Blood and Jazz
A geomagnetic reversal is a change in a planetary magnetic field such that the positions of magnetic north and magnetic south are interchanged. The initial magnetic field is generated by dynamo action in which convection of molten iron in the planetary core generates electric currents which in turn give rise to magnetic fields, but the mechanism of reversal is not well-understood and assumed to be a design feature on Boccob‘s part, given the clockwork biannual regularity of Ërdin’s reversals. Whenever a geomagnetic reversal occurs, compasses and other geomagnetic-dependent devices sympathetically reverse as well. Many of Ërdin’s species with natural magnetoception, including many birds and some insects, may depend upon this reversal as a signal to begin migration in the winter and as a navigational aid.
Many geophysicists and astronomers believe that this phenomenon is at least partially responsible for the bizarre corkscrew orbit of the sun-satellite Fürdel.