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back to article MOON SHRINKING FAST - shock NASA discovery

Imagery from a NASA spacecraft has revealed that the Moon has shrunk significantly in recent times: indeed, instruments placed by the Apollo astronauts are thought to have recorded the rumbling, crunching sounds of lunar shrinkage carrying on in just the last few decades. NASA LRO image showing lobate scarp cutting across small …

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Coat

Mooninites

This is what happens when the Mooninites overdo the whole quad lazer thing. I knew it would bite them in their 2 dimensional (but superior) asses somehow.

Oh, you not heard of ATHF? Never mind then.

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Go

Nothing to be alarmed of...

Probably just Dahak rearranging his camouflage...

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Boffin

Black Holes?

Micro Black Holes that will dissipate via Hawking radiation in nanoseconds. Micro Black Holes with the gravitic pull of less than an electron.

Did anybody take seriously that bovine byproduct?

If anyone believes that black holes keep getting bigger and bigger through accretion of nearby matter, they clearly have not read the mechanism that makes them work.

Accreting matter actually shrinks black holes.

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FAIL

What a load of a*se

"Accreting matter actually shrinks black holes" - total fail I'm afraid.

Black holes DO grow by swallowing matter.

Try this:

http://www.newscientist.com/article/dn14653-how-big-can-a-black-hole-grow.html

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Boffin

And nope.

The black hole itself is by definition a point object (at least in our physics - this may not actually apply inside a black hole, but there's no better explanation at present...).

The event horizon of a black hole (ie the Schwarzchild radius for a non-rotating black hole) *will* grow according to the mass of the object - but it's only a mathematical definition, there's nothing physical at that distance - for supermassive black holes (centre of galaxy type stuff) it would be possible for a human to cross the event horizon with no ill effects (no turning to spagetti, etc). You'd never get out again, and wouldn't be able to tell anyone about it though...

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FAIL

New Scientist == Wikipedia

You fail.

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Black hole as point object

Just a thought, but surely that - by definition - would preclude their existence in a string-theoretic universe?

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Coat

"New Scientist == Wikipedia".

I used New Scientist as I suspect it is pitched at a level which the original poster might understand.

I presume you get all your knowledge directly from PhysRev or MonRAS? I do love it when IT people spout it large about physics - there seems to be something inherent in them that makes them think they're experts on anything to do with physics, or military hardware.

Anyway, the weekend is here so I'll get my coat - mine's the one with a PhD in Astrophysics in the coat pocket.

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I'd give him partial credit, but he didn't show his work.

He's s partially right, though probably through no fault of his own. Black holes do grow by accreting matter, and do shrink as a result of Hawking radiation; the rate at which the black hole loses mass to Hawking radiation is inversely proportional to that mass, so a black hole with the mass of a star is going to stick around for a while, whereas a black hole with the mass of, say, a pencil is going to disappear in a violent explosion (whose energy is probably something like the mass of the pencil multiplied by a famous number squared, since the energy of its gravitational field is negligible) and a black hole with the mass of a proton will disappear into a tiny shower of energetic particles quite faster than you can say "femtosecond".

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Boffin

intresting

I never thought the gravitational pull of a micro black hole would stabalize i presumed it would keep on pulling in matter till it then slowly dives into the depths of our atmosphere and then kills us all.

Even if it had the same mass as our moon woulndt it be reppeled via magnetic waves etc differently ???

maybe i should stfu

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Troll

Do not feed

O_o

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Munch

see title

was intentionally trolling then i read it again and thought wtf

Today is not my day !!!

good thing tommorow is saturday !

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Pirate

Not to mention

It would make it harder to see cursed pirates for what they really arrrrre.

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Pint

MOON SHRINKING FAST - WTF?

So the estimates put it that the radius has shrunk by ~100M in the last billion years. So you think that a rate of 0.005% every billion years is FAST?

Tell you what, why don't you lend me some money? A million quid should do. I'll pay you a HIGH interest rate of 0.005% every billion years.

Now, where is the nearest bar........

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Must have been Americans

Why did they bomb the moon in the first place?

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Black Helicopters

Nope, it was the evil Martians.

They heard that we were planning on using the moon as a launch pad to send people to Mars.

So they figured if they got rid of the moon that they would stop our invasion.

