Surface older than the centre?

Our planet's outer surface is more than two years older than the center.

In Einstein’s general theory, a clock placed at Earth’s center will tick ever-so-slightly slower than a clock at its surface. Such time shifts are determined by the gravitational potential, a measure of the amount of work it would take to move an object from one place to another would be slightly higher as you are against gravity.

Over the 4.5 billion years of Earth’s history, fractions of a second adds up to a core that’s 2.5 years younger than the planet’s crust, researchers estimate in the May European Journal of Physics. Theoretical physicist Richard Feynman had suggested in the 1960s that the core was younger, but only by a few days.

by Arturo B., Carlos E. & Anne T. 3ºB
and Martina F. 3º Y