Just realized that this paper hadn't been posted here, and thought everyone might like to see this. http://xxx.lanl.gov/abs/astro-ph/0507619 Very interesting findings, not too hard to read. The ultimate point is that, traditional computer simulations of galactic rotation are done using newtonian physics, because they are simpler and easier to calculate. These simulations find that the rotation rates of galaxies cannot be explaines by the amount of visible mass requiring some amount of unseen dark matter to explain their observed motion. This paper reports that by using general relativity rather than newtonian gravity, the discrepancy disappears, even though the system appears to be non relativistic (very weak gravitational fields, very low velocities).