It's a common childhood fantasy: what if you dug a hole to the other side of the world, where would you end up? Parents in America are in the habit of telling their kids that they'd end up in China, but that's actually rather far from the truth. Earth is a sphere, so if you start digging in the Northern Hemisphere, then you've got to end up in the Southern Hemisphere. China is far away, but it's also in the Northern Hemisphere. So if you're digging from America, then China can be ruled out from the get-go.
Luckily, there's now a simple tool that scientific-minded parents can use that can give them a more accurate answer to their curious and industrious digging children: an antipodes map. Enter in your location, and it will tell you what's on the opposite side of the world — i.e., your location antipode. (The map shown above will also give you a pretty accurate idea too.)
There's some bad news for kids digging from pretty much anywhere in North America aside from the far north latitudes, however. You're going to end up smack-dab in the middle of the Indian Ocean. In fact, because the Earth is so extensively covered in ocean compared to land, chances are fairly strong that no matter where you start digging, you'll find yourself in an ocean on the other side.
There are some exceptions, though. If you're dead-set on digging to China, you can do so from Argentina. New Zealanders can dig themselves to Spain, and folks in Indonesia will find themselves in the Amazon rainforest. You can also dig yourself from Greenland to Antarctica, but for most other places, your antipode will be an ocean.
Of course, if you really want to get scientific with your kids, digging to the other side of the planet is pretty much an engineering impossibility. Even if it were possible, you'd have to pass through temperatures that are actually hotter than the surface of the sun. So good luck with that.
The furthest that humans have ever dug into the Earth is at the Kola Superdeep Borehole, a 7.5 mile-deep drill hole in northwestern Russia. That's deep, but it still doesn't come close to cracking the Earth's thin continental crust.
None of this is any reason to discourage the effort, however. There's also no reason you have to dig a hole straight down. With some clever planning, you could dig a hole that twists and turns and ends up somewhere else other than your antipode. So it's still possible to dig a hole to China from North America, if that's where you want to go. You just need to map out a more complicated route.