Note: this is a re-post because my initial post had problems, no one could reply to it. Ok this is my second in the series about dark matter. In a previous thread I asked where is dark matter https://www.physicsforums.com/threads/where-on-earth-is-dark-matter.764693/ The main response to my question in the other thread was dark matter has no way of losing energy so it doesn't clump basically it just slingshots off other DM and OM (dark matter and ordinary matter) but due to little or no friction can never clump into a large mass like say a dark planet or even a dark star. The responses seemed reasonable and made perfect sense. But I have had a sleep since then... DM interacts with OM due to its mass giving rise to gravity. That is a given. By definition that must mean dark matter which is small and light must be attracted to OM objects. For example planets, stars, galaxies, clusters etc.. As such like neutrinos we must have a constant barrage of DM passing through us all the time. Unlike neutrinos DM has considerable mass (relatively) hence when a neutrino passes through the globe or us it virtually passes unhindered. But DM has mass and lots of it! so if a DM particle passes through a massive object like a planet or star or human body it must interact with it. There must be a transfer of energy from the DM particle to the OM object. As the DM particle passes through the OM object it must try and drag the OM object along with it thereby losing a large proportion of its momentum (energy) and entering into an orbit around or even within the OM object. The net effect is the OM captures the DM. So while I can see individual DM particles dancing around themselves and other OM particles forever in some frenetic dance. Once captured by a more massive object I cannot see it dancing off wildly into the distance. As DM outweigh OM significantly these capture events must be very common. Which then implies much of ordinary matter is made up of dark matter.