Tunnel through the center of the Earth

lalalandlalaland Posts: 11,882
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May be a bit of a daft thought, but here goes.

Ignoring the hot core and other technicalities, if we had a tunnel that went directly through the center of the Earth, directly from one side to the other what would happen in the middle?

Each side being a hole, just straight down. So at each side of the planet it was just a crater that you could jump in to.

Obviously jumping in to the hole at your side of the world would mean you fall downwards, but what would happen as you got to the center of the planet? Obviously at some point down would no longer be down, however you couldn't keep falling and shoot upwards from the hole at the other side of the planet.

So at which point would you stop falling and how would it all work?
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  • Jennifer JayneJennifer Jayne Posts: 9,022
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    you would most likely just speed up as you fall down, as gravity would be getting stronger and stronger till you got to the middle and which point you would just stop.

    Thats what i think there is no scientific basis to that (apart from gravity)
  • [Deleted User][Deleted User] Posts: 127
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    iv thought about it before n it made my head hurt
    also why dont we realise we are walking upside down?
    i know gravity pulls us in anyway
    but the earth still goes upside down
  • KJ44KJ44 Posts: 38,093
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    Wouldn't you oscillate about the centre, almost reaching Australia on the first pass?
  • [Deleted User][Deleted User] Posts: 21,014
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    when you shoot to the otherside and fall back to the middle,

    you would fall onto one side of the hole, which ever is denser because seeing as there is no dead centre anymore you would fall to the bigger half or just be drownd as water would swamp you:)
  • Jed42Jed42 Posts: 194
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    You would be met by Doug McClure half way down
  • MAWMAW Posts: 38,777
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    In Vacuum or air? In vacuum, you'd come to a halt at the surface the other side, in air you'd stopp waaay down near the core.
  • [Deleted User][Deleted User] Posts: 21,014
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    Jed42 wrote: »
    You would be met by Doug McClure half way down

    no way, it would at least be chuck noris!
  • lalalandlalaland Posts: 11,882
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    *marv* wrote: »
    you would most likely just speed up as you fall down, as gravity would be getting stronger and stronger till you got to the middle and which point you would just stop.

    Thats what i think there is no scientific basis to that (apart from gravity)
    That's one thought I had, but I wasn't sure if you'd instantly stop and die from the sudden stop or if you'd stop in an elastic sense because of the speed, as in fall so far past the center but then be pulled back like a bouncy ball loosing it's energy.

    It's just something I've been thinking about :D
  • thecreepingmessthecreepingmess Posts: 3,070
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    From HowStuffWorks:
    Although it would be impossible to do this on earth, you actually could do this on the moon. The moon has a cold core and it also doesn't have any oceans or groundwater to mess things up. In addition, the moon has no atmosphere, so the tunnel would have a nice vacuum in it that eliminates aerodynamic drag.

    So, imagine that the tunnel through the moon is 20 feet (7 meters) in diameter. Down one side is a ladder. If you were to climb down the ladder, what you would find is that your weight decreases. Gravity is caused by objects attracting one another with their mass (see Question 232). As you descend into the tunnel, more and more of the moon's mass is above you, so it attracts you upward. Once you climbed down to the center of the moon you would be weightless. The mass of the moon is all around you and attracting you equally, so it all cancels out and you would feel weightless.

    If you were to actually leap into the tunnel and allow yourself to fall, you would accelerate toward the center to a very high speed. Then you would zoom through the center and start decelerating. You would eventually stop when you reached the tunnel's lip on the other side of the moon, and then you would start falling back down the tunnel in the other direction. You would oscillate back and forth like this forever.

    If you could do this on earth, one amazing effect would be the ease of travel. The diameter of the earth is about 12,700 kilometers (7,800 miles). If you drilled the tunnel straight through the center and could create a vacuum inside, anything you dropped into the tunnel would reach the other side of the planet in just 42 minutes! See the links for details.
  • lalalandlalaland Posts: 11,882
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    MAW wrote: »
    In Vacuum or air? In vacuum, you'd come to a halt at the surface the other side, in air you'd stopp waaay down near the core.

    So it's looking like you'd be stopping at the core then.

