Digging a Tunnel through the Earth
Discover, Tiny Fox Lab

If you jumped into the tunnel, you’d fall down towards the center of the Earth, accelerating constantly, thanks to gravity. By the time you reached the halfway point, after falling for 21 minutes, you’d be traveling at 28,000 kilometers per hour.Tiny Fox Lab Facts

Preview photo credit: Discover
Source: https://www.scientificamerican.com/article/would-you-fall-all-the-wa/