Theoretically, if you dug straight through the earth, at what point would you stop digging down and start up?

well somewhere in the middle you might become weightless as you would be in the center of a spinning mass. but most likely you would get to a point that the gravity would push you back. just like on a merry go round getting to the center is actually pretty hard.

OK, setting aside the whole issue of temperature, molten rock, disposal of excavated material, etc. As you dug you would gradually get lighter, until at the centre of the Earth you would be weightless, just as if you were in orbit, then as you kept on digging (assuming you are able to continue a straight line course) you would gradually acquire weight again, this time pulling you back the way you have come, so you would need to cut yourself footholds as you go and dig over your head for the last few thousand miles, emerging headfirst.

Coming from one side you would enter the other side feet first but gravity may pull your feet to the center once you pass it. However if you are turned the other way you would be standing on nothing. I think that because of this issue that helps make digging to the other side impossible.

Were it possible you'd most likely stop digging when you near the molten material and it's accompanying heat.

In theory I would think that you would technically be digging up once you passed the equator.

It's an interesting thought.

Once you got to the center of the Earth (the core) you would be suspended in a state of weightlessness. If you were to proceed along your current corse, this is when you would be digging 'up' to China.

offered which you're actually not overwhelmed by ability of the stress, and that there is not any air friction once you leap - then sure you will fall at present day by way of and only somewhat attain the different area. - because of the fact gravity will enhance up you to the middle, and then decelerate you once you attitude the different area of the earth. regrettably, you do comprehend that the middle of the earth is made up of molten chocolate, nevertheless, good?

First, from the US, you would end up in the Indian Ocean if you dug a straight tunnel.

Second, you would start going up after you pass the middle.

About halfway. But it wouldn't matter, you would be burned alive once you got down 5 miles or so.

Like the old "when do you stop running INTO the woods" question...at the very middle. (Or center, in this case...)

At the point where you get hungry, thirsty or have to go to the loo.