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Yes, there should be dark matter within the Earth, but at very low densities - a few $10^{-22}$ kg/m$^3$ (Bovy & Tremaine 2012), something like one hundredth of the density of the interplanetary medium. The whole of the Earth would contain few hundred grammes! Of course, this density averaged over a sphere a lot larger than the Galaxy adds up to a lot ...

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In terms of dark matter, there are two notions which are incorrect. One is that dark matter is a clump of stuff traveling with the matter. The other is that dark matter does not interact with matter. Dark matter fills 'empty' space. Dark matter is displaced by matter. The Milky Way moves through and displaces the dark matter. The Milky Way's halo is the ...

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Also asked at http://physics.stackexchange.com/questions/174080/how-do-we-know-dark-matter-isnt-curved-spacetime Basically no. Or at least you can't have this idea and General Relativity. GR demands that you have something (matter/energy density) to cause the curvature. Curvature without cause is not part of the model. That's not to say that what you ...

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Two reasons. We know from looking at galaxy rotation curves and the motion of galaxies in clusters and from gravitational lensing, that the amount of "dark matter" is some 30% of the density of the universe. But on the other hand, estimates of the abundances of deuterium, helium, tritium and lithium produced in the big bang indicate that only 5% of the ...

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