ALFVN, HANNES

born May 30, 1908, Norrkping, Sweden died April 2, 1995, Djursholm in full Hannes Olof Gsta Alfvn astrophysicist and winner, with Louis Nel of France, of the Nobel Prize for Physics in 1970 for his essential contributions in founding plasma physicsthe study of plasmas (ionized gases). Alfvn was educated at Uppsala University and in 1940 joined the staff of the Royal Institute of Technology, Stockholm. During the late 1930s and early '40s he made remarkable contributions to space physics, including the theorem of frozen-in flux, according to which under certain conditions a plasma is bound to the magnetic lines of flux that pass through it. Alfvn later used the concept to explain the origin of cosmic rays. In 1939 Alfvn published his theory of magnetic storms and auroral displays in the atmosphere, which immensely influenced the modern theory of the magnetosphere (the region of the Earth's magnetic field). He discovered a widely used mathematical approximation by which the complex spiral motion of a charged particle in a magnetic field can be easily calculated. Magnetohydrodynamics (MHD), the study of plasmas in magnetic fields, was largely pioneered by Alfvn, and his work has been acknowledged as fundamental to attempts to control nuclear fusion. After numerous disagreements with the Swedish government, Alfvn obtained a position (1967) with the University of California, San Diego. Later he divided his teaching time between the Royal Institute of Technology in Stockholm and the University of California. Alfvn was an early supporter of plasma cosmology, a concept that challenges the big-bang model of the origin of the universe. Those who support the theory of plasma cosmology hold that the universe had no beginning (and has no forseeable end) and that plasmawith its electric and magnetic forceshas done more to organize matter in the universe into star systems and other large observed structures than has the force of gravity. Much of Alfvn's early research was included in his Cosmical Electrodynamics (1950). He also wrote On the Origin of the Solar System (1954), Worlds-Antiworlds (1966), and Cosmic Plasma (1981).