New kind of metal in the deep Earth(sciencedaily.com)
sciencedaily.com
New kind of metal in the deep Earth
http://www.sciencedaily.com/releases/2011/12/111219112216.htm
37 comments
We definitely have the science to describe this.
It just happens to be very complicated. You're right in that it's a mixture of E&M, thermodynamics, and fluid mechanics. Whether it becomes computationally prohibitive to model is something I am unsure of, but may be possible with some simplifying assumptions.
Edit: after a bit more research, I found a paper where, if I follow correctly, they are laying out a framework for creating such a model: http://arxiv.org/abs/1004.1611
It just happens to be very complicated. You're right in that it's a mixture of E&M, thermodynamics, and fluid mechanics. Whether it becomes computationally prohibitive to model is something I am unsure of, but may be possible with some simplifying assumptions.
Edit: after a bit more research, I found a paper where, if I follow correctly, they are laying out a framework for creating such a model: http://arxiv.org/abs/1004.1611
Compressible Magnetohydrodynamics is what you are looking for. A search will turn up lots of articles. http://en.wikipedia.org/wiki/Magnetohydrodynamics#Geophysics
Seriously? Except its not a plasma, its a fluid, and computational fluid dynamics (CFD) simulations don't include (at this stage) electromagnetic forces. Show me a paper that can describe a fluid in motion where the force on each element is computed as a function of the electromagnetic state, the thermal state, and the viscosity state of each other element and I'll show you a candidate for a Nobel prize.
At least in the open literature I haven't seen CFD models that consider the influence of elements beyond a few centimeters, the magnetic forces in the Earth's core move elements meters, if not kilometers, away so the date sets do get very strange, and you have to mix in that if they cool to much or you hit an eddy current and the pressure drops the current gets cut off and the electrodynamic forces stop.
At least in the open literature I haven't seen CFD models that consider the influence of elements beyond a few centimeters, the magnetic forces in the Earth's core move elements meters, if not kilometers, away so the date sets do get very strange, and you have to mix in that if they cool to much or you hit an eddy current and the pressure drops the current gets cut off and the electrodynamic forces stop.
So these are the guys to watch then?
http://www.youtube.com/watch?v=2dm4RvDSkUY
http://www.youtube.com/watch?v=2dm4RvDSkUY
If you can blend that with a CFD simulation and then add in the changes in conductivity as the material goes in an out of its conductive and non-conductive modes sure.
Its the latter bit that seems so mind bending to me. MHD simulations start with a plasma and it can be conducting throughout the simulation in all places.
CFD simulations deal with the forces between elements that express as viscosity, turbulent, and laminar flows.
MHD assumes that elements in the flow are always affected by the electro-magnetic forces in play, CFD doesn't account for electro-magnetic forces.
CFD assumes that the elements in the flow are only affected by the forces of nearby elements and not the actions or state of elements that are further away.
An FeO simulation has to combine them somehow, and account for whorls and eddies converting elements from the MHD domain into the CFD domain and then back again.
Anyway, I am looking forward to the papers on this stuff. It combines two areas I enjoy, complex systems and physics!
Its the latter bit that seems so mind bending to me. MHD simulations start with a plasma and it can be conducting throughout the simulation in all places.
CFD simulations deal with the forces between elements that express as viscosity, turbulent, and laminar flows.
MHD assumes that elements in the flow are always affected by the electro-magnetic forces in play, CFD doesn't account for electro-magnetic forces.
CFD assumes that the elements in the flow are only affected by the forces of nearby elements and not the actions or state of elements that are further away.
An FeO simulation has to combine them somehow, and account for whorls and eddies converting elements from the MHD domain into the CFD domain and then back again.
Anyway, I am looking forward to the papers on this stuff. It combines two areas I enjoy, complex systems and physics!
Magnetohydrodynamics (MHD) is the combination of Maxwell's Equations in a moving frame of reference and The Navier Stokes Equation. So it includes both the impact of inertial and electromagnetic forces of the flow. MHD is the long wavelength limit of kinetic (particle) plasma theory. The Earths core has in the past been modeled as an MHD fluid but it is usually assumed to be incompressible. I am not aware of compressible models but I have not worked in this field in a decade.
To save you reaching for gunits or doing any upsetting mental arithmetic, 4000°F == 2204°C, and 3000°F == 1649°C.
So... really hot.
On a related note, I was astonished how many different states water (H20) can be in.
Many more than just solid, liquid, gas.
.
See http://www.lsbu.ac.uk/water/phase.html
My ice goes up to ice-eleven (XI) ?
Many more than just solid, liquid, gas.
.
See http://www.lsbu.ac.uk/water/phase.html
My ice goes up to ice-eleven (XI) ?
Disappointed, thought we would be expanding the Periodic Table.
The periodic table is pretty much complete at this point, the super-heavy elements after about 112 are very unstable and are probably very rare in nature.
There are however even heavier elements that are hypothesised to be stable. In that sense, the periodic table is not complete.
The probability of them occurring naturally in cosmic-scale events is also extremely small. For all practical purposes, probably for at least a thousand year to come, these elements do not exist naturally.
probably very rare in nature.The probability of them occurring naturally in cosmic-scale events is also extremely small. For all practical purposes, probably for at least a thousand year to come, these elements do not exist naturally.
Any condition you can create in a lab probably exists somewhere in the universe. There's probably a planet of molten Californium somewhere out there being bombarded by Einsteinium asteroids.
That's only true under the assumption of an infinite universe, in which even an event of the smallest probability will take place. Let's stick to the observable universe: it won't happen there.
