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the_ignored
SFN Addict
2562 Posts |
 Posted - 12/19/2004 : 22:17:46
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Hollow Earth Expedition.
More like his hollow head.
Well, he's willing to put his money where his mouth is, right on the arctic circle
quote:
Would you be interested in a once-in-a-life-time chance to discover Our Hollow Earth first hand? We invite you to join us now on an expedition to Our Hollow Earth!
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>From: enuffenuff@fastmail.fm
(excerpt follows):
> I'm looking to teach these two bastards a lesson they'll never forget.
> Personal visit by mates of mine. No violence, just a wee little chat.
>
> **** has also committed more crimes than you can count with his
> incitement of hatred against a religion. That law came in about 2007
> much to ****'s ignorance. That is fact and his writing will become well
> know as well as him becoming a publicly known icon of hatred.
>
> Good luck with that fuckwit. And Reynold, fucking run, and don't stop.
> Disappear would be best as it was you who dared to attack me on my
> illness knowing nothing of the cause. You disgust me and you are top of
> the list boy. Again, no violence. Just regular reminders of who's there
> and visits to see you are behaving. Nothing scary in reality. But I'd
> still disappear if I was you.
What brought that on? this. Original posting here.
Another example of this guy's lunacy here. |
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Ricky
SFN Die Hard
USA
4907 Posts |
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Plyss
Skeptic Friend
Netherlands
231 Posts |
 Posted - 12/20/2004 : 00:26:00 [Permalink]
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quote:
Originally posted by Ricky
How would the earth be any different if it was hollow? Do we know how much mass it takes to get 9.8m/s^2?
What else would change if the earth was in fact hollow?
If my memory of high school phsycis serves me we do indeed know the required amount of mass for that. To have a hollow earth would mean the mantle is of a vastly higher density.
Incidentally, considering gravity is aimed at the centre of mass of an object their wouldn't be any gravity on the inside surface of the sphere, just centrifugal force aimed perpendicular to the axis (and not perpendicular to the inner spehere surface. In other words, there would only be a very meagre force keeping you on the ground (say, 0.2 m/s^2 does that sound plausible?), and unless you were near the equator it would be aimed at an angle towards the ground.
(that 0.2 m/s^2 originates from estimates i heard about what the gain would be on launching spacecraft from equatorial regions instead of from the poles. I'm not sure i remember the math necessary for the calculation and i don't think i'll have the time to look into it anywhere soon.) |
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filthy
SFN Die Hard
USA
14408 Posts |
Posted - 12/20/2004 : 01:14:34 [Permalink]
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Dyson's sphere? Is that the name of it? I don't really remember, but Larry Niven did a sort of a take-off on it with his Ringworld trilogy. Everybody lived on the inside and were kept anchored down(?) by centripedal force.
As I read it, this is little more than an add for a fridgid, Carnaval Cruise. I like this part:
quote:
* If in the event we are unable to locate the North Polar Opening and enter into Inner Earth, we will continue south on the 141st Meridian from the geographic North Pole to the New Siberian Islands and spend a couple of days there checking out the exotic animal remains thought by Hollow Earth researchers to be of inner earth origin.
On the northern shores of the New Siberian Islands, we would look for the legendary deposits of mammoth skeletons and other exotic wildlife remains deposited after originating from a land within the North Polar Opening, according to Hollow Earth theorists. The mouths of rivers that empty into the Arctic ocean from inner earth, are covered with ice in winter, where animals wandering from nearby pastures sometimes fall into the crevasses in the ice and are instantly frozen. Later when the rays of the summer sun shine through the polar opening, the inner earth river mouths thaw out and push their freshwater icebergs out to sea loaded with their loads of frozen dead animals. Thus remains of woolly rhino, steppe lions, giant deer, mammoth and foxes and a hardy breed of horse which scientists claim are all prehistoric are preserved in the Arctic ice, but which Hollow Earth theorists claim more than likely come from inside the earth through the north polar opening, floating out in their tombs of ice, later unloading them onto arctic shores.
Sign up today for Our Hollow Earth expedition, and see first-hand what it is like to try to discover the North Polar Opening and explore Inner Earth!
At least they're honest about it:
quote:
GUARANTEES: By joining Our Hollow Earth Expedition, expedition members agree that there are NO GUARANTEES that this expedition will reach Inner earth. The expedition will make a good faith effort to locate the North Polar Opening and enter therein, but worst case scenario is that we visit the geographic North Pole, explore the region, and continue on to the New Siberian Islands. At all times the expedition will also be at the mercy of the weather, ice and sea conditions.
It might be kind of a fun trip, but I'll bet it'll cost the family fortune that few of us have to buy a ticket.
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"What luck for rulers that men do not think." -- Adolf Hitler (1889 - 1945)
"If only we could impeach on the basis of criminal stupidity, 90% of the Rethuglicans and half of the Democrats would be thrown out of office." ~~ P.Z. Myres
"The default position of human nature is to punch the other guy in the face and take his stuff." ~~ Dude
Brother Boot Knife of Warm Humanitarianism,
and Crypto-Communist! 
