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?

Question

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.

In: 83

Answer 1

Gravity just isn’t that strong of a force. If some massive force accelerated you into the ground, you would be crushed against the ground. Gravity is trying to do that to your right now – feel anything? At then center of the earth you would theoretically feel tension in every direction at once as your body is simultaneously pulled in all directions at the same time. But, it just wouldn’t be that much, you wouldn’t be pulled apart.

Tidal forces due to gravity can create tension and compression in objects, but the key here is scale. The object in question needs to be big enough to feel a difference in gravitational force across it’s volume, and your body just isn’t big enough, nor is the Earth’s gravitational field strong enough. But large bodies like Jupiter or Saturn can crush (weakly-held-together) asteroids and would-be moons with their tidal forces. An object with a really crazy gravitational field like a neutron star or a black hole could cause tidal forces across the size of your body that would kill you.

I guess if you were standing at a place equidistant from two neutron stars, that’s kind of like being inside a neutron star. And theoretically the gravity could be so great that you would be ripped in half.