Gravitational lensing

[Moseley]

Hi there, dunno if this is in the right place but seems to affect what we observe.

http://www.nature.com/news/2005/050214//fu...l/050214-5.html (http://www.nature.com/news/2005/050214//full/050214-5.html)

This article suggests that strong gravitational effects may not only 'bend' the path of light 'inwards'. I am struggling to find language to describe space-time curvature around a rotating supermassive black hole.
If these effects are correct, what proportion of the observed universe may need to be re-evaluated?

[Shoemoodoshaloo]

Not much of our sky would need to be re-evaluated I think. Since most black holes probably affect a very slight percent of an arcsecond on the background sky to an observer with no visual aid.

[GOURDHEAD]

I'm not sure that I fully grasp what is meant by negative refraction. What immediately comes to mind with respect to gravitational lensing is divergence where we should normally expect convergence. The effect of a gravitational lensing object, where divergence is the case, would be to make the more distant object even harder to detect and to erase Einstein rings. Could the Lens-Thirring effect be involved (not that I truly believe there is negative refraction)?

Does anyone believe there are non-rotating black holes? Are charged black holes so designated because of conditions inside the event horizon or outside it in the accretion disk?

Such a menagerie! (http://casa.colorado.edu/~ajsh/rn.html)