Eli5: why isn’t the earth core melting? If I understand correctly it is made out of iron and nickel and it floats in a molten bath of iron and nickel.

Question

Eli5: why isn’t the earth core melting? If I understand correctly it is made out of iron and nickel and it floats in a molten bath of iron and nickel.

In: 1

Answer 1

Pressure – there’s so much pressure from the entire rest of the Earth pressing down on the solid core that it stays solid despite its temperature being high enough for it to be liquid if it were at the Earth’s surface. Whether a substance is liquid, solid or gaseous depends on both temperature and pressure (for most things). Raise the pressure, and the melting point gets higher.