Quote:
Originally Posted by Robh
Craig,
I agree that the motion of the stars will largely evolve chaotically. The result of this intermix as per theoretical modelling should match real observation.
I find the proposal given here fairly palatable. If stars did not rotate with the arms then there would be no arms! Inner stars migrating inwards, outer stars migrating outward. This is a lot like what happens in globular clusters but no arms there of course.
The stars move with the spiral pattern at the same speed. Meaning what? The speed of rotation of the arm? If this is the case, what causes the shearing that breaks up the spiral arms?
Regards, Rob
|
Seems to me the speed of the stars (relative to the galactic centre, assuming zero relative speed), varies as the star moves either towards or away from the core anyway.
I think the forces causing the shear (or breakup) of the arms with Chaos Theory, would be exactly the same forces which cause the arms in the first place. This would be the chaotic phase of a 'cycle'. This is the unique thing about chaotic/complex systems .. the presence of order and chaos from exactly the same initial conditions.
By the way .. I apologise to all, if my original post/challenge seemed arrogant. More exasperated than anything. But the point remains .. if there was more thinking coming from complexity modelling area, in what these guys are attempting to do, I have a gut feel that the need for dark matter would disappear.
After all, we don't need dark matter to explain how a flock of geese form patterns whilst in flight, do we ? I just wish I knew more about complexity. Oh well, I've got a few years ahead of me ...
Cheers