Apparently spiral galaxies do not wind up tightly as would be expected if the speed of the outer stars was only twice the speed of the stars 5% of the way from the center. If the mass was mostly near the center we would expect the inner stars to be at least twice as fast, so there is a discrepency of at least 4 times, which it is explained as possible due to dark matter. I don't think so Tim. Perhaps the spiral galaxies started spiraling 137,000 years ago instead of 13,700,000,000 years ago. I don't know, but it does not compute. Neil