Superfly
Topic Author
Posts: 37705
Joined: Thu May 11, 2000 8:01 am

### Drilling A Hole Through Planet Earth

Inspired by the losing the sun thread.

Hypothetical question.

What if a whole of 6feet in diameter was drilled through the planet all the way to the other side?
What would happen?
Would molten lava shoot out both ends?
What effect on gravity would that have?
If a person or object fell in the whole, would they fly out the opposite end or would they be suspended in the middle?
Would everything on the surface near it get sucked in like rapid decompression?

Bring back the Concorde

TPASXM787
Posts: 1667
Joined: Tue Mar 29, 2005 6:31 am

### RE: Drilling A Hole Through Planet Earth

 Quoting Superfly (Thread starter):What if a whole of 6feet in diameter was drilled through the planet all the way to the other side?

That would be the biggerst drill bit ever.

 Quoting Superfly (Thread starter):What would happen?

There would be a 6ft diameter hole in the Earth

 Quoting Superfly (Thread starter):Would molten lava shoot out both ends?

That would be cool.

 Quoting Superfly (Thread starter):What effect on gravity would that have?

I'd say it would be a sure way to screw up the magnetic field if nothing else.

 Quoting Superfly (Thread starter):If a person or object fell in the whole, would they fly out the opposite end or would they be suspended in the middle? Would everything on the surface near it get sucked in like rapid decompression?

Both good questions. Perhaps this is where the servers go when a.net is down.
This is the Last Stop.

Logan22L
Posts: 4464
Joined: Fri Jul 16, 2004 5:59 am

### RE: Drilling A Hole Through Planet Earth

Assuming you could round up enough auger flights to do this, by the time you got down to the molten core, lava would indeed come gushing up. So, you'd never make it past the core unless you have an asbestos jumpsuit with a big "S" on it.

If someone fell in the hole, they'd be vaporized by the heat of the core, but leaving that aside, the person would go past the center, then get drawn back the other way, and would oscillate back and forth in damped motion until finally coming to rest in the center - all of this due to the pull of gravity, which eminates from the center of the Earth.

I don't believe that anything would necessarily get "sucked in." Then again, what the hell do I know? I don't even know how the can opener works. - Woody Allen

[Edited 2005-11-04 18:12:21]
"The deeper you go, the higher you fly. The higher you fly, the deeper you go."

Superfly
Topic Author
Posts: 37705
Joined: Thu May 11, 2000 8:01 am

### RE: Drilling A Hole Through Planet Earth

 Quoting Logan22L (Reply 2):leaving that aside, the person would go past the center, then get drawn back the other way, and would oscillate back and forth in damped motion until finally coming to rest in the center - all of this due to the pull of gravity, which eminates from the center of the Earth.

Well the earths gravity is really powerful. Is it possible that they wouldn't go past the core? Afterall, it's gravity that is pulling you down.

 Quoting Logan22L (Reply 2):So, you'd never make it past the core unless you have an asbestos jumpsuit with a big "S"

What does the "S" do?
Is that like a Ghostbuster?

Only Bon Jovi can stand temperatures that high. Remember there 7800 Fahrenheit album?
Also Rick Wakeman took a Journey to the Center of the Earth.
Bring back the Concorde

SlamClick
Posts: 9576
Joined: Sun Nov 23, 2003 7:09 am

### RE: Drilling A Hole Through Planet Earth

This has long been my transportation dream. Imagine, a tunnel straight from San Francisco to, say, Tokyo. It wouldn't be straight through the center but it would be pretty steep.

Now the actual vehicle is cylindrical. It sits on rollers and when everything and everyone is boarded you just tip it down a gentle ramp into the hole. Gravity takes over and it freefalls to the center. Then its momentum carries it fairly close to the surface on the other side (a few hundred miles maybe) Then we fire the steam rockets. The energy in the steam was imparted by passing through the really hot parts of the Earth's interior. It may just be the perfect mode of transport - no energy use from outside sources.

Okay, there are a couple of problems to solve and a couple of inherent solutions.

If the Earth's center is molten then it seems probable that the middle part is a giant pousse cafe of molten metals. Somewhere down there, arranged according to its specific gravity is a layer miles deep of pure molten gold. That will pay for the project. There are probably even elements that have never been found at the surface - that will provide the scientific justification.

