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so 0.999 = 1 and the plane flies, but what about drills and gravity?

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iamaelephant

Diamond Member
Jul 25, 2004
3,816
1
81
I can't believe there have been a couple of people in here thinking that gravity becomes stronger as you reach the center. Common sense FTW?
 

Exterous

Super Moderator
Jun 20, 2006
19,451
2,280
126
Originally posted by: yowolabi
Originally posted by: Exterous
Originally posted by: Vegitto
Originally posted by: radioouman
No gravity at the center of the earth. Equal from both sides.

But it would only take you 47 minutes if you jumped into your freshly drilled hole to go from one side of the earth to the other!
How would that work? Let's assume you've drilled a perfect hole and removed the core. You jump in the hole from one side, what will happen when you fall out?

You won't fall out, you'd have to climb.
So factoring in the climbing up from the center of the earth.... 48 minutes?


Given that the diameter of the earth is over 12km - unless you think you can climb 6km in less than 48 minutes I don't think so
 

KnickNut3

Platinum Member
Oct 1, 2001
2,382
0
0
Exterous, I think he means pulling yourself out the last few feet.

And do you mean 12,000km?
 

KnickNut3

Platinum Member
Oct 1, 2001
2,382
0
0
Originally posted by: iamaelephant
I can't believe there have been a couple of people in here thinking that gravity becomes stronger as you reach the center. Common sense FTW?
Well, you're being pulled toward the center of the earth, and gravity gets stronger as you get closer to something. It's not entirely non sequiter to make that assumption.
 

bsobel

Moderator Emeritus<br>Elite Member
Dec 9, 2001
13,346
0
0
There's no gravity at the center of the earth.
There is plenty of gravity at the center of the earth (gravitons just don't stop, it's the law ;)) but the combined effect balances out to a weightless effect.

 

flashbacck

Golden Member
Aug 3, 2001
1,921
0
76
Originally posted by: KnickNut3
Originally posted by: iamaelephant
I can't believe there have been a couple of people in here thinking that gravity becomes stronger as you reach the center. Common sense FTW?
Well, you're being pulled toward the center of the earth, and gravity gets stronger as you get closer to something. It's not entirely non sequiter to make that assumption.
As you're falling down the hole, more mass is above you, which is pulling you up. So the net magnitude decreases until you reach the center where it would be 0.
 

91TTZ

Lifer
Jan 31, 2005
14,374
1
0
Originally posted by: KnickNut3
Originally posted by: iamaelephant
I can't believe there have been a couple of people in here thinking that gravity becomes stronger as you reach the center. Common sense FTW?
Well, you're being pulled toward the center of the earth, and gravity gets stronger as you get closer to something. It's not entirely non sequiter to make that assumption.

Wrong. Learn some basic physics.
 

DrPizza

Administrator Elite Member Goat Whisperer
Administrator
Mar 5, 2001
49,606
162
111
www.slatebrookfarm.com
Assuming the earth had a uniform density (which it doesn't), the acceleration of gravity would decrease linearly with the distance you fell. Even assuming a vacuum, I'm guessing the 47 minute figure is wayyyyy low.

If we assumed air resistance, AND, we magically kept all the air at one atmosphere of pressure, you would slow to a stop before ever reaching the center (or, you would just barely pass the center and then slow to a stop as you re-approached the center... I struggled with the calculations)

If we magically created a tube and perfectly insulated it from the heat inside the earth, and kept it from collapsing under the pressure of the earth pushing on it, - it wouldn't matter anyway. The air pressure would be incredible.

So incredible, in fact, that I've decided the next hypothetical problem worth pursuing is: given a cylinder through the center of the earth, what radius would be necessary such that almost the entire atmosphere of the earth would pour into the hole.
 

Tom

Lifer
Oct 9, 1999
13,293
1
76
the air won't just go in, it will come out the other end too. So it should be possible to float through, carried by the wind.