    I presume you'd pick up a lot of speed traveling that far from the surface to the center though.
  • Jed42Jed42 Posts: 194
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    or Dinosaurs
  • lalalandlalaland Posts: 11,882
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    You would accelerate until you reached the centre then you would start decelerating until you reached the exit on the other side whence you would fall back down again and the process is repeated ad infinitum.

    Interesting thought. Do you think you'd reach the other side?
  • thecreepingmessthecreepingmess Posts: 3,070
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    lalaland wrote: »
    Interesting thought. Do you think you'd reach the other side?

    I just edited my post and quoted a HSW article on the subject. It looks like there'd be too much drag to reach the other side on Earth, so you'd probably - eventually - end up stuck in the centre.

    Which isn't ideal.
  • HotelierHotelier Posts: 13,100
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    Even assuming a vacuum, woudn't you start to slow down before you got to the centre?, because the mass of the earth above you would start to have an gravitational effect?
  • MAWMAW Posts: 38,777
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    lalaland wrote: »
    So it's looking like you'd be stopping at the core then.

    I presume you'd pick up a lot of speed traveling that far from the surface to the center though.

    About 120mph in air, like a skydiver. Head 1st, you can get up to about 220 in a skinny suit. In vacuum, I'd have to write a program on a scientific calculator to work it out, but as acceleration and deceleration would be equal, you'd finish at the surface.
  • lalalandlalaland Posts: 11,882
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    Post #10 seems to answer my question.

    So, anyone up for a spot of digging :D
  • lalalandlalaland Posts: 11,882
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    MAW wrote: »
    About 120mph in air, like a skydiver. Head 1st, you can get up to about 220 in a skinny suit. In vacuum, I'd have to write a program on a scientific calculator to work it out, but as acceleration and deceleration would be equal, you'd finish at the surface.

    If stopping in the center wouldn't kill you and stopped you comfortably, which I doubt, then it could make quite an exciting sport. Obviously we'd have to work out a way to get people back out from the center, but it'd certainly be a money maker and great hobby :D
  • thecreepingmessthecreepingmess Posts: 3,070
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    lalaland wrote: »
    If stopping in the center wouldn't kill you and stopped you comfortably, which I doubt, then it could make quite an exciting sport. Obviously we'd have to work out a way to get people back out from the center, but it'd certainly be a money maker and great hobby :D

    You can do it in Super Mario Galaxy. It is very fun :p
  • Jennifer JayneJennifer Jayne Posts: 9,022
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    I just edited my post and quoted a HSW article on the subject. It looks like there'd be too much drag to reach the other side on Earth, so you'd probably - eventually - end up stuck in the centre.

    Which isn't ideal.

    Unless you had a graple gun :D
  • Mrs TeapotMrs Teapot Posts: 124,896
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    Yeh but what if the tunnel was across the earth and not from top to bottom :confused:

    It would still be a tunnel through the centre of earth but sideways
  • thecreepingmessthecreepingmess Posts: 3,070
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    Mrs Teapot wrote: »
    Yeh but what if the tunnel was across the earth and not from top to bottom :confused:

    It would still be a tunnel through the centre of earth but sideways

    The result would be the same. It's all relative.
  • lalalandlalaland Posts: 11,882
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    Mrs Teapot wrote: »
    Yeh but what if the tunnel was across the earth and not from top to bottom :confused:

    It would still be a tunnel through the centre of earth but sideways

    I would have thought it would work whichever way it was viewed as being dug?
  • Mrs TeapotMrs Teapot Posts: 124,896
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    The result would be the same. It's all relative.
    lalaland wrote: »
    I would have thought it would work whichever way it was viewed as being dug?

    I'm really thinking hard here :D
  • Jennifer JayneJennifer Jayne Posts: 9,022
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    Mrs Teapot wrote: »
    Yeh but what if the tunnel was across the earth and not from top to bottom :confused:

    It would still be a tunnel through the centre of earth but sideways


    Wouldn't make any difference just as gravity is the same on the equator as it is at the north pole. (there maybe minute differences)

    you would still be going in the same direction

    dont think of space and north/south east/west, you dont have that in space its only a way of making directions
  • RadiomaniacRadiomaniac Posts: 43,510
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    The images this has put in my head have made me feel quite bilious!
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