So, fly, meet me at next year's Burning Man and we'll discuss it.
Happiness is not seeing another trite Ste. Maarten photo all week long.

aloges
Posts: 14842
Joined: Tue Jan 17, 2006 3:38 am

### RE: Drilling A Hole Through Planet Earth

think this is a bad idea.
Don't cry because it's over, smile because it happened.

Logan22L
Posts: 4464
Joined: Fri Jul 16, 2004 5:59 am

### RE: Drilling A Hole Through Planet Earth

 Quoting Superfly (Reply 3):What does the "S" do?

Think kryptonite.

 Quoting Superfly (Reply 3):Is it possible that they wouldn't go past the core?

Doubtful, although thinking about this, gravity is caused by mass, and at the center of the Earth the mass is largely "above" you. Hence the real answer is I have no freakin' clue. You know like the way ConcordeBoy and MaverickM11 talk about volcanos having more effect on global warming than man's activities.
"The deeper you go, the higher you fly. The higher you fly, the deeper you go."

SATL382G
Posts: 2679
Joined: Sat Aug 14, 2004 12:02 am

### RE: Drilling A Hole Through Planet Earth

 Quoting Superfly (Thread starter):What if a whole of 6feet in diameter was drilled through the planet all the way to the other side?

Unless you're "hypothetically" suspending the physical laws which govern the universe....

The hole will collapse when the pressures encountered overcome the bearing strength of the holes walls or of the drill bit.

If you are suspending the physical laws of the universe then I suggest we build a hi-speed rail link with a line change station and underground shopping area at the center of the earth. Such a train line would generate it's own energy, utilizing the potential energy it has prior to being dropped in the hole. The train will accelerate all the way to the line change station and decelerate all the way out to the other side of the earth coming to a complete stop only at the destination station. Passengers changing trains or going shopping will need to "jump" off at the at the change station, landing in a large pool of decelerative goo. Passengers leaving the station will be fired, by rail gun, into the observation car of a passing train.

Air travel, as we know it, will come to be seen as a slow and energy inefficient means of transportation. The phrase "catch a plane" will be replaced by "jump in a hole", as in "Sorry, gotta run. Gotta go jump in a hole". Atlanta Hartsfield will no longer be the predominant transportation hub in the U.S. That honor will go to the train change station, hereafter known as Hell (HLL). So to go from Poughkeepsie to Boise everyone would need to "go to Hell" first.

See, things really are easier if we just suspend reality.
"There’s nothing quite as exhilarating as being shot at and missed" --Winston Churchill

SlamClick
Posts: 9576
Joined: Sun Nov 23, 2003 7:09 am

### RE: Drilling A Hole Through Planet Earth

 Quoting SATL382G (Reply 7):See, things really are easier if we just suspend reality.

Well hell, if we are going to suspend reality let's get back to politics.
Happiness is not seeing another trite Ste. Maarten photo all week long.

Superfly
Topic Author
Posts: 37705
Joined: Thu May 11, 2000 8:01 am

### RE: Drilling A Hole Through Planet Earth

 Quoting SlamClick (Reply 4):This has long been my transportation dream.

 Quoting SlamClick (Reply 4):So, fly, meet me at next year's Burning Man and we'll discuss it.

Sounds cool!

The closest we can get to that experience is if I drive my car and bring my quad 8track tape of Rick Wakeman's 'Journey To The Center Of The Earth'.
You'd need some acid or LSD to really feel like your are there. I'd just stick to pot brownies.

Bring back the Concorde

SATL382G
Posts: 2679
Joined: Sat Aug 14, 2004 12:02 am

### RE: Drilling A Hole Through Planet Earth

 Quoting SlamClick (Reply 8):Well hell, if we are going to suspend reality let's get back to politics

I thought of that, but decided not to derail the thread.....
"There’s nothing quite as exhilarating as being shot at and missed" --Winston Churchill

SATL382G
Posts: 2679
Joined: Sat Aug 14, 2004 12:02 am

### RE: Drilling A Hole Through Planet Earth

 Quoting SlamClick (Reply 4):This has long been my transportation dream. Imagine, a tunnel straight from San Francisco to, say, Tokyo. It wouldn't be straight through the center but it would be pretty steep.

