Hollow Moon Theory facts

Could the Moon's density be accurately measured by slamming a
large object into the surface and measuring how much the Moon
"vibrates"? I seem to remember that we propelled something the
size of a Volkswagon into one of the planets a few years ago. The
scientists were very excited by the results. Was it Jupiter?

There's a pretty good book called "Who Built the Moon" by Christopher Knight and Alan Butler.

Very interesting read, talks about the Moon being 300 times closer and also 300 times smaller accounting for eclipses. Of course it does go crazy towards the end when he comes to the conclusion that humans went back in time to put the moon there so that we could evolve to put the moon there. (And I thought Terminator 2 had holes).

However it seems to be widely accepted that the moon is definitely lighter than it should be and whether it's hollow or just has a small core is open to debate.

"The Lunar orbiter experiments vastly improved our knowledge of thr moon's gravitational field... indicating the frightening possibility that the moon may be hollow"
Dr Sean C Solomon, Prof of Geophyics at MIT amongst other titles.

carewemust, according to NASA the moon "rang like a bell" after the apollo 13 guys sent the third stage of the Saturn V launch vehicle weighing 15tonnes into it. Apparantley with the equivalent of 11.5 tonnes of TNT.

well, it could be hollow, if humans made it but i will not go there.

but instead it could just be that the core is made of a lesser dense material, somehow. it is the only theory that is not man made that i can think of that could maybe follow information about gravitational fields. although i cant see this happening naturally also, what with the laws of physics and all.

Originally posted by carewemust
Could the Moon's density be accurately measured by slamming a
large object into the surface and measuring how much the Moon
"vibrates"?

you can find the density easily with simple physics equations.
1 you can use the Universal gravity equation [F = GMm/r2 ] to determine whichever variable you want. So if you find the supposed mass of the object, you can then use:
Density = Mass/Volume.
You can get the volume by determining the moons diameter and then getting the radius by dividing by two. the volume of a sphere is:
Volume = 4/3(pi)r^3

If you had any of the given factors such as earths mass which i dont right off know, and supposed distance between earth and moon. You could determine each objects gravitational force, or mass, or volume, or density, from those three equations.

Im not big on math, but it seems like the most logical way to prove or disprove something. if the numbers dont add up, thats a red flag right there. But if everything does work out mathematically, then it should in theory tell you the correct density and distance and size of the moon.

sometimes the best way to find and answer is simple. no need to shoot the moon or drill it or anything.

The problem is that density equations only give you a mean density for the entirety of the object, so if the outer shell of a hollow object were very very dense/heavy, then the object might have the same density (using an equation to figure it) as a solid object comprised off less dense materials. this is why we can't be 100% sure that it's not hollow simply based on gravity, supposed density, mass, etc.

the math gives values on the mean or whole body, disregarding geological information disregarding the structure of the moon its self. by drilling into it, or slamming an object into it we could figure out the internal structure.

again, regarding the theory of it being man made, what materials could be used, that are in such abundance that a planet could be made of it and where did it come from? would it be a death star kind of structure or a simple hollow sphere with a massive void in the middle.
could the outer layer(s) be made of rock, metal or some unknown mineral of some kind?

[edit on 23-5-2007 by funny_pom]

Originally posted by Nick Nightstalker
the reason the moon is said to have a mantle and a core is because that's our assumption of most planetary bodies. it's our standard model for a rounded celestial object the size of the moon, so we assume it to be true for luna as well

The moon is covered with large seas of lava which surround mounds that were once volcanic, correct me if i'm wrong bu volcanic activity can't take place without some form of internal structure involving a mantle

The crust also consists of crystalline rocks which is consistant with a magma ocean crystalising to form the surface, the lava lying on top of this surface is a type of basalt which means it definitely is a result of volcanic activity

The real evidence for it being solid is that moonquakes have been detected occurring over 1000km beneath the surface and occur almost monthly as they are caused by tidal stresses, which leaves a sphere of radius 737km that COULD be hollow.

