I have an interesting physics questions regarding the center of gravity

Bassically, you have the centre of gravity don't you, where theres the core in the middle of the earth,

so what is the core made out of?

I just think, that if someone dug a hole, from one side of the core , to the other, like a tunnel, and people could travel down it,

then, in the middle of the earth, would you just be floating? Since gravity up, and gravity down, it would stay the same???

I don't know what the core is made of, but I do know that it is very hot down there.

...but if you ignore the heat, there would be some pretty cool stuff that would happen. Yes, if you were just smack dab in the middle of earth, you would be floating. It would be as if you were in space. And if you dug a hole from one side of the earth to the other and just jumped into it, you would fall all the way down to the center of the earth and continue "falling" upwards until you get to about the same distance from the center of the earth but on the other side. You would keep going up and down until someone saved you or you grabbed onto the wall of the hole. Though, air friction will decrease the height you get on your way back to the surface each time, so eventually you will end up at the center of the earth without any speed to get you back up.