Quote:
Originally Posted by neilzero
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
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Actually, it's because only those stars within any given star's orbit contributes to it's orbital velocity. Thus, the innermost star is only affected by our galaxy's supermassive black hole, wile the outermost star is being affected by all other stars in our galaxy.
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