Ask HN: What would you ask Brian Greene (or a Nobel Prize winner)?

Hi guys,

I'm excited to have the opportunity to talk to Brian Greene at a banquet in a month or so, and a panel of Nobel Laureates a month after that. If you had the chance, what would you ask him? I've never really been able to talk to someone that prolific, so all of the questions that I can think of are fairly constrained. Thanks!