Slashdot Mirror
The Science of a Bottomless Pit
StartsWithABang writes It's the ultimate dream of many children with time on their hands and their first leisurely attempt at digging: to go clear through the Earth to the other side, creating a bottomless pit. Most of us don't get very far in practice, but in theory, it should be possible to construct one, and consider what would happen to a very clever test subject who took all the proper precautions, and jumped right in. Here's what you would have to do to travel clear through the Earth, come out the other side, and make the return trip to right back where you started.
24 hours *if* you have air resistance. And then you're moving so slow that you barely get past the center.
Note that no vacuum is perfect so you will lose velocity. Their scenario should have started the person off at the south pole, not the north, for the extra altitude.
Note that the heat isn't really the materials problem that they make it out to be - it's an energy problem. You don't need a material that can withstand 4000, you just need cooling. And not linearly high cooling, but an exponential decline. The longer you cool the rock down to your target temperature, the deeper your effect on the rock temperature behind your tunnel walls, and thus the shallower the temperature gradient, and thus the lower the rate of heat loss. It's like trying to cool a hot house - the air conditioner really struggles in the beginning but it gradually becomes easier with time as the walls and everything inside the house cool down.
Now, the pressures, those are insane, and the normal approach to pressure maintenance on deep drilling - filling with a heavy mud - obviously wouldn't work here.
We gotta go to a crappy town where I'm a hero.
Their scenario should have started the person off at the south pole, not the north, for the extra altitude.
Um, hello?
Everyone knows that north is on top, and you can't fall upwards.
The level of scientific illiteracy here is disgraceful.
To have a right to do a thing is not at all the same as to be right in doing it
I always told my kids it takes longer to drive north because it's all uphill.
Interesting to watch their reactions over the years go from unquestioning acceptance, to cognitive dissonance. to enlightened disagreement, to "Daaaaaaad!!!", to "When are we stopping to dinner?'.
When Fascism comes to America, it will call itself Anti-Fascism, and tell you to give up your guns.
Additionally, you would void the Earth's warranty.
When someone says, "Any fool can see