Richard Feynman, objected to the phrase that seemed to me to best symbolize the finding of one the graduate students: graduate student Jacob Bekenstein had shown that a black hole reveals by nothing outside it what went in, in the way of spinning electric particles. It might show electric charge; yes, mass; yes, but no other features - or as he put it, "A black hole has no hair" - and Richard Feynman thought that was an obscene phrase and he didn't want to use it. But that is a phrase now often used to state this feature of black holes, that they don't indicate any other properties other than a charge and angular momentum and mass.