• Question: If you really could dig a hole to China, and you did, and you fell in, would you stop in the middle because of gravity?

    Asked by joemcg to Amy, Drew, Julia, Kimberley, Sara on 17 Jun 2011. This question was also asked by mccro123.
    • Photo: Drew Rae

      Drew Rae answered on 16 Jun 2011:

      Hi Joe. If you dug a hole right through the middle of the earth, there would be gravity pulling you toward the middle right up until you got there. That means that you would be accelerating the whole time. Once you reached the middle, you still be accelerating toward the middle, which means that you would be decelerating right up until you arrived at China and came to a perfect stop.

      All that assumes zero friction, of course. If there was a bit of friction, you wouldn’t quite reach China, and you would fall almost all the way back again. Then almost all the way to China again, but not quite as much as last time. You would keep wizzing back and forward until eventually you were at a stop in the middle.

      Since I got my answer in first, one of the other scientists can show you how to work out how fast you’d be going as you went through the middle.

    • Photo: Amy MacQueen

      Amy MacQueen answered on 16 Jun 2011:

      Hey Joe!

      Right, well, I would postulate that…if you were going to dig a hole to China the best way to do this…instead of digging all the way down to the middle of the earth and back up again (which seems like a ridiculous waste of digging power!!) would be to dig down a few feet and then along…I mean you’d probably have to wiggle a bit to keep it under the land mass of europe and asia – and make a few tunnel sections for the channel etc…but yeah you could put supports up the whole way to stop it caving in.

      The advantage of this hole would be that, if you fell into it, you would only fall a few feet causing minimal damage to yourself due to the pull of gravity and might reach China alive… 🙂 🙂

    • Photo: Sara Imari Walker

      Sara Imari Walker answered on 17 Jun 2011:

      Hi Joe! Drew has described the gravitational situation perfectly, pending you fell in and didn’t jump or weren’t launched in =) The challenge you might have to face in the middle though is the extreme heat! The temperature of the inner core of the Earth is estimated to be about 5,700 K. That’s almost as hot as the Sun. I don’t know about you, but I am ok taking the long way around!!

Comments