Such a transportation scheme is going to require an outside source of energy as gravity will impart drag enroute. Of course with reality suspended you could pretty much do whatever you want.

That's the trouble with discussions like this, nobody but the thread originator knows what portions of reality are suspended and which are not.
"There’s nothing quite as exhilarating as being shot at and missed" --Winston Churchill

Banco
Posts: 14343
Joined: Mon Oct 29, 2001 11:56 pm

### RE: Drilling A Hole Through Planet Earth

 Quoting SATL382G (Reply 7):If you are suspending the physical laws of the universe then I suggest we build a hi-speed rail link with a line change station and underground shopping area at the center of the earth. Such a train line would generate it's own energy, utilizing the potential energy it has prior to being dropped in the hole. The train will accelerate all the way to the line change station and decelerate all the way out to the other side of the earth coming to a complete stop only at the destination station. Passengers changing trains or going shopping will need to "jump" off at the at the change station, landing in a large pool of decelerative goo. Passengers leaving the station will be fired, by rail gun, into the observation car of a passing train.

Of course, if the departure point was in the UK, services would be disrupted by any leaves that fell down the hole, or if it snowed.
She's as nervous as a very small nun at a penguin shoot.

stlgph
Posts: 9713
Joined: Tue Oct 12, 2004 4:19 pm

### RE: Drilling A Hole Through Planet Earth

 Quoting Superfly (Thread starter):If a person or object fell in the whole, would they fly out the opposite end or would they be suspended in the middle?

they would be suspended in the middle.
if assumptions could fly, airliners.net would be the world's busiest airport

SATL382G
Posts: 2679
Joined: Sat Aug 14, 2004 12:02 am

### RE: Drilling A Hole Through Planet Earth

 Quoting Stlgph (Reply 13):they would be suspended in the middle

What would happen to the kinetic energy the item developed as it fell to the middle? You would have to dissipate it somehow otherwise the object will tend to continue in motion....

Lots of kids who enjoy swingsets are going to be dissappointed when you explain this and all the swings stop their motion halfway thru there arc....   Also their parents are probably going to be unhappy with you due to the damage done to their offspring from the sudden stop....

[Edited 2005-11-04 20:07:03]

[Edited 2005-11-04 20:09:25]
"There’s nothing quite as exhilarating as being shot at and missed" --Winston Churchill

B744F
Posts: 2927
Joined: Sat Jan 21, 2006 4:52 pm

### RE: Drilling A Hole Through Planet Earth

 Quoting Superfly (Reply 3): Well the earths gravity is really powerful.

raise your hand, congrats you just defied the "powerful" gravity of earth

 Quoting Superfly (Thread starter):What if a whole of 6feet in diameter was drilled through the planet all the way to the other side? What would happen? Would molten lava shoot out both ends? What effect on gravity would that have? If a person or object fell in the whole, would they fly out the opposite end or would they be suspended in the middle? Would everything on the surface near it get sucked in like rapid decompression?

First, it has to be hypothetical, because we've yet to get past a few miles, the Russians drilled down the farthest.

Second, it would be possible, but the problems would be the extreme heat, the core of the planet is as hot as the sun.

Third, not much on gravity effects, it would be possible, and according to some scientists, once you get past the liquid between the mantle and the core, you would have zero gravity effects, since that liquid accounts for the gravitational pull to begin with.

And that person would be in a zero gravity environment, but would melt because of said extreme heat and pressure changes.

No because of the pressure from the core and the gravity from the liquid, it wouldn't effect the surface.

But this is all hypothetical, scientists are really guessing through most of it, and our knowledge of our planet past the mantle is extremely little

stlgph
Posts: 9713
Joined: Tue Oct 12, 2004 4:19 pm

### RE: Drilling A Hole Through Planet Earth

 Quoting SATL382G (Reply 14):You would have to dissipate it somehow otherwise the object will tend to continue in motion....

motion would continue. just suspended in a convectional current pattern.
if assumptions could fly, airliners.net would be the world's busiest airport

usnseallt82
Posts: 4727
Joined: Tue Jan 06, 2004 4:49 pm

### RE: Drilling A Hole Through Planet Earth

Leave it to you to actually think this is possible.
Crye me a river

B744F
Posts: 2927
Joined: Sat Jan 21, 2006 4:52 pm

### RE: Drilling A Hole Through Planet Earth

 Quoting Usnseallt82 (Reply 17):Leave it to you to actually think this is possible.

