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。