Space* » Galaxies*
The galaxies rotate like wheels. If there would exist a drafting force, should the galaxies have ten times larger mass than it is at present observed. This is because the farthest stars of galaxies circulate the centre of galaxy so fast. The gravity of observed mass is not able to keep them in their orbits. The stars that circulate the furthest should be thrown away from their tracks.
Although the modern physics does not understand how the gravitation is transfered, it still has found out that galaxies consist of some mystery substace that has this drawing force.
The dark substace is different from the observed substance. Yet it has the the same kind of drawing force as the observed substance has.
No, there is no gravitation!
All the stars of the galaxies have arised from the black holes of the giant centres of the galaxies. They expand three-dimentionally, opening up energywaves that have the nature of atoms. The stars expand and push themselves away from the galaxy centre in a curved orbit in a same relation as they expand.
That is to say that also the furthest stars are thrown away from the centre of the galaxy. The same way as their speed of movement around the galaxy centre lets us suppose. Only this is not observed, because everything expands three-dimentionally in same relation.