depth of the earth

leveldrummer · 02-16-2006, 08:42 PM

on a recent special about the core of the earth, i saw something that might be considered trivia, if not, its still very interesting.

if you sky-dive at about 10,000 feet, it would take about a minute to reach the ground. now if someone drilled a large enough hole to reach the center of the earth. how long do you think it would take to free fall to the center? (according to this show. because i dont think you can really be sure. 30 minutes? an hour?

THIRTY FOUR HOURS!!! yes you can fall for a day and a half. INSANE!!

MiSo · 02-17-2006, 03:38 AM

i read that it was 42 minutes.

leveldrummer · 02-17-2006, 11:48 AM

thats why i said (accoding to that show) it was on national geografic, i havent done the math myself, so i dont know what is right. just seemed crazy. and neat.

Buggy · 11-30-2006, 03:55 PM

I don't think I would want to try it to find out. lol

Ringo · 12-01-2006, 09:17 PM

Isn't the earth 25,000sq miles around?

Mazzy · 01-21-2007, 08:48 AM

The depth of the earth to the inner liquid core is 5100–6378 km or 3160–3954 miles deep. http://en.wikipedia.org/wiki/Structure_of_the_Earth

eon17 · 02-27-2007, 12:58 PM

it is because u would fall like 3\4 of the way then get turned around and fal the other way

CyberSpike · 02-28-2007, 02:41 PM

A really confusing question is, if they did drill a hole through the diameter of the earth, what would happened when you reach the center? Would you stop falling and have to climb?

Edit: Just noticed Eon stated it first. :P

NewGuy · 05-05-2007, 07:30 AM

Well, the idea of Gravity is the tendency of objects with mass to move towards each other, so, once your in the exact middle, things would probably even out and you'd get zero gravity.

**Scuba Kid** · 05-05-2007, 09:38 AM

Wouldn't you just stop in the center, since things are attracted to the center of the Earth?

Mazzy · 05-06-2007, 09:45 AM

well, regardless what mysterious gravitational issues would occur, you surely would never live to tell it once you reached the liquid hot nickle core

**Scuba Kid** · 05-06-2007, 10:12 AM

lol, obviously. But it ignore the whole magma thing for a minute.

Mazzy · 05-06-2007, 07:00 PM

OK, well ignoring the liquid hot magma

I would agree with the person who said you would have to start climbing once you reach the center since gravity pulls toward the middle, not toward one side or the other of the earth.
I think the original point of this thread was to show how long you would fall before you hit said liquid hot magma

(it just cracks me up to say that) and that, I still don't know the awnser to

What I do know, is that I'm gonna try and say "liquid hot magma" in a sentence tomorrow at work

CaysE · 05-13-2007, 07:17 AM

I imagine you would gradually slow down as you approached the center. That's why it would take so long.

Pareeeee · 06-22-2007, 06:23 AM

As you approached the centre, you'd already be burnt up from the heat of the magma around you :P

(sorry for being so 'cheery' LOL)

I know, I know, that's not the question. I think you would go back and forth past the centre (because of the speed you would have been going) until you stopped in the centre. Like, you would keep going past on either side until the gravity pulled you back toward the centre.

Did I make any sense??

Um like being on a swing. When you want to get off, you will keep swinging past the "stop point" until it finally stops where the swing sits naturally, because of gravity.

Albino_101 · 08-18-2008, 07:25 PM

when you eached the center of the earth just the pressure of the air alone would crush you.

**TheOldSalt** · 08-20-2008, 02:16 AM

Great googily moogily, now THIS is a major case of thread necromancy if ever there was one. Albino 101, what possessed you to bother replying to a two year old thread?

Anyway, I doubt you'd ever reach the center. At some point the gravity & mass of the world above you would be stronger than the little remaining core below you, and you'd stop.

jones57742 · 08-20-2008, 12:10 PM

Folks:

"The Readers Digest Version" is that at the Earth's surface the acceleration due the gravity of the Earth is 32.2 feet/second^2 but at the center (of mass) of the Earth the acceleration due to the gravity of the Earth is 0.0 feet/second^2.

A linear solution (which is not correct) yields 15.7 days and doubling this value in order to attain a quadratic solution (which is even more incorrect) yields 30.4 days.

The true analytical solution requires integration of the acceleration per the classical universal gravitation equation from the earth's surface to the center of mass of the earth (this is the "how to build a Swiss Chronometer Version" in which I believe that no one would be interested).

Quote:

Originally Posted by TheOldSalt

Anyway, I doubt you'd ever reach the center. At some point the gravity & mass of the world above you would be stronger than the little remaining core below you, and you'd stop.

Really to complicated to get into in a post but this assertion is not correct.

In a frictionless scenario a yoyo would exist. One would reach the center of mass of the Earth at maximum velocity, continue to the surface on the remote side of the earth at which point the velocity would be zero, and one would be pulled back to the center of the earth ...

