A Theory of the Permanent Magnetic Fields of the Sun and Earth

The motion of ions, executing short free paths under the influence of thermal agitation in an inhomogeneous magnetic field, in crossed magnetic and gravitational fields or in crossed magnetic and electric fields are shown to produce drift currents. The ion drifts are found to be opposite in direction to the drifts produced in the analogous cases of long free path. Under the condition of radial symmetry and a closed circuit the magnetic gradient gives rise to circular currents which flow in such a direction that magnetic regeneration takes place. Regeneration is limited by demagnetizing currents arising from the thermal motions of the ions interacting with the resultant magnetic field and an internal electric or gravitational field. The magnetic moments of the sun and earth are calculated from data which are approximately known and the correct magnitudes obtained. The permanent fields arise from the thermal energy of the body and would be maintained if the bodies ceased their rotation. The asymmetry of the earth's magnetic field indicates that the hemisphere embraced by the Pacific Ocean is at a higher mean internal temperature than the rest of the earth.