So they set up a small black hole that would slowly destroy the moon.

Them Martians are a patient breed and figure that they'll give us a fighting chance by making the decay slow.

Either that or they're really cruel bastids who wanted us to recognize our fate and watch us scramble and panic ...

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title

To force democracy on the ungrateful Clangers, of course.

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title? TITLE!

when we don't understand something, we bomb it. thats how we roll.

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Pint

There you are!

"when we don't understand something, we bomb it. thats how we roll."

I was wondering when an American would comment ;)

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@abremms

Thank you my new signature :)

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why bomb the moon?

It was a war that they were sure they could win. oh, the insanity of it all.

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The moon wasn't with us, so...

We heard there were some terrorists hiding there, and the moon failed repeatedly to respond to our requests for the terrorists' extradition. Thus, the moon was sponsoring terrorism and we had no choice but to take military action against it.

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It's not NASA

It's subsidence caused by the Clangers deep mine blue string operations.

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Pint

DANG!

Beat me to it!

Here's a pint, anyway!

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Black Helicopters

I knew it!

'has done so noticeably since the Apollo landers set down on it in the 1960s and 70s. '

..and I think you will find that the size of the average American has increased noticeably in the same period. Coincidence? I think not!

It should be clear to all now that what I have been saying for years is true- The Apollo 11 mission was actually an elaborate front which the Americans used to set up a cheese-mining operation on the dark side of the moon and they have been secretly extracting and consuming all that lovely pure lunar cheese for years now without sharing any with us. Bastards.

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Alert

They're onto us!

It's not our fault that we've been taking all the cheese! You Brits had your chance, but nooo, Wallace wasn't thinking large enough, and only brought back a basketful or two, if I recall.

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The mice did not pay their bills ...

to Slartibartfast & his mates, so they are gradually reclaiming what they built.

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No surprise.

It's no surprise that the moon is shrinking. Take a piece of cheese, and leave it out for a few days. It will end up noticably smaller. Since the moon is just a big piece of cheese, the same thing is happening to it.

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Boffin

Winking out?

Things only disappear smoothly into a black hole if they have no angular momentum. The moon is rotating about once a month so it would spin up into a very hot fiery disk well before it got down to pea size and we'd have a super-bright accretion disk thingy to look at in the sky and probably get fried by hard radiation.

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Good point

... and apart from that, none of the top boffins in the world think that the hardon collider could produce black holes and who do you is right... them or some armchair physicists?

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Joke

Its global warming

It is caused by global warming you fools!

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Happy

Rubbish....

It's the El Niño effect

(It's about time that one got an airing again)

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Go

Re: Its global warming #

Bah! Beat me to it!

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Clearly ...

Clearly, it's the acne creme God applied during creation 6,000 years ago starting to flake off, as any fule teenager knos ...

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Alien

Disclosure is coming...

They are here, Obama to announce one day.....

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Now it starts

Many of us warned what would happen when NASA attempted to blow up the moon. Fortunately they failed in bursting it immediately, but now, instead, we all get to watch as it slowly shrivels up, leaking out all the water inside bit by bit, causing floods across the world as it enters our atmosphere.

And what kind of nut job honestly believes that the hadron thing will make mini black holes?

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Volume of Water

I've done a small calculation to show how serious this is:

Volume of Moon = 21.9 billion cubic km.

Radius of Earth = 6400 km.

Volume of sphere = (4/3) Pi r^3

Assuming most of the Volume of the moon is water which will end up falling to Earth, the Volume of the Earth will increase by 21.9 billion cubic km which corresponds to an increase in radius of around 42 km.... or 138,000 feet.

We're doomed.

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Joke

TLDNR

maybe the camera just moved further away from the moon?

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Joke

The moon has mice!

It's been well established in nursery-science circles for some time that the moon is made of cheese and therefore one can conclude a mouse infestation is the probably cause of any shrinkage.

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Pint

Check the physics man

This is only true if a mouse is less dense than a piece of cheese, or the mice have some means of leaving the moon once they've had their fill.

More research needed before making unfounded claims!

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Joke

Hmmm...

