The hollow earth theory!

[TheExplorer]

Sir Edmund Halley believed that the Earth was hollow. While the Earth being hollow would explain many stories in ancient cultures, would it change physics?

 

Is it scientifically impossible?

[Strange]

It wouldn't affect some things. For example, gravity would still work in the same way. But the material of the Earth would have to be implausibly dense and strong.

 

Modern seismology allows us to "see" the interior of the Earth. It isn't hollow.

[StringJunky]

Strange, on 15 Aug 2014 - 08:32 AM, said:Strange, on 15 Aug 2014 - 08:32 AM, said:

It wouldn't affect some things. For example, gravity would still work in the same way. But the material of the Earth would have to be implausibly dense and strong.

 

Modern seismology allows us to "see" the interior of the Earth. It isn't hollow.

We need rotating molten core components to generate the magnetosphere as well don't we? One would have to think how this might be generated in a hollow-sphere model to make it feasible.

Edited August 15, 2014 by StringJunky

[Strange]

We need rotating molten core components to generate the magnetosphere as well don't we? One would have to think how this might be generated in a hollow-sphere model to make it feasible.

 

Good point!

[Nicholas Kang]

Sir Edmund Halley believed that the Earth was hollow. While the Earth being hollow would explain many stories in ancient cultures, would it change physics?

 

Is it scientifically impossible?

 

To answer your question, it would change geophysics- the physics of geology.

 

It is scientifically impossible because many modern geological theory would fail, for example how would you find evidences to proof that the Earth core is made up of iron metal, then the current theory about the origin of the moon would be redifined. Here is why. Our curent best theory of lunar origin is the Giant Impact Theory, which state that the moon was formed after a Mars-size space rock hits the young Earth full of larva and volcanoes. The debris upon hiting formed the moon. Yet, other previous alternative include co-creation theory and fission theory. Co-creation theory argue that the moon was formed exactly with the Earth. But lunar rocks dating disprove the theory. If the Earth was hollow, the fission theory would be accepted. One key is the amount of materials in the core. If the fission theory is true, then theoretically the amount of materials of core that make up the moon should be very close to Earth`s but sadly lunar geology survey disprove it. The metal core make up the moon is much more smaller than Earth`s. So, the speculation(not really since lack of scientific basis) would inevitably kick start a revolutionary scientific world. I don`t like that.

[sunshaker]

I would be very surprised if there was not vast caverns formed as our molten core/mantle cools down, Perhaps around our core are vast molten bubble chambers that countries and oceans would fit within. But i suppose these would be between the mantle/crust,

[billiards]

Rocks are simply too weak to support a cavity, unless it is a cavity very near the surface. As is the iron alloy which is under tremendous heat and pressure at the centre of the earth. Gravity may be exactly zero at the centre of the earth, but pressure and temperature are not. Under these conditions (earth) materials deform visco-plastically. Any hypothetical void would be infiltrated fluidly.

[Nicholas Kang]

Are you sure that gravity may be exactly zero at the centre of the Earth?

[imatfaal]

Are you sure that gravity may be exactly zero at the centre of the Earth?

Yes Nicholas - at the centre of a symmetrical sphere, or anywhere within a symmetrical spherical shell we know that gravity from the surrounding object is zero. This is a consequence of the inverse sqaured law and can be seen in Newtons Shell Theorem (which requires integration understanding) or through Gauss' Law of Gravity which some find more intuitive.

 

http://en.wikipedia.org/wiki/Shell_theorem

[Strange]

Because of the varying density of the Earth, the force of gravity initially increases slightly and then decreases to zero at the centre:

http://en.wikipedia.org/wiki/Gravity_of_Earth#Depth

[Nicholas Kang]

Ok, thanks for teaching me new theorem.