Once again, I suggest you quietly sit in the corner since you haven't a clue about the topic at hand

SATL382G
Posts: 2679
Joined: Sat Aug 14, 2004 12:02 am

### RE: Drilling A Hole Through Planet Earth

 Quoting Stlgph (Reply 16):motion would continue. just suspended in a convectional current pattern.

What force would suspend the travel of the body and start it in the "convectional current pattern"?. Let's not forget about conservation of momentum here.
"There’s nothing quite as exhilarating as being shot at and missed" --Winston Churchill

dl021
Posts: 10836
Joined: Fri May 21, 2004 12:04 pm

### RE: Drilling A Hole Through Planet Earth

Fly....stop drinking and typing! Or dropping acid and staring at album covers by wanna-be Frazettas......

 Quoting Superfly (Reply 3):Quoting Logan22L (Reply 2): So, you'd never make it past the core unless you have an asbestos jumpsuit with a big "S" What does the "S" do? Is that like a Ghostbuster?

Are you serious? Dude........stop the insanity! Tell us you know what he's talking about.....

 Quoting SlamClick (Reply 8):Quoting SATL382G (Reply 7): See, things really are easier if we just suspend reality. Well hell, if we are going to suspend reality let's get back to politics.

 Quoting Usnseallt82 (Reply 17):Quoting B744F (Reply 15): Leave it to you to actually think this is possible.

Well, the aliens told him it would work!
Is my Pan Am ticket to the moon still good?

ilikeyyc
Posts: 1326
Joined: Tue Dec 09, 2003 8:09 am

### RE: Drilling A Hole Through Planet Earth

 Quoting B744F (Reply 15):Third, not much on gravity effects, it would be possible, and according to some scientists, once you get past the liquid between the mantle and the core, you would have zero gravity effects, since that liquid accounts for the gravitational pull to begin with.

Interesting theory (source?) but I would believe that an object would simply be crushed by the force of gravity as it gets closer to the center of the earth. The inner core of the earth is believed to be solid iron and the most dense of all 4 layers of the earth. Gravity also acts from the center of mass, not the surface or any layer inbetween (such as the mantle in your theory). The Earth is approx. 7,900 miles (12,700 km) in diameter [3,950 miles (6,350 km)] in radius. The equations for gravity are exponential, not linear.

So if I go from the surface (3950 miles from the center of mass) to a point that is half the radius (1975 miles from the center of mass) I have decreased my distance by half, but the gravitational force has quadrupled.

But since someone pointed out that the laws of physics would have to be suspended to even have this scenario, why should we expect to be crushed by the force of gravity?

http://hypertextbook.com/facts/1999/RicardoMartinez.shtml
http://csep10.phys.utk.edu/astr161/lect/history/newtongrav.html
Fighting Absurdity with Absurdity!

Posts: 3697
Joined: Thu Nov 08, 2001 1:04 am

### RE: Drilling A Hole Through Planet Earth

There becomes a point in your "hole" where 'Up' is no longer 'Up'...

Remember DIRECTION is relational  ...
Whoever said "laughter is the best medicine" never had Gonorrhea

swisskloten
Posts: 317
Joined: Thu Dec 30, 2004 3:51 pm

### RE: Drilling A Hole Through Planet Earth

Believe it or not, Hitler thought the earth was hollow and carried out flights in WWII to determine an entry point into the core. His plan was to have the Nazis hide out there if the Allies won the war. Fortunately, he was dead wrong.

dl021
Posts: 10836
Joined: Fri May 21, 2004 12:04 pm

### RE: Drilling A Hole Through Planet Earth

Yeah, but the Flash is faster than Superman and Aquaman is capable of withstanding incredible pressure found at the bottom of the ocean and J'onn J'onzz is not related to Spike Jonz and Spiderman is not a mutant from birth simply from accident which proves that people should be careful in laboratories with nuclear reactors and spiders.
Is my Pan Am ticket to the moon still good?

jafa39
Posts: 4320
Joined: Wed Mar 23, 2005 2:14 pm

### RE: Drilling A Hole Through Planet Earth

Some of these answers make 9/11 conspiracy theories seem plausible!!
We, the undersigned, do hereby consent.....