 

Vegitto

Diamond Member
May 3, 2005
5,234
1
0
Originally posted by: Tom
the air won't just go in, it will come out the other end too. So it should be possible to float through, carried by the wind.
That'd be awesome.
 

XZeroII

Lifer
Jun 30, 2001
12,572
0
0
You all don't know what you're talking about. If you drill a hole through the earth then all of the gravity would escape into space and the earth would start to deflate like a balloon.
 

mercanucaribe

Banned
Oct 20, 2004
9,763
1
0
Originally posted by: 91TTZ
Originally posted by: KnickNut3
Originally posted by: iamaelephant
I can't believe there have been a couple of people in here thinking that gravity becomes stronger as you reach the center. Common sense FTW?
Well, you're being pulled toward the center of the earth, and gravity gets stronger as you get closer to something. It's not entirely non sequiter to make that assumption.

Wrong. Learn some basic physics.
Yeah, intuitively it makes sense that you're being pulled to the center of the earth.. when you're OUTSIDE of the earth. So to me it seems that it only appears that you're being pulled to the center, when you're being attracted to EVERY ATOM of the earth, and the net force is toward the center. If you're actually in the center, the net force would be outward.
 

mercanucaribe

Banned
Oct 20, 2004
9,763
1
0
http://hyperphysics.phy-astr.gsu.edu/hbase/mechanics/earthole.html

When I tell you that you would be pulled in all directions at once you
probably think of your arm being pulled one direction and your legs in
another and you head being pulled in entirely different direction. This
would not happen. Instead every tiny bit of your body would be pulled
equally in all directions at once and the forces would cancel each other
out. You would feel weightless because you cannot sense that there are
these competing forces which are cancelling each other.
 

Leros

Lifer
Jul 11, 2004
21,867
7
81
Originally posted by: Exterous
Originally posted by: Vegitto
Originally posted by: radioouman
No gravity at the center of the earth. Equal from both sides.

But it would only take you 47 minutes if you jumped into your freshly drilled hole to go from one side of the earth to the other!
How would that work? Let's assume you've drilled a perfect hole and removed the core. You jump in the hole from one side, what will happen when you fall out?

You won't fall out, you'd have to climb.
Assuming no restistance, you would fall out at the same speed you fell in the hole.

You would jump in the hole, falling at X m/s. You would accelerate until you go to the center. Once you passed the center you would start slowing down. Once you reached the other side, you would have slowed down to X m/s.

 

Ika

Lifer
Mar 22, 2006
14,267
3
81
Originally posted by: XZeroII
You all don't know what you're talking about. If you drill a hole through the earth then all of the gravity would escape into space and the earth would start to deflate like a balloon.
omg you're so right! omg what can we do? does anyone know where i can get gravity insurance?
 

MrPickins

Diamond Member
May 24, 2003
8,881
265
126
Originally posted by: Tom
the air won't just go in, it will come out the other end too. So it should be possible to float through, carried by the wind.
Wouldn't the air just pour in from both sides? If you tried to float through, you'd end up crushed in liquid(?) gas in the center of the tube.

As for the OP, the weight of the drill would provide force down (from the drillers' reference :p ) until the bit got to a n equal distance from the core on the other side.
 

Toastedlightly

Diamond Member
Aug 7, 2004
7,204
2
81
IIRC, gravity is based upon the mass, and as you go towards the center, the mass towards your rear becomes greater, while the mass in front of you decreases. Therefore it is the same both ways.
 

Toastedlightly

Diamond Member
Aug 7, 2004
7,204
2
81
Originally posted by: Aflac
Originally posted by: XZeroII
You all don't know what you're talking about. If you drill a hole through the earth then all of the gravity would escape into space and the earth would start to deflate like a balloon.
omg you're so right! omg what can we do? does anyone know where i can get gravity insurance?
My other post is stuipid. This is the only true solution.
 

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