Hole In Earth?

[midgetwars]

If someone drilled a hole right through the centre of the earth (supposing there was no heat, compression, magma).

 

AND THEN YOU WALKED RIGHT INTO THE HOLE, WHAT WOULD HAPPEN

[swansont]

You'd fall in. And exhibit a damped oscillation and eventually come to rest in the center (assuming no rotation)

[DrP]

If someone drilled a hole right through the centre of the earth (supposing there was no heat, compression, magma).

 

AND THEN YOU WALKED RIGHT INTO THE HOLE, WHAT WOULD HAPPEN

 

 

The person who dug the hole would shout 'MIND THAT BIG F@#;ING HOLE!!' and after you fell in he'd say 'what a dick!' :D:D:D

[Phi for All]

You'd fall in. And exhibit a damped oscillation and eventually come to rest in the center (assuming no rotation)

So, an 8000 mile freefall, then a 7999 mile fall back, followed by a 7998 mile fall, and another back 7997 miles, and so forth until you reach stability in the center of the earth?

 

If I build it, will you come? What would you be willing to pay (figure it takes about two to three days just for the first fall)? You may have to pay in US$ for the first fall, but pay in yuan for the second fall.

[insane_alien]

the degradation would be much more than that but essentially yes.infact, if it is air all the way down it'll pretty much 1 fall with a short(mile or less) fall the other way.

 

on the other hand if its turtles all the way down crazy stuff happens.

[Phi for All]

on the other hand if its turtles all the way down crazy stuff happens.

I think Turtles All The Way Down is an excellent name for this ride. You're in for 10%.

[midgetwars]

WHy would you fall? THERE IS NO GRAVITY SUNCE THERE IS JUST PLAIN AIR IN THE MIDDLE (damn i put caps lock)

[Cap'n Refsmmat]

Unless you suck all the magma out, there's still a good lot of mass in the center of the Earth that you'll be attracted to.

[DrP]

Would you not get attracted to the sides of the hole at hit the closest one? Or are we assuming we are going exaxtly down the middle?

[swansont]

I'm assuming the middle.

 

If you are standing on a sphere of radius R, all of the mass inside the sphere attracts you. (Uniformly distributed mass outside does not; everything cancels)

[Cmac22]

i was watching the TV show the universe, the new episode on gravity. in it they show what would happen if you built a hole through earth and put in a kind of transport car that ran off gravity. i think it was assuming like no air resistance or something but they were saying that it would go all the way through and stop on the other side. but the cool part was this. the time it would take to go straight through the earth to the other side is 42 minutes. but also the time to go from one city, to any other city, even if it is not straight through the earth, is 42 minutes! i dunno the conditions for this... like no air resistance and minimum serface resistance.. probably like mag lev or something. so it would take the same amount of time, 42 minutes, to go from seattle to paris, and to go from seattle to new york. i think thats pretty cool!

 

but when i was watching this i had a question. if you are inside the earth while going straight through the center, say 1/2 way to the center, does the fact that you are inside the mass of the earth change anything? by this i mean... well since your passed a lot of earth there is less below you, so even though gravity is stronger because you are closer to center, would it be stronger if you were the same distance away from an object of the same mass with a density that would put you outside of that object? or is the only thing that is importaint is the center of mass or center of gravity? i hope that makes sence heh.

[swansont]

but when i was watching this i had a question. if you are inside the earth while going straight through the center, say 1/2 way to the center, does the fact that you are inside the mass of the earth change anything? by this i mean... well since your passed a lot of earth there is less below you, so even though gravity is stronger because you are closer to center, would it be stronger if you were the same distance away from an object of the same mass with a density that would put you outside of that object? or is the only thing that is importaint is the center of mass or center of gravity? i hope that makes sence heh.

 

Yes. As I sated in my previous post, the mass outside of your radius makes no net contribution. The mass inside behaves as if it were all at one point; a very dense, small body will have an equal effect as a large body of the same mass, as long as you are outside of all of the mass. Any inverse-square law behaves this way, so it works for electrostatics and charge, too. It's called Gauss's law.

[pioneer]

I understand how the math works and I believe the results of the equations are correct. But one thing has always bothered me, is connected to the conservation of energy. The center of a mass has no gravity, yet it is often the hottest part of a sphere, like the sun. This is due to the gravitational work causing things to heat up. The paradox that arises is there is no gravity at the center, yet the most energy, as heat, coming gravity is coming from where there is no gravity.

 

One possible way to explain it is, the zero gravity at the center is due to vector addition of all the gravity force vectors in the mass. But the heat is connected to the scaler of the force of gravity, acting on surface area to create pressure and work. This will only make heat, if at least some of the vectors cancel so there are at some pure scaler components. The force acting in one direction gives motion. If we oppose motion with some vector canceling to get scalers we get heat.

 

This sort of makes sense since force is vector or directional. If we retain the guts of the force but get rid of it sense of direction, through vector canceling, the force becomes zero and it converts to energy. The center of gravity has lost all its force vectors, so all it can do is make heat. That makes the force vector the middle man between force and energy. Vector and force makes motion, while force with no vector makes energy.

 

We need to go one more step. Vector is a sense of direction. It is what allows a force to act in space-time. If it loses its sense of direction it appear to default back to the C reference by converting to energy. Does that make force energy with a sense of direction?

[Calabi-Yau]

Assuming there were no problems in creating the hole, it would still colapse upon itself afterwards. Ignoring this, or assuming the problem was rectified in some way, you would put international travel companies out of buisness

[CaptainPanic]

I propose a vacuum for extra fun.

