I was misreading ' K e r r ' as ' K e n ' , which is pretty funny, see post title. Now I have to go look up Kerr black holes.

Thanks, John M.

Edit: Ok, from the Wiki article on 'Black Hole', "In 1963 Roy Kerr extended Finkelstein's analysis by presenting the Kerr metric (coordinates) and showing how this made it possible to predict the properties of rotating black holes. In addition to its theoretical interest, Kerr's work made black holes more believable for astronomers, since black holes are formed from stars and all known stars rotate."

Wiki link: http://en.wikipedia.org/wiki/Kerr_bl...ral_relativity

The article is good reading, with the usual Wiki reservations (be skeptical).