Hi,
With Black Holes the Gravitational Attraction must be able to exert a coersive force greater than the speed of light or be able slow time to an extent where there is no perceivable light output.

The other anomoly which has turned current thinking upside down is that the universe is accelerating in its expansion - this is not possible, is it!

The above combined with the subject of Dark Matter, as I said things are getting stranger by the minute.

Regards N Mc Donald

P.S. There is an answer to it all, just some of us are having troubles coming to grips with it.