hilbert said the school boy in the street has more -- knows more mathematics than einstein. einstein knows physics. >> i think the word genius distances us from someone who was very human being, and i wanted to see a little bit about what the human qualities that led him to be able to make these discoveries. so thank you both very much. this has been fascinating. i think you guys would like to get into the conversation, and i encourage you to do so now. there are microphones at the back. if you want to ask a question, please go to the back and get a microphone -- >> the microphone will come to you, as in general relativity, the microphone will come to you. >> who this mountain and who muhammad. >> the lady in the white. >> is it possible -- is it possible that the infinite mass you describe in the singularity of a black hole could -- if you add those all up for the universe, could that account for dark matter and dark energy? >> no. actually not. because -- people have work that out. the stars start with matter and they know from meticulous calculations and examination of th