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A Hole in the Earth

Discussion in 'Issues Around the World' started by ditch, Feb 1, 2003.

  1. ditch

    ditch Downunder Member

    OK, I know its hot in the middle, but, if you drilled a hole from one side of the earth to the other, then jumped in, what effect would gravity have on you as you proceeded towards the other side?
  2. Biker

    Biker Administrator Staff Member

    Before or after you turned into a crispy critter?

    Now.... Put the beer down, step away from the keyboard, and step outside for some fresh air. :happy:
  3. joseftu

    joseftu ORIGINAL Pomp-Dumpster

    I seem to remember a Larry Niven essay on this (I may be deluding myself).
    But I always find How Stuff Works.com is perfect for this kind of question.
    Marshall Brain swears his name is just a coincidence, but his site definitely makes him seem like a Brainiac.
  4. Andy


    Way back when, I used to get a GREAT magazine called "OMNI" and I remember a scientist putting out a theory about just such a thing as a mode of travel from one side of the earth to the other.

    His theory was that if you were to have such a hole, and use some sort of transport "ball" dropped from a mechanism, you would then accelerate inward and then be propelled back out the other end only to slow down from the effect of gravity, and a sort of locking mechanism would "catch" the transport ball on the other side.

    I doubt that any such undertaking would be possible with todays technology though.
    It is quite hot and liquid in the core of the Earth, how would you get any such tube built, and kept up?
  5. Biker

    Biker Administrator Staff Member

    With gravity being so strong at the center, would not the greater force as you passed through stop the ball before it got close to the other side? I suspect one would have to take the "elipse" approach in order to accomplish this, using the gravitational pull to sling shot you to the other side.
  6. ShinyTop

    ShinyTop I know what is right or wrong!

    I remember an article theorizing a slanted tunnel from NY to Paris as an example. If you had a perfrect vacuum you could have a train travel the tunnel with very little power using gravity to accelerate and decelerate the train.
  7. Coot

    Coot Passed Away January 7, 2010

    Actually, I don't think you'd want to violate the core of the earth appreciably, as that is what generates the planet's magnetic field. Without this field, solar radiation and other cosmic radiation would boil off our atmosphere. As it is now, earth's magnetic field keeps out 99.9%, leaving only .1% of this radiation to be absorbed by the atmosphere.
  8. ethics

    ethics Pomp-Dumpster Staff Member

    Answer to the question is in the density and gravity. Where does the pull happen the most? If you were to drop in to the hole you would be stuck in the middle of the core.
  9. Frodo Lives

    Frodo Lives Luke, I am NOT your father!

    Or crushed like a grape. Ditch, it would be much easier to just jump on a plane if you want to come visit us. lmao.
  10. ditch

    ditch Downunder Member

    LOL. Theres another thread currently discussing the effect of sitting in front of a monitor for long periods of time. Gotta go...I'm fallingggggggggg.
  11. ditch

    ditch Downunder Member

    You're right there Frodo.
  12. Coot

    Coot Passed Away January 7, 2010

    Actually, you'd probably end up shredded. The core is actually two parts, a solid inner core and a liquid outer core. If you were somehow able to bore a hole through both, it wouldn't remain a contiguous hole as the inner core and the outer core rotate at different speeds (creating the magnetic field).
  13. ethics

    ethics Pomp-Dumpster Staff Member

    Interesting. So even if you were to isolate yourself in a bubble of sorts, you'd still be shredded?
  14. ditch

    ditch Downunder Member

    This question came up in the weekend papers. One of the answers fits yours ethics and yours Biker.
    It says " Gravity follows the laws of physics. We would be dragged towards the centre of the earth due to this force. As a result, when we jumped in, we would be suspended in the earth's core, rather than fall through it, because that is the centre of gravity."

    Another suggestion says "You would fall 6378 kilometers towards the centre, where gravity reduces to zero. This would take about 21 minutes, were there no friction from air. Then your momentum would take you to the other side. With friction you'd oscillate about the centre, eventually floating weightless about the centre. There, the temp is 5550 degrees C, which makes this an uncomfortable wat to lose weight."
  15. Coot

    Coot Passed Away January 7, 2010

    In answer to ethics...Yup
  16. ditch

    ditch Downunder Member

    Sounds like this is based on the principle of lack of air friction as one of the answers in the paper [above] suggested.
  17. joseftu

    joseftu ORIGINAL Pomp-Dumpster

    Did you read the link I posted?
    With no air resistance, the oscillation answer is right.
  18. ethics

    ethics Pomp-Dumpster Staff Member

    While it's logical, I don't see how your acceleration towards the core could equal the same acceleration for you to get out of.

    The body mass/density has finite gravity pull, you won't exceed it enough to get out of the core.

    Perhaps I am way off on this but... ;)
  19. IamZed

    IamZed ...

    The effects of gravity in this context can be demonstrated by a large bowl and a marble. The bowl represents the well in time-space the earths mass creates. Now hold the marble up to one edge of the bowl and let go.
    The behavior of the marble will closely resemble our hole jumpers fait. It will accelerate towards the center of the bowl, gaining in speed but lessening in acceleration till it will travel on its momentum thru the bottom and attempt to climb the far side.
    The friction of my proposed example will make it impossible for the marble to rise to the same height on the far side of the bowl and we can all guess what happens next. It is spirograph time till the marble comes to a stop.
    So let us assume this frictionless tube thru the earth. It would be a vacuum tube. I drop my marble into the vacuum tube and it falls thru the center of the earth and attempts to climb out the other side on its momentum. It also will fail.
    Gravity affects all mass involved, both the marble and the earth. As I hold the marble the earth is pulled toward it to the minutest extent. When I let it fall and it passes thru the center of the earth it then will attempt to draw the earth with it. This will eat at its momentum. It will not rise as high on the far side even with zero friction.
    The best translation of this to our dimension I have seen is rolling a bowling ball out onto a trampoline of soft rubber. That is the earth. Now roll a pool ball towards it. You see the drastic affects the gravitational well created by the bowling ball will have on the pool balls course. The trick here is to look at the pool balls affect on the bowling ball. It will move it as it moves around it. Energy is consumed from the pool balls initial roll in to make that which drew it in move.
    So in short, if you intend to travel thru the center of the earth carry extra weight and let it go as you pass thru the center. All will be well.
  20. RRedline

    RRedline Veteran MMember

    Assuming that 1) It is possible and 2) It is a vacuum(no air resistance) and 3) You are protected from heat, you would accelerate toward the center of the planet and achieve an extremely high velocity. Of course, as you approached the center, your acceleration would decrease, but your speed would continue to increase until you reached the exact, gravitational center. Once reaching the center, you would have an incredible amount of momentum which would allow you to continue traveling toward the other side of the planet. From the center outward, your speed would continue to decrease. The closer you get to the other side, the more rapidly your speed would diminish. I would imagine that, in a vacuum, you should reach a distance from the center equal to the distance from the center that you started. Unless something were there on the other side to "catch" you, you would begin traveling back toward the center and to the side you started from. I would guess that if you were to graph a function of your speed versus time, you would get a sinusoidal curve which would repeat indefinitely(but probably decay since a frictionless environment would probably be impossible).

    By the way, scientists are already contemplating how to go about creating long tunnels connecting major cities such as NYC and London. I think a project like that is probably at least a century away.

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