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Going further it would be interesting to see a galactic model with potential distributions of the previously unknown and hiding blackholes that would explain ga

Going further it would be interesting to see a galactic model with potential distributions of the previously unknown and hiding blackholes that would explain galaxy rotation we observe. I would assume there must be an unusual distribution of these blackholes to have the effect on galaxies that we observe but can't explain without dark matter. The other question/thought I have is would it be possible that so many previously unknown blackholes could actually explain our observations and could it be possible our observations are not consistent with reality rather these newly found blackholes cause the slowdown/bending of light escaping the outer portions of galaxies which simply give an illusion in how we observe the speeds of galaxies. In other words could the inner portion of galaxies be spinning faster than the outter parts as explained by gravity, but we observe a consistent speed across the entire galaxy because the light escapes at different speeds from the center out (consistent with blackhole distribution) giving us the appearance of consistent speeds across the galaxy.

gamblor956 6y ago
The study of galactic spin rates is based on other galaxies, not our own, since we can't actually see how fast our arm is spinning. So black holes would not explain why galaxies rotate like a wheel rather than a swirling drain.
- privong 6y ago
  > since we can't actually see how fast our arm is spinning. It's tougher, but we can. We know that the Sun has an orbital speed of approximately 220 km/s relative to the center of the galaxy. And we can measure the relative speeds of stars and gas clouds inside the Milky Way to derive a rotation curve for the Milky Way. This is discussed some here: https://ned.ipac.caltech.edu/level5/March01/Battaner/node9.html https://ned.ipac.caltech.edu/level5/March01/Battaner/node9.h... A side note that "speed of an arm" is potentially ambiguous. The arms in spiral galaxies are thought to be at least partly a reflection of density waves moving through disks. Those density waves can in principle have (pattern) speeds which are different than the orbital speeds of the gas and stars themselves. Talking about the speed of an arm could in principle refer to either the pattern speed of a density wave or to the velocities of the mass components which are overlapping with that density wave.

gamblor956 6y ago

The study of galactic spin rates is based on other galaxies, not our own, since we can't actually see how fast our arm is spinning. So black holes would not explain why galaxies rotate like a wheel rather than a swirling drain.

privong 6y ago
> since we can't actually see how fast our arm is spinning. It's tougher, but we can. We know that the Sun has an orbital speed of approximately 220 km/s relative to the center of the galaxy. And we can measure the relative speeds of stars and gas clouds inside the Milky Way to derive a rotation curve for the Milky Way. This is discussed some here: https://ned.ipac.caltech.edu/level5/March01/Battaner/node9.html https://ned.ipac.caltech.edu/level5/March01/Battaner/node9.h... A side note that "speed of an arm" is potentially ambiguous. The arms in spiral galaxies are thought to be at least partly a reflection of density waves moving through disks. Those density waves can in principle have (pattern) speeds which are different than the orbital speeds of the gas and stars themselves. Talking about the speed of an arm could in principle refer to either the pattern speed of a density wave or to the velocities of the mass components which are overlapping with that density wave.