system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What would happen to you if you fell through a tunnel going through the centre of the Earth? 

This question is in regard to Earth's gravity and whether you would fall through to the other side or oscillated to either side?

Also, let us assume you cannot die, there's no lava and that we are capable to drilling through to the other side.
gpt
You'd smack into the side of the tunnel. Coriolis force.

But *ignoring* that — in our imagination, the Earth is not spinning … and it's perfectly spherical and uniform … and it's entirely alone in the whole universe … and the tunnel has no air in it … and also all cows are spherical — you'd fall all the way through the center of the earth, come to a stop at the top of the tunnel on the other side, then fall back through ending up back where you started after about 84 minutes.

Fun fact? If you fall freely and frictionlessly through *any* straight-line tunnel through the Earth, the trip from one end to the other takes about 42 minutes. *Regardless of whether the tunnel goes through the center of the Earth or not.*