Trip to the Center of the Earth

What happens if you dig a hole straight down into the ground? How far until you reach the bottom? That’s what Bedtime Math fan Ajax wants to know. Well, it depends what you mean by “bottom.” Earth is a ball, so if you want to dig to the center of it, it’s 3,958 miles. But if you want to dig all the way through and pop out the other side, it’s twice as far, or 7,916 miles. By the way, the deepest humans have ever dug is just 7 1/2 miles, or less than 1/1000th of the way through! By the way, the cool website FreeMapTools shows you the spot exactly on the other side of Earth from you. Just remember that the center of Earth is a 10,000-degree F blob of metal, so if you do dig down, you’ll need your heat suit.

Wee ones: If you dig 7 miles down, then dig 1 more mile to beat the record, how far do you dig?

Little kids: Which is cooler, 1 thousand degrees or 10 thousand degrees?  Bonus: Earth is 7,916 miles across. Close your eyes and see if you can remember that number!

Big kids: Who digs farther, you if you dig down 6 miles a day for 6 days, or your friend who digs 5 miles a day for a whole week?  Bonus: If you dig exactly 20 miles every day, by how much will you overshoot the exact middle spot at 3,958?

The sky’s the limit: If you dig 10 miles the first day, 10 miles again the 2nd day, then 20 the 3rd day, then 30, then 50… how many miles do you think you dig the day after that?