methods and Results in Hydrodynamics) in 1927.
- We have mentioned above Oseen's membership of the Royal Swedish Academy of Sciences and, in particular, his membership of the Sciences' Nobel Committee for Physics.
- Let us note also that Oseen chaired the Nobel Committee for many years and also that he served as president of the Royal Swedish Academy of Sciences in 1934-35.
- He delivered the presidential address at the end of his term of office, giving the lecture Plato's idiom and mathematics.
- Oseen told his audience of his interest in philosophy in general and that Plato was his favourite philosopher.
- Oseen was a plenary speaker at the International Congress of Mathematicians in Oslo in 1936.
- He delivered his lecture, Probleme der geometrischen Optik Ⓣ(Problems in geometric optics), on the morning of Thursday 16 July 1936 with Ernst Lindelöf as chair of the session.
- He successfully combined his early interest in history with his field of physics and adjacent fields through a number of biographical works.
- In addition to a large number of shorter life sketches of prominent Swedish scientists, including his teacher Victor Bäcklund, he wrote a larger biography of Johan Carl Wilcke.
- On an assignment from the Royal Swedish Academy of Sciences, he edited the edition of Scheeles' abandoned paper that was published in 1942 to celebrate the 200th anniversary of the chemist's birth.
- Literature and art were also among Oseen's interests.
- He lectured on both classical and modern literature and was also a performing artist with a number of oil paintings, watercolours and drawings as a result.
- Pupils and friends have spoken of Oseen's characteristic features and, in addition to his intellectual capacity and sharpness, they emphasised his willpower and work ability, which, among other things, showed itself in the laborious and complicated calculations which he quickly perceived as challenges.
- The truth must be sought unconditionally.
- As an academic teacher, Oseen was inspiring through his engaging and interesting lectures.
- In 1982, the Royal Swedish Academy of Sciences inaugurated a medal, designed by the sculptor Léo Holmgren and dedicated to the memory of Oseen.
- The medal's inscription was Arcana umorum revelavit anisotropicorum Ⓣ(He revealed the secrets of the anisotropic liquids).

Born 17 April 1879, Lund, Sweden. Died 7 November 1944, Engelbrekts, Stockholm County, Sweden.

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Origin Sweden

**O’Connor, John J; Robertson, Edmund F**: MacTutor History of Mathematics Archive