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A Mission to the Earth’s Core
Published in the December-2003 issue of Analog Science Fiction & Fact Magazine ^
| 06/22/2003
| by John G. Cramer
Posted on 02/10/2005 10:59:13 AM PST by vannrox
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To: Little Ray
Iron density 7874kg/m^3
Volume 30m sphere (assuming 30m is diameter): Pi/6*(30m)^3 gives Pi*4500m^3 volume.
Mass = Pi*4500m^3*7874kg/m^3 (using 355/113 for Pi) = 111,316,061kg.
This is about the weight of the Battleship Missouri (which is bigger, but hollow.)
61
posted on
02/10/2005 1:20:27 PM PST
by
Doctor Stochastic
(Vegetabilisch = chaotisch is der Charakter der Modernen. - Friedrich Schlegel)
To: HuntsvilleTxVeteran
Another reason for abandoning the MOHOLE was that much of the stuff to be studied is just lying on the ground in northern California (actually, it is the ground.) Much of that area is sea-crust as opposed to continental crust.
62
posted on
02/10/2005 1:22:47 PM PST
by
Doctor Stochastic
(Vegetabilisch = chaotisch is der Charakter der Modernen. - Friedrich Schlegel)
To: labowski
63
posted on
02/10/2005 1:29:21 PM PST
by
Flightdeck
(Liberals see Saddam's mass graves as half full. I prefer to see them as half empty.)
To: Doctor Stochastic
The moho area was selected because it was one of the shortest paths through the crust to the mantle.
So you think the liquid mantle under the stress of the crust and the heat is the same as a lava flow?
64
posted on
02/10/2005 1:33:01 PM PST
by
HuntsvilleTxVeteran
(So I talk to myself, at least I am talking to a mind that is my equal)
To: HuntsvilleTxVeteran
So you think the liquid mantle under the stress of the crust and the heat is the same as a lava flow?No. I never said anything like that.
65
posted on
02/10/2005 1:40:57 PM PST
by
Doctor Stochastic
(Vegetabilisch = chaotisch is der Charakter der Modernen. - Friedrich Schlegel)
To: Doctor Stochastic
Pardon me, but it appears that you've computed the mass of a sphere with a 30m radius, not a 30m diameter...unless perhaps I'm missing something? Volume is 4/3rds pi*(r^3), yes?
66
posted on
02/10/2005 1:47:27 PM PST
by
Oberon
(What does it take to make government shrink?)
To: Not a 60s Hippy
Looks to me like they would just be drilling a hole for another volcano.Amen to that! It's bad enough when we get weak spots in the crust allowing the magma to punch through. Now we're talking about an engraved invite for the stuff?
67
posted on
02/10/2005 1:52:39 PM PST
by
SlowBoat407
(Speculating idiot)
To: bruin66
Are you talking about Schuler oscillation? Sounds familiar.
68
posted on
02/10/2005 1:53:55 PM PST
by
SlowBoat407
(Speculating idiot)
To: Doctor Stochastic
"Another reason for abandoning the MOHOLE was that much of the stuff to be studied is just lying on the ground in northern California (actually, it is the ground.) Much of that area is sea-crust as opposed to continental crust."
The mohole project was not about the crust it was about going through the crust to sample the mantle.
69
posted on
02/10/2005 1:56:19 PM PST
by
HuntsvilleTxVeteran
(So I talk to myself, at least I am talking to a mind that is my equal)
To: vannrox
70
posted on
02/10/2005 1:57:28 PM PST
by
Fresh Wind
(Where does bandwidth go when it is wasted?)
To: Oberon
That's why I have Pi/6 rather than 4*Pi/3.
71
posted on
02/10/2005 2:00:58 PM PST
by
Doctor Stochastic
(Vegetabilisch = chaotisch is der Charakter der Modernen. - Friedrich Schlegel)
To: HuntsvilleTxVeteran
The geologists I knew told me that lots of the MOHOLE work was for looking at oceanic crust. Of course, going to the mantle would be different. Now that Haliburton has absorbed Brown&Root and there's another Texan in the White House, maybe they'll try again.
72
posted on
02/10/2005 2:04:42 PM PST
by
Doctor Stochastic
(Vegetabilisch = chaotisch is der Charakter der Modernen. - Friedrich Schlegel)
To: Doctor Stochastic
That would work okay if you didn't have to cube the radius. Your result is off by a factor of 8 (2 cubed), as far as I can tell.
73
posted on
02/10/2005 2:04:54 PM PST
by
Oberon
(What does it take to make government shrink?)
To: Tarpaulin
Physicist, what do you think? Zero gravity inside a massive hollow sphere?Zero gravity from the sphere itself, yes. Put a black hole (or a planet, or a star, or a crouton, or...) somewhere, inside or outside of the sphere, and you'll feel the gravitational field from that, but the field from the sphere itself will be zero inside.
Consider any arbitrary chunk of the sphere. It subtends some patch of solid angle with respect to you. The gravitational pull from that chunk is opposed by the pull of a similarly-shaped chunk on the opposite side of you. Get this: the size (and therefore the mass) of each chunk will grow as the square of its distance from you. Its gravitational pull will fall off as the square of its distance from you. Those two factors cancel, thus the pull from each piece is equal and opposite. That zero-pull argument works for any arbitrary piece in any arbitrary direction. Integrate that zero over the entire sphere, and you get zero.
To: Oberon
Shows what I get for responding without reading the thread. <g>
To: Physicist
To: Vaquero
Sounds like a great idea. Let's blow up the planet for sh*ts and grins.
To: Physicist
Very succinctly put...much better than my explanation in
Post 52.
78
posted on
02/10/2005 2:12:52 PM PST
by
Oberon
(What does it take to make government shrink?)
To: Physicist
79
posted on
02/10/2005 2:14:22 PM PST
by
Tarpaulin
(Look it up.)
To: Doctor Stochastic
The geophysicists with whom I worked with knew the purpose of the mohole and the moho area.
During the time of the mohole project, we also set up a vibroseis crew in New Mexico that used both a long sweep and a very long listening time in order to try to get some more data on the mantle.
80
posted on
02/10/2005 2:14:31 PM PST
by
HuntsvilleTxVeteran
(So I talk to myself, at least I am talking to a mind that is my equal)
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