Eh, while the periodic table is not complete, Element UUUU will not be nearly as exciting as new properties for existing compounds.
Island of stability: http://en.wikipedia.org/wiki/Island_of_stability
It already got expanded a couple times this year.
Sounds like the kind of thing that would sent Tesla running back to his lab the moment he learned of it.
I wonder how the pressures were achieved. I remember a sciam article way back which discussed attempts to create metallic hydrogen in the lab using, in essence, g-clamps. (Only a tiny amount of substance could fit into the apparatus, of course. Still it was amazing that such a simple device could achieve the necessary pressure.)
Diamond anvil?
http://en.wikipedia.org/wiki/Diamond_anvil_cell
http://en.wikipedia.org/wiki/Diamond_anvil_cell
Yup, looks like the exact thing.
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Kind of makes you wonder why Mars doesn't have a magnetic field then?
Its composition is similar to Earth's, and I assume that it's big enough to have similar pressures and temperatures closer to the core?
Its composition is similar to Earth's, and I assume that it's big enough to have similar pressures and temperatures closer to the core?
Mars is about half the size of Earth, so it's possible that is too small to make enough of this conversion happen to generate a magnetic field. Also some theories of Mars formation would lead to a different composition of its core due to prior collision(s).
Do the electrons really get squeezed closer to their nuclei? I thought that only happened in massive collapsing stars where gravity overpowers everything.
There's a continuum. In the cores of stars that continuum bumps up against the physical limits of electron degenerate (white dwarf) matter. But even within ordinary planets like our own solid matter is compressed to a significant degree. For example, even though Earth's inner core is primarily comprised of Iron and Nickel it is compressed to such a degree that it is denser than Lead.
Disclaimer: I have no clue what I am talking about
What if gravity is an emergent result from the compression of matter? The greater the compression, the greater the density and gravity?
What if gravity is an emergent result from the compression of matter? The greater the compression, the greater the density and gravity?
"The greater the compression, the greater the density" is essentially tautological. Of course packing the same amount of stuff in a smaller space makes it more dense. It's true in the same way the statement "Enlarging things makes them bigger" is true.
But as for gravity, no. Gravity is a function of mass. Compressing a body into a smaller space will not increase the gravity you experience at a given distance from the mass's center of gravity (though it will allow you to get closer to the center of gravity). If you magically replaced the Sun with a black hole of equal mass, the planets would continue their orbits undisturbed — even though a black hole's singularity is infinitely dense and the Sun is less dense than the Earth on average.
But as for gravity, no. Gravity is a function of mass. Compressing a body into a smaller space will not increase the gravity you experience at a given distance from the mass's center of gravity (though it will allow you to get closer to the center of gravity). If you magically replaced the Sun with a black hole of equal mass, the planets would continue their orbits undisturbed — even though a black hole's singularity is infinitely dense and the Sun is less dense than the Earth on average.
Thanks for that reply!
The general theory of relativity does a really, really good job of describing gravity as a result of mass changing the shape of spacetime, and predicting its effects as a result of that. The strength of gravity only depends on the total mass, not its density, so I'd say that gravity is not an emergent phenomenon from the density of matter and energy.
(Mass is almost certainly caused by the interaction between some quantum particles and the Higgs field. I'm not clear on how that deforms spacetime, though.)
Edit: I should refresh the page before posting.
(Mass is almost certainly caused by the interaction between some quantum particles and the Higgs field. I'm not clear on how that deforms spacetime, though.)
Edit: I should refresh the page before posting.
The article begins with "in Earth's deep interior squeeze atoms and electrons so closely together that they interact very differently". The phrase is a little misleading.
The "position" of the inner electron orbitals is mostly determined by quantum rules (it is more complicated, but think that because of something like the Pauli Exclusion Principle the electrons can’t be very close together).
The conductivity of the material depends on the farther electrons, but it is not possible to bring them closer to the core because that space is "filled" with the inner orbitals. The farther orbitals of the atoms get mixed and are transformed into bands, which are not localized in an atom, but span all the crystal.
With more pressure, the nuclear cores get closer, but not very much. The main change is how the farther electron orbitals interact. So at some distance it is possible that some orbital get mixed and at other distance another orbital get mixed. So at some distance the bands are empty or full, and at another distance the bands are partially filled. And that changes the conductivity of the material.
So probabbly the correct way to begin the article is: "in Earth's deep interior squeeze atoms so closely together that their electrons (orbitals) interact very differently".
The "position" of the inner electron orbitals is mostly determined by quantum rules (it is more complicated, but think that because of something like the Pauli Exclusion Principle the electrons can’t be very close together).
The conductivity of the material depends on the farther electrons, but it is not possible to bring them closer to the core because that space is "filled" with the inner orbitals. The farther orbitals of the atoms get mixed and are transformed into bands, which are not localized in an atom, but span all the crystal.
With more pressure, the nuclear cores get closer, but not very much. The main change is how the farther electron orbitals interact. So at some distance it is possible that some orbital get mixed and at other distance another orbital get mixed. So at some distance the bands are empty or full, and at another distance the bands are partially filled. And that changes the conductivity of the material.
So probabbly the correct way to begin the article is: "in Earth's deep interior squeeze atoms so closely together that their electrons (orbitals) interact very differently".
Banish the thought, but for a moment, I thought of dwarves.
At 690,000 atmospheres, you can see this too!
Heavy.
Basically we don't have the science to describe the behavior of a planetary core made up of this type of material! Is that cool or what.