However the moon time-variable roatation suggests a core in this area which is partly molten.

Although i believe the moon to be solid, i'm warming up to the idea it was put there by some higher intelligence. There is an awful lot of huge craters on the moon that would have been on the earth without the moons shielding.

This is the only reason i can think of the mon being put here artificially, the only other thing it others is the tides, but it is the currents of the oceans that determine our season, not the tides and these are independant of the moons gravitational pull.

For the moon to be put here to act as a shield it makes sense it would be solid to withstand the impacts.

well when saying that the moon is there, shielding us from impacts, and that if it were not then life could possibly not exist, though i disagree as it would just be under developed due to more frequent impacts which would cause extinctions (then again that is only in the largest impacts). then what about the fact that there is life at all. life started in the worst conditions imaginable so i think that without the moon there would still be plenty of life. the chances of life evolving are massive, and when compared to the chances of the moon being there i think there is a big difference.
basically, why is it such a big deal as to why the moon formed? its not that special really.

Originally posted by funny_pom
well when saying that the moon is there, shielding us from impacts, and that if it were not then life could possibly not exist, though i disagree as it would just be under developed due to more frequent impacts which would cause extinctions (then again that is only in the largest impacts). then what about the fact that there is life at all. life started in the worst conditions imaginable so i think that without the moon there would still be plenty of life. the chances of life evolving are massive, and when compared to the chances of the moon being there i think there is a big difference.
basically, why is it such a big deal as to why the moon formed? its not that special really.

the protecting from extinction part might be a good reason for it, lol

anyway, i'm not really bothered anymore, i think the moon is composed of a crust, mantle and core, the only reason that it would be put there artificially is for protection from asteroid impact, although its pretty crap protection, because as stated by funny_pom, it isn't that special.

i'll leave you all to argue

However it seems to be widely accepted that the moon is definitely lighter than it should be....

The Moon is not "definitely lighter than it should be". Yes, it's density is appreciably less than that of Earth, but the leading theory for its formation explains this perfectly. An object roughly the size of Mars smashed into Earth over four billion years ago. This colossal impact resulted in Earth absorbing a large fraction of the impacting planet's metallic core. The rest of the planet (together with large chunks of Earth's mantle) were blasted into orbit around our planet. Most of this material was molten rock. Over a short period of time, these chunks of rock coalesced under the effects of gravity....and the Moon was born.

In other words, the reason why the Moon has a density significantly lower than that of Earth is because it contains a relatively small amount of metallic elements. Earth "stole" the vast majority of the impacting planet's core material during the collision.

It all makes perfect sense. A damn sight more sense than a hollow Moon.

At this point, I feel the need to do two things. first, since the Death Star was mentioned, and nobody's said this yet, I need to add the obligatory geek quote to the mix *ahem*

... That's no moon.... that's a Space Station!

sorry. done with silliness now. I'm too big a Star Wars geek for my own good

Secondly, I think I need to explain that I'm not arguing from the standpoint of believing, or even leaning towards, the moon being partially or completely hollow, but more from a standpoint of it very well may be, and there are too many other unusual things about our moon to disregard the idea easily.

as to what the others said.. well, the moons control the tides, and protect us from a fair number of minor impacts, but (if memory serves) Jupiter is really our galactic 'shield'; its gravity tends to suck objects in that would otherwise speed through the solar system to whomp earth, and I seem to recall hearing at least once or twice that life on earth likely wouldn't have had the chance to evolve without the protection Jupiter's gravity provides us.

the moon also alters the earth's axis slightly, I believe, and that would contribute a great deal to our overall climate and the passing of the seasons (which depend mostly on what angle the Sun's rays are striking the earth at).

in any event, the effects of having such a relatively large (and just the perfect size to eclipse the sun, which I've always found to be an utterly astronomical coincidence) 'natural' satellite are numerous and pretty much essential to maintaining life the way we understand it, which to me is enough to not outright toss any theories about it that we can't directly disprove, no matter how ridiculous they must seem (the worlds 'hollow moon' make me shake my head a little too).

