A Pipe Through the Earth

[UncleWai]

greatest amusement ride ever

 

[Jeff7]

Originally posted by: MeddyDuo

Originally posted by: Jeff7

The water would simply flow in, as would a liquid in a container with a pipe running out the bottom. The water wants to get to the center of Earth's mass, and with the pipe, there's suddenly a way to get there. How much water flows in depends on the diameter of the pipe.

But the only way for the air inside the pipe to escape is out one of the end of the pipe. And if both oceans give the same pressure, then the air would just stay in the pipe and no water would fill it.

I guess it depends on how the pipe is constructed. I assume it to be put in place with the ends beneath the ocean. If the pipe simply came into existence, would it be filled with air, or a vacuum? If air, well then the water would compress that air considerably, but not be able to fall to the center of Earth. If a vacuum, then the pipe would be entirely full of air.
If it's drilled down, then water would rush in immediately.

Originally posted by: Malak

Originally posted by: MeddyDuo
But if you take a straw, put your finger over the bottom end and submerge it into a tank of water, no air will come out of it.

Unless it is at an angle.

Can't have an angle if the pipe is going straight down to Earth's center. 😉
If there's air in the pipe, I guess how the water might flow in would depend on turbulence, and the diameter of the pipe.

 

[KillerCharlie]

Do your own homework...

 

[Malak]

Originally posted by: Jeff7

Originally posted by: Malak

Originally posted by: MeddyDuo
But if you take a straw, put your finger over the bottom end and submerge it into a tank of water, no air will come out of it.

Unless it is at an angle.

Can't have an angle if the pipe is going straight down to Earth's center. 😉

What is straight on a sphere that isn't perfectly round?

 

[iamaelephant]

Originally posted by: MeddyDuo
But if you take a straw, put your finger over the bottom end and submerge it into a tank of water, no air will come out of it.

Giant 13,000km tube != straw.

 

[DrPizza]

Originally posted by: silverpig
So yeah, this has been asked several times and the answer is quite complicated. The simple answer is they would oscillate from surface to opposite surface over and over again. If you add in air resistance, then the person would oscillate back and forth, but never regain the altitude from the previous fall, and would quite quickly come to a stop at the center of the earth. If you take into account the pressure gradient, the air would probably liquify under the intense pressure of the air above it, and you would fall into this liquid and possibly float.

I've spent countless hours on this problem in the past. If you could magically maintain a vacuum inside the pipe, the object bang off the sides, gradually slowing it while it oscillated back and forth (thanks to the correolis effect.) To avoid this, drill through the axis of rotation. Silverpig's correct - you aren't making it to the center if you take into account the air pressure gradient. No matter; you'd be crushed to death due to the air pressure long before you came close to the center.

If, somehow magically, you could maintain a 1 atmospheric pressure throughout the entire column, you would not oscillate back and forth. You would just barely reach the center... eventually. It's going to take a LONG time to get there though. Remember, the F_net due to gravity is going to decrease as you get closer to the center of the earth. IIRC, assuming a uniform density, the gravitational acceleration would decrease at a linear rate with distance. Just barely making it there also assumes that the drag is proportional to the square of the velocity; not that this matters much, I believe proportional to the velocity (unsquared) would also result in just barely making it there.

Think of it this way: terminal velocity occurs when the force due to gravity is equal to the air resistance. Well, half way to the center of the earth, you're only going to have 1/2 (or less) the force due to gravity. This means your terminal velocity 1/2 down the hole is going to be half of what it is near the surface. And, 3/4's of the way down, you'll only have 1/4 the velocity. Of course, the velocity won't change instantaneously. However, the drag forces have a relatively long time to slow the object. (Think about it; the fastest you're going to go is 120 mph... think of the distance involved - roughly 4000 miles -and how many hours it's going to take to get to the center, or rather, days.)

edit: and this assumes that the tube is able to insulate from the extremely high temperatures, radiation, etc.

