[SFMA (OP)]

The difficulties in determining the Centre of the Earth arise due to many reasons. One is that the earth is not static in the sense that it’s rotating around it's own axis. One particular place cannot be the centre while it’s moving unless it’s movement is followed by it’s surroundings. Then the centre would be the static point of attraction for it’s surroundings although it might be in motion too. 

This static centre of the attraction or the centre of gravity around which the earth is moving could be the innermost base of the earth. The earth as a whole and its every particle has at least a common thing to this centre. Thus if we extend towards its surface we can reach the whole circulating earth.

But the question is if we do the same inward what would we find the very last thing remaining at its innermost static centre? What ever it may be this would be the centre of the earth! Most common, most concentrated matter of all! It comes first encompass the whole thing and the last to remain. This could only be the water!

Water is in the bottom of things is at the Centre of the Earth!

[Bored chemist]

Abject nonsense.

[lyner]

SFMA are you saying that the centre of mass is the point to which everything is attracted?

[SFMA (OP)]

SFMA are you saying that the centre of mass is the point to which everything is attracted?

To explain the anisotropic speed of sound in the inner core or at the centre of the earth, some researchers had proposed that the inner core was, in fact, a single giant crystal with the hexagonal structure. The hexagonal structure is justified because experiments and calculations have revealed it to be the stable structure adopted by iron under high pressure and temperature.

My propositon is at the very inmost of the inner core, the last thing at the very bottom is water.

[lyner]

Why water?
What's the reason for a molecular compound even existing at such extreme temperature and pressure?
Why not Iron or even Pot Noodles, if the fancy takes you?

[Bored chemist]

SFMA,
There is, as you note, quite a lot of water on the earth's surface.
That's because the rocks sank.
If there were water at the bottome it would get forced out of the way to let the rocks sink a bit more.

[lyner]

You're trying to reason with them again, BC.
You never learn!

[SFMA (OP)]

Why water?

Of the four basic elements Earth, Water, Air and Fire only the water
is dependent from the others. Earth can't survive without water, air
has water elements and fire can't survive without the air. Alchemists
even calim that water is the essence of fire.

It's quite natural that's in the perpetual centre would be dependent from others. The rest would be dependent on it that is normal.

[BenV]

Why water?

Of the four basic elements Earth, Water, Air and Fire only the water
is dependent from the others. Earth can't survive without water, air
has water elements and fire can't survive without the air. Alchemists
even calim that water is the essence of fire.

It's quite natural that's in the perpetual centre would be dependent from others. The rest would be dependent on it that is normal.

But this is a science forum, so we don't think of "the four basic elements" and certainly wouldn't give two hoots about what alchemists have to say.

[Madidus_Scientia]

The hexagonal structure is justified because experiments and calculations have revealed it to be the stable structure adopted by iron under high pressure and temperature.

My propositon is at the very inmost of the inner core, the last thing at the very bottom is water.

And how is your proposition justified? by experiments and calculations?

[Andrew K Fletcher]

Compress water enough and you get Hot Ice, so water cannot exist at high pressure. The pressure at the core is capable of much more than hot ice.

[lyner]

The only hot ice I know of is a supersaturated solution which crystalises very fast (Utube is full of it). Is that what you mean?

[Andrew K Fletcher]

No I mean the compressed water experiment that generates hot ice instantly. Even at relatively low pressure compared to the anticipated pressure at the core which would be several million atmospheres in order to contain the thermal nuclear energy without it ripping our planet to bits. So expecting water to exist there as we know it may not be a logical conclusion.

