# Falling in theoritical hole on earth

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#### alokmohan

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Would you fall all the way through a theoretical hole in the earth?<br /><br /> <br />Mark Shegelski, an associate professor of physics at the University of Northern British Columbia, explains. <br /><br />The simple answer is, theoretically, yes. First, let us ignore friction, the rotation of the earth, and other complications, and focus on the case of a hole or tunnel entering the earth at one point, going straight through its center, and coming back to the surface at the opposite side of the planet. If we treat the mass distribution in the earth as uniform, one would fall into the tunnel and then come back up to the surface on the other side in a manner much like the motion of a pendulum swinging down and up again. Assuming that the journey began with zero initial speed (simply dropping into the hole), your speed would increase and reach a maximum at the center of the earth, and then decrease until you reached the surface, at which point the speed would again be zero. The gravitational force exerted on the traveler would be proportional to his distance from the center of the earth: it's at a maximum at the surface and zero at the center. The total time required for this trip would be about 42 minutes. The speed of our traveler at the center of the Earth would be 7,900 meters a second. If there were no friction, there would be no energy loss so our traveler could oscillate into and out of the tunnel. <br /><br />This trip could not take place in the real world for a number of reasons, including the implausibility of building a tunnel 12,756 kilometers long, displacing all of the material in the tunnel's proposed path, and having the tunnel go through both the earth's molten outer core and its inner core, where the temperature is about 6,000 degrees! It would be much easier to build such a tunnel in a small asteroid. Interestingly enough, for a tunnel that reaches from one point to another point on the earth's surface but does not pass through the center of the planet, t

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##### Guest
We can't ignore the rotation of the earth, or gravity, or mass distribution in the earth . Otherwise it's a completely fictitous picture, and not even worth classifying it as a thought exercise, IMHO. <div class="Discussion_UserSignature"> <p>.</p><p><font size="3">bipartisan</font>  (<span style="color:blue" class="pointer"><span class="pron"><font face="Lucida Sans Unicode" size="2">bī-pär'tĭ-zən, -sən</font></span></span>) [Adj.]  Maintaining the ability to blame republications when your stimulus plan proves to be a devastating failure.</p><p><strong><font color="#ff0000"><font color="#ff0000">IMPE</font><font color="#c0c0c0">ACH</font> <font color="#0000ff"><font color="#c0c0c0">O</font>BAMA</font>!</font></strong></p> </div>

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#### alokmohan

##### Guest
Published in scientific american.So I am afraid you may not be correct.

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##### Guest
I'm afraid you didn't read the whole article. As usual.<br /><br />In fact, if you continue reading (including the portion after you cut it off), they explore in great detail why it's an invalid exercise - and cover the points I brought up.<br /><br />ROFL!<br /><br />Your posts can be very amusing. <div class="Discussion_UserSignature"> <p>.</p><p><font size="3">bipartisan</font>  (<span style="color:blue" class="pointer"><span class="pron"><font face="Lucida Sans Unicode" size="2">bī-pär'tĭ-zən, -sən</font></span></span>) [Adj.]  Maintaining the ability to blame republications when your stimulus plan proves to be a devastating failure.</p><p><strong><font color="#ff0000"><font color="#ff0000">IMPE</font><font color="#c0c0c0">ACH</font> <font color="#0000ff"><font color="#c0c0c0">O</font>BAMA</font>!</font></strong></p> </div>

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#### alokmohan

##### Guest
I shll reread it .Thaks.I am amusing still then.Amusing is my hobby.

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#### vogon13

##### Guest
Something that might be a bit more plausible is to build a level pipe around the equator of the earth, pump all the air out, and accelerate an object in the pipe up to 17,000 mph or so.<br /><br />You could have an object in orbit around the earth at sea level. <br /><br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

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##### Guest
Sure - with enough thrust, anything is possible. <img src="/images/icons/wink.gif" /> <div class="Discussion_UserSignature"> <p>.</p><p><font size="3">bipartisan</font>  (<span style="color:blue" class="pointer"><span class="pron"><font face="Lucida Sans Unicode" size="2">bī-pär'tĭ-zən, -sən</font></span></span>) [Adj.]  Maintaining the ability to blame republications when your stimulus plan proves to be a devastating failure.</p><p><strong><font color="#ff0000"><font color="#ff0000">IMPE</font><font color="#c0c0c0">ACH</font> <font color="#0000ff"><font color="#c0c0c0">O</font>BAMA</font>!</font></strong></p> </div>

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#### vogon13

##### Guest
To clarify, the object would be in the pipe, the pipe would go around the earth's equator at sea level, the pipe would have vacuum in it, and the object in the pipe could be made to orbit the earth while inside the pipe.<br /><br />, <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

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#### alokmohan

##### Guest
I understand now.

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