Thank you for registering with Physics World If you'd like to change your details at any time, please visit My account. Conventional thinking going back to Albert Einstein is that a black hole can be described only in terms of its mass and spin. No-hair means that information about the physical state of matter must be lost as the matter is sucked into a black hole — otherwise, this information would distinguish one black hole from another. In Hawking made the landmark conjecture that black holes do not simply suck in everything, but rather behave as black bodies that emit radiation as well as absorbing it. He calculated the black-body temperature of a black hole using an equation that now graces his memorial in Westminster Abbey.
Stephen Hawking’s ‘final paper’ on hairy black holes hits the headlines
‘Hairy’ black holes | INFN-LNF
Professor Stephen Hawking is back with a new theory: the hairy black hole hypothesis. His new theory solves the problem of what happens when information from the universe goes into black holes. His new paper titled, "Soft hair on black holes," could help him win his first Nobel prize. The year-old British theoretical physicist said that black holes may have a head of hairs made of zero-energy particles.
Hairy black hole could show gaps in Einstein's theory
The no-hair theorem states that all black hole solutions of the Einstein—Maxwell equations of gravitation and electromagnetism in general relativity can be completely characterized by only three externally observable classical parameters: mass , electric charge , and angular momentum. Physicist John Archibald Wheeler expressed this idea with the phrase "black holes have no hair"  which was the origin of the name. In a later interview, John Wheeler says that Jacob Bekenstein coined this phrase. The first version of the no-hair theorem for the simplified case of the uniqueness of the Schwarzschild metric was shown by Werner Israel in
One thing that Stephen Hawking has in common with your local sage is that they both believe that everything happens for a reason. For scientists, Professor Hawking included, this is less religious or karmic and more to do with simply preserving the notion of cause and effect. Everything that happens must have been caused by what was happening before it and the laws of Nature.