BJERKNES, VILHELM ), Norwegian physi cist, a son of Carl Anton Bjerknes, professor of mathematics in the University of Christiania (Oslo), was educated at the uni versity of that city. At an early age he gave an experimental confirmation of his father's prediction, on theoretical grounds, of the remarkable apparent actions at a distance between pul sating and oscillating bodies in a fluid, and their analogy with electric and magnetic actions at a distance. From 1890-91 he studied electric waves at Hertz's Laboratory at Bonn in Ger many, and in 1895, after carrying out much valuable work at Oslo (Christiania) and at Stockholm, where he was appointed lecturer in the university in 1893 and professor of mechanics and mathematical physics in 1895, he gave a complete theory of the phenomenon of electric resonance which has contributed much to the development of wireless telegraphy.
Bjerknes subsequently returned to hydrodynamics and partic ularly the problems of meteorology, in which he was supported by the Carnegie Institute of Washington. Two introductory vol umes of a larger work, Dynamic Meteorology and Hydrography, were published in 1910–I1, under the auspices of this institution. In 1917 he went to Bergen, where, as professor of physics, in the new Geophysic Institute there, he was the originator of an improved and more scientific weather service, afterwards con trolled by his son and collaborator, Jakob Bjerknes (b. 1897), which occasioned a new view of cyclones and anticyclones. His papers on electric oscillations were published in Annalen der Physik (1891-95) . In his V orlesungen caber Hydrodynamische Fernkrd f to nach C. A. Bjerknes' Theorie (1900-02), he gave the first complete exposition of his father's discoveries, and in a later book Die Kra f t f elder 0909), he stated the same theory in a generalized form according to methods of his own.
Vilhelm Bjerknes was elected vice president of the Congress of Scandinavian Geophysicists in 1918 and an honorary member of the Royal Institution in 1922.