[meteorite-list] Molten Core? Solid Core? Rocky Core? Blue Cheese!?

From: Richard Kowalski <damoclid_at_meteoritecentral.com>
Date: Tue, 29 Dec 2009 22:55:13 -0800 (PST)
Message-ID: <518224.87602.qm_at_web113612.mail.gq1.yahoo.com>

Don't equate "freezing" with cold, at least not in everyday terms.

At the Inner Core, the Iron is freezing; going from a liquid to a solid. The same amount of energy to melt something is the exact same amount of energy that something gives off as it freezes. The change of state is key here.

It isn't obvious, but on a human scale, farmers in warmer climes will spray water on their crops on nights when there will be a hard freeze. The reason for this is two-fold. One, the ice insulates the fruit, but two, the act of the water freezing gives off heat.

--
Richard Kowalski
http://fullmoonphotography.net
IMCA #1081
--- On Tue, 12/29/09, Meteorites USA <eric at meteoritesusa.com> wrote:
> From: Meteorites USA <eric at meteoritesusa.com>
> Subject: Re: [meteorite-list] Molten Core? Solid Core? Rocky Core? Blue Cheese!?
> To: "Richard Kowalski" <damoclid at yahoo.com>
> Cc: meteorite-list at meteoritecentral.com
> Date: Tuesday, December 29, 2009, 10:48 PM
> 
> 
> 
> 
>   
> 
>  
> Thanks and that makes perfect sense. Thank goodness for the
> Wiki...
> 
> 
> 
> So why is the core supposedly "freezing" cold
> "...The current
> scientific explanation for the Earth's temperature
> gradient
> is a combination of the heat left over from the
> planet's initial
> formation, the decay of radioactive elements, and the
> freezing of the
> inner core..." And how do we know this?
> 
> 
> 
> Regards,
> 
> Eric
> 
> 
> 
> 
> 
> 
> 
> On 12/29/2009 8:09 PM, Richard Kowalski wrote:
> 
>   Solid Iron Inner Core. Liquid Iron Outer Core.
> 
> Wiki is a good read.
> 
> http://en.wikipedia.org/wiki/Structure_of_the_Earth
> 
> 
> --
> Richard Kowalski
> http://fullmoonphotography.net
> IMCA #1081
> 
> 
> --- On Tue, 12/29/09, Meteorites USA <eric at meteoritesusa.com>
> wrote:
> 
>   
>   
>     From: Meteorites USA <eric at meteoritesusa.com>
> Subject: [meteorite-list] Molten Core? Solid Core? Rocky
> Core? Blue Cheese!?
> To: meteorite-list at meteoritecentral.com
> Date: Tuesday, December 29, 2009, 9:02 PM
> OK,
> 
> A friend and I were watching a show on Discovery or NatGeo
> a couple months back. The program I think was about
> asteroids, and impacts, perhaps even "How the Earth
> Was
> Made" or another program. Don't really
> remember....
> 
> The point is during the show they said very
> matter-of-factly on three separate occasions that the
> Earth's core was made of three different materials. One
> scientist (or narrator I don't remember)? said
> Earth
> had a rocky core. Which we laughed at of course because we
> all know that the Earth's core is Solid iron right?
> Then
> another scientist confirmed our knowledge and stated what
> we
> already knew. The Earth core is made of SOLID iron.
> "Of
> course we said!" Now that's right... Then not 10
> minutes
> more into the show another person stated that the Earth had
> a molten iron core.
> 
> To make matters even more confusing the show went on to say
> that the SOLID iron core was surrounded by molten iron with
> lighter "rocky" materials "floating"
> out beyond that OK...
> sounded good at the time, but....
> 
> My question is simple. Which is it? Molten? Solid Iron? or
> Solid iron surrounded by molten iron. And if it's the
> latter
> how is this possible? Wouldn't the solid iron core NOT
> be
> solid if it were sitting in the middle of a molten lake of
> iron? Does the core cool faster than the surrounding
> material, and if so how is this possible considering this
> the logic that says an object cools from the outside in.
> 
> Now, I'd like to stop there but I just read an
> interesting
> article on National Geographic's website titled
> "North
> Magnetic Pole Moving East Due to Core Flux" here:
> http://news.nationalgeographic.com/news/2009/12/091224-north-pole-magnetic-russia-earth-core.html
> 
> At the end of the article it flatly states:
> 
> "...Wandering Pole -
> 
> Geologists think Earth has a magnetic field because the
> core is made up of a solid iron center surrounded by
> rapidly
> spinning liquid metal. This creates a "dynamo"
> that drives
> our magnetic field.
> 
> Scientists had long suspected that, since the molten core
> is constantly moving, changes in its magnetism might be
> affecting the surface location of magnetic north...."
> 
> I don't know about you, but this confuses me just a
> little
> bit...
> 
> Can anyone please clear this up for me? And perhaps the
> rest of the world? ;)
> 
> Regards,
> Eric Wichman
> Meteorites USA
> 
> 
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Received on Wed 30 Dec 2009 01:55:13 AM PST