B744F
Posts: 2927
Joined: Sat Jan 21, 2006 4:52 pm

### RE: Drilling A Hole Through Planet Earth

 Quoting DL021 (Reply 20):Well, the aliens told him it would work!

No, geologists have only been able to theorize

 Quoting Jafa39 (Reply 25):Some of these answers make 9/11 conspiracy theories seem plausible!!

Interesting how you can come to this conclusion, since the experts in the field know very little to begin with

 Quoting Ilikeyyc (Reply 21):but I would believe that an object would simply be crushed by the force of gravity as it gets closer to the center of the earth.

According to some scientists, the force of gravity is caused by the molten core which is liquid. Scientists are still not sure what is beyond that, some say solid though. So the theory is that once you are beyond this point of the magnetic field that creates the gravity, you may not feel the effects of gravity at all. But again, it is just a theory, so far scientists are just guessing, and that is all we know

ilikeyyc
Posts: 1326
Joined: Tue Dec 09, 2003 8:09 am

### RE: Drilling A Hole Through Planet Earth

 Quoting B744F (Reply 26):So the theory is that once you are beyond this point of the magnetic field that creates the gravity, you may not feel the effects of gravity at all. But again, it is just a theory, so far scientists are just guessing, and that is all we know

Whoa, whoa, whoa...time out. You mean to tell me that the earth's gravity is created by the magnetic field? [gasp!] I've been lied to by all of my physics teachers! HAHAHAHA. It sounds like you are the one who doing is doing all the guessing. The aliens really did something to your mind! Once again, can I please have a source to this theory?
Fighting Absurdity with Absurdity!

usnseallt82
Posts: 4727
Joined: Tue Jan 06, 2004 4:49 pm

### RE: Drilling A Hole Through Planet Earth

 Quoting Ilikeyyc (Reply 27):Once again, can I please have a source to this theory?

Yes.....his sources come from wavelength alpha emitted from the mothership. They are highly reliable and cannot be disputed by us mortal beings. Unfortunately, he is the only one selected to receive these transmissions.....as he has the only tin foil in the world that will work.

Crye me a river

B744F
Posts: 2927
Joined: Sat Jan 21, 2006 4:52 pm

### RE: Drilling A Hole Through Planet Earth

 Quoting Ilikeyyc (Reply 27):Whoa, whoa, whoa...time out. You mean to tell me that the earth's gravity is created by the magnetic field? [gasp!] I've been lied to by all of my physics teachers! HAHAHAHA. It sounds like you are the one who doing is doing all the guessing. The aliens really did something to your mind! Once again, can I please have a source to this theory?

How can your physics teachers tell you about something which we know so little about and you can call it the absolute truth?

ilikeyyc
Posts: 1326
Joined: Tue Dec 09, 2003 8:09 am

### RE: Drilling A Hole Through Planet Earth

 Quoting B744F (Reply 29):How can your physics teachers tell you about something which we know so little about and you can call it the absolute truth?

Look, the Gravitational LAW (not theory, a proven LAW) is based on mass, not magnetic fields (see my reply, #21). So for you to suggest that gravity comes from a magnetic field is just utterly hilarious!!!
Fighting Absurdity with Absurdity!

usnseallt82
Posts: 4727
Joined: Tue Jan 06, 2004 4:49 pm

### RE: Drilling A Hole Through Planet Earth

 Quoting Ilikeyyc (Reply 30):So for you to suggest that gravity comes from a magnetic field is just utterly hilarious!!!

You get to listen to him long enough and most of what he says becomes hilarious.

The only thing I will throw out there is quantum mechanics. While this field is so largely based on theory right now, it holds lots of weird things that common physics don't allow for. Still, what he churns out is nothing more than interference from his transistor hat.
Crye me a river

dl021
Posts: 10836
Joined: Fri May 21, 2004 12:04 pm

### RE: Drilling A Hole Through Planet Earth

 Quoting B744F (Reply 26):No, geologists have only been able to theorize

 Quoting B744F (Reply 29):How can your physics teachers tell you about something which we know so little about and you can call it the absolute truth?

