A Concave World

d60944:
You are absolutely correct! I AM close to denying the possibility of the existence of any objective reality. I think there is a very real possibility that nothing can or will ever be proven beyond a doubt. Parradoxically, the only thing we can really know is that we don't KNOW anythting at all. Your suggestion is noted, but I fail to see how reading up on the nature of proofs is going to change things, for I already have a reasonable grasp of what proof entails, I just haven't seen anything indisputable.

I wasn't going to raise the higher dimensions aspect into my reasoning behind why there is no proof, but since you brought it up, who's to say that anything is real. Even seeing may not be believing. Everything we perceive may just be an illusion.

To re-iterate my point, neither I, nor the original poster, is claiming that the Earth is concave, just that it is a possibility. The only thing I am trying to prove is that the Earth is definitely not, without debate, indisputably NOT concave, as science suggests. It may very well be the case, but is yet to be undeniably proven. Nothing here on this thread has proven otherwise, nor in all likelyhood, will anything ever.

The problem is that the proposition that the earth is hollow is a proposition of fact, something that stands to be accepted as objective, at least in theory. If you feel that all proofs are shaky because all proofs are filtered through subjective consciousness (i.e. empiricism is a myth because ultimately our sense have to perceive what our measurements seem to tell us) then your own proposition that the earth could be hollow is subject to the same lack of objective meaning. What you are saying seems to be that "I cannot know the objective truth about the earth" (and by extension, anything - including oneself). So to postulate a possible fact of hollowness on that basis is illogical.

All you can say is "My mind conjectures that the earth is hollow", because even were we to show to you a solid earth you could still claim it to be subjective because the perception of the showing that you get would be a fictitious product of your own senses and cognition. Kind of matrix-esque.

I am not sure you were going that far. I suggested literature on the nature of proofs becuase some of it explores this.

Cheers.

Rob.

d60944:
Don't get me wrong, Rob, I respect your view, and much of what you say makes perfect sense. However, I do not agree that the original poster or myself are proposing that the earth is in fact hollow, just that it is possible. That being said, the proposal that the earth is in fact not solid is not being raised, just that it is possible that it isn't.

As I alluded to in my last post, I was consciously trying to avoid the higher dimension argument for the very reason that it would be too easy to prove my point.

Originally posted by mytym
d60944:
Don't get me wrong, Rob, I respect your view, and much of what you say makes perfect sense. However, I do not agree that the original poster or myself are proposing that the earth is in fact hollow, just that it is possible. That being said, the proposal that the earth is in fact not solid is not being raised, just that it is possible that it isn't.

As I alluded to in my last post, I was consciously trying to avoid the higher dimension argument for the very reason that it would be too easy to prove my point.

If I may make a suggestion, instead of saying that it's possible that the Earth is flat, which go's a bit to far, as in it's saying there's a somewhat strong possibilty, instead say "it's not impossible that the Earth is hollow".

Just because we haven't dug all the way to the centre of the earth doesnt mean thats the only way we can tell whats under our feet.

Sound waves and shock waves from earthquakes etc. can be picked up from across the world, and depending on the type of wave that is recieved and when it is recieved, we can tell what is below us. Some waves travel through solids, but cannot travel through liquids, so are reflected. We can then use the data we recieve to plot the details of the earths structure.

If you want more information on the subject, theres a better explanation here:
www.visionlearning.com...

I am a geology student, so this is something i feel strongly about.

Of course though if someone feels they can dispove this, im all ears...

I'm sure I've been through all this previously, but the sound waves only indicate that the matter within the Earth shares the same characteristics of a solid, not that it is a solid. In all likelyhood the assumption is probably correct, but it is still an assumption, not proof.

Yes a valid point. Put to me a solid is defined as a mass with a certain atomic structure. I cannot visualise how anything can have tightly bonded atoms (as is the case with a solid structure) and yet be made up of free space, or at most some sort of gas.

Plus we have to bear in mind that under compression, states will change, so surely if we were to hypothesis that there was free space under the earth, the compression caused by the overlying crust (under the force of gravity) would become compressed to such a degree that it would become solid (or close, perhaps plastic like) anyway.

But this is just my ramblings, i find it hard to visualise anything more obscure than this

Sound travels much faster through solids than it does through liquids and gases therefore when using sound waves to give an indication of what lay beneath the earth's surface one may draw a conclusion from the resulting data received that is by no means accurate.
Bias towards the popular theory of the earth's structure would plays a large part when interpreting the results of any series of tests.

The sound waves could travel quicker through material of the same or similar relative density and follow the path of the most 'conductivity' like an electrical circuit.

Like hitting a bell with a hammer. The sound /vibration arrives at the opposite point of the circumference much faster by travelling in both(all) directions along the circumference of the bell than by travelling in a straight line through one side of the bell into air in between where sound waves would slow down considerably then hitting the other side.

I give up. All the arguments I can see from the proponents against the accepted wisdom, are grounded in both a severe lack of understanding of science, and an unshakeable belief that theory is never able to accurately predict anything, and everything must be individually verified by direct observation (scientific theory predicts that my alarm clock rings at the designated hour and I have no doubt that it does so even if I am out of the house, and the argument that it "might" not have done so makes little difference to me). Hmmm.

