Just like when you were a kid and you were digging on the beach, imagine if there was a tunnel directly through Earth. If you jumped in, how long would it take to reach the other side?
Life Noggin has created this 3-minute animation showing all the mathematics and physics you need to answer this question that has probably bothered you since you were four.
To make it a bit easier, lets assume the same density all throughout, the world is perfectly spherical, and the hole has no air in it. Even then, theres that annoying little fundamental force known as gravity. When we start our fall, the mass of Earth pulls us towards its center, but what happens when we reach the center and go beyond it?
Check out the video for all the answers.