Would gravity change as you get closer to Earth’s center?



Would gravity change as you get closer to Earth’s center?

In: Physics

Yes it does. The force of gravity comes from the mass of all the rock under your feet. If you start digging down there will be rocks over your head pulling you upwards and less rock under your feet pulling you downward so the force of gravity is reduced. If you are able to get to the center of the planet there is just as much rock in all directions so the force of gravity is zero.


Just to add some extra detail for explainlikeim17, the [shell theorem](https://en.wikipedia.org/wiki/Shell_theorem) proven by the man Newton himself states that a shell of a sphere of any size and thickness will have no gravity on the inside. So if you stand inside of a huge inflated basketball, you will feel no gravity from ut. The proof is calculus, but you can also imagine it as a version of two inverse-squares equalling each other, which is how Newton proved it.

Now, if you imagine the earth as a bunch of concentric shells (like a jaw breaker with different flavors), it is clear that gravity goes down as you tunnel through the center of the earth/shells.

There is a second part of the theorem that deals with outside of the gravity from outside of a shell or sphere, which is the intuitive gravity that you understand from planets.