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Plyss
Skeptic Friend
Netherlands
231 Posts |
Posted - 12/20/2004 : 01:35:17 [Permalink]
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quote:
Originally posted by filthy
Dyson's sphere? Is that the name of it? I don't really remember, but Larry Niven did a sort of a take-off on it with his Ringworld trilogy. Everybody lived on the inside and were kept anchored down(?) by centripedal force.
A Dyson sphere is something different. It's more like a huge sphere built around a star to capture its energy and provide space.
Still, gravity on the inside is going to be a problem: http://www.nada.kth.se/~asa/dysonFAQ.html#GRAV
These guys suggest that if you would want to build a Dyson sphere the best way to do it would be a ring, such as in Niven's ringworld trilogy. |
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Siberia
SFN Addict
Brazil
2322 Posts |
Posted - 12/20/2004 : 06:15:28 [Permalink]
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Mmm.
I guess someone's been reading one too many Verne's novel... |
"Why are you afraid of something you're not even sure exists?"
- The Kovenant, Via Negativa
"People who don't like their beliefs being laughed at shouldn't have such funny beliefs."
-- unknown
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Dude
SFN Die Hard
USA
6891 Posts |
Posted - 12/20/2004 : 06:22:59 [Permalink]
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Well, I think a trip to the north pole would be cool enough on it's own. No need to clutter it up with nonsense about a "hollow" earth.
And yeah, the "gravity" of one of Mr dyson's spheres would be centrivical force from the rotation of the sphere. Only a minimal space(compared to the entirety of the thing) would be habitable.
If such a construction were possible I think the best use of it would be to harness the energy output from the star, rather than massive living space. The concept is facinating though.
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Ignorance is preferable to error; and he is less remote from the truth who believes nothing, than he who believes what is wrong.
-- Thomas Jefferson
"god :: the last refuge of a man with no answers and no argument." - G. Carlin
Hope, n.
The handmaiden of desperation; the opiate of despair; the illegible signpost on the road to perdition. ~~ da filth |
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Plyss
Skeptic Friend
Netherlands
231 Posts |
Posted - 12/20/2004 : 07:14:30 [Permalink]
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Living on the inside of a hollow earth: A feasibility study
A number of assumptions:
1) For all reasonable purposes here, the earth is spherical.
2) The change in force for a falling object on earth is negligable.
3) Regular newtonian physics apply on earth.
4) Friction can be ignored
Formulas and constants:
Mass of the earth Me: 5.97 E24 kilograms
Radius of the earth Re: 6.36 E6 meters
Rotational period of earth Trot: 23h, 56m, 4s or 8.62 E4 seconds.
Newton's gravitational constant G: 6.67E-11 cubic meter per kg per square second.
Gravitational force: Fg = G*Me*Mbody/(Re^2)
Force: Facc = Mbody * Acc where Acc is the acceleration and Mbody the mass of the body.
Centrifugal force Fcent = Mbody*Vorb^2 / Rorb where Mbody is the mass of the body and Vorb and Rorb
the orbital velocity and radius respectively, and Vorb = 2*Pi*Rorb/Trot
All set? Let's commence.
Let's substitute the acceleration formula for a falling object into the formula for gravitational force: g = Mbody * Fg and F = GMeMbody/(Re^2):
We end up with g = G*Me/(Re^2).
We see that gravitational acceleration depends only on the mass of the earth and not on the mass of the falling body.
Now since the radius of the earth is known and G and g are constant we can conclude that the earth has a set, constant mass regardless of wether it is hollow or not.
The density of the earth is 5.5 kg/l so any decrease in occupied volume pushes up this density. The density of solid iridium (the densest known material outside of a neutron star) is 22.6 so if the earth were made of this material we could open up roughly 3/4 (75.7%) of the volume inside. This corresponds to a maximum inner radius of 5810 km.
Because the mass above you doesn't contribute to gravity (because it's precisely counterbalanced by the mass at the opposite side of the globe) the only force keeping you on the ground is the centrifugal force. At this radius the orbital velocity equals 424 m/s^2 good for a centrifugal acceleration of 3.1 cm/s^2 (roughly 0.3% of the gravity on earth surface. The moon has 1.6m/s^2 or 17%). In other words: You could jump really really far.
This might sound like a really cool thing but there's a catch: Oxygen. With this low an attraction the available oxygen would rapidly escape through the alleged holes at the pole suffocating anyone on the inside. I could look up the equation for residence times in atmospheres for different gases in different gravities but i can't be bothered as it won't be very long.
An additional problem: Light. without an energy source it gets pretty dark pretty quickly. Or course we can place an additional sun in the middle of the planet but this forms a problem : A sun has gravity. When this gravity exceedes the centrifugal force you will fall off the inner surface into this sun. The mass necessary to generate this gravitational pull is 1.57 E22 Kg (for reference: Mearth = 5.97E24 kg and Mmoon = 7.35E22 kg).
I don't know the necessary mass to sustain nuclear fusion but i'm pretty sure its more than this.
