On a sunny day (Mon, 29 Dec 2008 22:24:14 GMT) it happened Jan Panteltje
wrote in :

Some time ago I postulated that Le Sage (push gravity) particles could originate in stars.
But maybe those originate in black holes.

Now what would happen?

1) The universe would push itself apart (expanding faster and faster). Check.
2) It is said that the outer stars in a galaxy move too fast for the mass of
the galaxy, so there should be some extra invisible (dark) matter (around
that galaxy).
However, the problem could perhaps be solved when we say that the inner
stars are too SLOW.
This, because of the Le Sage particles originating from the black hole at
the centre of the galaxy, _reduce_ gravity near that black hole,
stars feel less attraction in that area, need a slower speed to keep in
orbit and not fall into the black hole.
That takes care of dark matter, and MOND. Check.

Simple explanation, that makes sense, and does not propose some unknown physics.

And this also puts a limit on black hole size. Check.