In other words, the reason why the Moon has a density significantly lower than that of Earth is because it contains a relatively small amount of metallic elements. Earth "stole" the vast majority of the impacting planet's core material during the collision.

It all makes perfect sense. A damn sight more sense than a hollow Moon.

BOOM you hit it. Science that makes perfect sense. I had known about such an event causing the creation of the moon but not about how that effected the following composition of the moon.

Also yes the moon has little effect on the protection of earth, as seen by the countless impacts by meteorites over time. One in particular hit unoccupied Siberia in the 1920's ('27 I think) which was relatively small but left a large crater and flattened acres of forest. If anything Jupiter protects us from the really big stuff, seeing as it has the gravity to do so.

in any event, the effects of having such a relatively large (and just the perfect size to eclipse the sun, which I've always found to be an utterly astronomical coincidence) 'natural' satellite are numerous and pretty much essential to maintaining life the way we understand it

Forgive me if I am wrong or off topic, but I was thinking that the moon was essential to all life on earth, which it isn’t. If people say that it is essential to human life, well then that is verging on the theory that "others" put it there for us.
It is only my opinion but such a belief is going towards the notion of a grater power (i.e. god or similar), which I don’t believe in, but again it’s my opinion so it is really irrelevant.


[edit on 23-5-2007 by funny_pom]

ON the the movie the Truman Show they watched him from inside the moon.
Whos to really say, there could be aliens inside the moon watching us.
Nobody really knows for sure so you have to assume there could be.

lol Yeah and maybe we are thier reality TV show, watching us for thier amusement. With us killing our selves and all.... j/k..

But seriously I've heard of some large structure on the back side of the moon! Who know's what it's purpose is? (If it exists)

And does any one know if other planets moons rotate around thier planet like ours does, with one side always faceing the planet! And say if the moon was rotating faster than it does, would it have a stronger or weaker gravitaional pull, affecting our tilt and tides diferantly????

Just a thought!!

Originally posted by Mogget
The Moon is not "definitely lighter than it should be". Yes, it's density is appreciably less than that of Earth, but the leading theory for its formation explains this perfectly.

The leading theory is Dr Robin Canup's "Big whack theory". However this theory is that there was a first impact and then relatively soon after there was another equal whack from the exact opposite direction to cancel out the speeding up from the first impact.

The big whack theory is accepted as there isn't a better one out there, it is flawed tho. And still just a theory.

The leading theory is a single, colossal impact. There is no need for a second one.

Originally posted by Mogget
The leading theory is a single, colossal impact. There is no need for a second one.

Ok then...

news.bbc.co.uk...
"Double Whammy created moon"

atropos.as.arizona.edu...
"Debate 3: Where Did the Moon Come From?"

atropos.as.arizona.edu...
"DECONSTRUCTING THE MOON"

Just a few links you may find interesting showing that the theory is actually like I said a double impact. Without the second impact the angular momentum would be 2 - 2 1/2 times what it is now.

So this still only involves a single body, although I grant you that it results in two impacts. It could be correct, but I find it rather strange that anyone knows the value of the Earth's angular momentum before the collision took place.

I don't know how they work it either but there must be some pretty solid science behind it. I haven't heard of anyone arguing against it. And Canup has got the best computers to work this stuff out so it's probably wise to trust her.

There is no solid answer to the moon, just a lot of theories. With the most popular being fairly unlikely as accepted by the person who made it.

In my earlier post I talked about the Geophysics Prof at MIT saying the moon could be hollow, many others have put the theory forward also. The most accepted theory for the creation of the moon is flawed, and basically we're clueless about many aspects.

"It all makes perfect sense. A damn sight more sense than a hollow Moon"

Care to change your stance on the subject?