How long it really takes to fall through the Earth

If you dig a tunnel straight through the center of the Earth - how long would it take you to reach the other side?

For decades the answer to that was about 42 minutes. But Alexander Klotz, a graduate student at McGill University in Canada, came up with new calculations that estimate it would actually take around 38 minutes. The 240 second difference is credited to density.

The original calculations assumed that the Earth has the same density throughout - and the gravitational force changes as you approach the center, much like the weight of a spring that bounces up and down.

But in reality, the planet's layers become more dense as you travel from the crust to the core.

As the density increases, the gravitational force increases meaning you'll fly through the tunnel even faster. At least until you pass through the center.

We can imagine what it's like to fall through the Earth, but you still don't want to fall into a black hole. The good news? They're pretty to look at.

Check out some supermassive black holes in the gallery below: