I'm reminded of the discussion with Isaac a while back about whether Jupiter even qualifies as a brown dwarf since it isn't fuzing hydrogen, and how much smaller it is than most extra-solar planets found to date (which I suppose still qualify as dark matter in cases only detectable as gravitational wobbles in a stars rotation). The comic's a good summary of the conventional wisdom, I'm just not sold on the underlying theory, and the reference to particle physicists is illustrative of why. Call me old fashioned, but I remain dubious when science contrives unverifiable aberrations to explain why some data doesn't fit the curve. For all the talk of radical new models, most of this strikes me as a bandaid obviating the need for new theories when something unaccounted for by the old one surfaces. There are simpler bandaids to be had but, regardless, the same rule applies to cosmology that applies to particle physics: Anything you can't test isn't physics, it's metaphysics. It may be valid metaphysics, but the one thing it's not is science.