Why Earth’s Core Is Younger Than Its Surface | What the Physics?!

Einstein's relativity means time runs slightly slower near stronger gravity, and this short uses that principle to explain a genuinely odd claim: Earth's core is younger than its surface. The difference is only a couple of years over the planet's whole history, but the physics behind it is not intuitive.

Why it's free: Free on NOVA PBS's own channel; GBH produces NOVA for PBS.