What’s at Earth’s core?
hideWhat’s at Earth’s core?: Revision 26
We know that at the center of the planet, about 4,000 miles down, sits a solid ball of iron the size of the moon.
We also know that we’re standing on about 1,800 miles of rock, which forms Earth’s crust and mantle. But what’s in between the mantle and the iron ball? A churning ocean of liquid of some sort, but scientists aren’t certain what it’s made of or how it reacts to the stuff around it.
We’re confident there’s a lot of iron in this ocean. But what else? Based on what researchers understand about the pressure, temperature, and density of materials down there, some maintain that the core also contains lots of hydrogen and sulfur. Raymond Jeanloz of UC Berkeley believes that another component is oxygen, which comes from rocks in the part of the mantle that borders the liquid core.
Knowing more about the molten concoction would give scientists clues about how Earth formed and how heat and convection affect plate tectonics. More information could help solve another mystery, too: whether, as many researchers suspect, the inner core is growing. If so, it could eventually overtake the molten metal surrounding it, throwing off Earth’s magnetic field.
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<<We know that at the center of the planet, about 4,000 miles down, sits a solid ball of iron the size of the moon.
No we don't. It is widely believed to be an iron-nickel alloy, and some theories even claim the possibility of it having the shape of a giant iron crystal.
contributed by on Jan 24 5:33am
I thought there was a giant Ant called Frederick, constantly peddling a tiny childs bicycle, feeding off the putrid droppings of the antelopes that live above.
contributed by on Jan 24 6:37am
I would guess that the most dense elements are at the core in relatively large quanties (such as Gold, Platinum,
and Uranium). Esp. Uranium since we know that most of the heat from the earth is at this time from radioactive
decay of isotopes. This would suggest that there are also the daughter products of these decays of (like radon and eventually lead 206).
Which one might think, these being less dense, would eventually setup convection currents in the inner most core as they try
to rise, being more buoyant.
contributed by on Jan 24 7:00am
Most of the heat is produced by the pressure, not by radioactive decay. Radioactive elements are very rare. The innermost core is solid, so no "convection currents" in there i'm afraid.
contributed by on Jan 24 7:14am
we don't know.
contributed by on Jan 24 7:30am
you don't : )
contributed by on Jan 24 7:42am
There is no center... The earth is a dinner plate supported on the back of a cosmic turtle.
What is the turtle standing on?
Well, sonny, it's tortoises all the way down.
contributed by on Jan 24 10:43am
radioactive elements are rare in all the places we can actualy go and study. so to say its impossible for there to be radioctive elements at the core would be like saying the big bang was blue colored. we've never been to the core, and its ipossible to see the big bang, so saying either would be arogant presumption.
nothing is ever proven, only disproven. and we havent disproven anything about the core save thats its hollow.
i would guestimate thats it is iron and some percentage of other dense elements(including uranium, you dont need much for it to effect the temparature.), oh and they are solid, but at the amount of pressure were talking about, iron would definatly act as liquid. so convection currents are a definate possibillty.
contributed by on Jan 24 10:48am
This is going to sound stupid but with the technology we have why don't we dig as far as we can to see whats actually there and what would happen if we dig all the way to the other side?
contributed by on Jan 24 1:16pm
this is the single most stupid thing i've ever seen! what is wired trying to do, reinvent wikipedia or howstuffworks.com?? or build a fan base which is doesn't have ??
contributed by on Jan 24 1:17pm
Sorry, we don't have the technology to dig that far down. Its almost 4 thousand miles to the center. And any equipment would melt once it hit the liquid mantle, and you wouldn't be able to push the liquid aside fast enough to dig anyways.
contributed by on Jan 24 1:22pm
We know that we do not know.
contributed by <span class="nlw_phrase"><a href="../../../wired-mag/index.cgi?guest_user">Guest User</a><!-- wiki: --></span> on <span class="nlw_phrase">Jan 24 1:42pm</span>
its not a nougaty centre? i'm so suing my alternative education school.
contributed by on Jan 24 6:35pm
Indeed, the earth has a thick, rich, chocolatey center. Number of bites it takes to reach it? Three.
contributed by on Jan 24 6:39pm
Note to Wired: It is not wise to allow the world to edit your wiki.
- Alex Zavatone
What's at the center of the earth? Hell is, according to this guy who's been there.
http://www.spiritlessons.com/Documents/BillWise_AllTracks.mp3
I would guess that the most dense elements are at the core ...
Is it really most dense at the centre of the earth? At the surface of the earth we experience all of the earths mass below us, but at the centre it would surround us resulting in zero gravity. So, if there's no gravity there then it's not going to be very dense is it? ;-)
Intersting to speculate what sort of relativistic effects one would see in a body almost as dense as a black hole: time slow on the outside but fast in the centre? (the stronger the grasvity the slower time)
contributed by on Jan 31 2:39pm
Yes, the gravity should balance out to zero somewhere in the center, but the pressure would not drop off to zero.
When at the center, the mass of the half planet to the left is pulling on the mass of the other half on the right,
in fact, every tiny bit of mass all around you is pulling on the rest, and you would be in the way.
Neutron stars are very dense, and some even could collapse into a black hole..
IE it's not Zero gravity, it's a whole lot of gravity all pulling in all directions so the net force due to gravity is zero.
There's no Zero gravity anywhere in the universe.
Cheers,
Gord Wait
contributed by on Jan 31 4:55pm
what we've been taught about the earth's core is at least partially wrong. someone made an educated guess sometime in the past and everyone agreed that it was right. doesn't necessarily mean that it is true.
I've got a better "guess" that the heat at the core (as well as our magnetic field) is generated by the tidal fluctuations between the core and our moon. the core (or at least some boundary layer) is molten and gets dragged around by the moons gravity (just like our tides on the surface). this generates heat as well as working as a dynamo generated an magnetic field. this would also explain why plate tectonics happen and the the continents haven't all been eroded into the oceans long ago.
just mine 2 cents worth.
-L
contributed by on Jan 31 11:44pm
NOUGAT!!!
contributed by on Feb 2 1:54pm
The earth's core is considered to be a nuclear fission reactor by Herndon and Hollenbach who have published a National Academy of Science paper on their work on this subject. See attached link. Forget the ball of iron. It is heavy enough.
contributed by on Mar 11 5:23pm
