Chapter 20 Panopticism (Foucault)

To me, this piece is one of the hardest to understand. The idea of Panoptican doesn't seem to be very hard - after listening to Greg's interpretation. But in this chapter, Foucault seems to have broadened this idea to a more general sense, and have made many new claims out of it. But to be honest, I do not quite get it - maybe due to the superabundant metaphors and abstract/difficult words...

My questions are, for instance: how to understand "certainty" and "uncertainty" in this article? what are the differences between sovereignty and discipline, and between discipline and social norms? What does Foucault mean by "carceral archipelago"? There just seem to be too many concepts that I can not understand right away. I'll have to listen to the lecture and class discussion.