Fluid motions try to reverse the field on a few thousand years timescale, but the solid inner core tries to prevent reversals because the field cannot change (diffuse) within the inner core as quickly as in the fluid, outer core.

• 尽管流体运动会在几千年的时间尺度上使磁场倒转，但因为磁场的变化（扩散）在内核里不能与在外核的流体中一样快，所以固体的内核会尽力阻止倒转。