Is my Pan Am ticket to the moon still good?

B744F
Posts: 2927
Joined: Sat Jan 21, 2006 4:52 pm

### RE: Drilling A Hole Through Planet Earth

 Quoting Ilikeyyc (Reply 30):Look, the Gravitational LAW (not theory, a proven LAW) is based on mass, not magnetic fields (see my reply, #21). So for you to suggest that gravity comes from a magnetic field is just utterly hilarious!!!

oops, my mistake. Long week at work. Anyway, the magnetic field is generated by the liquid core, while the core itself, made out of something unknown, has the most mass, and generates the graviational pull. If you drop something inside that mass, you won't feel the effects of it

Did you ask the same thing of your professors when they told you a particle can only give you its speed or its location, not both. Or how about a pair of electrons, when separated, will spin in opposite directions instantly no matter how far away you put them.

photopilot
Posts: 3101
Joined: Mon Jul 15, 2002 11:16 am

### RE: Drilling A Hole Through Planet Earth

Damn, I'm going to have to learn to say Beam Me Down Scotty

hahaha,
Steve

usnseallt82
Posts: 4727
Joined: Tue Jan 06, 2004 4:49 pm

### RE: Drilling A Hole Through Planet Earth

 Quoting B744F (Reply 33):Did you ask the same thing of your professors when they told you a particle can only give you its speed or its location, not both.

welcome to my world of quantum love
Crye me a river

SATL382G
Posts: 2679
Joined: Sat Aug 14, 2004 12:02 am

### RE: Drilling A Hole Through Planet Earth

 Quoting B744F (Reply 33):Anyway, the magnetic field is generated by the liquid core, while the core itself, made out of something unknown, has the most mass, and generates the graviational pull

Well if you know that the material generates a magnetic field and you know it's approximate mass it's not hard to figure out what the material is. In this case it's liquid iron..................
"There’s nothing quite as exhilarating as being shot at and missed" --Winston Churchill

jafa39
Posts: 4320
Joined: Wed Mar 23, 2005 2:14 pm

### RE: Drilling A Hole Through Planet Earth

 Quoting B744F (Reply 26):Interesting how you can come to this conclusion, since the experts in the field know very little to begin with

And the difference is?????
We, the undersigned, do hereby consent.....

cornish
Posts: 7651
Joined: Fri Feb 18, 2005 8:05 pm

### RE: Drilling A Hole Through Planet Earth

 Quoting Banco (Reply 12):Quoting SATL382G (Reply 7): If you are suspending the physical laws of the universe then I suggest we build a hi-speed rail link with a line change station and underground shopping area at the center of the earth. Such a train line would generate it's own energy, utilizing the potential energy it has prior to being dropped in the hole. The train will accelerate all the way to the line change station and decelerate all the way out to the other side of the earth coming to a complete stop only at the destination station. Passengers changing trains or going shopping will need to "jump" off at the at the change station, landing in a large pool of decelerative goo. Passengers leaving the station will be fired, by rail gun, into the observation car of a passing train. Of course, if the departure point was in the UK, services would be disrupted by any leaves that fell down the hole, or if it snowed.

and of course a replacement bus service would be offered on weekends due to "Essential Engineering Works"
Just when I thought I could see light at the end of the tunnel, it was some B*****d with a torch bringing me more work

KevinL1011
Posts: 2858
Joined: Fri Mar 04, 2005 3:48 pm

### RE: Drilling A Hole Through Planet Earth

 Quoting SlamClick (Reply 4):This has long been my transportation dream. Imagine, a tunnel straight from San Francisco to, say, Tokyo. It wouldn't be straight through the center but it would be pretty steep.

 Quoting B744F (Reply 15):First, it has to be hypothetical, because we've yet to get past a few miles, the Russians drilled down the farthest.

Of course!....Cherynoble!
474218, Carl, You will be missed.

dl021
Posts: 10836
Joined: Fri May 21, 2004 12:04 pm

### RE: Drilling A Hole Through Planet Earth

 Quoting B744F (Reply 26):Quoting DL021 (Reply 20): Well, the aliens told him it would work! No, geologists have only been able to theorize

Wow...hey everyone! The aliens are talking to geologists now! Hooray!

