why is the earth hot inside?

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Why is the earth's core hot and not just cold hard rock? how is the heat generated? could it run out? what would happen if it cooled?

[MelchyBeau]

heat leftover from the formation of earth as well as radioactive decay.

No more volcanoes for one. I imagine that life in the deepest depths of the ocean would have face major difficulty in surviving. there are plumes of sulfer that heat the area down there and allow life to live at those depths

Melch

[Deamon2]

first OT post!

I think the implications of the earth's core cooling are more insteresting than the reasons why it is hot...

since life at the bottom of the ocean would die, I suspect that life eventually would end on the surface as well. This is because it would disrupt the decomposition of dead organisms (dead fish, ect). The energy stored in those organisms would not be put back into the ecosystem. It would act like a hole in a bucket. Even though you are filling it up (plants storing energy through photosynthesis),the bucket still slowly empties, and life on earth would eventually end.

[Zeno]

The earth's interior is made of layers and the center of the earth (inner core) is probably solid with a shell (outer core) of molten material surrounding the solid core. It is this outer core that produces the earth's magnetic field, which has changed polarization numerous times (magnetic reversals) thoughout earth's history. Here is a fairly good link Earth's Core

-Zeno

[coolhandluke]

bad things man, bad things.

No more magnetic fields,

which would not only be annoying to boy scouts who's compasses no longer work, but everyone else when the solar energy it deflects is let in, and skin cancer rates sky rocket, as well as temp.

[imported_anacardo]

Is none of this just a simple function of pressure?

High pressure = high temp, no?

[tek]

This reminds me of how the gum with the liquid center is made. They put powder in the center and the pressure turns it into liquid.

[CCass]

Have you ever seen the movie The Core? One of Hillary Swanks best performances.

[Beerfund]

[ QUOTE ]
what would happen if it cooled?


[/ QUOTE ]

Doesn't look good

It happened on Mars. It happened on the Moon. And now, billions of years later, it looks like our world is on death row, too. Earth should be the next planet to experience freezing of its core -- turning our world into an empty, lifeless chunk of rock, quite much like Mars.


It’s a nasty way to go, really. Imagine the land under your feet suddenly wasn’t there anymore. Imagine sticking your head into a microwave oven. Imagine all air is no longer there. Now, imagine all these things combined. I think we can agree on one thing: you would die.

Still, this unpleasant triple whammy is coming our way. A few billions of years more, and the disaster should kick in. We would drown, then die of radiation, and finally choke to death. That’s what happens, when the center of the Earth freezes.

As you may know, our planet is filled with super hot fluid, much like a Belgian chocolate. When volcanoes erupt, they spew out the liquid -- it’s magma. Even deeper in the Earth’s core, there should be a massive, searing ocean of molten metal sloshing about. The core of the Earth is made of liquid iron, peppered with liquid nickel.

Now really, we at Exit Mundi don’t like volcanoes and earthquakes and all that any more than you do. But still, you’re one lucky bastard to have all of this molten stuff under your feet. For without the molten stuff, we would have had no land! The magma constantly replenishes the land: it boils up in the Atlantic ocean, freezes and thus constantly adds rock and soil to our world. Just think of it: every mountain you see, every piece of stone you pick up: it was all once liquid magma!

But there’s trouble ahead. Very slowly, the Earth is cooling down from outside in, much like an oven dish placed in a fridge. The Earth is freezing. In the end, the Earth’s core will no longer be liquid, but solid. Our planet’s restless bowels will calm down -- forever.


The Core, before and after

The first thing you would notice is less volcanoes, and less earthquakes. Hey, that’s fun -- but it’s just the beginning. Slowly, wind and rain will begin to erode the Earth away. Very gradually, mountains will shrink. Grain by grain, they will crumble down, and get washed away by rain and rivers, into the sea. It will take hundreds of millions of years, that’s the good news. But the bad news is that in the end, there will be no more land left! It’s a bit strange to imagine, but when you level out all the land evenly across the globe, and smear it out onto the bottom of the sea, you would find nothing will be stick out of the water. No continents, no rocks, no islands, not even a sand bank. All that will be gone forever.

So okay, you decide to live on some kind of ship from now on -- with many millions of years ahead, there’s plenty of time to build some sort of Ark. But wait. Next thing you know, the deeper, liquid metal core starts to freeze up, too. And that means the Earth’s magnetic field will weaken -- and go out. Forever.

Now that really brings out the beast. As we explained elsewhere on this site, no magnetic field means: no protection against space radiation. We will have more cancers, and more blackouts. But that’s not the big issue. The worst part is, our atmosphere will begin to vanish. Very slowly, molecule by molecule, the stuff we call air will be lost in space.

It’s the solar wind doing this, my friends. Without magnetic field, the stream of particles coming from the sun can quietly eat away the atmosphere. The atmosphere will literally be blown away, direction deep space!

According to some researchers, exactly this is what happened on Mars a few billions of years ago. Mars is much smaller than our planet, and accordingly, it froze up sooner. Scientists believe this is what killed Mars. With it’s magnetic field down, the Sun could blow away Mars’ early atmosphere. After a few hundreds of millions of years, it was gone.


Can "The Core" really happen?

In the Hollywood movie "The Core" (2003), the Earth’s core suddenly becomes ‘deactivated’ -- for reasons that remain unclear throughout the movie.
It’s a bad movie, and so is the science behind it. There’s just no way the huge, soaring sea of molten metal below our feet can suddenly ‘stop’. The core is bigger than the planet Mars! Really, there’s no stopping it. What’s more, ‘reactivating’ the core with a nuke is total nonsense, too. It’s the kind of stuff that only happens in movies -- not on the real planet. "Monumentally dumb" -- that’s what The New York Times called it.



Hey, but Mars has this other thingie too: it has no liquid water. Well -- the same lies in store for our planet. With no atmosphere, there is no air pressure to hold down the water. All water would simply vanish into thin air -- literally.

So just imagine it: you’re sitting in your Ark, wearing a space suit -- when suddenly, ahoy, land in sight! But pretty soon after that, you’ll find that land is about the only thing left. Oceans become lakes, and lakes become ponds. And in the end, the ponds will evaporate too. Oh, now that’s cool -- now you’re without water, too.

We’ll find ourselves on a kind of Mars the Second: a lifeless, airless, waterless, dead world -- with only some gullies and dried-up river beds remembering of its more lively past.

If that doesn’t depress you, there’s this: the freezing of the core seems quite inevitable. It isn’t some speculative, weird phenomenon -- most experts agree the freeze-up is indeed going to happen one day.

[PairTheBoard]

Beerfund --
"If that doesn’t depress you, there’s this: the freezing of the core seems quite inevitable. It isn’t some speculative, weird phenomenon -- most experts agree the freeze-up is indeed going to happen one day."


I think you must be right. I just felt a shiver down my spine.


PairTheBoard