A Concave World

I've always been facinated by the belief that the planet is structured more like an egg shell rather than a mostly solid sphere. That there is an environment/ ecosystem/ civillisation on the inner surface of the Earth just as we exist on the outer surface.
The actual crust could act like a magnet producing the gravity effect on both sides of the shell.
Instead of a solid or liquid core at the centre of the earth there could be maybe a small type of sun giving out light and heat to the inhabitants of the inner earth.
I think the theory was popular in the nineteenth century.

While it is a very fanciful tale, and good story line for fiction, thats all it is.

The Earth's crust is'nt massive enough to produce a gravitational field for one.

And well, my mind's gone blank now, there are other reasons for it to be impossible.

Quite a few threads abiout this somewhere.

This is a fascinating thought. I see no reason why it couldn't be possible. The gravity on both sides of the shell is an interesting concept. I suppose if the density of the shell was high enough it could exist. I think the fact that it may contradict the teachings of science is as much a reflection on science's limitations in understanding the world around us, as it is on the feasibility of this scenario.

Originally posted by mytym
I think the fact that it may contradict the teachings of science is as much a reflection on science's limitations in understanding the world around us, as it is on the feasibility of this scenario.

Unfortunately Science has proven quite conclusively time and time again that no - the earth is not hollow. No contradictions there. =)

just off the top of my head i can think of afew problems with this theory.

1. its incredably hot down there notice the furth down you dig the hotter it gets

2. theres no way for this heat to disapate

3. volcanos.....that lavas comeing from somewhere

4. atmosphere, as we all know there are several layers of this for it to work as we know it the civilization would have to be floating in the center of the earth

from these 4 point i cant see anyway the theory is possable but i have to admit it would be kinda cool if it were true

How far has anyone drilled into the earth. A couple of kilometres at most and that's on land which is considerably higher up than say the ocean floor.

So what does science (the new god on the block) really know about what's below our feet. Not much at all. It has literally just scratched the surface.

So many scientific theories are taken as fact.

There are also FACTUAL means of detecting what the inside of earth is like, while we cant see with our eyes, using computers and modern technology we can "see" with sound, radiation, etc. Its not rocket science (although rocket science by todays standards is childsplay )

These FACTUAL means you speak of are tests that give an indication of what the Earth might be made of, based on the perceived density of the matter within. I imagine the density is measured by the speed it takes for sound waves to travel from one side to the other, I'm, not sure. At any rate it is certainly not the only conclusion one can draw, simply the one the fits best based on the information at hand.

Hundreds of years ago if you had proposed that the Earth was a sphere you world have been labelled a nutcase. All the information available at the time suggested the most likely scenario is that the Earth was flat, thus it was taken as fact. Who's to say in hundreds of years time that all the things we believe science has proven today as fact will not be thought of as primitive?

The difference being, that hundreds of years ago, science was considered pretty much evil, and wahat the church said wwas what was the "truth", in weserrn society atleast.
At that time, they did'nt have science to help them see what the Earth was shaped like.
Now with us, we have science, and we use it to see the answers to our questions, we know the inside of the Earth is magma because our science allows us to see that without seeing it, that is, instead of seeing it like we see things normally, photon energy hittihng our eyes, we use technology to see it in ways we can't and than look at the picture the technology creates.

But the technology doesn't think for itself. It is just painting a picture for us within the confines of the parameters we place on it.

Yes, but the conifnes we place on that technology, are so we can understand what it sees.

Regardless of the motive it requires making assumptions such as limiting density readings to matter composed of a few likely elements.

Originally posted by point
How far has anyone drilled into the earth. A couple of kilometres at most and that's on land which is considerably higher up than say the ocean floor.

In the United States, the deepest drilling is the Bertha Rogers well, with a depth of 9,583 m (31,441 ft).

In the Kola Penisula, in Russia, they have reached a depth of 12,262 metres.

Do not forget the natural Marianas' trench, with a depth of 10,911m bellow sea level.