 Quoting Kevinl1011 (Reply 39):Quoting SlamClick (Reply 4): This has long been my transportation dream. Imagine, a tunnel straight from San Francisco to, say, Tokyo. It wouldn't be straight through the center but it would be pretty steep. Bugs Bunny already did it.

No...he missed the turn at Albequerque
Is my Pan Am ticket to the moon still good?

Mr Spaceman
Posts: 2723
Joined: Thu Mar 15, 2001 5:09 am

### RE: Drilling A Hole Through Planet Earth

Hi guys.

 Quoting Superfly (Thread starter):What if a whole of 6feet in diameter was drilled through the planet all the way to the other side? What would happen?

Finally, you would find Jimmy Hoffa.

Chris
"Just a minute while I re-invent myself"

MD11Engineer
Posts: 13916
Joined: Sun Oct 26, 2003 5:25 am

### RE: Drilling A Hole Through Planet Earth

I had to calculate this problem once as an assignment when I was still studying physics. When you jump into the hole (assuming there is no friction), you will accelerate due to gravity, but since with every meter you fall there is more mass above you pulling you upwards, the acceleration will go from 9.81 m/sec square to zero when you reach the center. Due to your kinetic energy you will fall through the center and will feel an increased deceleration force until you reach the surface on the other side, by which time you will have slowed dwn to standstill. Then you will fall back into the hole, go through the center and come up again on the original side. So no friction involved, you will oscillate through the center of earth forever.

Jan
Je Suis Charlie et je suis Ahmet aussi

2H4
Posts: 7960
Joined: Tue Oct 19, 2004 11:11 pm

### RE: Drilling A Hole Through Planet Earth

 Quoting Logan22L (Reply 2):but leaving that aside, the person would go past the center, then get drawn back the other way, and would oscillate back and forth in damped motion until finally coming to rest in the center

Market this as an amusement park ride, and the revenue generated would pay for the research, construction, and then some.

2H4

Intentionally Left Blank

SATL382G
Posts: 2679
Joined: Sat Aug 14, 2004 12:02 am

### RE: Drilling A Hole Through Planet Earth

 Quoting MD11Engineer (Reply 42):I had to calculate this problem once as an assignment when I was still studying physics. When you jump into the hole (assuming there is no friction), you will accelerate due to gravity, but since with every meter you fall there is more mass above you pulling you upwards, the acceleration will go from 9.81 m/sec square to zero when you reach the center. Due to your kinetic energy you will fall through the center and will feel an increased deceleration force until you reach the surface on the other side, by which time you will have slowed dwn to standstill. Then you will fall back into the hole, go through the center and come up again on the original side. So no friction involved, you will oscillate through the center of earth forever.

Ok, great as far is it goes. Now, how to compensate for the rotational speed of the earth? At the surface the object will appear motionless in relation to the rest of the earth, but in fact will be moving in a trajectory around the center of the earth at approx. 2000 MPH. Assuming a frictionless environment and considering that objects in motion tend to remain in motion the object will NOT fall in a straight line (in relation to the earth) to the center. What shape will the tunnel take? My puny brain can't quite picture this but I know it's an arc and will intersect the surface and the exact center.

edit: After thinking about it for a minute it'll work like a ball on a roulette wheel perhaps even a arc greater than 360 degrees i.e. a spiral....

[Edited 2005-11-05 17:50:35]
"There’s nothing quite as exhilarating as being shot at and missed" --Winston Churchill

MD11Engineer
Posts: 13916
Joined: Sun Oct 26, 2003 5:25 am

### RE: Drilling A Hole Through Planet Earth

Obviously with a rotating planet and the hole not equal to the axis of rotation the falling body would be subject to the Corriolis force and the path through earth would be a curve looking like a flower, not a spiral.
You can easily plot it with a protractor and a compass.

Jan
Je Suis Charlie et je suis Ahmet aussi

SATL382G
Posts: 2679
Joined: Sat Aug 14, 2004 12:02 am

### RE: Drilling A Hole Through Planet Earth

 Quoting MD11Engineer (Reply 45):the path through earth would be a curve looking like a flower, not a spiral.

