He came up with the second law of black hole mechanics, he showed that black holes should emit heat and eventually vanish, he explained how galaxies might arise, he proposed the "wave function of the universe", he worked on the "no hair" theorem of black holes, and proved that singularities can form black holes.
Because his theory about blackhole is very wrong according to me . According to me blackhole is like a tesseract and tesseract is 4D which moves forward and backward with speed of light and so a ray of light coming into get relative velocity same and becomes stable into it making it light absorber. I agree with him that on surface of blackhole there is less effect and do the anti particles forming and destroying at the same time release energy which make them shine because according to me it is dimension which connect 3D and 4D world together which I name as astral dimension which can't be seen by our eyes hence the blackhole shine but their shine get diminished in astral dimension. So I believe that he is smart but not so intelligent.