By passing the 20 million amperes of current through a small aluminum chamber, a magnetic field is created that isentropically compresses aluminum plates that sandwich a thin (25 micron) layer of water to pressures ranging from 50,000 to 120,000 atmospheres. For reference, what you experience at sea level is one atmosphere of pressure. What the researchers found was at these incredibly high pressures, water was squeezed into ice—ice VII to be exact, which was subsequently hotter than the boiling point of water at atmospheric pressure. As described by Sandia researcher Daniel Dolan, "Apparently it's virtually impossible to keep water from freezing at pressures beyond 70,000 atmospheres." Maybe that's a bit of an understatement, but it is very important to know for future operation of the Z machine and similar devices.  The physical properties of ice—any ice phase—are vastly different from their liquid counter part.
http://arstechnica.com/journals/science.ars/2007/03/18/turing-water-into-very-hot-ice-very-very-quickly

[lyner]

Oh, that Hot Ice - just looked it up.
At those temperatures and pressures, surely every other substance would behave differently too. The notion of normal chemical bonds must surely not hold, in any case so how could (and why would you want to think it could) water be down there. On a simple density argument, the heavier elements would be expected to dominate down there. 
What is the attraction of the idea of having water down there, in any case? You seem to be implying almost mystical significance to it. Is there any evidence for it?
I know they have some fairly good reasons for the present model of the interior of the Earth, based on Seismographic recordings but I didn't think it included any necessity for water to be present to account for the behaviour of seismic waves - or the magnetic field - or the rate of cooling.

[Bored chemist]

Earlier today a colleague of mine was bemoaning the fact that the word "quintessentially" was grossly overused. I asked why the other 4 essences (or elements) didn't get the same attention.
I'm now happy to say that this story of the 4 elements is quintessentially nonsense.

(Sophie, is that far enough from reasoning?)

[Andrew K Fletcher]

The idea of water at the core has not been shown to have merrit. And should water ever reach the core in sufficient quantity it would cause a spectacular eruption. Take an experiment we did as kids while messing around with molten lead. “Definitely not to be tried at home! The molten lead was poured onto a tray that had a few drops of water on it. The lead exploded spraying everyone. There was a loud whoosh as the Lead could not exist in its molten state next to the water and the Lead really went awol.

However, the same molten lead was poured into a large tank of cold water with no problems and this purified the lead taking out all of the oxidised metal and leaving shiny lead. This fits with lava flowing into the ocean and solidifying and also fits with explosions observed when the ratio of lava to water increases as water evaporates from the lakes found in inactive volcano

So even if water could withstand the pressure down there which it can’t. It would cause a huge explosion because its atomic energy would be liberated.

Eruptions into crater lakes can be entirely benign or extremely violent. In 1971-72, slow extrusion of lava onto the floor of a crater lake at La Soufriere Volcano, on the Caribbean island of St. Vincent, heated and eventually evaporated 75 percent of the water, with no harm to anyone. Then, in 1979, rapidly rising magma mixed with some of the remaining lake water, resulting in strong explosions and eruption columns 18 km (11 miles) high. Magma rising rapidly into any crater lake can lead to such explosions; a fissure opening across the floor of Green Lake could do it.
http://hvo.wr.usgs.gov/volcanowatch/1998/98_11_05.html

[SFMA (OP)]

The idea of water at the core has not been shown to have merrit. And should water ever reach the core in sufficient quantity it would cause a spectacular eruption.

"We also note that The Earth’s core does not contains pure iron, but contains light impurities (carbon, oxygen, silicon or sulphur) at a total concentration of up to 10%." The full article
appeared on Nature
http://www.google.co.uk/imgres?imgurl=http://chianti.geol.ucl.ac.uk/~dario/earthfg.gif&imgrefurl=http://chianti.geol.ucl.ac.uk/~dario/resint.htm&h=536&w=600&sz=26&tbnid=-UwkRLOSS3IJ:&tbnh=121&tbnw=135&prev=/images%3Fq%3DEarth%2B%2Bcore&hl=en&sa=X&oi=image_result&resnum=1&ct=image&cd=3

[SFMA (OP)]

CNN - July 1996

Deep inside the Earth, spinning in a watery pool of iron, the Earth's core is a giant iron crystal slightly smaller but more dense than the moon. Beyond that, the substance at the heart of our planet always has been a mystery.

[Bored chemist]

"It would cause a huge explosion because its atomic energy would be liberated."
No it wouldn't.

Quoting CNN as the source of all truth generally gets you laughed at, but to do so where it plainly proves you are wrong (please note iron isn't the same as water) is even funnier.
Thanks for that, I needed a good giggle.

[Andrew K Fletcher]

Well youve got me there BC because I dont have £ billions of diposable income to go test this to prove it.