I see where your coming from point. And if a single wave was transmitted and then recieved at a single station i might entertain your notion. However a range of waves over a range of frequences are transmitted from several stations and then received at many other stations around the world. To me this eliminates the chance of anomalous results. If the waves as you say were to travel, electricity like through conduits of solid rock, then gaps would appear on the recieving data where the waves had been slower or not at all.

I was having a bit of think about gravity for an unrelated reason last night and came up with an interesting scenario. In a supposed gas planet such as Jupiter, using the gravity is directly related to mass idea, if you were at the centre of the planet wouldn't the gravity be zero. The centre of mass would form a ring around the planet at some point between the surface and the centre, possibly 1/3 of the way down, causing all of the matter to gravitate to this region. If this was the case the centre would actually be free from matter, as the bonds in a gas a weak in comparison to gravity. I suppose the same conditions would apply to solid planets, thus a struggle would exist between the force holding the solid at the centre together and the force of gravity drawing it towards the donut shaped centre of mass. Does this sound plausable?

This has to be one of, if not the classic work on hollow earth theory. This is a link to the e-book version. It's out there somewhere in PDF too, but it moves around alot. It is now considered to be public domain, but several sites (including Amazon) are still selling copies. Rights are not reserved on this work. For my part, I'll rate it conceivable, if not believable.

The Hollow Earth

mytym,
Not quite sure I understand what you're saying.
Can you explain further the donut theory of yours.
Aren't the gas giants (according to current scientific theory) supposed to have a small solid core?

In a supposed gas planet such as Jupiter, using the gravity is directly related to mass idea, if you were at the centre of the planet wouldn't the gravity be zero. The centre of mass would form a ring around the planet at some point between the surface and the centre, possibly 1/3 of the way down, causing all of the matter to gravitate to this region. If this was the case the centre would actually be free from matter, as the bonds in a gas a weak in comparison to gravity. I suppose the same conditions would apply to solid planets, thus a struggle would exist between the force holding the solid at the centre together and the force of gravity drawing it towards the donut shaped centre of mass. Does this sound plausable?

There's a bit more to it than that... (Also, a hollow planet is not the same as a donut planet)

Some references that ought to answer the query:
en.wikipedia.org...
www.straightdope.com...
home.cord.edu...
www.merlyn.demon.co.uk... (probably the most relevant)

Cheers.

Rob.

point:
I'm not sure if gas giants are supposed to have a small solid core, it's definitely a possibility. It's a little hard to explain without a diagram, but here goes:
In theory, mass generates gravity in the direction of the mass. At the centre of a planet the mass should be zero, thus there should be no gravity drawing other other objects toward the centre. The greater mass would actually be away from the centre thus generating a gravitational force in the direction of the surface and away from the centre. In theory this would leave a void in the centre of the planet and create a hollowness.

The reason I specify gas planets as opposed to solid planets is that there are no strong bonds holding the gas molecules together and resisting an opposing force. I suppose even with a small solid core, the mass of the surrounding gas would still be greater than that of the core, thus a void would form between the solid core and the gaseous outer layer. In a solid planet a struggle would exist between the strength of the bonds holding the solid together, and the strength of gravity opposing the bonds.

I would imagine that large solid planets would also be concave, due to the mass of the generating a greater gravitational force towards the surface than the strength of the bonds holding the core together. The only question is how large is a large planet?

Rob:
I suppose the donut shape is not a very accurate analogy. If you were to look at the cross section of the planet it would look like a donut, but in reality it would be more like a tennis ball.

Thanks for the links, I will have to have a look at them when I get a chance.

[edit on 29/3/06 by mytym]

Hollow Earth No
I would be more inclined to beleive that the Earth is solid as our geo-sciences have concluded. I would put forth though that the solid Earth does not preclude the Earth being "honeycombed" with vast caverns and tunnels as is demonstrated by the underground aquafers. Or even the large undersea Fresh water sinkholes that our scientists have been studying for years.

In theory, mass generates gravity in the direction of the mass. At the centre of a planet the mass should be zero, thus there should be no gravity drawing other other objects toward the centre. The greater mass would actually be away from the centre thus generating a gravitational force in the direction of the surface and away from the centre. In theory this would leave a void in the centre of the planet and create a hollowness.

Caveat - I'm not a physicist.

The proposition is that all the mass is concentrated in a band some way out from the core.

I guess that - even were all the mass to be hypothetically concentrated in a band a distance away from the centre - all the matter further out from that band would still be attracted to the centre of mass (which is at the suggested empty core). A lack of gravity pulling "inwards" would only be relevant to the comparitively much smaller amount of matter nearer the centre than this concentration band. So to me I think the immediate question would be one of pressures. If all the gas towards the outside is being pulled inward, then it will exert a pressure on the gas beneath it. Due to the fact that circumference increases with radius, there is more gas pushing downwards per unit area than gas pushing upwards. This pressure will therefore - it seems to me - cause the gas beneath it to be pushed inwards. The limit of the ability of this pressure to push would be at the point when all the gas beneath it has filled every available empty space, including the core. This means the core is not empty. (If the pressure were great enough, the gas would be compressed into liquid or solid). Becuase the core is not empty, there is no concentration of mass further out either. Which means the original proposition is dynmaically unstable and immediately collapses to a conventional modeal of the solid sphere, getting denser the nearer the core you get.

I hope that didn't read too inpenetrably!

Cheers.

Rob.