why is the earth's core still molten?
84285
Of course, the inner core is solid. It is the outer core that is fluid. \n\nNo one really knows what is producing heat in the inner core, and in what proportions:\n\n1. radioactive decay\n2. tidal forces heating, due to gravity gradient of moon, sun etc graviational field \n3. exothermic reactions\n4. gravitational energy release as denser materials settle down into the middle\n5. insulation (some of the heat is still primoridial)\n6. frictional forces from movement of materials in the earth\n\nand so on. This is obviously a fairly complicated nonlinear system, and we do not understand all the physics involved.
49283
The heat is radiated from the core of the Earth - from the heat buildup from when the Earth was forming - the conversion of gravitational energy to heat.  It is cooler now than when the planets were forming, but it's still pretty dang hot at the core, and that's the heat that warms up the asthenosphere.
1150478
It's widely believed in the scientific community that the earth has a liquid mantle (that's where magma/lava comes from) and a solid super-hot iron core.  Good luck digging through that.
566231
It is mainly from residual heat from when the earth first formed & the breakdown of radioactive elements w/in the earth. Pressure from the overlying material can also create heat.\n\nThe earth is actually cooling but it will take a very long time for it to "completely" cool.
231903
In general, I agree with nacho track. There is more to it though. There is a huge mass of material in the core of the earth. A small portion of that is undergoing radioactive decay and creates heat which has to go to a colder place, as heat moves from places of greater heat to those of lesser heat as part of entropy,such as the surface of the earth. The magmas are heated by this decay and as they work their way to the surface of the earth, the pressure of rock and soil over them is lessened and the magma goes from a slightly plastic material to more or less a liquid.\n\nThe plates that underlie the crust of the earth are kept in motion because the heats does not escape evenly. There are places where continental plates are thicker and places where they are thinner.\n\nIf you ever made fudge candy, you will have observed pieces of crustier materials floating on a bed of liquid. They do move and create fissures and breaks and move slowly. Of course, if you are a good candy maker, you will stir the pot and spread the heat around so that the entire batch has reached the same degree of cooking. Earth is not stirred but just sits there like a big pot of fudge.
553094
I would believe that analogy to be inaccurate.  The inner core is more of a very dense, solid mass of mostly iron and with its spin, among other things, gives our Earth its magnetic field.  The outer core, while quite hot, I would not call it a ball of fire.  It is more in the state of fluid, plastic like state which churns and, and at its boundary, mixes with the mantle to some degree.  Our planets core is dense and hot, but not a ball of fire.
1122546
No, for two reasons.\n\nFirst, the centre of the Earth is under two much pressure and too hot.\n\nSecond, diamonds are made of carbon, which doesn't exist in the centre of the earth. The centre of the earth is solid nickel and iron.
710689
It does not help.  It is the LACK of sufficient conduction in the mantle that forces the core to get rid of its heat by mantle convection instead.  If the mantle conducted better, it wouldn't need to convect, and then there would be no plate tectonic movement at all.
1010692
ok first of all just because one thing the bible says is true,that wouldnt make the entire thing true and second of all,originally the Earth was a ball of molten rock that cooled down.water didnt come around till later(im not sure how though)
792355
The nature of Earth's core is known from several types of evidence.  First, we know the mass of the Earth from applying the laws of gravity to orbital information about the Moon.  The enables scientists to calculate information about the density of the portions of the Earth that are deeper than the locations from which any samples have been obtained.  This lets the scientists make deductions about what substances are present in the core.  Secondly, the Earth's magnetic field tells us that a conductor is moving inside the Earth.  This is the solid iron core, surrounded by molten iron.  Additional information about this structure is gained through seismic analysis.
169563
The earth's magnetic field is generated by the molten core deep inside the planet.  The magnetic North pole is positioend in the North of Canada (Churchill Bay) I believe, and this is due to an iron rich element of the magma core being near the surface.  \n\nThe magnetic North Pole is moving, and there is eveidence to show that this is quite normal over time, and that at points in history the poles have reversed.
934445
A molten core of super heated metal (believed to be Iron and Nickel) is spinning at the center of the earth faster than the exterior of the earth is rotating.\n\nCharged Particles create a magnetic field when they move.
59074
Radioactivity deep within the earth provides a constant supply of heat that prevents the earth from cooling.  The heat given up by radioactive decay within the mantle is trapped and helps keep the mantle hot or even molten.  Although this contributes to volcanoes and earthquakes, it also helps recycle the earth's crust.  For example, it is believed that the earth at one time had no atmosphere or perhaps lost it.  Recycling the earth's crust freed up carbon dioxide and plant life (at first microbial) converted the carbon dioxide to the oxygen we breath.\n\nStrong radioactive sources are used to expose X-ray film to check the quality of metal welds in large pipe joints.  Very small samples are used to ionize air that permits smoke detectors to in fact detect smoke, saving countless lives.
716046
When lava (melted rock) is extruded onto the surface of the Earth, it forms new igneous rock. Lava doesn't last long on the Earth's surface before it cools. \n\nIs your question actually concerning the oldest igneous rocks?
329455
It becomes rock on the surface of the ocean floor. It is eventually carried further & further away.\n\nSome older rock created by this process has already been "recycled" in the rock cycle; it became molten when it was subducted under continental plates.\n\nAn interesting fact is that as new rock is being created at the Mid Atlantic Ridge, the earth's magnetic field is being recorded right into the rocks. Any time there is a change in the direction of the earth's magnetic field it has been recorded.\n\n:)
1156287
it's the core of the earth. lava. melted rock.etc
538992
Earth's core is thought to be made of molten nickel-iron. The core is about 2100 miles in radius, with a temperature of approximately 13,000 degrees Fahrenheit.