If you imagine yourself at the center of the earth your are floating since the pull is the same around you. But let us say you could turn up the gravity as much as you want. Why aren’t you pulled apart? The net forces are zero, sure. But wouldn’t the body experience tension?

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If we compare it to a rope pulled by two equal forces in each end. The net forces would be zero and you would have static equilibrium, but the rope would still break if pulled hard enough.

Additionally, wouldn’t a metal ball uniformly surrounded by powerful magnets be pulled apart as well?

I am not sure why I can’t wrap my head around this, when it comes to the center of the earth.

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Anonymous 0 Comments

To be at the center of the Earth you would need to be in a hollow chamber right? So you’re in a hollow space surrounded by the rest of the Earth. Maybe we just simplify that to you’re inside a large spherical shell made of some dense material.

You know the rubber sheet model of gravity, where you put a heavy ball on a rubber sheet and it bends representing kind of what’s happening to spacetime due to gravity?

Lets imagine that spherical shell you’re in as 2D, so you’re inside a circle right? Lets apply that to the rubber sheet gravity and take a pipe to represent the circle you’re in and press it against the rubber sheet.

What happens? Everything outside the pipe bends down, representing how objects outside the original spherical shell would be pulled towards its surface due to gravity. But inside the pipe, the rubber sheet is just pulled flat. No curvature = you’re weightless inside the center.

So it’s not just that you’re being pulled equally in 2 directions by gravity, there is no curvature of spacetime so no force due to gravity at all so no kind of tension or any other force. It would be as if there was no gravity at all.

This should hold true even for very strong gravity fields (say if you were in the dead center of the sun), but I don’t know if going as far as say a sphere made of neutron star material would start to break things. Maybe a physicist here could help with that.

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