TR

akangelfood · 08-20-2008, 12:25 PM

I know it's an old thread, but I thought it was interesting. I posted it to another forum (go go gamer nerds!) that I frequent, and this was the most thorough response I got:

Quote:

We did something like this in physics a long time ago. Prepare to get bored.
Ignore the immense temperatures and pressures. Ignore the effects of the earths rotation. Assume the hole is a vacuum (no air resistance).
Stepping off the surface into this hole, you'd accelerate at
a= -g * r / R
where g = 9.81 m/s/s, R = 6378 km and r is your distance from the center.
The force acting on you will be
f = m * a = -m * g * r / R.
If the hole went all the way through the earth, you would theoretically fall to the center, then fall 'up' to the other side, then fall back through the center to your original starting point. With no friction, you would continue oscillating back and forth thru the center like a spring.
Recall Hooke's law, F= -k * r, and angular frequency, w = sqrt(k / m) where k is a constant (in this case k = m * g / R). Solving, we get
w = sqrt(g / R)
Recall your period of oscillation is
T = 2 * pi / w.
Then plug in,
T = 2 * pi * sqrt(R / g) = 5066 sec = 84.4 min.
This is the time for one trip back and forth, thus the time to the center is 1/4 of this: 21.1 min.

Plecostomus · 08-25-2008, 12:01 PM

http://www.youtube.com/watch?v=FAFUS...eature=related

02-16-2006, 08:42 PM	#1
leveldrummer something like a pimp Join Date: May 2005 Location: atlanta Age: 29 Posts: 1,933	depth of the earth on a recent special about the core of the earth, i saw something that might be considered trivia, if not, its still very interesting. if you sky-dive at about 10,000 feet, it would take about a minute to reach the ground. now if someone drilled a large enough hole to reach the center of the earth. how long do you think it would take to free fall to the center? (according to this show. because i dont think you can really be sure. 30 minutes? an hour? THIRTY FOUR HOURS!!! yes you can fall for a day and a half. INSANE!!

11-30-2006, 03:55 PM	#4
Buggy Room Mother Join Date: Oct 2006 Location: Oklahoma Age: 42 Posts: 700	I don't think I would want to try it to find out. lol __________________ Fish are people too! My animal family Dixie - Boxer/Lab Peanut -Chihuahua Cali - American Short-hair Cat B.B. - Parakeet Flower - Western Ornate Box Turtle Newly Aquired Cosmo - Rescue kitten Loki - White Ferret Odin - Brown Ferret Aquariums 55 gal tropical Fresh Water -14 various fish 29 gal tropical Fresh Water - 4 various cichlids 20 gal tropical Fresh Water - 5 skirt tetras, 8 zebra danios, 2 cherry barbs, 1 glass catfish, 1 rosey minnow, 1 corydora, 1 ghost shrimp.

12-01-2006, 09:17 PM	#5
Ringo I'm just a Twig Join Date: Apr 2006 Location: The Sticks Age: 16 Posts: 964	Isn't the earth 25,000sq miles around? Last edited by Ringo; 12-19-2006 at 10:14 AM.

01-21-2007, 08:48 AM	#6
Mazzy Senior Member Join Date: Dec 2006 Location: Adrian, Michigan Posts: 129	The depth of the earth to the inner liquid core is 5100–6378 km or 3160–3954 miles deep. http://en.wikipedia.org/wiki/Structure_of_the_Earth __________________ "We can bomb the world to pieces, but we can't bomb it into PEACE!" ~Michael Franti

02-28-2007, 02:41 PM	#8
CyberSpike Member Join Date: Mar 2006 Age: 19 Posts: 92	A really confusing question is, if they did drill a hole through the diameter of the earth, what would happened when you reach the center? Would you stop falling and have to climb? Edit: Just noticed Eon stated it first. :P __________________ Ryan Woodford ~* Planted 10 Gallon ~ 2 Cherry Barbs 2 Mystery Snails 6 Neon Tetras 1 Otto Cat ~ Planted 3/4 Gallon Bowl *~ 1 Crowntail Betta

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02-17-2006, 03:38 AM	#2
MiSo Ballin' Alan Join Date: May 2005 Age: 27 Posts: 146	i read that it was 42 minutes.

02-17-2006, 11:48 AM	#3
leveldrummer something like a pimp Join Date: May 2005 Location: atlanta Age: 29 Posts: 1,933	thats why i said (accoding to that show) it was on national geografic, i havent done the math myself, so i dont know what is right. just seemed crazy. and neat.

02-27-2007, 12:58 PM	#7
eon17 Banned Join Date: Jan 2007 Location: kansas Posts: 151	it is because u would fall like 3\4 of the way then get turned around and fal the other way

05-05-2007, 07:30 AM	#9
NewGuy Fishy Member Join Date: Apr 2007 Age: 15 Posts: 18	Well, the idea of Gravity is the tendency of objects with mass to move towards each other, so, once your in the exact middle, things would probably even out and you'd get zero gravity.