Actually, the mice would be able leave the Moon, so to speak, after death. It goes like this: Mice eat the cheese and use it to produce muscle, bone, brains and more mice. When the mice dies, decay turns their bodies partly into gas. As Moon's gravity is not big enough to keep an atmosphere, said gas goes straight into space.

For those of you thinking that decay doesn't occur in vacuum, consider this: mice have to breathe somehow, and the only possible explanation is that the Moon is a giant PRESSURIZED cheese. Its inhabitants sometimes can´t cope with the stench -a mixture of really ancient cheese, mouse droppings and living and dead mice *- and open the airlocks to allow some of that smell to escape the Moon.

Finally, if some stubborn denialist argues that there wouldn't be any oxygen in the Moon, as there are no plants there to perform photosynthesis, the explanation is that the mice outsourced their oxygen production to China.

You're welcome! ^_^

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Boffin

More _useful_ as a black hole?

While based on an inadequate understanding of the slingshot effect, wouldn't the moon be a sight more useful for interplanetary travel as a black hole? If the accelerations/decelerations possible do increase the closer to a body's center of mass you can come then voilà we will have made the moon into a roundabout to the solar system!

All this discussion of what can we do with the moon (with being deficient in water, metals, beaches, etc.) is resolved. Make it near nothing and you've made it quite something!

The only problem I can see is that with such a small area for action and with the boost towards private space efforts, we're going to have to have a central body to do traffic control. Otherwise we'll have the entertainment of hobby airshows and planes colliding, with the added cute sparkly effects as pieces fall into the black hole.

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hmm dodgy

What if somebody takes the wrong exit and heads towards earth at a couple of thousand MPS

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There is a Tide

The idea of a black hole orbiting Earth as a moon reminded me of a short story by Larry Niven called "There is a Tide" which has a planet with this feature.

As for why the Moon is shrinking, it is obviously caused by collapse of the Selenite tunnels after they made too much Cavorite. :-)

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Headmaster

There is a tide?

That short story by Larry Niven was about a planet with a fragment of a neutron star orbiting it, not a black hole.

One of his other short stories "The Hole Man" was about a quantum black hole that fell into Mars and swallowed up the planet.

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'Geologically recent'

On the Moon, 'recent' means anything after the formation of the Mare (the dark areas seen from Earth) which ended around 1 billion years ago.

The Moon is still seismically active as there are regular moonquakes which come in a variety of flavours. There are deep quakes which can go down to about 700km which seem to be associated with lunar tides, then there are the very shallow weak thermal 'quakes which are kicked off when at lunar dawn when temperatures skyrocket and rocks expand. In between there are shallow 'quakes down to about 30km which are caused by crustal movements. These tend to be bigger - IIRC the biggest measured by Apollo sensors was Richter 5.something. So rocks are definitely moving - why, well that's an interesting question. But it is only creating a tiny fraction of the seismic activity found here on Earth.

There's also some suggestion of intermittent volcanic activity or outgassing. Astronomers regularly report seeing glowing patches of light around certain craters which go by the name of Transient Lunar Phenomena:

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

Finally there are similar scarps on Mercury known as rupes. The accepted explanation is that Maercury's surface cooled relatively quickly and became rigid before the underlying Mantle and Core solidified. As the Core and Mantle cooled and contracted, the crust buckled along the rupes.

Nice image here:

http://en.wikipedia.org/wiki/File:Rupes_discovery.jpg

The scarp is the dark line running almost vertically through the middle of the image cutting through the large crater. It's 2km high.

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Coat

Real question

"Based on the size of the scarps, we estimate the distance between the moon's center and its surface shrank by about 300 feet"

My question is, did the surface move, or did the center move. Think about it..

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Unhappy

Secret aim

Perhaps if some of you doubters saw the leaked documents proving that the primary goal of scientists at the Large Hardon Collider is to to produce a Large Black Hole you'd stop poo-pooing those of us trying to stop them.

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Grenade

@Anonymous Coward "Secret aim"

Please tell me you are taking the piss. BAWHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHA

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Black Helicopters

Taking the piss...?

You've clearly not seen the document then.

The whole *reason* for the large black hole is to take the piss. Think about it -- with a massive black hole above our heads, we won't even be able to urinate downwards. Our hydrogen and oxygen will be slowly stolen, one toilet break at a time, until we have NONE LEFT!!!

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