kaksmet said:
If I am not completely out of my mind that is because there is black matter within the galaxy as well..
I continue to do a few math computations to understand this, and I just looked at gravity within a disc of matter.
Now while gravity at radius R within a sphere of matter experiences zero pull from the spherical shells at radius greater than R, unless I have a bug in my prgram, this is not true for a disc. The Gravity at radius R within a disc of matter is affected by annuli of matter at radius greater than R. There is an outward pull due to them, which reduces gravity in the interior of the disc significantly. Conversely, the gravity further out increases faster than you would thin it should due to this effect.
The problem with the dark matter explanation is that it would take a VERY SPECIFIC distribution of dark matter, different than the distribution of luminous matter, to explain the flat rotation curves. Note that these curves are not flat ANGULAR velocity, which is what you would get with a spherical distribution, but flat VELOCITY.
So the dark matter explanation has two probelms: 1. What is dark matter, and 2) Why does it have a distribution different than the luminous matter, and exactly the right distribution to give flat velocity versus radius curves?
I am on the verge of a novel explanation, but I need to solve Einstein's equations in he 4D, non-static case to see if it works, and I don't have sheet of paper big enough to expand all the products of Christoffel symbols and WHY. I plan to get MAPLE to do the algebra and formulate the partial differential equations.
My explanation is that we are already in a Black Hole, and our inexorable chute to the central singularity is the passage of time, while what was time outside this Black Hole is one of our spatial dimensions. It turns out that the mass of this black hole, most of which has already reached the central singularity, is an order of magnitude higher than the mass of the matter in our universe, but exerts the same effect on galactic rotation as if it were distributed throughout our spatial dimensions. Dark matter is therefore matter which exists in our space with a time-shift relative to us so that we do not interact with it except insofar as it affects the metric of our spacetime. My original question relates to the fact that an infinite, uniform, spherical distribution of matter in our universe would seem, under the Newtonian approximation, to have no effect. But I believe under GR it will, and that when I compute the orbits of stars in galaxies under this metric, it will show the flat rotation curves.
That is what I am hoping, as if it does, since this model already explains the accelerating expansion of our universe and also gives answers to a bunch of hitherto unanswerable questions, then it is probably the truth.
