Reader Louis sends in an interesting question, asking “If it was possible to dig a hole all the way through the Earth, what would happen if you jumped into it?”
This is a terrific, thought-provoking question. Thanks again, Louis.
First of all, no, it’s not possible. Sorry to disappoint. After all, you would have to dig through:
- More than 8,000 miles of solid rock and molten magma.
- Temperatures up to 6,000 degrees.
- Extreme pressures up to 300 million times more than what we experience on the surface of the Earth.
But, let’s say that somehow it was possible. That a hole, going straight through our planet, did exist. What would the properties of that hole be?
Firstly, falling or jumping straight down the hole is more difficult than it sounds. After about a mile of falling, you would crash into the side of the hole and likely never even make it to the other side. But why?
Because of the Coriolis Effect. The surface of Earth is constantly spinning at more than 1,000 miles per hour. If you go deeper into the Earth, it’s still moving all around you, but the mass inside doesn’t have as far to travel. It’s a bit like the lanes on a running track. The inside lane is shortest, and they get lengthier as you move out. So, if you jumped into the hole, you would soon be traveling faster than the sides of the hole around you, causing you to crash into the sides.
The only way to make it work, would be to dig the hole straight through Earth’s poles. Then the Coriolis Effect wouldn’t apply, and this hypothetical gets much more interesting.
Without the Coriolis Effect getting in the way, you would fall straight down, being pulled by gravity the same as if you jumped off of a building or bride or other high platform. And, with nothing to stop your rate of speed, you would soon be traveling at 6 miles per second. Yikes.
But, as you approached the center of the Earth, something wild would happen. The mass above you would begin to cancel out the attraction of the mass below you, meaning that the downward pull would weaken until you reach the center. And this is where things get crazy.
Once you reach the center, you would experience NO gravitational pull. Achieving, in effect, weightlessness. You would just float, being pulled equally by gravity in all directions. That said, you would still be traveling at an unparalleled speed, so you’d zip right through that awesome feeling pretty quickly.
As you pass through Earth’s center, still moving at 6 miles per second, the process would begin to reverse. And the pull would strengthen again, until you popped out on the other side of the globe about 40 minutes later.
So, supposing this impossibility were actually possible, it sounds pretty cool, right? You would be able to travel to the other side the world while experiencing weightlessness and the speed of sound. And the whole trip would take less than an hour.
Want a more detailed answer? The video below does a great job of explaining science behind this answer.
Also, for kicks, let’s say that it was possible to dig straight through the Earth. If you started at your home, where would you pop out on the other side? Click here to figure it out.