05-05-2007, 09:38 AM	#10
Scuba Kid Moderator Join Date: Jan 2005 Location: RI Age: 17 Posts: 4,165	Wouldn't you just stop in the center, since things are attracted to the center of the Earth? __________________ Current setups: 1800 gallon koi pond, 10 gallon planted, 150 gallon reef, other FOWLR tanks

05-06-2007, 09:45 AM	#11
Mazzy Senior Member Join Date: Dec 2006 Location: Adrian, Michigan Posts: 129	well, regardless what mysterious gravitational issues would occur, you surely would never live to tell it once you reached the liquid hot nickle core __________________ "We can bomb the world to pieces, but we can't bomb it into PEACE!" ~Michael Franti

05-06-2007, 10:12 AM	#12
Scuba Kid Moderator Join Date: Jan 2005 Location: RI Age: 17 Posts: 4,165	lol, obviously. But it ignore the whole magma thing for a minute. __________________ Current setups: 1800 gallon koi pond, 10 gallon planted, 150 gallon reef, other FOWLR tanks

05-06-2007, 07:00 PM	#13
Mazzy Senior Member Join Date: Dec 2006 Location: Adrian, Michigan Posts: 129	OK, well ignoring the liquid hot magma I would agree with the person who said you would have to start climbing once you reach the center since gravity pulls toward the middle, not toward one side or the other of the earth. I think the original point of this thread was to show how long you would fall before you hit said liquid hot magma (it just cracks me up to say that) and that, I still don't know the awnser to What I do know, is that I'm gonna try and say "liquid hot magma" in a sentence tomorrow at work __________________ "We can bomb the world to pieces, but we can't bomb it into PEACE!" ~Michael Franti Last edited by Mazzy; 05-06-2007 at 07:03 PM.

05-13-2007, 07:17 AM	#14
CaysE Stowaway Winner Join Date: May 2006 Location: Bloomfield, NJ Age: 29 Posts: 311	I imagine you would gradually slow down as you approached the center. That's why it would take so long. __________________ 20gal tall! The display tank. Flourite substrate, Nutrafin CO2 system, Aquaclear 50, 55W 6.5k bulb @ 10hrs, 65W 10k bulb @ 2hrs, 100W Visi-Therm 4 furcata rainbows (and 8 fry!), 1 albino longfin bristlenose pleco, 6 crystal red shrimp, ramshorn & physa snails 5gal hex! Mini planted tank Eclipse Hex5 with Eco-Complete substrate, 25W heater, 1 male crowntail betta, some ramshorn and physa snails.

06-22-2007, 06:23 AM	#15
Pareeeee Stargate Fan! Join Date: Jan 2005 Location: Ontario, Canada, EH! Age: 21 Posts: 350	As you approached the centre, you'd already be burnt up from the heat of the magma around you :P (sorry for being so 'cheery' LOL) I know, I know, that's not the question. I think you would go back and forth past the centre (because of the speed you would have been going) until you stopped in the centre. Like, you would keep going past on either side until the gravity pulled you back toward the centre. Did I make any sense?? Um like being on a swing. When you want to get off, you will keep swinging past the "stop point" until it finally stops where the swing sits naturally, because of gravity. __________________ Pareeeeee ><((((º> -------------- Please Visit my site! --------------- My Critters: FW 33gal heavily planted and overstocked Blue, a lonely male killer melanochromis in a 5gal... Auzzie, a lazy Bearded dragon gal Pepper and Little Missy - my two cutest ratties in the world.

08-18-2008, 07:25 PM	#16
Albino_101 Albino fish breeder Join Date: Aug 2008 Location: texas, san antonio Age: 19 Posts: 74	when you eached the center of the earth just the pressure of the air alone would crush you. __________________ current tank setups: a 65 gallon turtle tank with 2 mississippi map turtles a 10 gallon species tank with 2 figure eight puffers and 1 albino pleco a 29 gallon community tank currently cycling going to have 6 mickey mouse platys and other tropical fish (some fish not currently mentioned)

08-20-2008, 02:16 AM	#17
TheOldSalt Darth Ichthyos Join Date: Jan 2005 Posts: 4,255	Great googily moogily, now THIS is a major case of thread necromancy if ever there was one. Albino 101, what possessed you to bother replying to a two year old thread? Anyway, I doubt you'd ever reach the center. At some point the gravity & mass of the world above you would be stronger than the little remaining core below you, and you'd stop.

08-25-2008, 12:01 PM	#20
Plecostomus Member Join Date: Jul 2006 Location: California Age: 15 Posts: 75	http://www.youtube.com/watch?v=FAFUS...eature=related __________________ 20g tank: 2 Hatchetfish 1 Bumblebee Catfish 7 Neon Tetras 4 Kuhli Loaches

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