I was wondering, center of gravity is the point in the object where other objects are pulled to. (they want to get to the center, but the onject itself is stopping it, like we wont fall to the center of the earth, because the eart itself are stopping us.) Anyway, let's assume that. What if we dug a hole from the top of the earth, (assuming the earth is a perfectly shaped round ball) straight to the other side, and in the middle, digging out a room with let's say 20 km in diameter. If we jumped into this hole, (with air resistance) would we then in the end be at the gravity center of the earth? (since if you cut the earth in 2, the mass of these would be the same, the digging removed the same mass on each sides.) Would we float in the middle?