I just got wind of a new paper submitted to the Astrophysical Journal where flat galactic rotation curves, one of the best and clearest pieces of evidence in favor of dark matter, are apparently explained using accepted general relativity as mentioned in the Cern newsletter. I'll post a follow-up as this paper is evaluated by the comminuty. If this is right, this represents decades of seriously wrong thinking in the field. I'll be flabbergasted, frankly.
Addendum: A new paper on astro-ph here suggests that the above result is unphysical, requiring a "singular disk" that may be more problematic than a dark matter halo. In any event, the above paper has not been refereed, and should be viewed as a suggestion for the time being, rather than a proof that dark matter isn't needed to explain galacitc rotation curves.
Also, the existence of exotic dark matter is used to explain many things in astronomy, not just this one issue, so even if the paper is right, dark matter doesn't suddenly vanish.
Posted by Mike at October 10, 2005 3:38 PM