David Enskog

David Enskog (born April 22, 1884 in Västra Ämtervik , Sunne municipality , † June 1, 1947 in Stockholm ) was a Swedish theoretical physicist who worked in statistical mechanics .

Enskog studied at Uppsala University , where he graduated from Gustav Granqvist in 1911 (with an experimental thesis on gas diffusion) and obtained his doctorate in 1917 with Carl Wilhelm Oseen (using the mathematical methods of David Hilbert in the kinetic theory of gases). His main occupation was a teacher after graduation. It was not until 1930 that he became a professor of mathematics and mechanics at the Royal Stockholm University of Technology , on the recommendation of Sydney Chapman , who was in Sweden at the time (Enskog's dissertation had previously only been assessed as mediocre in Sweden and received little response, so that he before an academic career was blocked).

Enskog worked since his diploma on the Maxwell-Boltzmann distribution law in the kinetic gas theory . In 1911, independently of Chapman, he predicted a paradoxical behavior of mixtures of two gases with different molecular sizes if a temperature imbalance existed, but this was confirmed experimentally (namely that the gas with the larger molecules concentrates at a lower temperature). This work was later applied in the methods of uranium enrichment through gas diffusion in the Manhattan Project of World War II. In 1921 he expanded the kinetic gas theory of Maxwell and Boltzmann to include dense gases in which collisions of more than two particles play a role. This was taken up by Chapman, who presented the "Chapman-Enskog theory" with Thomas George Cowling in 1939 in the book "The mathematical theory of non uniform gases".

In 1941 he was elected to the Royal Swedish Engineering Academy and in 1947 to the Royal Swedish Academy of Sciences .

Web links

• John J. O'Connor, Edmund F. Robertson :  David Enskog. In: MacTutor History of Mathematics archive .

Remarks

1. ↑ Hilbert began to be interested in mathematical physics at the beginning of the 20th century and at the same time in functional analysis, especially the theory of integral equations.
2. ↑ Chapman and Enskog are named in the official “Smyth Report” on the Manhattan Project as the originators of the “thermal diffusion” method