Hollow Moon? no way

[kk20]

This thread made me lol. Basic maths proves that the moon is not hollow. The gravitational field strength of the moon is roughly 1.61m/s/s at the surface.

Using the formula g=MG/r^2

M=mass of the moon. G=The universal constant. r=radius of the moon.

Rearrange to find M

M=(g*r^2)/G

(1.61*1737400^2)/(6.67*10^-11) = M

M is approximately 73,000,000,000,000,000,000,000kg

Now are these articles telling me that the mass is only on an outer layer? Similar to a ping pong ball?

 

[niky]

I read the moons gravity isn't 'global' like the earths is, it can vary and caused orbiting objects to bob.

The Earth's gravity varies, too. Not by a huge* amount, but it does.

Depending on what you regard as huge.

 

[BobK]

This thread made me lol. Basic maths proves that the moon is not hollow. The gravitational field strength of the moon is roughly 1.61m/s/s at the surface.

Using the formula g=MG/r^2

M=mass of the moon. G=The universal constant. r=radius of the moon.

Rearrange to find M

M=(g*r^2)/G

(1.61*1737400^2)/(6.67*10^-11) = M

M is approximately 73,000,000,000,000,000,000,000kg

Now are these articles telling me that the mass is only on an outer layer? Similar to a ping pong ball?

Useless "proof" is useless.

You've calculated the mass of the Moon. Very good. Now show us where in your equation the shape (ie, hollow or solid) of the Moon is described.

 

[kk20]

Useless "proof" is useless.

You've calculated the mass of the Moon. Very good. Now show us where in your equation the shape (ie, hollow or solid) of the Moon is described.

Radius of moon is calculated. Gravity between two objects is from the centre of the sphere. How can there be gravity if there is no mass at the centre? For there to be gravity, there must be mass. Everything has mass, even photons which is why light cannot escape the gravity of a black hole.

 

[Skuh]

Define hollow. They say the earth's core is filled with lava so it would kinda be hollow with a liquid center. Like a rollo or caramilk bar. For the moon to be truly hollow I don't even think it would be possible based on current thoughts of how planets are made. Assuming a bunch of gas particles in space all came together and made the moon it would have to be very precise to create a spherical shell only. I think it's much more likely the moon is more like earth with a liquid center. Maybe an ice/slush center which would explain excessive quakes.

I thought the inner core was liquid iron as the pressure and heat should surely make it turn into a paste like liquid at least.

The Earths core is molten Lava/metal with a solid metal ball of iron–nickel alloy roughly 70% the size of the moon at the centre.



As we try and go deeper towads the earth's core, we discover that the earcth 'wants' to close any gaps that we make. We have mined about 2km into the Earth's crust and the pressure even at that distance down (something like 0.02% towards the core) forces our tunnels to crush.
Why would the moon have such less pressure (would no centre = less pressure) that it could be possible for it to be hollow, let alone how would it have formed?

 

[Exorcet]

Radius of moon is calculated. Gravity between two objects is from the centre of the sphere. How can there be gravity if there is no mass at the centre? For there to be gravity, there must be mass. Everything has mass, even photons which is why light cannot escape the gravity of a black hole.

Gravity does not require mass at the center. It can be anywhere. The gravity outside would be the same. You stopped one step too early. You should have taken the mass and then shown what would be required of density, which would be something ridiculous, as Famine pointed out on page 1.

Also, photons have zero mass, they have momentum though. They can't escape black holes because all paths past the event horizon only point inward.

 

[Rossticles]

Define hollow. They say the earth's core is filled with lava so it would kinda be hollow with a liquid center. Like a rollo or caramilk bar. For the moon to be truly hollow I don't even think it would be possible based on current thoughts of how planets are made. Assuming a bunch of gas particles in space all came together and made the moon it would have to be very precise to create a spherical shell only. I think it's much more likely the moon is more like earth with a liquid center. Maybe an ice/slush center which would explain excessive quakes.