 

[DrPizza]

Originally posted by: MeddyDuo

Originally posted by: Jeff7

The water would simply flow in, as would a liquid in a container with a pipe running out the bottom. The water wants to get to the center of Earth's mass, and with the pipe, there's suddenly a way to get there. How much water flows in depends on the diameter of the pipe.

But the only way for the air inside the pipe to escape is out one of the end of the pipe. And if both oceans give the same pressure, then the air would just stay in the pipe and no water would fill it.

Hopefully, you don't have a career where your thinking skills could have any impact upon my life. 😛 🙂
Ever heard of bubbles? (And, I saw your reply to this point) - Are you implying that if I drilled a hole only part way through the earth, and did this from the ocean floor, that water wouldn't fill the hole??

 

[silverpig]

Originally posted by: MeddyDuo
But if you take a straw, put your finger over the bottom end and submerge it into a tank of water, no air will come out of it.

But if you turn the straw upside down, the air will bubble out the top. With a tube going through the earth, it essentially has two tops.

 

[compuwiz1]

When you hear that the world is "going down the tubes", that is what they mean. There is a pipe though the earth, but it flows much higher volume, than any pipe you could conceive of, pushing through the earth. It's all the sewers in USA, Europe, Asia, and everywhere else in the world, except, Africa, where they still use out houses, and try not to get eaten by lions, while taking a constitutional. 😉

 

[jagec]

Originally posted by: iamaelephant
A person would not be crushed, he would feel weightless. I don't know about the final question.

Yes, a person would be crushed...the air will be VERY dense indeed at the center.

Originally posted by: Malak
I would like to point out that since nobody even knows what the center of the earth is even made of, there is no real answer. The object could spontaneously turn into cheesecake for all we know.

we're fairly sure it's iron.

 

[judasmachine]

Originally posted by: silverpig

Originally posted by: iamaelephant

Originally posted by: Malak
The object could spontaneously turn into cheesecake for all we know.

:Q

Hello China? Yeah, I'd like a cheesecake please.

*Chinese guy dumps a load of garbage down the hole*

A pipe through the Earth originating in the continental US would end up in the middle of the Indian Ocean.

 

[elektrolokomotive]

I'm going to go home tonight and break out my cordless drill to start the pilot hole for my "Tube the Earth" project. Feel free to paypal donations. This is a burning question that needs a demonstratable answer before the end of the millenium.

 

[tmc]

btw, this is a standard problem in physics.

it would take only 84 minutes for an object dropped on one side to reach the other side.

could serve as super fast delivery. 🙂

 

[SoulAssassin]

Originally posted by: UncleWai
greatest amusement ride ever

I was thinking the exact same thing....like bungee jumping times 1 million. I'd be first in line to ride it. Ok, well, second...assuming the first guy wasn't crushed or killed by radiation. Maybe they could put you in some kind of pressurized capsule.

 

[Phoenix86]

Wouldn't the air pressure equalize as both ends are open?

 

[SoulAssassin]

Originally posted by: judasmachine

Originally posted by: silverpig

Originally posted by: iamaelephant

Originally posted by: Malak
The object could spontaneously turn into cheesecake for all we know.

:Q

Hello China? Yeah, I'd like a cheesecake please.

*Chinese guy dumps a load of garbage down the hole*

A pipe through the Earth originating in the continental US would end up in the middle of the Indian Ocean.

Well, that explains the earthquake/tsunami from a couple years ago. 😉 Hopefully they have the tube almost done by now....I'm ready to give it a try.

 

[So]

Originally posted by: tmc
btw, this is a standard problem in physics.

it would take only 84 minutes for an object dropped on one side to reach the other side.

could serve as super fast delivery. 🙂

Can't you get anywhere in the world in ~90 minutes with suborbital transport? I'd think that'd eat up the market. 😛

 

[Mo0o]

would it make it through to the other side? Or would it osscilated back and force then eventually stop at the center?

 

[FoBoT]

I, for one, welcome our new core of the earth Cheesecake Overlords!!

 

[Slacker]

The plane takes off

The bullet doesnt care that the car is going 100 mph

and

it takes 94 licks to get to the tootsie roll center of the earth.

 

[meltdown75]

this pipe is awesome