Recent research on Earth's inner core confirms a 70-year cycle of rotation changes.

The core slows down and even moves backward relative to the mantle.

This influences Earth's magnetic field and impacts the planet's rotation speed.

Changes in rotation speed can ultimately affect the length of a day.

Ongoing research aims to understand the inner core's structure and its role in Earth's dynamics.

The core's dynamics are crucial for powering the magnetic field and understanding the planet's deep interior.