The predominant theory on how the Moon was made is that there was a giant impact between the Earth and another forming planet about the size of Mars.

Remove your tin foil hats people. Why would anyone lie about the Moon's hollowness?

 

[DK]

Remove your tin foil hats people. Why would anyone lie about the Moon's hollowness?

 

[kk20]

Gravity does not require mass at the center. It can be anywhere. The gravity outside would be the same. You stopped one step too early. You should have taken the mass and then shown what would be required of density, which would be something ridiculous, as Famine pointed out on page 1.

Also, photons have zero mass, they have momentum though. They can't escape black holes because all paths past the event horizon only point inward.

You are wrong my friend. Gravity on the surface of the earth is weaker than the gravity 2 metres inside the earth. Gravity depends on two masses and how far away they are. Working out the density means nothing because this takes an average. Density doesnt disprove that all mass is on an outer layer, leaving the inside hollow. Whereas the equation for gravity does.

You just disproved yourself. You say photons dont have mass but the have momentum? The equation for momentum is veclocity*mass. Photons do have mass. Everything has mass. Even waves when you consider wave-particle duality. Light can behave like a wave such as in diffraction or it can behave like a particle such as in the photoelectric effect...

 

[PeterJB]

You are wrong my friend. Gravity on the surface of the earth is weaker than the gravity 2 metres inside the earth. Gravity depends on two masses and how far away they are. Working out the density means nothing because this takes an average. Density doesnt disprove that all mass is on an outer layer, leaving the inside hollow. Whereas the equation for gravity does.

You just disproved yourself. You say photons dont have mass but the have momentum? The equation for momentum is veclocity*mass. Photons do have mass. Everything has mass. Even waves when you consider wave-particle duality. Light can behave like a wave such as in diffraction or it can behave like a particle such as in the photoelectric effect...

Gravity is dependent on the mass of a single object. It just happens that all objects pull towards each other. The point of wave-particle duality is that light has mass as a particle, but that doesn't mean it has it as a wave too, All waves are is radiation, they don't have mass, Photons are simply pockets of light.

 

[Exorcet]

You are wrong my friend. Gravity on the surface of the earth is weaker than the gravity 2 metres inside the earth. Gravity depends on two masses and how far away they are. Working out the density means nothing because this takes an average. Density doesnt disprove that all mass is on an outer layer, leaving the inside hollow. Whereas the equation for gravity does.

I don't know what gravity below the surface of the Earth has to do with this.

However, gravity does not require two masses. The moon by itself would produce 1 mg (moon-g) of gravity at its surface if it was the only thing in the universe, and it would also produce 1 mg at its surface if it was hollow, but had the same mass.

Density determines what kind of material the moon is made out of. A hollow moon would have extremely high density that you would not find in nature, which was Famine's point. This is why density is relevent here, but the equation for gravity (which is for point masses by the way, which is why it will tell you absolutely nothing about whether something is hollow or not) is not.

You just disproved yourself. You say photons dont have mass but the have momentum? The equation for momentum is veclocity*mass.

No, the equation for photon momentum is h/lamba. You're leaving out relativity.

http://hyperphysics.phy-astr.gsu.edu/hbase/relativ/relmom.html

Everything has mass.

Not photons. Everything has mass-energy though.

Even waves when you consider wave-particle duality. Light can behave like a wave such as in diffraction or it can behave like a particle such as in the photoelectric effect...

Has nothing to do with mass.

 

[Pupik]

So if nobody here really believes the moon is hollow, why the continued existence of this thread?

Although once we found out the moon wasn't made of swiss cheese, we haven't returned. Just saying...

 

[ScouserInExile]

Something that's puzzling me about this hollow moon theory. Where has it come from? Who, when and why has anyone come up with this theory? What made them come up with the idea in the first place?

And, given what is (from what I can see) a complete lack of evidence to support this, how is it a more valid theory than it being full of peanut butter?

 

[Joel]

Of course the Moon is hollow. That's where the Space Nazis keep their neutronium bombs.

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