Abstract for Edward Ott
Colloquium Speaker for
February 16, 1999

Edward Ott
University of Maryland

COLLOQUIUM
Tuesday, February 16, 1999
4:10 pm Room 118 PA
Refreshments at 3:45 in Room 224 PA


CHAOTIC FLOWS AND MAGNETIC DYNAMOS: THE ORIGIN OF MAGNETIC FIELDS IN THE UNIVERSE

One way of attempting to explain the prevalence of magnetic fields in natural large scale objects (planets, stars, galaxies) is the "kinematic dynamo problem": given an initially unmagnetized, flowing, electrically conducting fluid, will a small seed magnetic field tend to grow exponentially with time? If the answer is yes, then the fluid flow generates its own field. Recent work on this problem in the physically important regime of very high electrical conductivity has shown, somewhat surprisingly, that concepts of chaotic dynamics and fractals are the key to obtaining interesting solutions. This talk will explain some of these recent ideas.