I need the help of a physics major...
A friend and I were having a discussion about the nature of gravity and we were unable to agree on how exactly gravity works.
The scenario is this: Let's say you were able to go to the center of the earth.... encased in a hollow sphere with the same atmospheric pressure as on the surface of the Earth... so you could breathe easily.
My friend looks at gravity as a force that would be pushing in from all sides. In other words, the person in the sphere would be feeling pressure from all sides and therefore it would be somewhat difficult to move.
My theory is that gravity is greater depending on where the mass is relative to you. For example... when you sit in chair.... you have the entire mass of the Earth pulling you down. However, if you were at the center of the Earth, you would only have half the mass of the Earth, in any direction, affecting you. And beyond that... instead of it pushing inwards... you would actually be pulled outward in all directions by 1/2 the amount of gravity you would experience on the surface of the Earth.
What do you all think?