9:00 AM-9:45 AM
Chair: Anna Lawniczak, University of Guelph, Canada
Room: Convocation Hall
The directional property of the magnetic compass needle has been known for over 4000 years, but it was only in 1919 that Sir Joseph Larmor gave the explanation that has stood the test of time: the magnetic field of the Earth is created by the motion of its electrically-conducting fluid core. The theory of such self-excited homogeneous dynamos has, after many vicissitudes, produced simulated fields that behave in a similar way to the geomagnetic field. Meanwhile observation has revealed many other examples of cosmic magnetism -- that of planets, satellites, and galaxies -- that are explained by similar dynamo mechanisms. The subject is currently being actively developed by several groups in several countries, but much remains to be done. The speaker will present an assessment of the subject as it stands today.
Paul H. Roberts
Department of Mathematics
University of California, Los Angeles