Hi Amos, not sure the allusions to strange attractors is valid. The Great attractor is a postulated gravitaional source which would explain the anomolous realtive motions of and within the local group of galaxies. Anomolous that is in terms of the motion predicted by current models of cosmic evolution. The volume and hence mass of so called dark matter within the universe has been a point of argument for years and is critical in determining if the universe is open or closed with reference to an expansion from a singularity. The interesting thing or at least one interesting thing about the great attractor is not the mass which would be required to exert the observed behaviour but that it has to be in relatively concentrated area. I understand that it has been postulated that the attractor is in fact a singulatity (black hole) and that there is observational evidence of behaviour that supports this, but until we get a long enough stick to give it a damn good poke, no one knows for sure.