What if....?

Question

Ok. What if there was no mantle or core in the Earth, it was all crust. And You dug to the center of the Earth. Now someone on the other side of the world digs a hole opposite of your hole. If someone falls into your hole then what would happen when they reached the center? Gravity is still in play here. Wouldn't you just float in the middle? The exact middle?

Answer 1

Fun question, good imagination! You'd fall down towards the center of the earth. But you'd be moving pretty quickly when you got there, so then you'd overshoot and fly up the other person's tunnel. Then eventually you'd slow down, stop, and fall back down again towards the center.

It also depends on whether there's air in the giant tunnel. If there were, the air resistance would turn some of your motion energy into heat, and you wouldn't rise all the way to the top of the other tunnel after passing the center. Eventually, after a long time of zipping back and forth, you'd finally come to rest at the center of the earth and float there.

But if there were no air and you were able to avoid hitting the sides, you could jump in your tunnel and eventually pop out the entrance of the other person's tunnel, leaving their tunnel with the same speed with which you jumped into yours.

Answer 2

Inertia would hurtle them past the center and back towards the other side, but drag wouldn't allow them to make it all the way out. Then they would fall back towards the center, back and forth until they hovered, assuming the hole went through the EXACT center of gravity. Then, the rotation of the Earth might allow them to climb out.

Of course, temperature variance and air-pressure changes would most likely prove to be fatal. You'd probably also catch yourself on the walls of the hole and die on the way down.

Answer 3

not perfectly but yes