Re: Why is the pressure at the Earth's center so great?

Hi Matt

Yes, you are right.

But the stuff at the center of the earth has all the weight of the stuff 
ABOVE it squashing it down. So the pressure is high - just like at the 
bottom of the sea.

The whole earth was once molten, so any pressure was transmitted right 
down to its centre, where it is highest of all. It is so high the 
material (perhaps iron) is in a molten state never yet directly 
investigated by science [Note added by MadSci Admin:  The study of seismic
waves gives us SOME idea of what the interior of the Earth is like.]
You might think that the earth's crust, like an eggshell, could support 
its own weight without pushing on stuff inside (lower down). But the 
crust is, in proportion, just about as thick as the skin on an apple. Its 
weight is negligible, it was not always there, and it is not strong 
enough even to support its own weight. 

John