Cause of Geomagnetic Polarity Reversal: A View of Collision Dynamics of a Celestial Body with Earth

It is generally acknowledged that geomagnetic polarity has reversed many times in geological history. However, the cause has been unknown up to now. Based on the theory of a generator effect for the formation of the Earth's magnetic field, and the dynamic effect of a collision with a celestial body, the possibility of a geomagnetic polarity reversal caused by the collision of an asteroid with the Earth is considered in this paper. When a celestial body collides with the Earth in a direction positive or negative to the rotation of the Earth, the rotation speed of the Earth could be quickened or slowed. This could change the direction of the relative movement between Earth's core and mantle. Consequently, the direction of the vortex movement in the liquid core and the geomagnetic field may change, therefore realizing geomagnetic polarity reversal. This new concept gives a simple and clear explanation for the dynamic cause of geomagnetic polarity reversal.