
Originally Posted by
Gary Anthony Kent
The gravitational fields of any supermassive black hole and its associated galactic disk are perfectly and precisely co-axial. This means that the gravitational fields will be indistinguishable from a distance, say, at and beyond the periphery of the disk. The fields merge into one, especially at the coaxial center. The fields must reinforce each other. So, the effective mass of a supermassive black hole at the center will not be just a few hundred to a few million suns, it will be a few tens of billion suns.
Show it! Show us the math. What you are saying here is wrong and disproved by the analysis of Keplerian motions of stars around the centre of the Milky Way. These motions were the very measurements that determined the mass of the central BH. If your claim were true, the analysis would have indicated the mass you are claiming. The orbits of objects in galaxies are determined by the mass that is encircled by these orbits.
You cannot first say that a BH produces a gravitational field that is proportial to 1/r and the rest produces something that goes like 1/r^2 and then claim that the global field goes like 1/r anyway. It is either the one or the other. How would a million solar mass BH with a 1/r field surrounded by matter that produces a 10 billion solar mass 1/r^2 field merge into a 10 billion solar mass 1/r field?
And even if this were all true, you have yet to demonstrate that this is the cause for the flat rotational curves or, if you will, the cause for the new MOND a0 constant. Remember that for a gravitational field you need the mass or mass distribution and the shape of the potential.
What you are proposing is yet another version of the Dark Matter mass conspiracy that would now turn into a BH mass/disk mass conspiracy. Both masses would have to be very finely tuned in order to produce flat rotation curves. This phenomenon would require that all galaxies have the same BH/disk mass ratio in order to be universal. How should this be possible?
In addition, a BH is spherical if not singular, i.e. the resulting gravitational field is radially symmetric. The gravitational field of a galactic disk is different, because the mass is distributed across a large disk, i.e. the resulting field is not radially symmetric, rather cylindrically or toroidally symmetric.
Come up with some simple math, and you might have point.