How is it possible that the core is several years younger if the core and the surface have gone around the sun the same number of times?

Here is a more accessible explanation for those (like me) who are unfamiliar with the maths: https://www.sciencealert.com/earth-s-core-is-2-5-years-young...

> The pedagogical value of this discussion is to show students that any number or observation, no matter who brought it forward, must be critically examined.

Excellent, I hope this value is also encouraged more in schools now than when I was there.

What's the deepest core sample; 10 km? I assume isotope dating is no where near accurate enough to see the difference.

It seems like it would be the opposite:

- If you are smack dab in the middle of the Earth, although you'd be mashed, gravitational forces should be equal in all directions and therefore cancel out to zero.

- Ergo, if you are on the surface of the Earth, gravity should make your clocks run slower than in the middle.

What am I missing that makes this untrue?

What about the center of a black hole? Is it younger than the surface?

This only works because the core is denser than the surface.

(hint: imagine the limit case where the earth were a hollow sphere)

Does the same apply to the Sun? How old is the centre of the Sun compared to its surface?

> Comments: Published version, apart from minor editing (e.g. corrections of 'center' to 'centre')

> Journal reference: Eur.J.Phys. vol. 37, 035602 (2016)

If Brexit occurs, Britain will no longer be a European nation, and therefore the European Journal of Physics will no longer be obliged to accept "centre" as the standard spelling of "center", right?

It's all a wibbly-wobbly, timey-wimey big BIG ball of string.

There's a "yo momma" joke just waiting to be made here...