Explaining away your real problem!
So far so good. The occult agency doesn´t do anything.
More explaining away your problem.
You STILL have to explain the abrupt 90 degree turn from the bars and out in the arms.
Well, shall we start by looking at the variety of bars, arm systems, angles, etc in different galaxies? Do you think that maybe some pattern recognition would help when looking at a wide variety of cases?
You can ONLY explain this logically by asserting a central rotational formation and an outgoing motion, out in the bars and out in the galactic arms. A formation which logically explain the galactic rotation curve.
On the contrary, This sort of 90 degree angle shows it *cannot* be such an outgoing system. Otherwise, there is no way for the outgoing material to suddenly change direction by 90 degrees.
Instead, I say it isn't a change of direction of motion at all. it is simply a change in the density of the stars. And that *can* be explained, in part, by the fact that gravity isn't instantaneous: it takes time for its influence to move. That makes for resonant systems and bars are such.
Allegorically this motion and formation is very like a rotating two arm garden sprinkler.
Really? What is causing the 90 turn, then? Some magical metal corner?
A logical motion DIRECTLY AGAINST Newtons occult agency which led to the invention of another stupid occult agency of "dark matter". There isn´t even a "heavy dark hole" in barred galactic centers as the formative motion obviously goes outwards in these.
I´ve explained this logics 117 times and it´s about high time you grasp this logics.
You have made claims. That isn't the same as explaining. For example, *you* haven't explained the 90 degree turn. You just claim it doesn't fit into the usual theory of gravity *in spite* of numerical simulations showing it does.