Imagine, You have dug a hole clear through the Earth. From one side to the other. Don't ask me how, you just did. Let's pretend that the hole is totally perfect: Same diameter thoughtout, no cave-ins, and it somehow doesn't get hot or filled with magma in the center. It's just a clear shot of a hole. Now, picture someone jumping into it. I have two discussion topics: 1. Would the person fall through the entire hole and come out on the other side? - I mean, wouldn't gravity stop them in the center, as it comes at the person from all sides? Would this cause them to sort of float in the center of the Earth (remember, we're pretending that there's no magma in the center, so our guy is safe). - Or, would the great pressure in the center of the Earth crush our jumper to death? 2. What if he made it to the other side? - What would the people watching him leave the hole see? Would he come out the ground, followed by gravity forcing him down back to Earth? - Or, would his velocity keep him falling (or in this case, flying) out the hole, into the atomsphere? (This is obviously not possible, but whatever) What do you think?