The center of the earth (1 Viewer)

[David Von Pein]

I wonder if there's a Dunkin Donuts down there?

I just checked...No, no Dunkin'. :frowning:

But I did find a slew of McDonald's Hamburger Stands. (Only 4 Million Served to this point...curious.)

This now explains all those lawsuits regarding the hot coffee!

(Pat Boone and James Mason are stuck down there still, too. Can't find the danged elevator I guess.)

 

[NickSo]

From family guy:

Peter (as an ex-umpire now bartender at the center of the earth): Say! We don't get many of you molten-rock men in here...

Rock-man: Well, at these prices, I'm not surprised.

Peter: That's it buddy, YOU.....ARE....OUTTA HERE!

 

[BrianW]

But I tried to say that pressure or a radioactive process wasn't warming the earth up.

I stand corrected. Previous remarks had set a train of thought going in my head, and I read your response with the wrong context in mind. Consequently, I completely failed to recognize that you were actually answering the question.

 

[Clinton McClure]

I'm gonna hafta go with the salsa.

 

[Andrew Testa]

If you want a physics question answered, you need to ask a physicist. Don't rely on what you think you remember from that geology class you took 5 years ago.

Really, we're here to help.

The truth is that several factors are responsible for the core temperature. You can find many articles using Google. Here's one that answers the question right up front:
Earth's core temp

It's a combination of residual heat from accretion, friction from convection in the molten outer core, and decay from radioactive elements.

The residual heat from formation alone would cool relatively quickly, since the energy would be constantly radiated away with no mechanism to replenish it. The radioactive decay and friction are elements that ADD heat to the interior, keeping the temperature at it's current level. Both of these processes occur in the liquid outer core, not the solid inner core. Keep in mind that there is NO fission or fusion reaction occurring at the core. The right elements and pressures are not present. The heat comes from normal decay of radioisotopes, releasing heat and radiation. It's the same process used to power deep space probes in RTGs.

Tidal forces aren't a factor: they're too small relative to other forces near the core. Tidal forces are more an influence on surface conditions, such as heating and flexing the crust.

For BrianW, the magnetic field is a consequence of the rotation of the liquid outer core. When the liquid core cools and solidifies, the magnetic field will collapse. Here's a great article on simulations of the rotation and subsequent magnetic field generation, where the simulation spontaneously performed a magnetic field reversal:
geodynamo simulation

'Cause I like you folks, I'll answer physics questions in addition to space program questions at no extra charge.

Andy

 

[Jack Briggs]

So ... there are no dinosaurs at the core? I was just screening my copy of 20th Century Fox's Journey to the Center of the Earth two weekends ago. There were large lizards, gigantic mushrooms, glowing rocks that made gas lamps unnecessary, a huge ocean at the very center of the planet where pots and pans go flying ever which way. And, best of all, there was a volcano-assisted express elevator back to the surface, so that James Mason and Pat Boone could return to a heroes' welcome.

How disappointing none of that is true.

 

[Andrew Testa]

How disappointing none of that is true.

Don't be too sure:

Crackpots abound!

With a little knowledge of math and a head full of voices, you can prove anything!

Andy

 

[Jack Briggs]

We agree.

 

[Hunter P]

This is a trick question. Everybody knows that the Earth is Flat.

 

[MarkHastings]

g0= (g0'e3/(4sqr(a)e03/2melmpr2))2/3 = (e3/(4sqr(a)e03/2melmpr2))2/3*(exp(1/a))-2/3, (16)
ga = (ga'e3/(4sqr(a)e03/2melmpr2))2/3 = (e3/(4sqr(a)e03/2melmpr2))2/3*(exp(a+1/a))-2/3, (17)
g = g0/ga = (exp(a+1/a))-2/3/ (exp(1/a))-2/3 = 1/exp(2a/3) = 0.995146913, (18)

Ahh yes! It all now makes complete sense!

And may I add, Eep Opp Ork Ahh hah!

 

[Jack Briggs]

Gort, Klaatu barada nikto.

 

[RobertR]

Gort, Klaatu barada nikto

If you do not speak English, I am at your disposal with 187 other languages along with their various dialects and subtongues.

 

[BrianW]

the magnetic field is a consequence of the rotation of the liquid outer core. When the liquid core cools and solidifies, the magnetic field will collapse.

Thanks, Andrew. That makes me feel better. I recently took an online science test, and the ONLY question I missed was, True or False: The Earth's magnetic field is a consequence of the rotation of the liquid core." I answered that it was true, even though it implied that the entire core is liquid.

When I checked my answers, it said that the answer to this question was FALSE. It went on to explain that it's a common myth that the magnetic field is caused by rotation of the liquid outer core, when in fact it's the other way around. It didn't bother to mention what actually causes the magnetic field, but it did say that it would be around long after the core cools and becomes rock solid.

This seemed like utter nonsense to me, so your corroboration of what I thought I knew is quite welcome.

When the outer core solidifies and stops moving, and the magnetic field collapses, what will be the consequences regarding the Earth's habitability? Don't forget how the Earth's magnetic field sheilds all but the upper- and lower-most latitudes from the solar wind. Will we be able to see the Northern lights from the equator? Will our communications satellites need to be beefed up in order to survive the extra dose of radiation? Will there be any significant climate change?

 

[Rob Gardiner]

Andrew, maybe you can answer this for me. How many licks does it take to get to the center of a TOOTSIE POP?

 

[nolesrule]

Andrew, maybe you can answer this for me. How many licks does it take to get to the center of a TOOTSIE POP?

Everyone knows the answer is 3. That's what the owl said, and the owl is wise.

 

[Cees Alons]

Thanks Andrew. Knowledge updated again.

About the solidifation of the liquid core and the consequences on the Earth as we know it: it's hardly believable that something like that happens, independently so to say, while the rest of the earth-cum-climate-cum-inhabitants-cum-communication-satellites go on like "minding their own business". Even if there wasn't a direct effect, what's the timespan we would be talking about? What would cause it? Beefing up the satellites might be the very least of 'our' problems.

Cees

 

[Todd Hochard]

The radioactive decay and friction are elements that ADD heat to the interior, keeping the temperature at it's current level. Both of these processes occur in the liquid outer core, not the solid inner core. Keep in mind that there is NO fission or fusion reaction occurring at the core.

So you believe the article to be bunk? Pressure isn't really one of the requirements for fission.

The whole friction/radioactive decay thing doesn't seem right to me. The whole heat balance aspect of it doesn't quite work in my mind, considering the length of time that has passed. And, given that one of the more plentiful radioisotopes is bound to be U-238, it's half gone by now.

The fission aspect was something that popped into my head years ago when reading something else, and then when this article came along, it piqued my interest (it was in Discover last year). I split my last atom more than 10 years ago, and most of my math skills went with it, so I'm not sure I'm up to the task of figuring it out now (without some refreshers, that is). But, considering Google, a lot more info is available that I didn't have back then (late '80s when I was trying to figure it out).

I'm re-reading the article now.

Todd

 

[Andrew Testa]

CRAP! DOUBLE CRAP!

I spent over 30 minutes crafting an explanation and answers to your very thoughtful questions when IE crashed. When, oh when will I learn to compose in wordpad and paste? When?

I'm too overcome right now. I'll try again later.

Andy

 

[Andrew Testa]

Andrew, maybe you can answer this for me. How many licks does it take to get to the center of a TOOTSIE POP?

Of course Joe is correct, but the REAL question is what's the temperature at the center of the tootsie pop. eh?

Andy

 

[Cees Alons]

.... and how large is the tongue.

Cees