and joyce chaplin who i met at the johns hopkins university when we were both in graduate school together. i prided myself on being the first person to the library every morning, there was only one person who was there always before me and that was joyce chaplin. do you remember that, joyce? >> you're going to tell everything about -- >> no, that's it. i stopped right there. joyce is the james duncan phillips professor of early american history at harvard university. her most recent works include "roundabout the earth: circumnavigating image land to orbit." and with allison bashford the new world of thomas robert mouthace rereading the principle of population. joyce has been kind enough to be a guest on backstory three times. >> three times. >> and she's going to talk to us a little bit about what it is to be like dropped into a show where people know each other pretty well and bring scholarship to bear on a topic that we hope will reach a broader public. not an easy thing to do and joyce has done it masterfully as a guest three times. so let me take five or ten minutes and just give you