Replies

Well let’s say you’re not quite at the center but maybe a few hundred or a thousand miles out and the metals there are all liquified.

I'm not really sure. I'm not at all sure that the metals there are all liquid. I don't see why they would be liquefied. But if you are 1000 miles from the center of the earth, you are surrounded by a more or less uniform mass field 3000 miles in diameter which cancels itself out gravitationally, and another shell of mass about half of the mass of the entire earth which would act gravitationally upon you from its center of mass which is about 4400 miles away from you. (which reduces the gravitational attraction by another 20% or so because surface gravitation acts from only 4000 miles away)

ML/NJ

I'm not at all sure that the metals there are all liquid.

Radioactive decay. When the Earth formed the heavier elements naturally settled to the bottom. So you end up with the low density rock on the top, then the iron and nickle that make up most of the planet. Finally at the very center you get material rich in uranium. And it is still breaking down and giving off a lot of heat.

Caused Pascal a lot of problems. He couldn't figure out why the center of the Earth hadn't cooled down yet. Of course back then they didn't know about radiation or nuclear fission.