Of course its always possibly to make a smaller hole in the earth than the maximum-sized one i calculated but its centrifugal force will always be lower, so a less-than-maximum-sized hole will
always be darker and less habitable than the one described above. Oh, that reminds me, did i mention lava somewhere? Or the fact that you would probably need pretty tough material to prevent the hole from caving in on itself? Ah, nevermind, i think i made my point[1].
[1] For those who are wondering: The point i'm trying to make is: Ohmygod, did i actually bother to calculate *that*? I really need a new girlfriend. Oh, and also a hollow earth is nonsense, especially with living beings inside.
[type edit] |
| Edited by - Plyss on 12/20/2004 07:51:12 |
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Kil
Evil Skeptic
USA
13477 Posts |
Posted - 12/20/2004 : 08:44:14 [Permalink]
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| Wouldn't all of this make Jules Vern proud... |
Uncertainty may make you uncomfortable. Certainty makes you ridiculous.
Why not question something for a change?
Genetic Literacy Project |
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Siberia
SFN Addict
Brazil
2322 Posts |
Posted - 12/20/2004 : 09:01:13 [Permalink]
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Plyss... you need a life
Nah, really. That was great, very helpful (especially for my sci-fi novel-to-be!), thanks a ton! |
"Why are you afraid of something you're not even sure exists?"
- The Kovenant, Via Negativa
"People who don't like their beliefs being laughed at shouldn't have such funny beliefs."
-- unknown
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Dave W.
Info Junkie
USA
26022 Posts |
Posted - 12/20/2004 : 21:23:11 [Permalink]
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From filthy's quote:quote:
The expedition will make a good faith effort to locate the North Polar Opening and enter therein...
Good faith? In light of the fact that submarines have travelled around under the ice at the North Pole and failed to find anything but water? The very offer of such a trip is a lawsuit waiting to happen. |
- Dave W. (Private Msg, EMail)
Evidently, I rock!
Why not question something for a change?
Visit Dave's Psoriasis Info, too. |
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Plyss
Skeptic Friend
Netherlands
231 Posts |
Posted - 12/21/2004 : 01:47:10 [Permalink]
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quote:
Originally posted by Siberia
very helpful (especially for my sci-fi novel-to-be!), thanks a ton!
Does this mean i get a free copy?
Also, yay, 100 posts! Do i get frequent poster miles now?  |
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filthy
SFN Die Hard
USA
14408 Posts |
Posted - 12/21/2004 : 03:09:56 [Permalink]
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quote:
Originally posted by Dave W.
From filthy's quote:quote:
The expedition will make a good faith effort to locate the North Polar Opening and enter therein...
Good faith? In light of the fact that submarines have travelled around under the ice at the North Pole and failed to find anything but water? The very offer of such a trip is a lawsuit waiting to happen.
Indeed. I was going to mention that the Nautalus spent months (forgot how many) exploring under the polar ice cap, breaking all of the submerged records of the era, but got involved with rings and spheres and forgot it. Thanks for bringing it up.
I think that it would be a fun trip and wish that I could go.
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"What luck for rulers that men do not think." -- Adolf Hitler (1889 - 1945)
"If only we could impeach on the basis of criminal stupidity, 90% of the Rethuglicans and half of the Democrats would be thrown out of office." ~~ P.Z. Myres
"The default position of human nature is to punch the other guy in the face and take his stuff." ~~ Dude
Brother Boot Knife of Warm Humanitarianism,
and Crypto-Communist!
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questionit
New Member
21 Posts |
Posted - 01/10/2005 : 19:33:12 [Permalink]
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Does the Earth have to be hollow to allow some pockets of ecosystems, like Verne talks about? I can picture a few caves here and there deep enough but not so deep that all life has ceased to develop there. |
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Plyss
Skeptic Friend
Netherlands
231 Posts |
Posted - 01/11/2005 : 03:43:58 [Permalink]
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quote:
Originally posted by questionit
Does the Earth have to be hollow to allow some pockets of ecosystems, like Verne talks about? I can picture a few caves here and there deep enough but not so deep that all life has ceased to develop there.
I don't think i've read that specific book. Could you describe the specific ecosystems in question or name the specific story this relates to?
Also, considering these ecosystems are apparently fictional the hole[1] question becomes rather academic.
[1] I spotted this mis-spelling in the preview, however it makes a nice pun, so i let it in ;) |
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ktesibios
SFN Regular
USA
505 Posts |
Posted - 01/12/2005 : 00:04:46 [Permalink]
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quote:
Originally posted by Plyss
I don't think i've read that specific book. Could you describe the specific ecosystems in question or name the specific story this relates to?
A Journey To the Center of the Earth by Jules Verne. The travelers encounter a vast sea which is full of life, including aquatic reptiles from the dinosaur era.
They don't get there via the North Pole; their entrance is through the crater of Mt. Sneffels, a volcano in Iceland. After traveling for months in the subterreanean world, they wind up getting ejected through the crater of Stromboli.
It's a pretty fun read, with plenty of thoroughly outmoded scientific ideas. You can probably find a copy at your favorite bookstore. |
"The Republican agenda is to turn the United States into a third-world shithole." -P.Z.Myers |
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