If Earth were hollowed out only to it's outer layer of crust, what would happen? Would the Gravity decrease? Would the Gravity, if it remained, would it implode into itself? or just break apart into space? I'm in middle school, so a simple answer would be helpful.

 

 

In the words of Friedrich Nietzsche, "The"

If the mass stayed the same, surface gravity would not change. For spherically symmetric masses, the force is determined by the mass inside the sphere, just as if it were all at the center. So the mass distribution is unimportant as long as the symmetry is there. (Anyone inside the shell would feel no force)

Removing the center of the Earth would decrease its mass. Moreover, the remaining crust would probably break apart and mostly collapse into a smaller body, with some perhaps flying away into space. Exactly what happens might be modeled in a computer simulation, but could not be modeled without knowing what you think happens to that missing core. Does it just magically disappear, does it eject into space, or what? Note, you need not answer, I will not (probably cannot) write such a simulation.

Assuming the interior just disappeared, gravity would decrease dramatically, and the crust would probably break apart and fall in on itself.