We had an interesting thread on this a while back. Here's an idea I was throwing around at the time:
Each of the four fundamental forces has its intermediary particle(s) -
By intermediary particles I mean the Force Carriers.
The weak force has the W and Z bosons
The strong force has the gluons
The electromagnetic force has the photons
The gravitational force has the gravitons (which still have not been directly observed, I believe)
Now, the force carriers cannot be affected by the force they carry (i.e., a photon cannot exhibit an electromagetic charge- it only CARRIES it). So, by symmetry a graviton cannot be affected by the gravitational force.
Now, the first thing I though of was "Wait a minute, but space-time is bent by mass, creating a type of 'well' that things like matter and photons are forced to fall into?!?!?!?" Then, I remember that this is only a visualization, not necessarily what REALLY happens.
A gravitational field is like an electromagnetic field, right? Well perhaps the graviton would just glide right through the graviational field, no matter how strong it is, at the speed of light.
On a side note, maybe the speed of light should be renamed the speed of force or something similar since it seems that all of the four forces travel at the speed of light.
Something struck me in your post, about space being 'absorbed' by the black hole. Correct me if I'm wrong, but do you mean that space itself is being 'sucked in' (like a vacuum?)? This would imply that space is being streched in all directions from black holes 'sucking in' space (or, even from space falling in). Hmmm, strange implications if space gets stretched past some sort of threshold, hehe.
So, if what I've asserted turns out to be correct, no virtual gravitons would be needed to experience the gravitational effects of the black hole.
Of course, any response or criticism (be it good or bad) is always welcome!
-Michael Wright (Bladesinger)