Why do marbles form spiral patterns in water but not air?

[Spin_Network]

I have a container of Marbles, if I place a rod in the centre, and proceed to stir clockwise, the marbles do not form any collective pattern, they just collide and move away in all directions.

Now if I place the Marbles into a container of Water, and perform the above, there are moments when the marbles form a pattern such as this:http://hubblesite.org/newscenter/newsdesk/archive/releases/1999/25/

If I just remove the stirrer, I can still get the same pattern, or as good as, by rotating the whole bowl?

Is the Galaxy being 'stirred' or rotated by a far off effect?

 

[ramollari]

It seems to be a far different effect that keeps the stars in a pattern, that is, the Gravitational Forces. On the other hand there is negligible gravitation among the marbles and what keeps them rotating in a pattern is the water currents that result from steering.

 

[hypermorphism]

I have a container of Marbles, if I place a rod in the centre, and proceed to stir clockwise, the marbles do not form any collective pattern, they just collide and move away in all directions.

Now if I place the Marbles into a container of Water, and perform the above, there are moments when the marbles form a pattern such as this:http://hubblesite.org/newscenter/newsdesk/archive/releases/1999/25/

If I just remove the stirrer, I can still get the same pattern, or as good as, by rotating the whole bowl?

Is the Galaxy being 'stirred' or rotated by a far off effect?

If you could remove the effect of the Earth's gravitational field from your marbles (ie., some weightless environment), then the marble's gravitational attraction to each other would become the dominant force. Of course, since this force is very weak, stirring the marbles would probably just send them flying. Giving each marble a tiny random velocity and random position should result in some approximation of a galaxy over a long period of time, and given enough marbles.