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Gravitational Time Dilation and the Galaxy Rotation Curve

  1. Mar 3, 2009 #1
    Is it possible that the very high concentration of mass at the centers of galaxies is causing a significant enough time dilation to explain a non-negligible part of the rotational curve problem? i.e. time is traveling more slowly in the super-massive, black hole rich cores of galaxies and faster in the relatively diffuse extremities.
  2. jcsd
  3. Mar 3, 2009 #2


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    No .
  4. Mar 3, 2009 #3
    No. The central black hole usually accounts for less than 2% of the galaxy mass, and the region where its gravity causes any significant time dilation is, liberally, one cubic parsec out of 10^12 of them in the galaxy. Most stars in the galaxy don't even know it exists.
  5. Mar 3, 2009 #4
    There is much more mass in the center of a galaxy than just the central black hole though. There are other black holes and a vast majority of the stellar mass. And its not just the very center that would need to be considered right? Its the huge discrepancy between the amount of matter near the core and the amount on the fringes.
  6. Mar 3, 2009 #5
    No. The center of the galaxy does not contain "the vast majority of the stellar mass." The mass of a galaxy is very well distributed throughout the disk.
  7. Mar 3, 2009 #6
    OK. Thanks for commenting.
  8. Mar 3, 2009 #7
    Gravitational lensing beyond that attritubtable to visible mass also seems to support the existence of additional unseen dark mass over vast cosmological distances. It's embarassing, but little is known about 96% of the "stuff" in the universe....
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