John’s guest this week is Erika Szotek, in charge of the laboratory at Roosevelt University, Chicago, as well as a science instructor. They talk of a wide range of phenomena, interrelationships between the human body and physics and chemistry. What is it we see when standing in Saint Joseph and looking at what appears to be the Chicago skyline? How do rocks affect our health? What is DNA, and how do we match ours with other people, like our ancestors?