One of the reasons for not considering the possibility of a hollow Earth is the way the seismic waves travel inside the planet.

That is the reason scientists say that the Earth is solid until a certain depth and bellow that depth it is liquid, because the waves travel in different ways in different mediums.

Also, how could we explain the Earth's internal heat, if it is hollow then it must be a hell down there.

As someone else has said, in order to generate the measured gravitational field of the earth, you need to have enough mass to create it. Spookily the mass of a solid earth is just that amount.

One might claim that the equations are wrong, and that one can generate gravity with far less mass (say, the mass of just the crust). However, we know that the formulae for creation of gravity by mass are correct: For example, a solid metal sphere can have its (miniscule but there nonetheless) gravitational field measured very accurately, and this is found to be what is predicted by equations on the basis of its mass. (And one would have to claim from the OP's proposal that in fact all planets, asteroids, stars and all other matter with gravitational properties was also hollow in order for the equations to be consistent with measurement.)

We also know that gravity "sucks" towards the centre of gravity, the centre of mass, which in a hollow earth is still at the empty centre (eg. look at a binary star where the two stars orbit around their common centre of mass in empty space). So a hollow earth would have a gravitational force pulling towards the centre like normal. No way for people to walk un the underside of the crust. The crust would in fact most likely collapse inwards to the centre unless the earth was spinning so much ludicrously faster than it currently is to create a balancing centripetal force.

In short, the earth is not hollow.

Cheers.

Rob.

The previously mentioned points all make compelling arguments, there is no doubt about that. There is avery real possibility that they are correct.

However, the seismic waves indicate the earth is made up a different substances at different points which bear the same characteristics as liquids and solids.

The heat generation indicate that humans may not find it the most desirable place to inhabit.

The gravity/mass relationship would have to be a huge coincidence if the earth is hollow, however science does have a theory about donut shaped black holes which are contradictory to the idea that gravity pulls to the central point of an object.

I see many logical assumptions, but no absolute proof.

science does have a theory about donut shaped black holes which are contradictory to the idea that gravity pulls to the central point of an object.

Please explain this. As far as I am aware any desciption of toroid topology at a singularity is fraught with problems when translated into the everyday macroscopic kind of topology that you have just suggested. As I don't know the "theory" you mean, could you reference the theory and tell me where to look for it, and I'll get back to you?

On the other hand it smacks of double standards when you dismiss all of science both in practice and in theory, and then go on to cite a very speculative piece of purely scientific theory to try to back your idea up.

Cheers.

I'm sure if you do a google search you will find something on it. It has to do with rotating and non-rotating black holes and the possibility of being able to travel back in time without being annihilated. i think Stephen Hawking touches on the subject.

I am not trying to back up the theory with science, nor am I dismissing other scientific views. I am merely pointing out that scientific theories are just that, theories, that involve many assumptions, some quite logical. This being the case, there is room for the possibility of a concave world, no matter how far fetched it may seem, and in turn absolute statements such as "The world is solid" are unproven.

interesting idea, you should read ER burroughs' works on it, "at the earths core. One of my favorite books, but a really lousy movie






pubs.usgs.gov...
Data from earthquake waves, rotations and inertia of the whole Earth, magnetic-field dynamo theory, and laboratory experiments on melting and alloying of iron all contribute to the identification of the composition of the inner and outer core. The core is presumed to be composed principally of iron, with about 10 percent alloy of oxygen or sulfur or nickel, or perhaps some combination of these three elements.

I am merely pointing out that scientific theories are just that, theories, that involve many assumptions, some quite logical. This being the case, there is room for the possibility of a concave world, no matter how far fetched it may seem, and in turn absolute statements such as "The world is solid" are unproven.

I suggest you read up on the nature of proofs, as you seem to be close to denying the possiblity of apprehending any objective reality.

As for donut-shaped black-holes, having found a little about them, they are postulates in multidimensional space. Gravity still attracts to the centre of mass in 3D/4D space, but the actual spacetime being inhabited by the hole is warped to toroid in 5+D space.

Cheers.