Radiating black hole at the center of Centaurus A - NASA/Goddard Space Flight Center
'Hairy' Black Holes
Up until recently it has been thought that black holes are all identical, save for their mass and rate of 'spin'. The thinking has been that aside from these two criteria black holes are completely featureless, perfect points of mass in space.
However, new research data analyzed by a group of scientists that includes Thomas Sotiriou, a physicist of the International School for Advanced Studies (SISSA) of Trieste, suggests that black holes may have at least one other defining property, a custom 'hairdo'. More precisely, the pattern of gravity waves that is generated by an individual black hole gives each a unique fingerprint, seemingly preserving a record of the 'meal' consumed by the black hole. Up until this discovery, it has been theorized that all information must be lost with respect to matter falling into a black hole. But like a shrunken head, the hairy part remains in tact albeit distorted.
Up until recently it has been thought that black holes are all identical, save for their mass and rate of 'spin'. The thinking has been that aside from these two criteria black holes are completely featureless, perfect points of mass in space.
However, new research data analyzed by a group of scientists that includes Thomas Sotiriou, a physicist of the International School for Advanced Studies (SISSA) of Trieste, suggests that black holes may have at least one other defining property, a custom 'hairdo'. More precisely, the pattern of gravity waves that is generated by an individual black hole gives each a unique fingerprint, seemingly preserving a record of the 'meal' consumed by the black hole. Up until this discovery, it has been theorized that all information must be lost with respect to matter falling into a black hole. But like a shrunken head, the hairy part remains in tact albeit distorted.

This gravitational tid-bit was suggested by. R. Douglas Hamilton of Burlington, Ontario.
"I have a quite a fondness for the idea of hairy black holes", says Hamiltion. "To think that the history of everything that has ever happened in the universe may eventually be recorded on the surface of an enormous black hole at the 'south pole' of our universe, I find intriguing. "