 

If you leave it open to the outside air, the pressure would be immense. (If you extrapolate the increase in gas pressure as you decrease in height, the pressure at -10 km is already 3 bars). I was not in the mood to adapt my little model to the changing gravity as you go down, so I don't know the final air pressure, but the hugely dense air is probably as efficient in slowing you down as a 20 meter thick concrete wall... Not much oscillations.

 

Vacuum is the way to go!

 

Can I propose another silly idea, that might theoretically work, but that won't be built for the next 1000 years?

Theoretically you can build a tunnel along the surface of the earth, and remove all air. If it stays perfectly at the same altitude, then you could put an object in orbit in that tunnel, at ground level. That'd remove the need to build passenger space ships. Just a train (with a big, big engine) would do. Funny idea, but it didn't seem worth a separate thread.

[thedarkshade]

Theoretically you can build a tunnel along the surface of the earth, and remove all air. If it stays perfectly at the same altitude, then you could put an object in orbit in that tunnel, at ground level. That'd remove the need to build passenger space ships. Just a train (with a big, big engine) would do. Funny idea, but it didn't seem worth a separate thread.

Removing all air would first require (IMO) isolation of that tunnel, then take our everything. I dunno but this seems too rough to me, even as a thought. But... any practical use out it?

[Mr Skeptic]

Can I propose another silly idea, that might theoretically work, but that won't be built for the next 1000 years?

Theoretically you can build a tunnel along the surface of the earth, and remove all air. If it stays perfectly at the same altitude, then you could put an object in orbit in that tunnel, at ground level. That'd remove the need to build passenger space ships. Just a train (with a big, big engine) would do. Funny idea, but it didn't seem worth a separate thread.

 

Well, that would work (unlike drilling through the earth, which would have trouble with pressure and the different spinning rates of the earth and its core), but of course it would be expensive. I'd say it would have more use than just passenger entertainment or transportation, though. There are a few manufacturing techniques that could use zero gravity too. Dunno if it would be more cost effective than just going to space though.

[jsispat]

may be death of our planet

[SkepticLance]

Most of this speculation assumes no rotation. However, we cannot assume that. The surface of the Earth travels at about 1000 kph at the equator in the direction of west to east. As you fell, the rotation speed gets less. That means you are going faster west to east than the part of the hole you are falling through, and you will smash into the eastern side of the hole. Thereafter you slide down that side of the hole. Assuming normal friction, you will abrade into hot powder well before you get very deep at all.

 

The only way to avoid this would be drill a straight hole between the poles. You would start out very cold, and as you fell, you would get very hot very quickly!

 

Of course, the pressure even a few kilometres down would be so great, the hole would collapse before it could be dug. If this was a fantasy forum, you could postulate a force field (magic) holding the hole open.

[swansont]

Most of this speculation assumes no rotation. However, we cannot assume that.

 

Sure we can. It's an idealized physics problem. We can assume anything we want, as long as it doesn't violate constraints placed by the laws of physics — it happens all the time. Assume no friction, assume constant gravitational acceleration, assume no outside influences.

[Cap'n Refsmmat]

If we develop the ability to drill a hole all the way through the Earth, I think it's safe to assume that stopping the planet entirely wouldn't be all that hard.

[Think it thru]

The first thing that would happen upon entering a hole into the interior of the earth is that we would quickly learn what has never been known before.

 

One must assume that you are not familiar with the theories of John Cleves Symmes, Jr. who in 1818suggested that the Earth consisted of a hollow shell about 800 miles thick with openings at each pole, nor subscribe to his beliefs.

http://en.wikipedia.org/wiki/Hollow_Earth

 

For your entertainment: http://www.ourhollowearth.com/SmokyGod.htm'>http://www.ourhollowearth.com/SmokyGod.htm

http://books.google.com/books?id=ZG0mAAAAMAAJ&pg=PA170&vq=%22A+strange+manuscript+found+in+a+copper+cylinder%22

 

May I also suggest the Jules Verne classic "Journey to the Center of the Earth". http://www.online-literature.com/verne/journey_center_earth/

 

There have been a number of movies on the topic as center earth exploration.

 

For further reading: http://www.ourhollowearth.com/

 

Perhaps you would like to take an exploration trip yourself in 2009.

http://www.phoenixsciencefoundation.org/APEX_apply.htm

 

As to what I personally believe---does it matter? What you believe is all that really matters.

[insane_alien]

the earth is not hollow.

 

seismology pretty much proves this. if the earth was only a shell 800 miles thick vibrations from earthquakes and nuclear bombs and strip mining would propagate much differently.

 

also, many people have flew over the pole. submarines have been under the ice there, we've seen it from space. there is no entrance there.(or anywhere)

[Sisyphus]

If you're so worried about the rotation of the earth, why don't you just curve the tunnel to match the natural path of a falling body?

 

Also, if you make the walls of frictionless unobtanium, you needn't worry about even making it straight down. Just make straight (or not) tunnels between any two points on the surface, and grab a sled. Fastest way to travel most places, and it doesn't even use any energy! Of course, we'll feel awfully silly with all those infinitely strong, vacuum-sealed, frictionless tunnels all over the place once the teleporter networks are up and running.

[D H]

As to what I personally believe---does it matter? What you believe is all that really matters.

 

No. You need not only a tin foil hat to believe in the hollow earth garbage, you need full body suit tin foil armor.

 

Everyone is entitled to their own opinions, but they are not entitled to their own facts.