Rotational changes to the Earth’s core may be responsible for the “flipping” of the magnetic poles that occurs every few thousand years. It also could explain fluctuations in the Earth’s magnetic field. Which has been weakening for a while. The magnetic field or “Magnetosphere” protects us from cosmic and solar radiation. So this is pretty important.

Strange Transformation of Earth’s Inner Core Revealed in New Findings That ‘Confounded’ Scientists

Youtube “Cliff notes” version…