Themuffinman said:
This is just an idea but if galaxies have or develop a black hole in their center couldn't it be possible that darkmatter uses the electromagnetic field of the black hole to keep the galaxy in place and also keeps it from colliding with another galaxy.
What electromagnetic field of a black hole? I've never heard of anything of that sort. Of course, that is not to say there isn't one, but I see no reason that there should be one.
Edit: as for galaxies colliding, our own gallaxy has an appointment with our nearest neighbor, the Andromeda galaxy, scheduled for about 3-6 billion years from now.
I can't really explain what i am thinking but I am trying to explain why a large number of galaxies have black holes in their centers and the expasion of the universe. please correct me if this i am completely uninformed and if this makes no sense at all.
Actually,
all galaxies have a super-massive black hole in their center. And the reason for that is that the BH are instrumental in the process of the very formation of a galaxy.
The expansion of the univesre is thought to be caused by the big bang, but also assisted by the cosmological constant.
Didd said:
The two stars are in continious motion. And they will create magnetic property.
AFAIK, a star has a net electrical charge of 0. So the motion of a star cannot produce a magnetic field. That said, stars do in fact have magnetic fields, but these arise from different effects, mostly the motion of plasma *within* a star.
So this magnetic property will overcome the force which this stars expreiance on each other.
I think the stars' magnetic fields are much weaker than their gravitational pull.
If the stars were not moving they would have collided with each other.
Actually, the reverse is true. If they were not moving, they could not collide, since a collision requires movement. The reason they do not collide, is because their orbits around the gallactic center do not intersect (at least not usually... which raises an interesting question - I will start a new thread).