A simple chair is more than just a place to sit. From colonial rockers to the ergonomic tasks chair, where we choose to sit reflects a social history of our own tastes and attitudes. This hour, we’ll talk about the history of the chair with Witold Rybcznski, University of Pennsylvania emeritus professor of architecture. He writes about the topic in, “Now I Sit Me Down: From Klismos to Plastic Chair – A Natural History” (Farrar Straus & Giroux).