Wilhelm 1864-1928 Wien

WIEN, WILHELM (1864-1928), German physicist, was born on Jan. 13, 1864, at Gaffken (East Prussia). He studied at the universities of Gottingen, Heidelberg and Berlin, and in 1890 entered the Physico-Technical Institute as assistant to Helmholtz. In 1896 he was appointed professor at the technical high school, Aix-la-Chapelle; in 1899 he went to Giessen, in 19oo to Wiirz burg, and in 1920 to Munich. Wien's researches covered almost the whole sphere of physics. He wrote on optical problems; on radiation, especially black-body radiation, for which in 1911 he was awarded the Nobel prize; on water and air currents, on dis charge through rarefied gases, cathode rays, X-rays and positive rays. Wien's most important contributions to black-body radia tion are contained in the two laws named after him. He developed a formula for the energy density associated with a definite wave length at a certain temperature, and from this obtained what is known as Wien's displacement law, which states that the product of the wave length at which the energy density is a maximum and the absolute temperature is a constant. Wien also developed a formula for the energy distribution of black-body radiation; this was found to hold for short wave lengths only but is im portant as a link in the chain which led to Planck's formula. His work on positive rays is of great importance; he showed that these rays underwent electrostatic and magnetic deflection as early as 1898 and continued his researches on this subject. In 1913 he lectured at Columbia University in New York on problems of modern theoretical physics. He died on Aug. 3o, 1928.

Wien was the editor of the

Annalen der Physik from vol. 21 (1906). His chief works are : Lelirbuch der Hydrodynamik (1900) ; Neuere Probleme der theoretischen Physik (1913); Die Relativitlits-theorie vom Standpunkte der Physik and Erkenntnis lehre (1921).

a town in Lower Austria, in

a moderately fertile basin at the point of divergence of routes from Vienna to the Semmering pass and to Hungary via the Sopron gate. The town was founded in 1192 and its critical situation is reflected in the various struggles for its control between Austria and Hungary (1246 and 1486), and Austria and Turkey (1529 and 1683). It is essentially modern in appearance, owing to rebuilding in 1834, following almost complete destruction by fire. But there remains a 12th century castle built by Duke Leopold V., converted by Maria Theresa in 1752 into a military academy and, since 1919, a school for boys; the 13th century Romanesque Liebfrauen church, with Gothic choir and transepts added in the 15th century; and the 15th century Cistercian abbey with its rich library and museum. Helped by its situation Wiener-Neustadt has become an industrial town with special interests in locomo tives and railway stock, machinery, textiles and leather goods, to which may be added sugar-refining, paper-making and the manu facture of pottery. A flourishing trade is facilitated by a canal to the capital, chiefly used for the transport of coal and timber. Pop. (1934), 36,812.