Can someone explain to me (earth's core)

need assistance

Can someone explain to me why if the core of the earth is at an extremely high temperature why the heat hasn't radiated out from the core to the surface of the earth and resulted in a fairly uniformal temperature throughout the earth. As I underdtand it there is no energy being created at the centre of the earth so given the age of the earth one would have expected the heat to become more uniformally distributed by conduction?

Spear

need assistance wrote: »

As I underdtand it there is no energy being created at the centre of the earth so given the age of the earth one would have expected the heat to become more uniformally distributed by conduction?

There is heat being released by radioactive decay.

Gurgle

need assistance wrote: »

Can someone explain to me why if the core of the earth is at an extremely high temperature why the heat hasn't radiated out from the core to the surface of the earth and resulted in a fairly uniformal temperature throughout the earth. As I underdtand it there is no energy being created at the centre of the earth so given the age of the earth one would have expected the heat to become more uniformally distributed by conduction?

The earth's crust is a very thick and effective insulator. The core is slowly cooling, with heat being lost to the surface through hot springs, volcanic eruptions etc, but there is more or less no conduction through the crust.

ian_m

I believe it may be due to resistance.

onechewy

Well, without the heat of the sun, surely the surface temp of the whole of the earth be uniform - relative to the thickness of the crust.

Say, if the sun didn't provide us with heat, any two points on the earth where the earths crust is the same, would have the same surface temp?

intrigued

well the primary source of heat in the earths core is the radioactive decay of uranium and radium.I would guess that the reason why the crust is not heated by the core is due to discontinuities(different mediums,= of different densities within the earth), the outer core may act as an insulator too. Then again what about geothermal heat?

ApeXaviour

intrigued wrote: »

Then again what about geothermal heat?

That's convected

intrigued

ha ha yeah i only thought about that afted i put up the reply maybe the cores heat is what makes convection currents or else their is a whole other heat source in the mantle

12barblues

I'm dragging this thread up, but i've been thinking about this recently and searched on the science forum on here and found this so here goes:

The core of the earth is extremely hot. As hot as the surface of the sun according to some articles I've seen. How is this? the two main the arguments seem to be:

heat left over from the formation of the planet
radioactive decay of certain elements in the outer layers of the core (the innermost layer of which is assumed to be molten Iron)

Well, here's the reason I'm posting. I read somewhere that it's entirely possible that the core of the earth is, in fact, a nuclear fission reactor. this explains a few things:

1) the heat
2) the source of the earths magnetic field (if i get any replies to this I'll post up some links to some articles). the current argument is based on convection currents in the molten metal, but there's a good argument against this. (more later)

it seems very possible to me that this is the case, evidence of nautral fission reactors have been found on earth before in Oklo in Gabon,

wadda you think?

fox65

Could you post up the articles, i'd love to read them

12barblues

here's a few to start:

http://geology.about.com/od/wildgeotheories/a/nuclearcore.htm
http://www.pnas.org/content/98/20/11085.full
http://www.nuclearplanet.com/Herndon's%20Nuclear%20Georeactor.html

look up oklo aswell. the whole thing really makes sense. the second nuclear bomb the dropped on japan used an explosive charge to compress a subcritical pile of atoms into a critical pile. if there's fissile material at the core of the earth, then with the pressures down there.....

krd

Another cause of the heat in the earth's core is friction caused by earth's orbit of the sun. The tilting and spinning puts energy in the core.

I think the only way of telling if a planet has a molten core is by setting off an explosion on it's surface and then measuring the echos.

ch750536

^this. There are a number of sources of heat in the core, they all play a part. Look at IO for reference on how much heat can be indirectly caused by gravity.

FISMA

need assistance wrote: »

Can someone explain to me why if the core of the earth is at an extremely high temperature why the heat hasn't radiated out ...

It took science a while to figure out what heat was.

For a while, we believed that heat was a material that flowed mechanically from hot to cold. This material was believed to be a fluid and was called the Caloric.

Later on we discovered heat to be immaterial. Heat is just energy in motion.

Heat flows slowwwwwwwly. Hence, it takes a while to get from the inside out.