It's a spiral, there are many examples of the effect in nature. Something lost in translation perhaps?

This video is an even better example of the spiral effect....

http://www.divnick.com/images/Vortx_Medium.swf

Or are you saying that the acceleration of gravity is such that the trajectory becomes ballistic vs. orbital?

[Edited 2005-11-05 19:03:44]

[Edited 2005-11-05 19:09:37]
"There’s nothing quite as exhilarating as being shot at and missed" --Winston Churchill

Jet-lagged
Posts: 830
Joined: Mon Mar 04, 2002 11:58 pm

### RE: Drilling A Hole Through Planet Earth

 Quoting SATL382G (Reply 44):the object will NOT fall in a straight line (in relation to the earth) to the center.

Yes! So if you are falling down this hypothetical hole, your body would tend to move to the 'east' (since the earth rotates from west to east) and you'll be scraping along the eastern edge of the hole. Before you reach the center you will be a long red stain.

Now, if the hole went from exact north pole to exact south pole, then you could fall, and then oscilate back and forth, rotating around the north-south axis as you went. Wheeee!

Actually, if such a hole suddenly came to exist, I think it would simply immediately collapse.

SATL382G
Posts: 2679
Joined: Sat Aug 14, 2004 12:02 am

### RE: Drilling A Hole Through Planet Earth

 Quoting Jet-lagged (Reply 47):Yes! So if you are falling down this hypothetical hole, your body would tend to move to the 'east' (since the earth rotates from west to east) and you'll be scraping along the eastern edge of the hole. Before you reach the center you will be a long red stain.

Exactly, but our engineers will dig a perfect, frictionless hole so the falling body will never contact the east wall. Coming in contact with the east wall would add drag and screw up all physics

 Quoting Jet-lagged (Reply 47):Now, if the hole went from exact north pole to exact south pole, then you could fall, and then oscilate back and forth, rotating around the north-south axis as you went. Wheeee!

I hadn't thought of that. Seems reasonable but given that the earth is orbiting the sun a straightline along the north south axis may not possible either --- that's way to much math for my brain to process though...

On second thought I take that back. The north/south axis is roughly (within 23 deg) perpendicular to the plane of the ecliptic so the velocity along the length of the axis should be pretty much constant. A hole down the axis should be relatively straight.

 Quoting Jet-lagged (Reply 47):Actually, if such a hole suddenly came to exist, I think it would simply immediately collapse.

That's why we had to suspend reality real early in this thread

[Edited 2005-11-06 04:38:08]
"There’s nothing quite as exhilarating as being shot at and missed" --Winston Churchill

SATL382G
Posts: 2679
Joined: Sat Aug 14, 2004 12:02 am

### RE: Drilling A Hole Through Planet Earth

Oh BTW:

I just realized there's another factor we haven't accounted for: tidal forces

In other words, the path a falling body takes to the center of the earth will vary depending on where the moons mass is located relative to the falling body.

A hole sufficiently wide might be enough to compensate, but I don't know.

... and I'm tired....
"There’s nothing quite as exhilarating as being shot at and missed" --Winston Churchill

### Who is online

Users browsing this forum: No registered users and 9 guests

### Popular Searches On Airliners.net

Top Photos of Last:   24 Hours  •  48 Hours  •  7 Days  •  30 Days  •  180 Days  •  365 Days  •  All Time

Military Aircraft Every type from fighters to helicopters from air forces around the globe

Classic Airliners Props and jets from the good old days

Flight Decks Views from inside the cockpit

Aircraft Cabins Passenger cabin shots showing seat arrangements as well as cargo aircraft interior

Cargo Aircraft Pictures of great freighter aircraft

Government Aircraft Aircraft flying government officials

Helicopters Our large helicopter section. Both military and civil versions

Blimps / Airships Everything from the Goodyear blimp to the Zeppelin

Night Photos Beautiful shots taken while the sun is below the horizon

Accidents Accident, incident and crash related photos

Air to Air Photos taken by airborne photographers of airborne aircraft

Special Paint Schemes Aircraft painted in beautiful and original liveries

Airport Overviews Airport overviews from the air or ground

Tails and Winglets Tail and Winglet closeups with beautiful airline logos