Reader survey: what open question would you ask Dick Gross?

I’m speaking on an “open problems” panel in honor of Dick Gross’s 60th birthday.  I’ve got 10 minutes.  I think I know what I’m going to say, but I was just informed that the panel is to be allowed to run late if audience interest demands it.  So I thought it would be good to stock up a little more material.  And it occurred to me this might be a good opportunity to blogsource!  So, readers:  if you were going to promote an open problem in front of Dick Gross and his wellwishers, what would it be?